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Sample records for heteropolynuclear copperii complexes

  1. Heteropolynuclear complex compounds as precursors of LaCrO{sub 3}

    Energy Technology Data Exchange (ETDEWEB)

    Jitaru, I.; Guran, C.; Stoica, L.; Berger, D.; Andronescu, E. [Politehnica Univ., Bucharest (Romania). Dept. of Inorg. Chem.; Fruth, V.; Danescu, M. [Romanian Academy, Inst. of Physical Chemistry, Bucharest (Romania); Novac, A.; Magureanu, M.; Mosteanu, T. [IFA-National Inst. of Research and Development for Materials Physics, Bucharest (Romania)

    1997-12-31

    Some new heteropolynuclear complex compounds isolated in: CrX{sub 3}-LaX{sub 3}-NH{sub 3}-H{sub 2}O and CrX{sub 3}-LaX{sub 3}-MX{sub 2}-NH{sub 3}-H{sub 2}O (X=CH{sub 3}COO{sup -} M=Cu,Ca) systems were used as precursors for pure and respectively doped LaCrO{sub 3} synthesis. The polynuclear complex precursors and lanthanum chromites were characterized by chemical analysis, electronic, EPR and FT-IR spectra, DTA-TG and XRD analysis. Cu and Ca doped lanthanum chromites have high sintered density. (orig.) 13 refs.

  2. Pentagonal Bipyramid FeII Complexes: Robust Ising-Spin Units towards Heteropolynuclear Nanomagnets.

    Science.gov (United States)

    Bar, Arun Kumar; Gogoi, Nayanmoni; Pichon, Céline; Goli, V M L Durga Prasad; Thlijeni, Mehrez; Duhayon, Carine; Suaud, Nicolas; Guihéry, Nathalie; Barra, Anne-Laure; Ramasesha, S; Sutter, Jean-Pascal

    2017-03-28

    Pentagonal bipyramid FeII complexes have been investigated to evaluate their potential as Ising-spin building units for the preparation of heteropolynuclear complexes that are likely to behave as single-molecule magnets (SMMs). The considered monometallic complexes were prepared from the association of a divalent metal ion with pentadentate ligands that have a 2,6-diacetylpyridine bis(hydrazone) core (H2 LN3O2R ). Their magnetic anisotropy was established by magnetometry to reveal their zero-field splitting (ZFS) parameter D, which ranged between -4 and -13 cm-1 and was found to be modulated by the apical ligands (ROH versus Cl). The alteration of the D value by N-bound axial CN ligands, upon association with cyanometallates, was also assessed for heptacoordinated FeII as well as for related NiII and CoII derivatives. In all cases, N-coordinated cyanide ligands led to large magnetic anisotropy (i.e., -8 to -18 cm-1 for Fe and Ni, +33 cm-1 for Co). Ab initio calculations were performed on three FeII complexes, which enabled one to rationalize the role of the ligand on the nature and magnitude of the magnetic anisotropy. Starting from the pre-existing heptacoordinated complexes, a series of pentanuclear compounds were obtained by reactions with paramagnetic [W(CN)8 ]3- . Magnetic studies revealed the occurrence of ferromagnetic interactions between the spin carriers in all the heterometallic systems. Field-induced slow magnetic relaxation was observed for mononuclear FeII complexes (Ueff /kB up to 53 K (37 cm-1 ), τ0 =5×10-9  s), and SMM behavior was evidenced for a heteronuclear [Fe3 W2 ] derivative (Ueff /kB =35 K and τ0 =4.6 10-10  s), which confirmed that the parent complexes were robust Ising-type building units. High-field EPR spectroscopic investigation of the ZFS parameters for a Ni derivative is also reported. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Homo- and heteropolynuclear platinum complexes stabilized by dimethylpyrazolato and alkynyl bridging ligands: synthesis, structures, and luminescence.

    Science.gov (United States)

    Forniés, Juan; Fuertes, Sara; Martín, Antonio; Sicilia, Violeta; Lalinde, Elena; Moreno, M Teresa

    2006-11-06

    This work describes the synthesis of cis-[Pt(C[triple bond]CPh)2(Hdmpz)2] (1) and its use as a precursor for the preparation of homo- and heteropolynuclear complexes. Double deprotonation of compound 1 with readily available M(I) (M = Cu, Ag, Au) or M(II) (M = Pd, Pt) species affords the discrete hexanuclear clusters [{PtM2(mu-C[triple bond]CPh)2(mu-dmpz)(2)}(2)] [M = Cu (2), Ag (3), Au (4)], in which both "Pt(C[triple bond]CPh)2(dmpz)(2)" fragments are connected by four d(10) metal centers, and are stabilized by alkynyl and dimethylpyrazolate bridging ligands, or the trinuclear complexes [Pt(mu-C[triple bond]CPh)2(mu-dmpz)(2){M(C/\\P)}2] (M = Pd (5), Pt (6); C/\\P = CH(2)-C(6)H(4)-P(o-tolyl)2-kappaC,P), respectively. The X-ray structures of complexes 1-4 and 6 are reported. The X-ray structure of the platinum-copper derivative 2 shows that all copper centers exhibit similar local geometry being linearly coordinated to a nitrogen atom and eta(2) to one alkynyl fragment. However in the related platinum-silver (3) and platinum-gold (4) derivatives the silver and gold atoms present three different coordination environments. The complexes have been studied by absorption and emission spectroscopy. The hexanuclear complexes exhibit bright luminescence in the solid state and in fluid solution (except 4 in the solid state at 298 K). Dual long-lived emission is observed, being clearly resolved in low-temperature rigid media. The low-energy emission is ascribed to MLM'CT Pt(d)/pi(C[triple bond]CPh)-->Pt(p(z))/M'(sp)/pi*(C[triple bond]CPh) modified by metal-metal interactions whereas the high-energy emission is tentatively attributed to an emissive state derived from dimethylpyrazolate-to-metal (d(10)) LM'CT transitions pi(dmpz)-->M'(d(10)).

  4. binuclear copper(II) complexes

    Indian Academy of Sciences (India)

    Administrator

    403. Synthesis, electrochemical and magnetic properties of new acylic. 'end-off' binuclear copper(II) complexes. T M RAJENDIRAN, R KANNAPPAN, R VENKATESAN and. P SAMBASIVA RAO. Department of Chemistry, Pondicherry University, R.V. Nagar, Kalapet,. Pondicherry 605 014, India. A series of nonbridged nitrito ...

  5. ANTIMICROBIAL ACTIVITY OF COPPER(II COMPLEXES

    Directory of Open Access Journals (Sweden)

    Andrea Čongrádyová

    2014-02-01

    Full Text Available Two novel copper(II 5-chlorosalicylate complexes with either 1,10-phenantroline or its methyl derivative 2,9-dimethyl-1,10-phenanthroline (neocuproine have been prepared and studied. A potential antimicrobial or antifungal activity of both complexes has been tested on prokaryotic Escherichia coli and eukaryotic Saccharomyces cerevisiae model organisms. Crystal structure of [Cu(phen(5-Clsal(5-ClsalH2]2 a dimeric structure, whereas the second complex of formula [Cu(H2O(5-Clsal(Neo] has been shown to be monomeric. Our results confirmed the toxic effect of prepared copper complexes as well as bioactive ligands on the yeast and bacteria growth. The effect of copper complexes was stronger compared to the solutions of free ligands. Our preliminary results showed that the complex [Cu(H2O(5-Clsal(Neo] exhibited higher antimicrobial activity compared to the complex [Cu(phen(5-Clsal(5-ClsalH2]2.

  6. Copper(II) complexes with aroylhydrazones

    Indian Academy of Sciences (India)

    Unknown

    The coordination chemistry of copper(II) with tridentate aroylhydrazones is briefly discussed in this article. ... the metal ions 3. In the following account, the results obtained in our study on copper(II) chemistry with these ..... Rev.77165;. (b) Fenton D E 1983 Advances in inorganic and bio-organic mechanisms (ed.) A G Sykes.

  7. Photocleavage of DNA by copper(II) complexes

    OpenAIRE

    Chakravarty, Akhil R

    2006-01-01

    The chemistry of ternary and binary copper(II) complexes showing efficient visible lightinduced DNA cleavage activity is summarized in this article. The role of the metal in photo-induced DNA cleavage reactions is explored by designing complex molecules having a variety of ligands. Ternary copper(II) complexes with amino acid like L-methionone or L-lysine and phenanthroline base are efficient photocleavers of DNA. Complexes of formulation $[Cu(L^n)(phen)](ClO_4)$ with NSO-donor Schiff base $(...

  8. A copper complex (2,2¢-bipyridine)(salicyclideneglycinato) copper(II ...

    Indian Academy of Sciences (India)

    Administrator

    In aqueous–methanol, ascorbic acid reduces the copper(II) complex to form a brown copper(I) species which readily converts to the green precursor copper(II) complex in the presense of dioxygen. The proposed catalytic cycle for this conversion in air is shown below. The copper(II) complex is also catalytically active in.

  9. Photocleavage of DNA by copper(II) complexes

    Indian Academy of Sciences (India)

    pathway) as the reactive species. Keywords. Copper(II) complexes; DNA photocleavage; red light laser; phenanthroline bases. 1. Introduction. Transition metal complexes that are suitable for binding and cleaving double-stranded DNA are of con- siderable current interest due to their various appli- cations in nucleic acid ...

  10. COPPER(II) COMPLEXES OF o -VANILLIN ACETYLHYDRAZONE ...

    African Journals Online (AJOL)

    COPPER(II) COMPLEXES OF o-VANILLIN ACETYLHYDRAZONE (H2L) AND THE SINGLE-CRYSTAL X-RAY STRUCTURE OF [{Cu(HL)(HO)(HPZ)}].NO3. Ousmane Diouf*, Mohamed Gaye, Diariétou Gningue Sall, Abdou Salam Sall, Yves Pontillon, Andrea Caneschi ...

  11. Copper(II) complex of 3-cinnamalideneacetylacetone: Synthesis and ...

    Indian Academy of Sciences (India)

    Unknown

    Abstract. A bidentate ligand derived from cinnamaldehyde and acetylacetone and its copper(II) complex have been synthesized and characterized by elemental analysis,. UV-Vis, IR, ESR and magnetic susceptibility measurements. Magnetic susceptibility measurements, ESR and electronic spectral data indicate the ...

  12. Copper(II) Schiff base complexes and their mixed thin layers with ...

    Indian Academy of Sciences (India)

    the possibility of using the spin coating technique for deposition of the copper(II) complexes and ZnO nanoparticles on different substrates and the likely flu- orescence behavior of the obtained layers, prompted us to synthesize a series of new copper(II) complexes with. Schiff bases derived from ethylenediamine and several.

  13. metal complexes of copper(ii)

    African Journals Online (AJOL)

    Zinc(II) complex is diamagnetic. The cobalt(II) complex was found with paramagnetic character (4.11 B.M.). Also, in the FT-IR spectra of oligomer-metal complexes, there was no evidence associated with coordinated water molecules. Because this band generally was observed at 3700-3500 cm-1 region as a broad band.

  14. Synthesis and characterization of copper(II) complexes of semicarbazones

    Science.gov (United States)

    Chandra, Usha; Chandra, Sulekh

    1992-08-01

    Copper(II) complexes of the general composition Cu(ligand) 2X 2 (where X=CI -, Br -, NO -3, ClO -4 and 1/2 SO 2-4) and Cu(ligand) (CH 3COO) 2 have been synthesized with methyl n-pentyl ketone and methyl n-hexyl ketone semicarbazones. All the complexes prepared have been characterized by elemental analysis, magnetic moment, molar conductance, IR, electronic and electron spin resonance spectral studies. The complexes Cu(ligand) 2X 2 (X = Cl -, Br -, NO -3) and Cu(ligand) (CH 3COO) 2 may have tetragonal geometry, while the complexes Cu(ligand) 2X 2 (X = ClO -4 and 1/2 SO 2-4) may be assigned a five-coordinated trigonally distorted square pyramidal geometry.

  15. Spectral studies of copper(II) complexes of 6-(3-thienyl) pyridine-2-thiosemicarbazone

    Science.gov (United States)

    Mahjoub, Omima Abdalla; Farina, Yang

    2014-09-01

    Two novel copper(II) complexes [Cu(HL)Cl]Cl˙H2O (1) and [Cu(L)NO3]˙H2O (2) of the three NNS donor thiosemicarbazone ligand 6-(3-thienyl) pyridine-2-thiosemicarbazone have been synthesized. The ligand and its copper(II) complexes were characterized by elemental analysis (C, H, N, and S), FT-IR, UV-visible, magnetic susceptibility and molar conductance. The thiosemicarbazone is present either as the thione form in complex 1 or as thiol form in complex 2 and is coordinated to copper(II) atom via the pyridine nitrogen atom, the azomethine nitrogen atom and the sulfur atom. The physicochemical and spectral data suggest square planar geometry for copper(II) atoms.

  16. Synthetic bioactive novel ether based Schiff bases and their copper(II) complexes

    Science.gov (United States)

    Shabbir, Muhammad; Akhter, Zareen; Ismail, Hammad; Mirza, Bushra

    2017-10-01

    Novel ether based Schiff bases (HL1- HL4) were synthesized from 5-chloro-2-hydroxy benzaldehyde and primary amines (1-amino-4-phenoxybenzene, 4-(4-aminophenyloxy) biphenyl, 1-(4-aminophenoxy) naphthalene and 2-(4-aminophenoxy) naphthalene). From these Schiff bases copper(II) complexes (Cu(L1)2-Cu(L4)2)) were synthesized and characterized by elemental analysis and spectroscopic (FTIR, NMR) techniques. The synthesized Schiff bases and copper(II) complexes were further assessed for various biological studies. In brine shrimp assay the copper(II) complexes revealed 4-fold higher activity (LD50 3.8 μg/ml) as compared with simple ligands (LD50 12.4 μg/ml). Similar findings were observed in potato disc antitumor assay with higher activities for copper(II) complexes (IC50 range 20.4-24.1 μg/ml) than ligands (IC50 range 40.5-48.3 μg/ml). DPPH assay was performed to determine the antioxidant potential of the compounds. Significant antioxidant activity was shown by the copper(II) complexes whereas simple ligands have shown no activity. In DNA protection assay significant protection behavior was exhibited by simple ligand molecules while copper(II) complexes showed neutral behavior (neither protective nor damaging).

  17. Transition metal complexes of neocryptolepine analogues. Part I: Synthesis, spectroscopic characterization, and invitro anticancer activity of copper(II) complexes

    Science.gov (United States)

    Emam, Sanaa Moustafa; El Sayed, Ibrahim El Tantawy; Nassar, Nagla

    2015-03-01

    New generation of copper(II) complexes with aminoalkylaminoneocryptolepine as bidentate ligands has been synthesized and it is characterized by elemental analyses, magnetic moment, spectra (IR, UV-Vis, 1H NMR and ESR) and thermal studies. The IR data suggest the coordination modes for ligands which behave as a bidentate with copper(II) ion. Based on the elemental analysis, magnetic studies, electronic and ESR data, binuclear square planar geometry was proposed for complexes 7a, 7b, square pyramidal for 9a, 9b and octahedral for 8a, 8b, 10a, 10b. The molar conductance in DMF solution indicates that all complexes are electrolyte except 7a and 7b. The ESR spectra of solid copper(II) complexes in powder form showed an axial symmetry with 2B1g as a ground state and hyperfine structure. The thermal stability and degradation of the ligands and their metal complexes were studied employing DTA and TG methods. The metal-free ligands and their copper(II) complexes were tested for their in vitro anticancer activity against human colon carcinoma (HT-29). The results showed that the synthesized copper(II) complexes exhibited higher anticancer activity than their free ligands. Of all the studied copper(II) complexes, the bromo-substituted complex 9b exhibited high anticancer activity at low micromolar inhibitory concentrations (IC50 = 0.58 μM), compared to the other complexes and the free ligands.

  18. Copper(II) complexes with heterocyclic hydroxyimino-containing ligands

    Energy Technology Data Exchange (ETDEWEB)

    Kogan, V.A.; Burlov, A.S.; Popov, L.D.; Lukov, V.V.; Koshchienko, Yu.V.; Tsupak, E.B.; Barchan, G.P.; Chigarenko, G.G.; Bolotnikov, V.S.

    1988-05-01

    The reaction of oximes (R = Ph (L'), C=N (L'')) with the copper(II) salts CuA/sub 2/ in methanol has given the complexes CuL/sub 2/ ' x H/sub 2/O and CuL/sub 2//sup ''/ x 2H/sub 2/O (I) (A = Acet/sup -/), CuHLCl/sub 2/ x H/sub 2/O (II) (A = Cl/sup -/), CuLOH(ClO/sub 4/)/sub 2/ x 2H/sub 2/O (III) (A = ClO/sub 4//sup -/) and the complexes Cu/sub 3/L/sub 3//sup '/OH(NO/sub 3/)/sub 2/ and Cu/sub 3/L/sub 3//sup ''/(OH)/sub 2/NO/sub 3/ (IV) (A = NO/sub 3//sup -/). Their physicochemical properties have been studied by the methods of IR spectroscopy and magnetochemistry. It has been shown that complexes I have a chelate structure and that their magnetic moments are not dependent on the temperature. An anti-ferromagnetic exchange interaction takes place in complexes II-IV. On the basis of magnetochemical measurements over a broad temperature range and data calculated in the framework of the Heisenberg-Dirac-Van Vleck model of isotropic exchange interactions, a dimeric structure has been proposed for the complexes of type II, and a trinuclear cluster structure has been proposed for complexes III and IV.

  19. The encapsulation of ferrocyanide by copper(II) complexes of tripodal tetradentate ligands. Novel H-bonding networks incorporating heptanuclear and pentanuclear heterometallic assemblies.

    Science.gov (United States)

    Parker, R J; Spiccia, L; Batten, S R; Cashion, J D; Fallon, G D

    2001-08-27

    Substitution of the weakly binding aqua ligand in [Cu(tren)OH2](2+) and [Cu(tpa)OH2](2+) (tren = tris(2-aminoethyl)amine; tpa = tris(2-pyridylmethyl)amine) by a cyano ligand on ferricyanide results in the assembly of heteropolynuclear cations around the cyanometalate core. In water, the reduction of the Fe(III) core to Fe(II) generates complexes that feature heteropolycations in which ferrocyanide is encapsulated by the Cu(II) moieties: [(Cu(tpa)CN)6Fe][ClO4]8-3H2O 1, [(Cu(tren)CN)6Fe][ClO4]8-10H2O 2, [(Cu(tren)CN)6Fe][Fe(CN)6]2[ClO4]2-15.8H2O 3, and [(Cu(tren)CN)6Fe][(Cu(tren)CN)4Fe(CN)2][Fe(CN)6)]4-6DMSO-21H2O 4. The formation of discrete molecules, in preference to extended networks or polymeric structures, has been encouraged through the use of branched tetradentate ligands in conjunction with copper(II), a metal center with the propensity to form five-coordinate complexes. Complex 3 crystallizes in the monoclinic space group P2(1)/c (#14) with a = 14.8674(10), b = 25.9587(10), c = 27.5617(10) A, beta = 100.8300(10) degrees, and Z = 4, and it is comprised of almost spherical heptanuclear cations, [(Cu(tren)CN)6Fe](8+), whose charge is balanced by two ferricyanide and two perchlorate counteranions. Complex 4 crystallizes in the triclinic space group P1 (# 1) with a = 14.8094(8), b = 17.3901(7), c = 21.1565(11) A, alpha = 110.750(3), beta = 90.206(2), gamma = 112.754(3) degrees, and Z = 1, and it is comprised of the heptanuclear [(Cu(tren)CN)6Fe](8+) cation and pentanuclear [(Cu(tren)CN)4Fe(CN)2](4+) cation, whose terminal cyano ligands are oriented trans to each other. The charge is balanced exclusively by ferricyanide counteranions. In both complexes, H-bonding interactions between hydrogens on primary amines of the tren ligand, terminal cyano groups of the ferricyanide counterions, and the solvent of crystallization generate intricate 3D H-bonding networks.

  20. Surface Structures Formed by a Copper(II Complex of Alkyl-Derivatized Indigo

    Directory of Open Access Journals (Sweden)

    Akinori Honda

    2016-10-01

    Full Text Available Assembled structures of dyes have great influence on their coloring function. For example, metal ions added in the dyeing process are known to prevent fading of color. Thus, we have investigated the influence of an addition of copper(II ion on the surface structure of alkyl-derivatized indigo. Scanning tunneling microscope (STM analysis revealed that the copper(II complexes of indigo formed orderly lamellar structures on a HOPG substrate. These lamellar structures of the complexes are found to be more stable than those of alkyl-derivatized indigos alone. Furthermore, 2D chirality was observed.

  1. Template Syntheses, Crystal Structures and Supramolecular Assembly of Hexaaza Macrocyclic Copper(II) Complexes

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Taehyung; Kim, Ju Chang [Pukyong National Univ., Busan (Korea, Republic of); Lough, Alan J. [Univ. of Toronto, Toronto (Canada)

    2013-06-15

    Two new hexaaza macrocyclic copper(II) complexes were prepared by a template method and structurally characterized. In the solid state, they were self-assembled by intermolecular interactions to form the corresponding supramolecules 1 and 2, respectively. In the structure of 1, the copper(II) macrocycles are bridged by a tp ligand to form a macrocyclic copper(II) dimer. The dimer extends its structure by intermolecular forces such as hydrogen bonds and C-H···π interactions, resulting in the formation of a double stranded 1D supramolecule. In 2, the basic structure is a monomeric copper(II) macrocycle with deprotonated imidazole pendants. An undulated 1D hydrogen bonded array is achieved through hydrogen bonds between imidazole pendants and secondary amines, where the imidazole pendants act as a hydrogen bond acceptor. The 1D hydrogen bonded supramolecular chain is supported by C-H···π interactions between the methyl groups of acetonitrile ligands and imidazole pendants of the copper(II) macrocycles. In both complexes, the introduction of imidazoles to the macrocycle as a pendant plays an important role for the formation of supramolecules, where they act as intermolecular hydrogen bond donors and/or acceptors, C-H···π and π-π interactions.

  2. Synthesis and characterization of a chiral dimeric copper(II) complex ...

    Indian Academy of Sciences (India)

    Unknown

    IR, UV–visible and EPR spectroscopy and circular dichroism (CD) studies. Keywords. Dinuclear copper(II) complex; crystal structure; chiral properties. 1. Introduction. Binuclear complexes of copper have received much attention because of their relevance to the type 3 copper found in multicopper-containing proteins such.

  3. Human topoisomerase IB is a target of a thiosemicarbazone copper(II) complex.

    Science.gov (United States)

    Vutey, Venn; Castelli, Silvia; D'Annessa, Ilda; Sâmia, Luciana B P; Souza-Fagundes, Elaine M; Beraldo, Heloisa; Desideri, Alessandro

    2016-09-15

    The human topoisomerase IB inhibition and the antiproliferative activity of 3-(4-bromophenyl)-1-pyridin-2-ylprop-2-en-1-one thiosemicarbazone HPyCT4BrPh alone and its copper(II) complex [Cu(PyCT4BrPh)Cl] was investigated. [Cu(PyCT4BrPh)Cl] inhibits both the DNA cleavage and religation step of the enzyme, whilst the ligand alone does not display any effect. In addition we show that coordination to copper(II) improves the cytotoxicity of HPyCT4BrPh against THP-1 leukemia and MCF-7 breast cancer cells. The data indicate that the copper(II) thiosemicarbazone complex may hit human topoisomerase IB and that metal coordination can be useful to improve cytotoxicity of this versatile class of compounds. Copyright © 2016 Elsevier Inc. All rights reserved.

  4. Complexation between the fungicide tebuconazole and copper(II) probed by electrospray ionization mass spectrometry.

    Science.gov (United States)

    Dytrtová, Jana Jaklová; Jakl, Michal; Schröder, Detlef; Čadková, Eva; Komárek, Michael

    2011-04-30

    Electrospray ionization mass spectrometry (ESI-MS) is used to probe the complex formation between tebuconazole (1) and copper(II) salts, which both are commonly used fungicides in agriculture. Experiments with model solutions containing 1 and CuCl(2) reveal the initial formation of the copper(II) species [(1)CuCl](+) and [(1)(2)CuCl](+) which undergo reduction to the corresponding copper(I) ions [(1)Cu](+) and [(1)(2)Cu](+) under more drastic ionization conditions in the ESI source. In additional experiments, copper/tebuconazole complexes were also detected in samples made from soil solutions of various origin and different amount of mineralization. The direct sampling of such solutions via ESI-MS is thus potentially useful for understanding of the interactions between copper(II) salts and tebuconazole in environmental samples. Copyright © 2011 John Wiley & Sons, Ltd.

  5. Copper(II) complex as a precursor for formation of cyano-bridged ...

    Indian Academy of Sciences (India)

    chemsci

    Copper(II) complex as a precursor for formation of cyano-bridged pentanuclear Fe. III. -Cu. II bimetallic assembly: Synthesis, characterization, crystal structure and antibacterial ... Single-crystal X-ray analysis indicated that 2 crystallized in the monoclinic system with ..... maximum absorption band at 431nm was assigned to.

  6. Synthetic, Crystallographic, and Computational Study of Copper(II) Complexes of Ethylenediaminetetracarboxylate Ligands

    NARCIS (Netherlands)

    Matovic, Zoran D.; Miletic, Vesna D.; Cendic, Marina; Meetsma, Auke; van Koningsbruggen, Petra J.; Deeth, Robert J.; Matović, Zoran D.; Miletić, Vesna D.; Ćendić, Marina

    2013-01-01

    Copper(II) complexes of hexadentate ethylenediaminetetracarboxylic acid type ligands H(4)eda3p and Rieddadp (H(4)eda3p = ethylenediamine-N-acetic-N,N',N'-tri-3-propionic acid; ateddadp = ethylenediamine-N,N'-diaceticN,N'-di-3-propionic acid) have been prepared. An octahedral trans(O-6) geometry (two

  7. Preparation, characterization and biological evaluation of copper(II) and zinc(II) complexes with cephalexin.

    Science.gov (United States)

    Iqbal, M S; Ahmad, A R; Sabir, M; Asad, S M

    1999-04-01

    Copper(II) and zinc(II) complexes of cephalexin have been prepared and characterized by microanalysis and by thermogravimetric, magnetic and spectroscopic analysis. The complexes were found to be five-coordinate, monohydrate, and ML2 type. The electron paramagnetic resonance spectral lines revealed rhombic distortion from axial symmetry, with g(parallel) > g(perpendicular) > g(e), in the elongated-tetragonal copper(II) complex. The geometry of the zinc(II) complex seems to be square-pyramidal. On complexation with copper and zinc the antimicrobial activity of cephalexin improved significantly. The copper complex was found to be active against kaolin paw oedema whereas the parent drug was inactive. These results suggest that the metallic elements should be seriously considered during drug design, and that complexes already reported should be subjected to clinical evaluation. Their use could provide an easy way of improving the activity and reducing the toxicity of drug substances.

  8. Polyethyleneimine anchored copper(II) complexes: synthesis, characterization, in vitro DNA binding studies and cytotoxicity studies.

    Science.gov (United States)

    Lakshmipraba, Jagadeesan; Arunachalam, Sankaralingam; Riyasdeen, Anvarbatcha; Dhivya, Rajakumar; Akbarsha, Mohammad Abdulkader

    2015-01-01

    The water soluble polyethyleneimine-copper(II) complexes, [Cu(phen)(L-tyr)BPEI]ClO4 (where phen=1,10-phenanthroline, L-tyr=L-tyrosine and BPEI=branched polyethyleneimine) with various degree of copper(II) complex units in the polymer chain were synthesized and characterized by elemental analysis and electronic, FT-IR, EPR spectroscopic techniques. The binding of these complexes with CT-DNA was studied using UV-visible absorption titration, thermal denaturation, emission, circular dichroism spectroscopy and cyclic voltammetric methods. The changes observed in the physicochemcial properties indicated that the binding between the polymer-copper complexes and DNA was mostly through electrostatic mode of binding. Among these complexes, the polymer-copper(II) complex with the highest degrees of copper(II) complex units (higher degrees of coordination) showed higher binding constant than those with lower copper(II) complex units (lower degrees of coordination) complexes. The complex with the highest number of metal centre bound strongly due to the cooperative binding effect. Therefore, anticancer study was carried out using this complex. The cytotoxic activity for this complex on MCF-7 breast cancer cell line was determined adopting MTT assay, acridine orange/ethidium bromide (AO/EB) staining and comet assay techniques, which revealed that the cells were committed to specific mode of cell death either apoptosis or necrosis. Copyright © 2014 Elsevier B.V. All rights reserved.

  9. Structural correlation of catecholase-like activities of oxy-bridged dinuclear copper(II) complexes.

    Science.gov (United States)

    Kao, C H; Wei, H H; Liu, Y H; Lee, G H; Wang, Y; Lee, C J

    2001-04-01

    Eight oxy-bridged dinuclear copper(II) complexes with catecholase-like sites, [Cu(L1)X]2 (HL1 = 1-diethylaminopropan-2-ol, X=N3- 1, NCO- 2, and NO2- 3), [Cu(L2)X]2 (HL2=N-ethylsalicylaldimine, X=NO3- 4, Cl- 5, N3- 6, NCS- 7), and [Cu(L3)]2(ClO4)2, 8 (HL3=N-(salicylidene)-N'-(2-pyridylaldene)propanediamine) have been prepared and characterized. The single crystal X-ray analysis show that the structures of complexes 6 and 8 are dimeric with two adjacent copper(II) atoms bridged by pairs of micro-oxy atoms from the L2 and L3 ligands. Magnetic susceptibility measurements in the temperature range 4-300 K indicate significant antiferromagnetic coupling for 4, 5 and 7 and ferromagnetic coupling for 6 between the copper(II) atoms. The catecholase activity of complexes for the oxidation of 3,5-di-tert-butylcatechol by O2 was studied and it was found that the complexes with the bond distance of Cu(II)...Cu(II) located at 2.9-3.0 A show higher catecholase activity.

  10. Copper(II) Chlorate Complexes - the Renaissance of a Forgotten and Misjudged Energetic Anion.

    Science.gov (United States)

    Wurzenberger, Maximilian H H; Szimhardt, Norbert; Stierstorfer, Jörg

    2018-02-16

    A convenient synthetic route toward new copper(II) chlorate complexes with potential use in modern advanced igni-tion or initiation systems is described. Obtained compounds were not only accurately characterized (XRD, IR, UV/Vis EA and DTA) but also investigated for their energetic character (sensitivities, initiation capability and laser ignition). The copper 4-aminotriazolyl chlorate complex showed excellent initiation of PETN, while also being thermally stable and safe to handle. Solid-state UV-Vis measurements were performed to get a possible insight toward the laser initia-tion mechanism. In contrast to expectations, the presented copper(II) chlorate energetic coordination compounds show manageable sensitivities that can be tamed or boosted by the appropriate choice of nitrogen-rich ligands.

  11. Catalytic aspects of a copper(II) complex: biological oxidase to ...

    Indian Academy of Sciences (India)

    BISWAJIT CHOWDHURY

    2017-10-03

    Oct 3, 2017 ... assigned to the ligand field transition for the copper(II) complex. The X-band EPR spectrum of the copper com- plex (Figure S2 in SI) at low temperature (LT, 77K) was recorded in frozen MeCN solution (Figure S2 (Left)) and in powder state at 77 K (Figure S2 (Right) in SI) to examine the geometry of copper ...

  12. Mononuclear and binuclear copper(II) complexes of the antiinflammatory drug ibuprofen: synthesis, characterization, and catecholase-mimetic activity.

    Science.gov (United States)

    Abuhijleh, A L

    1994-09-01

    Two mononuclear copper(II) ibuprofenate adducts with imidazole or 2-methylimidazole and two binuclear copper(II) ibuprofenate adducts with metronidazole or caffeine have been prepared and characterized. Elemental analyses, UV-VIS, IR, EPR, and magnetic moment data for imidazole or 2-methylimidazole adducts are consistent with mononuclear square planar complexes that contain two ibuprofenato ligands and two N-containing imidazole ligands to give essentially a CuO2N2 chromophore. The above data for metronidazole or caffeine adducts are consistent with a binuclear structure as found for copper(II) acetate monohydrate and other copper(II) carboxylate dimers. In these complexes four carboxylate groups are bridging two copper(II) atoms, and two added bases coordinated at axial positions to form CuO4N chromophore around each copper. The catecholase-mimetic catalytic activities of the complexes have been determined by monitoring the formation of o-quinone from catechol. The catalytic activities of the mononuclear complexes are lower than those of the binuclear copper(II) ibuprofenate or its metronidazole or caffeine mono-adducts.

  13. Immobilized copper(II) macrocyclic complex on MWCNTs with antibacterial activity

    Energy Technology Data Exchange (ETDEWEB)

    Tarlani, Aliakbar, E-mail: Tarlani@ccerci.ac.ir [Inorganic Nanostructures and Catalysts Research Lab., Chemistry & Chemical Engineering Research Center of Iran, Pajoohesh Blvd., km 17, Karaj Hwy, Tehran 14968-13151 (Iran, Islamic Republic of); Narimani, Khashayar [Inorganic Nanostructures and Catalysts Research Lab., Chemistry & Chemical Engineering Research Center of Iran, Pajoohesh Blvd., km 17, Karaj Hwy, Tehran 14968-13151 (Iran, Islamic Republic of); Mohammadipanah, Fatemeh; Hamedi, Javad [Department of Microbial Biotechnology, School of Biology and Center of Excellence in Phylogeny of Living Organisms, College of Science, University of Tehran, Tehran 14155-6455 (Iran, Islamic Republic of); University of Tehran Biocompound Collection (UTBC), Microbial Technology and Products Research Center, University of Tehran, Tehran (Iran, Islamic Republic of); Tahermansouri, Hasan [Department of Chemistry, Ayatollah Amoli Branch, Islamic Azad University, Amol (Iran, Islamic Republic of); Amini, Mostafa M. [Department of Chemistry, Shahid Behshti University, 1983963113, Tehran (Iran, Islamic Republic of)

    2015-06-30

    Graphical abstract: In an antibacterial test, grafted copper(II) macrocyclic complex on the surface of MWCNT showed higher antibacterial activity against Bacillus subtilis compared to the individual MWCNT-COOH and the complex. - Highlights: • Copper(II) tetraaza macrocyclic complex covalently bonded to modified MWCNT. • Grafting of the complex carried out via an interaction between −C(=O)Cl group and NH of the ligand. • The samples were subjected in an antibacterial assessment to compare their activity. • Immobilized complex showed higher antibacterial activity against Bacillus subtilis ATCC 6633 compared to separately MWCNT-C(C=O)-OH and CuTAM. - Abstract: In a new approach, a copper(II) tetraaza macrocyclic complex (CuTAM) was covalently bonded on modified multi-walled carbon nanotubes (MWCNTs). To achieve this purpose, MWCNTs were converted to MWCNT-COCl and then reacted to NH groups of TAM ligand. The prepared material was characterized by Fourier Transform Infrared (FT-IR), X-ray diffraction (XRD), Raman spectroscopy, thermal gravimetric analysis (TGA), and FESEM (field emission scanning electron microscopy). FT-IR and TGA demonstrated the presence of the organic moieties, and XRD proved that the structure of MWCNTs remained intact during the three modification steps. An increase in the I{sub D}/I{sub G} ratio in Raman spectra confirmed the surface modifications. Finally, the samples were subjected to an antibacterial assessment to compare their biological activity. The antibacterial test showed that the grafted complex on the surface of the nanotube (MWCNT-CO-CuTAM) has higher antibacterial activity against Bacillus subtilis ATCC 6633 than the MWCNT-COOH and CuTAM with 1000 and 2000 μg/mL.

  14. Oligocyclopentadienyl transition metal complexes

    Energy Technology Data Exchange (ETDEWEB)

    de Azevedo, Cristina G.; Vollhardt, K. Peter C.

    2002-01-18

    Synthesis, characterization, and reactivity studies of oligocyclopentadienyl transition metal complexes, namely those of fulvalene, tercyclopentadienyl, quatercyclopentadienyl, and pentacyclopentadienyl(cyclopentadienyl) are the subject of this account. Thermal-, photo-, and redox chemistries of homo- and heteropolynuclear complexes are described.

  15. Synthesis and spectroscopic study of copper(II) and manganese(II) complexes with pipemidic acid.

    Science.gov (United States)

    Szymańska, Beata; Skrzypek, Danuta; Kovala-Demertzi, Dimitra; Staninska, Malgorzata; Demertzis, Mavroudis A

    2006-03-01

    The interaction of copper(II) and manganese(II) with pipemidic acid, Hpipem, afforded the complexes [Cu(pipem)(2)(H(2)O)] x 2H(2)O, 1 and [Mn(pipem)(2)(H(2)O)], 2. The new complexes have been characterised by elemental analyses, infrared, UV-vis and X-band EPR spectroscopy in the temperature range from 4 to 300 K. The monoanion, pipem, exhibits O,O ligation through the carbonyl and carboxylato oxygen atoms. Five coordinate square-pyramid configuration has been proposed for 1 and 2, and the fifth apical position is occupied by a coordinated water molecule.

  16. Synthesis and spectroscopic study of copper(II) and manganese(II) complexes with pipemidic acid

    Science.gov (United States)

    Szymańska, Beata; Skrzypek, Danuta; Kovala-Demertzi, Dimitra; Staninska, Malgorzata; Demertzis, Mavroudis A.

    2006-03-01

    The interaction of copper(II) and manganese(II) with pipemidic acid, Hpipem, afforded the complexes [Cu(pipem) 2(H 2O)]·2H 2O, 1 and [Mn(pipem) 2(H 2O)], 2. The new complexes have been characterised by elemental analyses, infrared, UV-vis and X-band EPR spectroscopy in the temperature range from 4 to 300 K. The monoanion, pipem, exhibits O,O ligation through the carbonyl and carboxylato oxygen atoms. Five coordinate square-pyramid configuration has been proposed for 1 and 2, and the fifth apical position is occupied by a coordinated water molecule.

  17. Characterisation of the interactions between substrate, copper(II) complex and DNA and their role in rate acceleration in DNA-based asymmetric catalysis

    NARCIS (Netherlands)

    Draksharapu, Apparao; Boersma, Arnold J; Browne, Wesley R; Roelfes, Gerard

    2015-01-01

    Interactions of the azachalcone derived substrate Aza with copper(II) complexes in the presence and absence of st-DNA were studied in detail by UV/Vis absorption, EPR and Raman and (UV and vis) resonance Raman spectroscopies. The binding of Aza to the Lewis acidic copper(II) complexes, which results

  18. Antimalarial, antimicrobial, cytotoxic, DNA interaction and SOD like activities of tetrahedral copper(II) complexes

    Science.gov (United States)

    Mehta, Jugal V.; Gajera, Sanjay B.; Patel, Mohan N.

    2015-02-01

    The mononuclear copper(II) complexes with P, O-donor ligand and different fluoroquinolones have been synthesized and characterized by elemental analysis, electronic spectra, TGA, EPR, FT-IR and LC-MS spectroscopy. An antimicrobial efficiency of the complexes has been tested against five different microorganisms in terms of minimum inhibitory concentration (MIC) and displays very good antimicrobial activity. The binding strength and binding mode of the complexes with Herring Sperm DNA (HS DNA) have been investigated by absorption titration and viscosity measurement studies. The studies suggest the classical intercalative mode of DNA binding. Gel electrophoresis assay determines the ability of the complexes to cleave the supercoiled form of pUC19 DNA. Synthesized complexes have been tested for their SOD mimic activity using nonenzymatic NBT/NADH/PMS system and found to have good antioxidant activity. All the complexes show good cytotoxic and in vitro antimalarial activities.

  19. Fluorescent copper(II complexes: The electron transfer mechanism, interaction with bovine serum albumin (BSA and antibacterial activity

    Directory of Open Access Journals (Sweden)

    Madhumita Hazra

    2017-01-01

    Full Text Available Dinuclear copper(II complexes with formula [Cu2(L2(N32] (1 and [Cu2(L2(NCS2] (2 HL = (1-[(3-methyl-pyridine-2-ylimino-methyl]-naphthalen-2-ol were synthesized by controlling the molar ratio of Cu(OAC2·6H2O, HL, sodium azide (1 and ammonium thiocyanate (2. The end on bridges appear exclusively in azide and thiocyanate to copper complexes. The electron transfer mechanism of copper(II complexes is examined by cyclic voltammetry indicating copper(II complexes are Cu(II/Cu(I couple. The interactions of copper(II complexes towards bovine serum albumin (BSA were examined with the help of absorption and fluorescence spectroscopic tools. We report a superficial solution-based route for the synthesis of micro crystals of copper complexes with BSA. The antibacterial activity of the Schiff base and its copper complexes were investigated by the agar disc diffusion method against some species of pathogenic bacteria (Escherichia coli, Vibrio cholerae, Streptococcus pneumonia and Bacillus cereus. It has been observed that the antibacterial activity of all complexes is higher than the ligand.

  20. (azo anils and oxalate ion) copper(ii) complexes

    African Journals Online (AJOL)

    B. S. Chandravanshi

    transition metal complexes compared to corresponding free ligands may be attributed to structural symmetry of transition metal. ... proved higher antibacterial activities when coordinated to central metal atom in compared to free ligand [5]. ... central metal atom led the complexes for numerous biomedicinal functions such as.

  1. (azo anils and oxalate ion) copper(ii) complexes

    African Journals Online (AJOL)

    B. S. Chandravanshi

    54890, Pakistan. 2Nano Science and Catalysis Division, National Centre for Physics, Islamabad-45320, Pakistan. (Received October ... Antibacterial activities of free ligands (azo anils and oxalate) and Cu(II) complexes were determined. Gram.

  2. Coordination chemistry, thermodynamics and DFT calculations of copper(II) NNOS Schiff base complexes

    Science.gov (United States)

    Esmaielzadeh, Sheida; Azimian, Leila; Shekoohi, Khadijeh; Mohammadi, Khosro

    2014-12-01

    Synthesis, magnetic and spectroscopy techniques are described for five copper(II) containing tetradentate Schiff bases are synthesized from methyl-2-(N-2";-aminoethane), (1-methyl-2";-aminoethane), (3-aminopropylamino)cyclopentenedithiocarboxylate. Molar conductance and infrared spectral evidences indicate that the complexes are four-coordinate in which the Schiff bases are coordinated as NNOS ligands. Room temperature μeff values for the complexes are 1.71-1.80 B.M. corresponding to one unpaired electron respectively. The formation constants and free energies were measured spectrophotometrically, at constant ionic strength 0.1 M (NaClO4), at 25˚C in DMF solvent. Also, the DFT calculations were carried out to determine the structural and the geometrical properties of the complexes. The DFT results are further supported by the experimental formation constants of these complexes.

  3. Spectroscopic studies on copper(II) halide complexes with isomeric benzoylpyridines: Electronic and electron spin resonance spectral evidence for five-coordinate copper(II) species in solution

    Science.gov (United States)

    Ahuja, I. S.; Tripathi, Shailendra

    1992-05-01

    Coordination compounds formed by copper(II) chloride and bromide with 2-, 3- and 4-benzoylpyridines (BOP)Cu(2-BOP)Cl 2, Cu(3-BOP) 2Cl 2, Cu(4-BOP)Cl 2, Cu(2-BOP) 2Br 2, Cu(3-BOP) 2Br 2 and Cu(4-BOP) 2Br 2—have been characterized by elemental analyses, molar conductance, magnetic moments, electronic, IR and ESR spectral studies. It is suggested that Cu(2-BOP)Cl 2 is monomeric tetrahedral, Cu(3-BOP) 2Cl 2 and Cu(4-BOP)Cl 2 are dimeric octahedral and tetrahedral structures, respectively, bridging through chlorines while all the bromo complexes are polymeric octahedral structures with bridging bromine atoms in the solid state. Powder ESR data reveal rhombic symmetry for all the chloro complexes. Cu(2-BOP) 2Br 2 is suggested to have an axial symmetry while the other bromo complexes are isotropic in nature. Electronic and ESR spectral studies in DMSO solution suggest the interaction of solvent molecules with copper(II) ions in the axial plane. The solution spectral data are almost comparable suggesting same local symmetry for all the compounds consistent with five-coordinate square pyramidal geometry in each case. ESR spectra also suggest considerable CuCu interactions in Cu(3-BOP) 2Cl 2. Various Spin—Hamiltonian parameters calculated from ESR data indicate the presence of an unpaired electron in the d x2- y2 orbital of the copper(II) ion in an axial symmetry.

  4. Enantiopure copper(II) complex of natural product rosin derivative: DNA binding, DNA cleavage and cytotoxicity.

    Science.gov (United States)

    Fei, Bao-Li; Yin, Bin; Li, Dong-Dong; Xu, Wu-Shuang; Lu, Yang

    2016-12-01

    To develop chiral anticancer drug candidates for molecular target DNA, the synthesis and characterization of a novel enantiomerically pure copper(II) complex [Cu 1 Cl 2 ] (2) of an optically pure ligand N-(pyridin-2-ylmethylene) dehydroabietylamine (1) was carried out. The coordination geometry of the copper center is a distorted square-planar arrangement. The interactions of 1 and 2 with salmon sperm DNA were investigated by viscosity measurements, UV, fluorescence and circular dichroism (CD) spectroscopic techniques. All the results reveal that 1 and 2 interacted with DNA through intercalation and 2 exhibited a higher DNA binding ability. Further, 1 and 2 could cleave supercoiled pBR322 DNA by single strand and 2 displayed stronger cleavage ability in the presence of ascorbic acid. In vitro cytotoxicity of 1 and 2 against HeLa, SiHa, HepG-2 and A431 cancer cell lines was studied using CCK-8 assay. The results indicate that 2 had a superior cytotoxicity than 1 and the widely used drug cisplatin under identical conditions. Flow cytometry analysis demonstrates 2 produced death of HeLa cancer cells through an apoptotic pathway. Cell cycle analysis shows that 2 mainly arrested HeLa cells at the S phase. A novel enantiomerically pure copper(II) complex [Cu 1 Cl 2 ] (2) of an optically pure ligand N-(pyridin-2-ylmethylene) dehydroabietylamine (1), based on natural product rosin has been synthesized. 2 has the potential to act as effective anticancer drug.

  5. Unprecedented hetero-geometric discrete copper(II) complexes ...

    Indian Academy of Sciences (India)

    hydrogen peroxide. The generation of Cu(I) species in the catalytic pathway established by electrochemi- cal analysis was further confirmed by electron para- magnetic resonance (EPR) spectroscopy. EPR titration suggests that the generation of radical of catechol in presence of copper complex is playing a key role towards ...

  6. Photocytotoxic ternary copper(II) complexes of histamine Schiff base ...

    Indian Academy of Sciences (India)

    show efficient DNA photocleavage and photocytotoxic activity in various cancer cells in visible or near-IR red light.25–30 In addition, dichloro-oxovanadium(IV) complexes are shown to form photo-induced ds-DNA crosslinks resulting apoptotic cell death.31. The present work stems from our interest to design new copper(II) ...

  7. Photocytotoxic ternary copper(II) complexes of histamine Schiff base ...

    Indian Academy of Sciences (India)

    ARC

    color codes: C black, N green, O blue, Cu red, and H white]. Figure S8. The spectral traces showing the decrease of emission intensity of ct-DNA bound ethidium bromide on increasing complex 2concentration in 5 mM Tris-HCl buffer medium.

  8. Salicylaldimine Copper(II) complex catalyst: Pioneer for ring ...

    Indian Academy of Sciences (India)

    in surgery as orthopedic applications, tissue engineer- ing and biodegradable internal fixation devices.8,9. The preventive use in biomedical application is .... showed a weight loss of 37.0 wt%, which indicates that. Cu(MBED) complex was more stable42 in compari- son to ligand (figure 2). In addition to thermal analy-.

  9. Synthesis, crystal structure and reactivity of copper(II) complexes of tetradentate N2S2 donor ligands

    Science.gov (United States)

    Sarkar, Sandipan; Paul, Hena; Drew, Michael G. B.; Zangrando, Ennio; Chattopadhyay, Pabitra

    2009-09-01

    Two new hexa-coordinated mononuclear copper(II) complexes of two ligands L 1 and L 2 containing NSSN donor sets formulated as [Cu(L)(H 2O) 2](NO 3) 2 [ 1a, L = 1,2-bis(2-pyridylmethylthio)ethane (L 1), 1b L = 1,3-bis(2-pyridyl-methylthio)propane (L 2)] were synthesized and characterized by physico-chemical and spectroscopic methods. In 1a the single crystal X-ray crystallography analysis showed a distorted octahedral geometry about copper(II) ion. The crystal packing evidences pairs of complexes arranged about a center of symmetry and connected through a H-bond occurring between aquo ligands and nitrate anions. On reaction with chloride and pseudohalides (N 3- and SCN -), in acetonitrile at ambient temperature, complexes 1 changed to monocationic penta-coordinated mononuclear copper(II) species formulated as [Cu(L)(Cl)]NO 3 ( 2), [Cu(L)(N 3)]NO 3 ( 3), and [Cu(L)(SCN)]NO 3 ( 4). These copper(II) complexes have been isolated in pure form from the reaction mixtures and characterized by physico-chemical and spectroscopic tools. The solid-state structure of 2a, established by X-ray crystallography, shows a trigonal bipyramidal geometry about the metal ion with a trigonality index ( τ) of 0.561.

  10. Correlation of Electronic and Geometric Structure in Mononuclear Copper(II) Superoxide Complexes

    Science.gov (United States)

    Ginsbach, Jake W.; Peterson, Ryan L.; Cowley, Ryan E.; Karlin, Kenneth D.; Solomon, Edward I.

    2013-01-01

    The geometry of mononuclear copper(II) superoxide complexes has been shown to determine their ground state where side-on bonding leads to a singlet ground state and end-on complexes have triplet ground states. In apparent contrast to this trend, the recently synthesized (HIPT3tren)CuII–O2•− (1) was proposed to have an end-on geometry and a singlet ground state. However, re-examination of 1 with resonance Raman (rR), magnetic circular dichroism (MCD), and 2H NMR spectroscopy indicates that 1 is in fact an end-on superoxide species with a triplet ground state that results from the single CuII–O2•− bonding interaction being weaker than the spin pairing energy. PMID:24164429

  11. Nanostructured lipid carriers for incorporation of copper(II complexes to be used against Mycobacterium tuberculosis

    Directory of Open Access Journals (Sweden)

    Sato MR

    2017-03-01

    Full Text Available Mariana R Sato,1 João A Oshiro Junior,1 Rachel TA Machado,1 Paula C de Souza,2 Débora L Campos,2 Fernando R Pavan,2 Patricia B da Silva,1,* Marlus Chorilli1,* 1Department of Drugs and Medicines, Faculdade de Ciências Farmacêuticas, UNESP – Univ Estadual Paulista, Campus Araraquara, Araraquara, SP, Brazil; 2Department of Biological Sciences, Faculdade de Ciências Farmacêuticas, UNESP – Univ Estadual Paulista, Campus Araraquara, Araraquara, SP, Brazil *These authors contributed equally to this work Abstract: Tuberculosis (TB is a disease caused by Mycobacterium tuberculosis. Cessation of treatment before the recommended conclusion may lead to the emergence of multidrug-resistant strains. The aim of this study was to develop nanostructured lipid carriers (NLCs for use in the treatment of M. tuberculosis. The NLCs comprised the following lipid phase: 2.07% polyoxyethylene 40 stearate, 2.05% caprylic/capric triglyceride, and 0.88% polyoxyl 40 hydrogenated castor oil; the following aqueous phase: 3.50% poloxamer 407 (F1–F6, and 0.50% cetyltrimethylammonium bromide (F7–F12; and incorporated the copper(II complexes [CuCl2(INH2]·H2O (1, [Cu(NCS2(INH2]·5H2O (2, and [Cu(NCO2(INH2]·4H2O (3 to form compounds F11.1, F11.2, and F11.3, respectively. The mean diameter of F11, F11.1, F11.2, and F11.3 ranged from 111.27±21.86 to 134.25±22.72 nm, 90.27±12.97 to 116.46±9.17 nm, 112.4±10.22 to 149.3±15.82 nm, and 78.65±6.00 to 122.00±8.70 nm, respectively. The polydispersity index values for the NLCs ranged from 0.13±0.01 to 0.30±0.09. The NLCs showed significant changes in zeta potential, except for F11.2, with F11, F11.1, F11.2, and F11.3 ranging from 18.87±4.04 to 23.25±1.13 mV, 17.03±1.77 to 21.42±1.87 mV, 20.51±1.88 to 22.60±3.44 mV, and 17.80±1.96 to 25.25±7.78 mV, respectively. Atomic force microscopy confirmed the formation of nanoscale spherical particle dispersions by the NLCs. Differential scanning calorimetry determined

  12. Synthesis, characterization, antibacterial activity, SOD mimic and interaction with DNA of drug based copper(II) complexes

    Science.gov (United States)

    Patel, Mohan N.; Dosi, Promise A.; Bhatt, Bhupesh S.; Thakkar, Vasudev R.

    2011-02-01

    Novel metal complexes of the second-generation quinolone antibacterial agent enrofloxacin with copper(II) and neutral bidentate ligands have been prepared and characterized with elemental analysis reflectance, IR and mass spectroscopy. Complexes have been screened for their in-vitro antibacterial activity against two Gram (+ve)Staphylococcus aureus, Bacillus subtilis, and three Gram (-ve)Serratia marcescens, Escherichia coli and Pseudomonas aeruginosa organisms using the double dilution technique. The binding of this complex with CT-DNA has been investigated by absorption titration, salt effect and viscosity measurements. Binding constant is ranging from 1.3 × 10 4-3.7 × 10 4. The cleavage ability of complexes has been assessed by gel electrophoresis using pUC19 DNA. The catalytic activity of the copper(II) complexes towards the superoxide anion (O 2rad -) dismutation was assayed by their ability to inhibit the reduction of nitroblue tetrazolium (NBT).

  13. Synthesis, characterization and biological studies of copper(II) complexes with 2-aminobenzimidazole derivatives

    Science.gov (United States)

    Joseph, J.; Suman, A.; Nagashri, K.; Joseyphus, R. Selwin; Balakrishnan, Nisha

    2017-06-01

    Novel series of four copper(II) complexes with 2-aminobenzimidazole derivatives (obtained from the Knoevenagel condensate of acetylacetone (obtained from acetylacetone and halogen substituted benzaldehydes) and 2-aminobenzimidazole) were synthesized. They were structurally characterized using elemental analysis, molar conductance, FAB mass, FT- IR, 1H &13C-NMR, UV-Vis., and EPR techniques. On the basis of analytical and spectral studies, the distorted square planar geometry was assigned for all the complexes. The antibacterial screening of the ligands and their copper complexes indicated that all the complexes showed higher anti microbial activities than the free ligands. Superoxide dismutase and antioxidant activities of the copper complexes have also been performed. In the electrochemical technique, the shift in ΔEp, E1/2 and Ipc values were explored for the interaction of the complexes with CT-DNA. During the electrolysis process, the present ligand system stabilizes unusual oxidation state of copper in the complexes. It is believed that the copper complexes with curcumin analogs may enhance chemotherapeutic behavior.

  14. Structural variety and magnetic properties of oxime-bridged copper(II) complexes

    Science.gov (United States)

    Hołyńska, Małgorzata

    2015-10-01

    A series of new oxime-bridged copper(II) complexes is introduced with phenyl 2-pyridyl ketoxime (ppkoH) as a ligand: polymeric [Cu2(ppko)2(ppkoH)2](NO3)(BF4)·CH3OH (1), dinuclear [Cu2(ppko)2(ppkoH)2](ClO4)2 (2), [Cu2(ppko)2(ppkoH)](ClO4)2·0.75CH3OH (3), trinuclear [Cu3(OH)(ppko)3(CH3OH)]·[Cu3(OH)(ppko)3(CH3OH)2](ClO4)4·CH3OH (4) and [Cu3(OH)(ppko)3(CH3OH)](BF4)(NO3) (5). Structural aspects are described in detail, other characterization techniques include elemental analyses, IR and EDX spectra.

  15. Copper(II Complexes of 4, 4- Diaminodiphenylsulphone: Synthesis, Characterization and Biological Studies

    Directory of Open Access Journals (Sweden)

    Adedibu C. Tella

    2009-01-01

    Full Text Available Five complexes of copper(II 4,4-diaminodiphenylsulphone have been synthesized. Copper salts of counter ion (sulphate, nitrate, chloride and different reaction media (solvents were used for the synthesis. The complexes varied in colour and composition. The compounds were characterized by conductivity, IR, UV, NMR and mass spectroscopies. The ligand coordinated to metal ion in a monodentate and bidentate manner. All the five complexes have tetrahedral configuration. The biological activities data showed that the complexes are more active against Esherichia coli, Klebbsiella pneumoniae and Staphylococcus aureus than the free ligand (4,4- diaminodiphenyl sulphone. Antimalaria activities of the complexes and the ligand were investigated using mice infected with Plasmodium berghei. All the complexes exhibited lower activity than the ligand and chloroquine. The effect of administration of the complexes on alkaline phosphatase activities of kidney, liver and serum of Albino rats were investigated. The serum ALP activity showed no significant change (P> 0.05, suggesting non-damaging effect on the plasma membrane of liver and kidney cells.

  16. Anti-proliferative effects of copper(II) complexes with hydroxyquinoline-thiosemicarbazone ligands.

    Science.gov (United States)

    Rogolino, Dominga; Cavazzoni, Andrea; Gatti, Anna; Tegoni, Matteo; Pelosi, Giorgio; Verdolino, Vincenzo; Fumarola, Claudia; Cretella, Daniele; Petronini, Pier Giorgio; Carcelli, Mauro

    2017-03-10

    The possibility to influence the physiological concentration of copper ions through the careful choice of ligands is emerging as a novel intriguing strategy in the treatment of pathologies such as cancer and Alzheimer. Thiosemicarbazones play an important role in this field, because they offer a wide variety of potential functionalizations and different kinds of coordination modes. Here we report the synthesis of some 8-hydroxyquinoline thiosemicarbazone ligands containing an ONN'S donor set and their Zn(II) and Cu(II) complexes. The metal complexes were characterized in solution and in the solid state and the X-ray structure of one of the copper(II) complex is reported. The Cu(II) complexes were characterized also by means of quantum mechanical calculations. The Cu(II) complexes displayed cytostatic activity in different cancer cell models. In particular, the most active Cu(II) complex significantly inhibited cell proliferation with an IC50 value lower than 1 μM; this effect was associated with a block of the cell cycle in the G2/M phase. This Cu(II) complex induced neither the production of reactive oxygen species (ROS) nor the accumulation of p53 protein, suggesting the lack of DNA damage. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  17. Ternary copper(II) complexes with amino acid chains and heterocyclic bases: DNA binding, cytotoxic and cell apoptosis induction properties.

    Science.gov (United States)

    Ma, Tieliang; Xu, Jun; Wang, Yuan; Yu, Hao; Yang, Yong; Liu, Yang; Ding, Weiliang; Zhu, Wenjiao; Chen, Ruhua; Ge, Zhijun; Tan, Yongfei; Jia, Lei; Zhu, Taofeng

    2015-03-01

    Nowadays, chemotherapy is a common means of oncology. However, it is difficult to find excellent chemotherapy drugs. Here we reported three new ternary copper(II) complexes which have potential chemotherapy characteristics with reduced Schiff base ligand and heterocyclic bases (TBHP), [Cu(phen)(TBHP)]H2O (1), [Cu(dpz)(TBHP)]H2O (2) and [Cu(dppz)(TBHP)]H2O (3) (phen=1,10-phenanthroline, dpz=dipyrido [3,2:2',3'-f]quinoxaline, dppz=dipyrido [3,2-a:2',3'-c]phenazine, H2TBHP=2-(3,5-di-tert-butyl-2-hydroxybenzylamino)-2-benzyl-acetic acid). The DNA-binding properties of the complexes were investigated by spectrometric titrations, ethidium bromide displacement experiments and viscosity measurements. The results indicated that the three complexes, especially the complex 13, can strongly bind to calf-thymus DNA (CT-DNA). The intrinsic binding constants Kb of the ternary copper(II) complexes with CT-DNA were 1.37×10(5), 1.81×10(5) and 3.21×10(5) for 1, 2 and 3 respectively. Comparative cytotoxic activities of the copper(II) complexes were also determined by 3-(4,5-dimethylthiazol-2yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The results showed that the ternary copper(II) complexes had significant cytotoxic activity against the human lung cancer (A549), human esophageal cancer (Eca109) and human gastric cancer (SGC7901) cell lines. Cell apoptosis were detected by AnnexinV/PI flow cytometry and by Western blotting with the protein expression of p53, Bax and Bcl-2. All the three copper complexes can effectively induce apoptosis of the three human tumor cells. Copyright © 2014 Elsevier Inc. All rights reserved.

  18. DNA binding and cleavage studies of copper(II) complexes with 2'-deoxyadenosine modified histidine moiety.

    Science.gov (United States)

    Borowska, Justyna; Sierant, Malgorzata; Sochacka, Elzbieta; Sanna, Daniele; Lodyga-Chruscinska, Elzbieta

    2015-09-01

    This work is focused on the study of DNA binding and cleavage properties of 2'-deoxyadenosines modified with ester/amide of histidine (his(6)dA ester, his(6)dA amide) and their copper(II) complexes. To determine the coordination mode of the complex species potentiometric and spectroscopic (UV-visible, CD, EPR) studies have been performed. The analysis of electronic absorption and fluorescence spectra has been used to find the nature of the interactions between the compounds and calf thymus DNA (CT-DNA). There is significant influence of the -NH2 and -OCH3 groups on binding of the ligands or the complexes to DNA. Only amide derivative and its complex reveal intercalative ability. In the case of his(6)dA ester and Cu(II)-his(6)dA ester the main interactions can be groove binding. DNA cleavage activities of the compounds have been examined by gel electrophoresis. The copper complexes have promoted the cleavage of plasmid DNA, but none of the ligands exhibited any chemical nuclease activity. The application of different scavengers of reactive oxygen species provided a conclusion that DNA cleavage caused by copper complexes might occur via hydrolytic pathway.

  19. Synthesis, crystallographic characterization and electrochemical property of a copper(II) complex of the anticancer agent elesclomol.

    Science.gov (United States)

    Vo, Nha Huu; Xia, Zhiqiang; Hanko, Jason; Yun, Tong; Bloom, Steve; Shen, Jianhua; Koya, Keizo; Sun, Lijun; Chen, Shoujun

    2014-01-01

    Elesclomol is a novel anticancer agent that has been evaluated in a number of late stage clinical trials. A new and convenient synthesis of elesclomol and its copper complex is described. X-ray crystallographic characterization and the electrochemical properties of the elesclomol copper(II) complex are discussed. The copper(II) cation is coordinated in a highly distorted square-planar geometry to each of the sulphur and amide nitrogen atoms of elesclomol. Electrochemical measurements demonstrate that the complex undergoes a reversible one-electron reduction at biologically accessible potentials. In contrast the free elesclomol is found electrochemically inactive. This evidence is in strong support of the mechanism of action we proposed for the anticancer activity of elesclomol. © 2013.

  20. DNA binding affinity of a macrocyclic copper(II) complex: Spectroscopic and molecular docking studies.

    Science.gov (United States)

    Shahabadi, Nahid; Hakimi, Mohammad; Morovati, Teimoor; Fatahi, Navid

    2017-08-03

    The interaction of a novel macrocyclic copper(II) complex, ([CuL(ClO 4 ) 2 ] that L is 1,3,6,10,12,15-hexaazatricyclo[13.3.1.1 6,10 ]eicosane) with calf thymus DNA (ct-DNA) was investigated by various physicochemical techniques and molecular docking at simulated physiological conditions (pH = 7.4). The absorption spectra of the Cu(II) complex with ct-DNA showed a marked hyperchroism with 10 nm blue shift. The intrinsic binding constant (K b ) was determined as 1.25 × 10 4 M -1 , which is more in keeping with the groove binding with DNA. Furthermore, competitive fluorimetric studies with Hoechst33258 have shown that Cu(II) complex exhibits the ability to displace the ct-DNA-bound Hoechst33258 indicating that it binds to ct-DNA in strong competition with Hoechst33258 for the groove binding. Also, no change in the relative viscosity of ct-DNA and fluorescence intensity of ct-DNA-MB complex in the present of Cu(II) complex is another evidence to groove binding. The thermodynamic parameters are calculated by van't Hoff equation, which demonstrated that hydrogen bonds and van der Waals interactions played major roles in the binding reaction. The experimental results were in agreement with the results obtained via molecular docking study.

  1. Synthesis, structural characterization, cytotoxic properties and DNA binding of a dinuclear copper(II) complex.

    Science.gov (United States)

    Ferreira, B J M Leite; Brandão, P; Meireles, M; Martel, Fátima; Correia-Branco, Ana; Fernandes, Diana M; Santos, T M; Félix, V

    2016-08-01

    In this study a novel dinuclear copper(II) complex with adenine and phenanthroline has been synthesized and its structure determined by single crystal X-ray diffraction. In the dinuclear complex [Cu₂(μ-adenine)₂(phen)₂(H2O)2](NO3)4·0.5H2O (phen=1,10-phenanthroline) (1) the two Cu(II) centres exhibit a distorted square pyramidal coordination geometry linked by two nitrogen donors from adenine bridges leading to a Cu-Cu distance of 3.242(3)Å. Intramolecular and intermolecular π⋯π interactions as well as an H-bonding network were observed. The antitumor capacity of the complex has been tested in vitro against human cancer cell lines, cervical carcinoma (HeLa) and colorectal adenocarcinoma (Caco-2), by metabolic tests, using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide as reagent. The complex 1 has remarkable low IC50 values of 0.87±0.06μM (HeLa) and 0.44±0.06μM (Caco-2), when compared with values for cisplatin against the same cell lines. The interaction of complex 1 with calf thymus DNA (CT DNA) was further investigated by absorption and fluorescence spectroscopic methods. A binding constant of 5.09×10(5)M(-1) was obtained from UV-vis absorption studies. Copyright © 2016 Elsevier Inc. All rights reserved.

  2. Copper(II) complexes of a hexadentate mixed-donor N3S3 macrobicyclic cage: facile rearrangements and interconversions.

    Science.gov (United States)

    Bell, Craig A; Bernhardt, Paul V; Gahan, Lawrence R; Martínez, Manuel; Monteiro, Michael J; Rodríguez, Carlos; Sharrad, Clint A

    2010-03-08

    The potentially hexadentate mixed-donor cage ligand 1-methyl-8-amino-3,13,16-trithia-6,10,19-triazabicyclo[6.6.6]eicosane (AMME-N(3)S(3)sar; sar=sarcophagine) displays variable coordination modes in a complex with copper(II). In the absence of coordinating anions, the ligand adopts a conventional hexadentate N(3)S(3) binding mode in the complex [Cu(AMME-N(3)S(3)sar)](ClO(4))(2) that is typical of cage ligands. This structure was determined by X-ray crystallography and solution spectroscopy (EPR and NIR UV/Vis). However, in the presence of bromide ions in DMSO, clean conversion to a five-coordinate bromido complex [Cu(AMME-N(3)S(3)sar)Br](+) is observed that features a novel tetradentate (N(2)S(2))-coordinated form of the cage ligand. This copper(II) complex has also been characterized by X-ray crystallography and solution spectroscopy. The mechanism of the reversible interconversion between the six- and five-coordinated copper(II) complexes has been studied and the reaction has been resolved into two steps; the rate of the first is linearly dependent on bromide ion concentration and the second is bromide independent. Electrochemistry of both [Cu(AMME-N(3)S(3)sar)](2+) and [Cu(AMME-N(3)S(3)sar)Br](+) in DMSO shows that upon reduction to the monovalent state, they share a common five-coordinated form in which the ligand is bound to copper in a tetradentate form exclusively, regardless of whether a six- or five-coordinated copper(II) complex is the precursor.

  3. Monopicolinate cross-bridged cyclam combining very fast complexation with very high stability and inertness of its copper(II) complex.

    Science.gov (United States)

    Lima, Luís M P; Halime, Zakaria; Marion, Ronan; Camus, Nathalie; Delgado, Rita; Platas-Iglesias, Carlos; Tripier, Raphaël

    2014-05-19

    The synthesis of a new cross-bridged 1,4,8,11-tetraazacyclotetradecane (cb-cyclam) derivative bearing a picolinate arm (Hcb-te1pa) was achieved by taking advantage of the proton sponge properties of the starting constrained macrocycle. The structure of the reinforced ligand as well as its acid-base properties and coordination properties with Cu(2+) and Zn(2+) was investigated. The X-ray structure of the free ligand showed a completely preorganized conformation that lead to very fast copper(II) complexation under mild conditions (instantaneous at pH 7.4) or even in acidic pH (3 min at pH 5) at room temperature and that demonstrated high thermodynamic stability, which was measured by potentiometry (at 25 °C and 0.10 M in KNO3). The results also revealed that the complex exists as a monopositive copper(II) species in the intermediate pH range. A comparative study highlighted the important selectivity for Cu(2+) over Zn(2+). The copper(II) complex was synthesized and investigated in solution using different spectroscopic techniques and DFT calculations. The kinetic inertness of the copper(II) complex in acidic medium was evaluated by spectrophotometry, revealing the very slow dissociation of the complex. The half-life of 96 days, in 5 M HClO4, and 465 min, in 5 M HCl at 25 °C, show the high kinetic stability of the copper(II) chelate compared to that of the corresponding complexes of other macrocyclic ligands. Additionally, cyclic voltammetry experiments underlined the perfect electrochemical inertness of the complex as well as the quasi-reversible Cu(2+)/Cu(+) redox system. The coordination geometry of the copper center in the complex was established in aqueous solution from UV-vis and EPR spectroscopies.

  4. Copper(II) complex formation equilibria involving L-carnosine, the role in the catalysis of amino acid ester hydrolisis

    Energy Technology Data Exchange (ETDEWEB)

    Shoukry, E.M.; Shoukry, M.M.; Mahgoub, A.E.; Galal, H.M. [Cairo Univ., Cairo (Egypt). Faculty of Science

    2000-10-01

    The binary and ternary complexes of copper(II) involving carnosine (H{sub 3}L), amino acids and DNA constituents were examined. Copper(II) was found to form CuL and CuLH{sub 1} complexes with carnosine. The ternary complexes of Copper(II) with carnosine and DNA constituents are formed in a stepwise mechanism, whereby carnosine binds to copper(II), then followed by ligation of the DNA constituents. The concentration distribution of the various complex species has been evaluated. The hydrolysis of amino acid ester is catalysed by the Cu-carnosine complex. The rate enhancement compared with the fee ester hydrolysis is investigated in terms of the ester coordination mode. [Italian] Sono stati considerati i complessi binari e ternari del rame(II) con la carnosina (H{sub 3}L), amino acidi e constituenti del DNA. Si e' trovato che il rame(II) forma complessi CuL e CuLH{sub 1} con la carnosina. I complessi ternari di rame(II) con carnosina e constitutenti del DNA si formano con un meccanismo a stadi, prima la carnosina lega il rame e successivamente sono legati i constituenti del DNA. E' stata valutata la distribuzione della concentrazione delle varie specie complesse. Il complesso Cu-carnosina catalizza l'idrolisi degli esteri di aminoacidi. L'incremento di velocita', rispetto all'idrolisi dell'estere libero, e' stato studiato in termini di modo di coordinazione dell'estere.

  5. Synthesis, structure, and catecholase activity of bispyrazolylacetate copper(II) complexes.

    Science.gov (United States)

    Gajewska, Małgorzata J; Ching, Wei-Min; Wen, Yuh-Sheng; Hung, Chen-Hsiung

    2014-10-21

    A series of six-coordination copper(ii) complexes containing bis(3,5-di-t-butylpyrazol-1-yl)acetate (bdtbpza) and N-heterocycles or chelating aliphatic ligands have been synthesized. The steric bulkiness of bis(pyrazol-1-yl)acetate anchors two bdtbpza to situate a trans position and to adopt an O-bound monodentate coordination mode with other nitrogen bases occupying the basal plane. Five mononuclear mixed ligand complexes, [Cu(bdtbpza)2(py)4] , [Cu(bdtbpza)2(t-Bupy)4] , [Cu(bdtbpza)2(pym)2(MeOH)2] , [Cu(bdtbpza)2(eda)2] , [Cu(bdtbpza)2(tmeda)(H2O)2] , where py = pyridine, t-Bupy = tert-butylpyridine, pym = pyrimidine, eda = ethylenediamine, and tmeda = tetramethylethylenediamine, were isolated and thoroughly characterized. Intriguingly, the heteroleptic complex , which has two aquo-ligands oriented in the cis positions, demonstrates higher catecholase-like activity in performing aerial oxidation of 3,5-di-tert-butylcatechol (3,5-DTBC) to 3,5-di-tert-butylquinone (3,5-DTBQ) than other bis(pyrazolyl)acetate-embedded copper complexes reported herein, which suggests the essential role of labile cis-aquo ligands to promote the catalytic reaction.

  6. Synthesis, structure characterization, DNA binding, and cleavage properties of mononuclear and tetranuclear cluster of copper(II) complexes.

    Science.gov (United States)

    Vafazadeh, Rasoul; Hasanzade, Naime; Heidari, Mohammad Mehdi; Willis, Anthony C

    2015-01-01

    Two copper(II) complexes, cluster 1, and mononuclear 2, have been synthesized by reacting acetylacetone and benzohydrazide (1:1 ratio for 1 and 1:2 ratio for 2) with CuCl(2) in a methanol solution. In 2, which is a new complex, the ligand acts as a tetradentate which binds the metal ion via two amide-O atoms and two imine-N atoms providing an N(2)O(2) square-planar around the copper(II) ion. The absorption spectra data evidence strongly suggested that the two copper(II) compounds could interact with CT-DNA (intrinsic binding constant, K(b) = 0.45×10(4) M-1 for 1 and K(b) = 2.39×10(4) M-1 for 2). The super coiled plasmid pBR322 DNA cleavage ability was studied with 1 and 2 in the presence and absence of H(2)O(2) as an oxidant. In both the absence and the presence of an oxidizing agent, complex 2 exhibited no nuclease activity. However, even in the absence of an oxidant, complex 1 exhibited significant DNA cleavage activity.

  7. Calorimetric study on complexation of copper(II) ion with some amide solvents in acetonitrile

    Energy Technology Data Exchange (ETDEWEB)

    Fujii, Kenta [Department of Chemistry, Faculty of Science, Kyushu University, Hakozaki, Higashi-ku, Fukuoka 812-8581 (Japan); Endoh, Toshihiko [Department of Chemistry, Faculty of Science, Shinshu University, Asahi, Matsumoto 390-8621 (Japan); Yokoi, Masatoki [Department of Chemistry, Faculty of Science, Shinshu University, Asahi, Matsumoto 390-8621 (Japan); Umebayashi, Yasuhiro [Department of Chemistry, Faculty of Science, Kyushu University, Hakozaki, Higashi-ku, Fukuoka 812-8581 (Japan); Ishiguro, Shin-Ichi [Department of Chemistry, Faculty of Science, Kyushu University, Hakozaki, Higashi-ku, Fukuoka 812-8581 (Japan)]. E-mail: analsscc@mbox.nc.kyushu-u.ac.jp

    2005-06-15

    Complexation of copper(II) ion with some amide solvents such as N-methylformamide (NMF), formamide (FA), N,N-dimethylacetamide (DMA) and N-methylacetamide (NMA) has been studied by titration calorimetry in acetonitrile containing 0.1 mol dm{sup -3} (C{sub 2}H{sub 5}){sub 4}ClO{sub 4} as an ionic medium at 298 K. These amides coordinate to the metal ion to form a series of mononuclear complexes, and their formation constants, enthalpies and entropies have been obtained. Thermodynamic parameters of formation of Cu(NMF){sup 2+} and Cu(FA){sup 2+} are not significantly different from those of Cu(DMF){sup 2+} (DMF: N,N-dimethylformamide), implying that a strong hydrogen-bonded structure of liquid NMF and FA are practically ruptured in the acetonitrile solution examined. The formation of Cu(DMA){sup 2+} and Cu(NMA){sup 2+} are appreciably less exothermic than the respective formation of Cu(DMF){sup 2+} and Cu(NMF){sup 2+} complexes, implying that the presence of the acetyl group causes steric hindrance upon its coordination to the metal ion.

  8. Synthesis, characterization, DNA-binding and cleavage studies of polypyridyl copper(II) complexes

    Science.gov (United States)

    Gubendran, Ammavasi; Rajesh, Jegathalaprathaban; Anitha, Kandasamy; Athappan, Periyakaruppan

    2014-10-01

    Six new mixed-ligand copper(II) complexes were synthesized namely [Cu(phen)2OAc]ClO4ṡH2O(1), [Cu(bpy)2OAc]ClO4ṡH2O(2), [Cu(o-ampacac)(phen)]ClO4(3), [Cu(o-ampbzac)(phen)]ClO4(4), [Cu(o-ampacac)(bpy)]ClO4(5), and [Cu(o-ampbzac)(bpy)]ClO4(6) (phen = 1,10-phenanthroline, bpy = 2, 2‧-bipyridine, o-ampacac = (Z)-4-(2-hydroxylamino)pent-3-ene-2-one,o-ampbzac = (Z)-4-(2-hydroxylamino)-4-phenylbut-3-ene-2-one)and characterized by UV-Vis, IR, EPR and cyclic voltammetry. Ligands were characterized by NMR spectra. Single crystal X-ray studies of the complex 1 shows Cu(II) ions are located in a highly distorted octahedral environment. Absorption spectral studies reveal that the complexes 1-6 exhibit hypochromicity during the interaction with DNA and binding constant values derived from spectral and electrochemical studies indicate that complexes 1, 2 and 3 bind strongly with DNA possibly by an intercalative mode. Electrochemical studies reveal that the complexes 1-4 prefer to bind with DNA in Cu(I) rather than Cu(II) form. The shift in the formal potentials E1/2 and CD spectral studies suggest groove or electrostatic binding mode for the complexes 4-6. Complex 1 can cleave supercoiled (SC) pUC18 DNA efficiently into nicked form II under photolytic conditions and into an open circular form (form II) and linear form (form III) in the presence of H2O2 at pH 8.0 and 37 °C, while the complex 2 does not cleave DNA under similar conditions.

  9. Chiral copper(II) complex based on natural product rosin derivative as promising antitumour agent.

    Science.gov (United States)

    Fei, Bao-Li; Huang, Zhi-Xiang; Xu, Wu-Shuang; Li, Dong-Dong; Lu, Yang; Gao, Wei-Lin; Zhao, Yue; Zhang, Yu; Liu, Qing-Bo

    2016-07-01

    To evaluate the biological preference of chiral drug candidates for molecular target DNA, the synthesis and characterization of a chiral copper(II) complex (2) of a chiral ligand N,N'-(pyridin-2-ylmethylene) dehydroabietylamine (1) was carried out. The interactions of 1 and 2 with salmon sperm DNA were investigated by viscosity measurements, UV, fluorescence and circular dichroism (CD) spectroscopic techniques. Absorption spectral, emission spectral and viscosity analysis reveal that 1 and 2 interacted with DNA through intercalation and 2 exhibited a higher DNA binding ability. In the absence/presence of ascorbic acid, 1 and 2 cleaved supercoiled pBR322 DNA by single-strand and 2 displayed stronger DNA cleavage ability. In addition, in vitro cytotoxicity of 1 and 2 against HeLa, SiHa, HepG-2 and A431 cancer cell lines study show that they exhibited effective cytotoxicity against the tested cell lines, notably, 2 showed a superior cytotoxicity than the widely used drug cisplatin under identical conditions, indicating it has the potential to act as effective anticancer drug. Flow cytometry analysis indicates 2 produced death of HeLa cancer cells through an apoptotic pathway. Cell cycle analysis demonstrates that 2 mainly arrested HeLa cells at the S phase. The study represents the first step towards understanding the mode of the promising chiral rosin-derivative based copper complexes as chemotherapeutics. Copyright © 2016 Elsevier B.V. All rights reserved.

  10. Immobilized copper(II) macrocyclic complex on MWCNTs with antibacterial activity

    Science.gov (United States)

    Tarlani, Aliakbar; Narimani, Khashayar; Mohammadipanah, Fatemeh; Hamedi, Javad; Tahermansouri, Hasan; Amini, Mostafa M.

    2015-06-01

    In a new approach, a copper(II) tetraaza macrocyclic complex (CuTAM) was covalently bonded on modified multi-walled carbon nanotubes (MWCNTs). To achieve this purpose, MWCNTs were converted to MWCNT-COCl and then reacted to NH groups of TAM ligand. The prepared material was characterized by Fourier Transform Infrared (FT-IR), X-ray diffraction (XRD), Raman spectroscopy, thermal gravimetric analysis (TGA), and FESEM (field emission scanning electron microscopy). FT-IR and TGA demonstrated the presence of the organic moieties, and XRD proved that the structure of MWCNTs remained intact during the three modification steps. An increase in the ID/IG ratio in Raman spectra confirmed the surface modifications. Finally, the samples were subjected to an antibacterial assessment to compare their biological activity. The antibacterial test showed that the grafted complex on the surface of the nanotube (MWCNT-CO-CuTAM) has higher antibacterial activity against Bacillus subtilis ATCC 6633 than the MWCNT-COOH and CuTAM with 1000 and 2000 μg/mL.

  11. Catecholase activity of a copper(II) complex with a macrocyclic ligand: unraveling catalytic mechanisms.

    Science.gov (United States)

    Koval, Iryna A; Selmeczi, Katalin; Belle, Catherine; Philouze, Christian; Saint-Aman, Eric; Gautier-Luneau, Isabelle; Schuitema, Anna Maria; van Vliet, Marcel; Gamez, Patrick; Roubeau, Olivier; Lüken, Matthias; Krebs, Bernt; Lutz, Martin; Spek, Anthony L; Pierre, Jean-Louis; Reedijk, Jan

    2006-08-07

    We report the structure, properties and a mechanism for the catecholase activity of a tetranuclear carbonato-bridged copper(II) cluster with the macrocyclic ligand [22]pr4pz (9,22-dipropyl-1,4,9,14,17,22,27,28,29, 30-decaazapentacyclo[22.2.1.1(4,7).1(11,14). 1(17,20)]triacontane-5,7(28),11(29),12,18, 20(30),24(27),25-octaene). In this complex, two copper ions within a macrocyclic unit are bridged by a carbonate anion, which further connects two macrocyclic units together. Magnetic susceptibility studies have shown the existence of a ferromagnetic interaction between the two copper ions within one macrocyclic ring, and a weak antiferromagnetic interaction between the two neighboring copper ions of two different macrocyclic units. The tetranuclear complex was found to be the major compound present in solution at high concentration levels, but its dissociation into two dinuclear units occurs upon dilution. The dinuclear complex catalyzes the oxidation of 3,5-di-tert-butylcatechol to the respective quinone in methanol by two different pathways, one proceeding via the formation of semiquinone species with the subsequent production of dihydrogen peroxide as a byproduct, and another proceeding via the two-electron reduction of the dicopper(II) center by the substrate, with two molecules of quinone and one molecule of water generated per one catalytic cycle. The occurrence of the first pathway was, however, found to cease shortly after the beginning of the catalytic reaction. The influence of hydrogen peroxide and di-tert-butyl-o-benzoquinone on the catalytic mechanism has been investigated. The crystal structures of the free ligand and the reduced dicopper(I) complex, as well as the electrochemical properties of both the Cu(II) and the Cu(I) complexes are also reported.

  12. The coordination structure of the extracted copper(II) complex with a synergistic mixture containing dinonylnaphthalene sulfonic acid and n-hexyl 3-pyridinecarboxylate ester

    Science.gov (United States)

    Zhu, Shan; Hu, Huiping; Hu, Jiugang; Li, Jiyuan; Hu, Fang; Wang, Yongxi

    2017-09-01

    In continuation of our interest in the coordination structure of the nickel(II) complex with dinonylnaphthalene sulfonic acid (HDNNS) and 2-ethylhexyl 4-pyridinecarboxylate ester (4PC), it was observed that the coordination sphere was completed by the coordination of two N atoms of pyridine rings in ligands 4PC and four water molecules while no direct interaction between Ni(II) and deprotonated HDNNS was observed. To investigate whether the coordination structure of nickel(II) with the synergistic mixture containing HDNNS and 4PC predominates or not in the copper(II) complex with the synergistic mixtures containing HDNNS and pyridinecarboxylate esters, a copper(II) synergist complex with n-hexyl 3-pyridinecarboxylate ester (L) and naphthalene-2-sulfonic acid (HNS, the short chain analogue of HDNNS), was prepared and studied by X-ray single crystal diffraction, elemental analyses and thermo gravimetric analysis (TGA), respectively. It was shown that the composition of the copper(II) synergist complex was [Cu(H2O)2(L)2(NS)2] and formed a trans-form distorted octahedral coordination structure. Two oxygen atoms of the two coordinated water molecules and two N atoms of the pyridine rings in the ligands L defined the basal plane while two O atoms from two sulfonate anions of the deprotonated HNS ligands occupied the apical positions by direct coordination with Cu(II), which was distinguished from the coordination structure of the nickel(II) synergist complex as reported in our previous work. In the crystal lattice, neighboring molecules [Cu(H2O)2L2(NS)2] were linked through the intermolecular hydrogen bonds between the hydrogen atoms of the coordinated water molecules and the oxygen atoms of the sulfonate anions in the copper(II) synergist complex to form a 2D plane. In order to bridge the gap between the solid state structure of the copper(II) synergist complex and the solution structure of the extracted copper(II) complex with the actual synergistic mixture containing

  13. New dinuclear copper(II) and zinc(II) complexes for the investigation of sugar-metal ion interactions.

    Science.gov (United States)

    Bera, Manindranath; Patra, Ayan

    2011-10-18

    We have studied the binding interactions of biologically important carbohydrates (D-glucose, D-xylose and D-mannose) with the newly synthesized five-coordinate dinuclear copper(II) complex, [Cu(2)(hpnbpda)(μ-OAc)] (1) and zinc(II) complex, [Zn(2)(hpnbpda)(μ-OAc)] (2) [H(3)hpnbpda=N,N'-bis(2-pyridylmethyl)-2-hydroxy-1,3-propanediamine-N,N'-diacetic acid] in aqueous alkaline solution. The complexes 1 and 2 are fully characterized both in solid and solution using different analytical techniques. A geometrical optimization was made of the ligand H(3)hpnbpda and the complexes 1 and 2 by molecular mechanics (MM+) method in order to establish the stable conformations. All carbohydrates bind to the metal complexes in a 1:1 molar ratio. The binding events have been investigated by a combined approach of FTIR, UV-vis and (13)C NMR spectroscopic techniques. UV-vis spectra indicate a significant blue shift of the absorption maximum of complex 1 during carbohydrate coordination highlighting the sugar binding ability of complex 1. The apparent binding constants of the substrate-bound copper(II) complexes have been determined from the UV-vis titration experiments. The binding ability and mode of binding of these sugar substrates with complex 2 are indicated by their characteristic coordination induced shift (CIS) values in (13)C NMR spectra for carbon atoms C1, C2, and C3 of sugar substrates. Copyright © 2011 Elsevier Ltd. All rights reserved.

  14. Synthesis and characterization of mononuclear copper(II complex of tetradentate N2S2 donor set and the study of DNA and bovine serum albumin binding

    Directory of Open Access Journals (Sweden)

    Sandipan Sarkar

    2014-12-01

    Full Text Available One mononuclear copper(II complex, containing neutral tetradentate NSSN-type ligands, of formulation [Cu II(L 1Cl]ClO 4 (1, was synthesized and isolated in pure form [where L 1˭ 1,3-bis(3-pyridylmethylthiopropane]. Green-colored copper(II complex was characterized by physicochemical, spectroscopic methods and conductivity measurement. These experimental data matched well with the proposed structure of the complex. Biological activity of the complex (1 toward calf thymus DNA and bovine serum albumin has been examined systematically and groove-binding behavior of the Copper(II complex 1 with calf thymus DNA has been observed from the spectral study.

  15. Synthesis, crystal structures and antitumor activities of copper(II) complexes with a 2-acetylpyrazine isonicotinoyl hydrazone ligand

    Science.gov (United States)

    Xu, Jun; Zhou, Tao; Xu, Zhou-Qing; Gu, Xin-Nan; Wu, Wei-Na; Chen, Hong; Wang, Yuan; Jia, Lei; Zhu, Tao-Feng; Chen, Ru-Hua

    2017-01-01

    Five complexes, [Cu(L)2]·4.5H2O (1), [Cu(HL)2](NO3)2·CH3OH (2) {[Cu2(L)2(NO3)(H2O)2]·(NO3)}n (3), [Cu2(HL)2(SO4)2]·2CH3OH (4) and [Cu4(L)4Cl4]·5H2O (5) based on HL (where HL = 2-acetylpyrazine isonicotinoyl hydrazone) have been synthesized and characterized by X-ray diffraction analyses. The counter anion and organic base during the synthesis procedure influence the structures of the complexes efficiently, which generate five complexes as mono-, bi-, tetra-nuclear and one-dimensional structures. The antitumor activities of the complexes 1-5 (except for complex 3 with the poor solubility) against the Patu8988 human pancreatic cancer, ECA109 human esophagus cancer and SGC7901 human gastric cancer cell lines are screened by MTT assay. The results indicate that the chelation of Cu(II) with the ligand is responsible for the observed high cytotoxicity of the copper(II) complexes and the 1:2 copper species 1 and 2 demonstrate lower antitumor activities than that of the 1:1 copper species 4 and 5. In addition, the in vitro apoptosis inducing activity of the copper(II) complex 5 against SGC7901 cell line is determined. And the results show that the complex can bring about apoptosis of the cancerous cells in vitro.

  16. Synthesis and characterization of mononuclear copper(II) complex of tetradentate N2S2 donor set and the study of DNA and bovine serum albumin binding

    OpenAIRE

    Sandipan Sarkar; Biswajit Das

    2014-01-01

    One mononuclear copper(II) complex, containing neutral tetradentate NSSN-type ligands, of formulation [Cu II(L 1)Cl]ClO 4 (1), was synthesized and isolated in pure form [where L 1˭ 1,3-bis(3-pyridylmethylthio)propane]. Green-colored copper(II) complex was characterized by physicochemical, spectroscopic methods and conductivity measurement. These experimental data matched well with the proposed structure of the complex. Biological activity of the complex (1) toward calf thymus DNA and bovine s...

  17. Synthesis and crystal structure of thiosemicarbazide complexes of nickel(II) and copper(II)

    Science.gov (United States)

    Sadikov, G. G.; Antsyshkina, A. S.; Koksharova, T. V.; Sergienko, V. S.; Kurando, S. V.; Gritsenko, I. S.

    2012-07-01

    Thiosemicarbazide complexes of nickel(II) [Ni( TSC)2](H Sal)2 ( I) and copper(II) [Cu( TSC)2](H Sal)2 ( Ia) ( TSC is thiosemicarbazide and H Sal is a salycilate anion), as well as complexes [Ni( TSC)2](SO4) · 2H2O ( II) and [Ni( TSC)3]Cl2 · H2O ( III), are synthesized and characterized by IR spectroscopy and X-ray diffraction. Monoclinic crystals I and Ia are isostructural; space group P21/ n, Z = 2. Crystals II are monoclinic, space group P21/ m, Z = 2. Crystals III are orthorhombic, space group Pbca, Z = 8. In I and Ia, two planar salycilate anions sandwich a planar centrosymmetric [Ni( TSC)2]2+ cation to form a supermolecule. The cation and anions are additionally bound by hydrogen bonds. Other hydrogen bonds connect supermolecules into planar layers. In structure II, centrosymmetric [Ni( TSC)2]2+ cations are connected by π-stacking interactions into supramolecular ensembles of a specific type. The ensembles, water molecules, and (SO4)2- anions are bound in the crystal via hydrogen bonds. In the [Ni( TSC)3]2+ cation of structure III, ligands coordinate the Ni atom by the bidentate chelate pattern with the formation of five-membered metallocycles. These metallocycles have an envelope conformation unlike those in I and II, which are planar. In III (unlike in analogous complexes), a meridional isomer of the coordination octahedron of the Ni atom is formed. Together with Cl1- and Cl2- anions, cations form supermolecules, which are packed into planar layers with a square-cellular structure. The layers are linked by hydrogen bonds formed by crystallization water molecules that are located between the layers.

  18. Synthesis, spectroscopic and thermal studies of the copper(II) aspartame chloride complex

    Science.gov (United States)

    Çakır, S.; Coşkun, E.; Naumov, P.; Biçer, E.; Bulut, İ.; İçbudak, H.; Çakır, O.

    2002-08-01

    Aspartame adduct of copper(II) chloride Cu(Asp) 2Cl 2·2H 2O (Asp=aspartame) is synthesized and characterized by elemental analysis, FT IR, UV/vis, ESR spectroscopies, TG, DTG, DTA measurements and molecular mechanics calculations. Aqueous solution of the green solid absorbs strongly at 774 and 367 nm. According to the FT IR spectra, the aspartame moiety coordinates to the copper(II) ion via its carboxylate ends, whereas the ammonium terminal groups give rise to hydrogen bonding network with the water, the chloride ions or neighboring carboxylate groups. The results suggest tetragonally distorted octahedral environment of the copper ions.

  19. Synthesis, characterization and DNA interaction of new copper(II) complexes of Schiff base-aroylhydrazones bearing naphthalene ring.

    Science.gov (United States)

    Gökçe, Cansu; Gup, Ramazan

    2013-05-05

    Two new copper(II) complexes with the condensation products of methyl 2-naphthyl ketone with 4-hydroxybenzohydrazide, 4-hydroxy-N'-[(1Z)-1-(naphthalen-2-yl)ethylidene]benzohydrazide [HL(1)] and (Z)-ethyl 2-(4-(2-(1-(naphthalen-2-yl)ethylidene)hydrazinecarbonyl)phenoxy)acetate (HL(2)) were synthesized and characterized by elemental analysis, infrared spectra, UV-Vis electronic absorption spectra, magnetic susceptibility measurements, TGA, powder XRD and SEM-EDS. The binding properties of the copper(II) complexes with calf thymus DNA were studied by using the absorption titration method. DNA cleavage activities of the synthesized copper complexes were examined by using agarose gel electrophoresis. The effect of complex concentration on the DNA cleavage reactions in the absence and presence of H2O2 was also investigated. The experimental results suggest that the copper complexes bind significantly to calf thymus DNA by both groove binding and intercalation modes and cleavage effectively pBR322 DNA. The mechanistic studies demonstrate that a hydrogen peroxide-derived species and singlet oxygen ((1)O2) are the active oxidative species for DNA cleavage. Copyright © 2013 Elsevier B.V. All rights reserved.

  20. Synthesis, Crystal Structure, and Characterization of Ternary Copper(II Complex Derived from N-(salicylidene-L-valine

    Directory of Open Access Journals (Sweden)

    Sundaramurthy Santha Lakshmi

    2016-01-01

    Full Text Available Ternary Schiff base copper(II complex [CuL(tmpda] (where H2L is N-(salicylidene-L-valine; tmpda is N,N,N′,N′-tetramethyl-1,3-propanediamine has been characterized by UV-Vis., FTIR, and single crystal XRD. The crystal structure displays a distorted square pyramidal geometry in which Schiff base is bonded to the Cu(II ion via phenolate oxygen, imine nitrogen, and an oxygen atom of the carboxylate group through the basal plane and the chelating diamine, N,N,N′,N′-tetramethyl-1,3-propanediamine, displays an axial and equatorial mode of binding via NN-donor atoms.

  1. DNA condensation by copper(II) complexes and their anti-proliferative effect on cancerous and normal fibroblast cells.

    Science.gov (United States)

    Rajalakshmi, Subramaniyam; Kiran, Manikantan Syamala; Nair, Balachandran Unni

    2014-06-10

    In our search towards copper(II) based anticancer compounds, copper(II) complexes [Cu(bitpy)2](ClO4)21, [Cu(bitpy)(phen)](NO3)22 and [Cu(bitpy)(NO3)](NO3) 3 were synthesized and characterized. All the three complexes contain the tridentate ligand bitpy, which bears biologically relevant benzimidazolyl head group, as one of the ligands. Because of the presence of the planar benzimidazolyl group in the bitpy ligand, the complexes exhibited intercalative mode of binding with DNA. The DNA binding constant, K(b), for complexes 1, 2 and 3 were determined to be (1.84 ± 0.32) × 10(4), (1.83 ± 0.57) × 10(4) and (1.87 ± 0.21) × 10(4) M(-1) respectively. All the three complexes possessed DNA condensing ability. The DNA condensing ability of the complexes was in the order 2 > 1 > 3. The DNA condensation induced by these three complexes was found to be reversed in the presence of 1 M NaCl. In vitro cytotoxicity of three complexes was tested against osteosarcoma MG63 cell line as well as normal fibroblast NIH3T3 cell line by MTT reduction assay. Complexes 1 and 2 were found to be highly toxic towards MG63 than NIH3T3 cell line and both these complexes brought about cell death in the MG-63 cell line due to apoptosis. Whereas, complex 3 exhibited almost equal toxic effect towards both MG63 and NIH3T3 cell lines. Based on the fact that both complexes 1 and 2 brought about reversible condensation of DNA and induced apoptosis in osteosarcoma MG-63 cell line, it is hypothesized that they might possess potential pharmaceutical applications. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

  2. Copper(II) complexes of methimazole, an anti Grave's disease drug. Synthesis, characterization and its potential biological behavior as alkaline phosphatase inhibitor.

    Science.gov (United States)

    Urquiza, Nora M; Manca, Silvia G; Moyano, María A; Dellmans, Raquel Arrieta; Lezama, Luis; Rojo, Teófilo; Naso, Luciana G; Williams, Patricia A M; Ferrer, Evelina G

    2010-04-01

    Methimazole (MeimzH) is an anti-thyroid drug and the first choice for patients with Grave's disease. Two new copper(II) complexes of this drug: [Cu(MeimzH)(2)(NO(3))(2)]*0.5H(2)O and [Cu(MeimzH)(2)(H(2)O)(2)](NO(3))(2)*H(2)O were synthesized and characterized by elemental analysis, dissolution behavior, thermogravimetric analysis and UV-vis, diffuse reflectance, FTIR and EPR spectroscopies. As it is known that copper(II) cation can act as an inhibitor of alkaline phosphatase (ALP), the inhibitory effect of methimazole and its copper(II) complexes on ALP activity has also been investigated.

  3. Copper(II) complexes derived from di-2-pyridyl ketone- N4-phenyl-3-semicarbazone: Synthesis and spectral studies

    Science.gov (United States)

    Reena, T. A.; Kurup, M. R. Prathapachandra

    2010-08-01

    Five copper(II) complexes [CuLCl] 2·CuCl 2·4H 2O ( 1), [CuLOAc] ( 2), [CuLNO 3] 2 ( 3), [CuLN 3] ( 4) and [CuLNCS]·3/2H 2O ( 5) of di-2-pyridyl ketone- N4-phenyl-3-semicarbazone (HL) were synthesized and characterized by elemental analyses and electronic, infrared and EPR spectral techniques. In all these complexes the semicarbazone undergoes deprotonation and coordinates through enolate oxygen, azomethine and pyridyl nitrogen atoms. All the complexes are EPR active due to the presence of an unpaired electron. EPR spectra of all the complexes in DMF at 77 K suggest axial symmetry and the presence of half field signals for the complexes 1 and 3 indicates dimeric structures.

  4. Copper(II) and palladium(II) complexes with tridentate NSO donor Schiff base ligand: Synthesis, characterization and structures

    Science.gov (United States)

    Kumar, Sujit Baran; Solanki, Ankita; Kundu, Suman

    2017-09-01

    Mononuclear copper(II) complex [CuL2] and palladium(II) complexes [Pd(X)L] where X = benzoate(bz) or salicylate(sal) and HL = 2-(methylthio)phenylimino)methyl)phenol, a Schiff base ligand with NSO coordination sites have been synthesized and characterized by microanalyses, IR, UV-Visible spectra, conductivity measurement and magnetic studies. Crystal structures of all the complexes have been solved by single crystal X-ray diffraction studies and showed that there are two molecules in a unit cell in the [CuL2] complex - one molecule has square planar geometry whereas second molecule has distorted square pyramidal geometry and palladium(II) complexes have distorted square planar geometry.

  5. Inhibition of the hemolytic activity caused by Staphylococcus aureus alpha-hemolysin through isatin-Schiff copper(II) complexes.

    Science.gov (United States)

    Melo, Maria C A; Teixeira, Luciana R; Pol-Fachin, Laercio; Rodrigues, Claudio G

    2016-01-01

    A great number of pathogens secrete pore-forming proteins during infection. Such molecules, from either bacterial or viral origin, are considered important virulence factors, which makes them attractive targets in the study of new therapeutic agents. Thus, the inhibitory activity of isatin-Schiff base copper(II) complexes was evaluated against membrane damage activity of Staphylococcus aureus α-hemolysin (α-HL). For this purpose, a standard hemolysis assay with rabbit erythrocytes and micromolar concentrations of the compounds was employed. Additionally, planar artificial lipid membranes with a single α-HL ion channel and molecular docking studies were used to elucidate the molecular mechanism of the complexes. Accordingly, the compounds were observed to possess a significant anti-hemolytic activity, capable of interacting with the constriction region of α-HL channel and blocking it in a potential dependent manner. Based on these results, it is expected that such isatin-Schiff base Copper(II) complexes may be employed as cotherapeutic agents for the treatment of staphylococcal infections. © FEMS 2015. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  6. New tridentate azo-azomethines and their copper(II) complexes: Synthesis, solvent effect on tautomerism, electrochemical and biological studies

    Science.gov (United States)

    Sarigul, Munire; Deveci, Pervin; Kose, Muhammet; Arslan, Ugur; Türk Dagi, Hatice; Kurtoglu, Mukerrem

    2015-09-01

    In this study, three azo-azomethines and their copper(II) complexes were prepared and characterized by analytical and spectroscopic methods. The complexes prepared were found to be mononuclear and the chelation of the ligands to the copper(II) ions occurs through two phenolic oxygens and a nitrogen atom of the azomethine group of the ligand. The tautomeric behaviors of the azo-azomethines in solution were studied by UV-Vis. spectra in three organic solvents with different polarity (CHCl3, DMSO and DMF) at room temperature. The redox behaviors of the azo-azomethines and their Cu(II) complexes were investigated by cyclic voltammetry (CV) in DMSO solution containing 0.1 M tetrabutylammonium tetrafluoroborate (TBATFB) as supporting electrolyte. Additionally, the antibacterial activity was also evaluated by the broth microdilution methods against Staphylococcus aureus, Enterococcus faecalis, Escherichia coli, Klebsiella pneumoniae and Pseudomonas aeruginosa. The compounds were found to be less effective against all bacteria tested than two reference antibiotics (ampicillin and gentamicin).

  7. Synthesis of mononuclear copper(II) complexes of acyclic Schiff's base ligands: spectral, structural, electrochemical, antibacterial, DNA binding and cleavage activity.

    Science.gov (United States)

    Jayamani, Arumugam; Thamilarasan, Vijayan; Sengottuvelan, Nallathambi; Manisankar, Paramasivam; Kang, Sung Kwon; Kim, Young-Inn; Ganesan, Vengatesan

    2014-03-25

    The mononuclear copper(II) complexes (1&2) of ligands L(1) [N,N'-bis(2-hydroxy-5-methylbenzyl)-1,4-bis(3-iminopropyl)piperazine] or L(2) [N,N'-bis(2-hydroxy-5-bromobenzyl)-1,4-bis(3-iminopropyl) piperazine] have been synthesized and characterised. The single crystal X-ray study had shown that ligands L(1) and L(2) crystallize in a monoclinic crystal system with P21/c space group. The mononuclear copper(II) complexes show one quasireversible cyclic voltammetric response near cathodic region (-0.77 to -0.85 V) in DMF assignable to the Cu(II)/Cu(I) couple. Binding interaction of the complexes with calf thymus DNA (CT DNA) investigated by absorption studies and fluorescence spectral studies show good binding affinity to CT DNA, which imply both the copper(II) complexes can strongly interact with DNA efficiently. The copper(II) complexes showed efficient oxidative cleavage of plasmid pBR322 DNA in the presence of 3-mercaptopropionic acid as reducing agent through a mechanistic pathway involving formation of singlet oxygen as the reactive species. The Schiff bases and their Cu(II) complexes have been screened for antibacterial activities which indicates that the complexes exhibited higher antimicrobial activity than the free ligands. Copyright © 2013 Elsevier B.V. All rights reserved.

  8. Synthesis of mononuclear copper(II) complexes of acyclic Schiff's base ligands: Spectral, structural, electrochemical, antibacterial, DNA binding and cleavage activity

    Science.gov (United States)

    Jayamani, Arumugam; Thamilarasan, Vijayan; Sengottuvelan, Nallathambi; Manisankar, Paramasivam; Kang, Sung Kwon; Kim, Young-Inn; Ganesan, Vengatesan

    2014-03-01

    The mononuclear copper(II) complexes (1&2) of ligands L1 [N,N";-bis(2-hydroxy-5-methylbenzyl)-1,4-bis(3-iminopropyl)piperazine] or L2 [N,N";-bis(2-hydroxy-5-bromobenzyl)-1,4-bis(3-iminopropyl) piperazine] have been synthesized and characterised. The single crystal X-ray study had shown that ligands L1 and L2 crystallize in a monoclinic crystal system with P21/c space group. The mononuclear copper(II) complexes show one quasireversible cyclic voltammetric response near cathodic region (-0.77 to -0.85 V) in DMF assignable to the Cu(II)/Cu(I) couple. Binding interaction of the complexes with calf thymus DNA (CT DNA) investigated by absorption studies and fluorescence spectral studies show good binding affinity to CT DNA, which imply both the copper(II) complexes can strongly interact with DNA efficiently. The copper(II) complexes showed efficient oxidative cleavage of plasmid pBR322 DNA in the presence of 3-mercaptopropionic acid as reducing agent through a mechanistic pathway involving formation of singlet oxygen as the reactive species. The Schiff bases and their Cu(II) complexes have been screened for antibacterial activities which indicates that the complexes exhibited higher antimicrobial activity than the free ligands.

  9. Mixed-ligand copper(II) phenolate complexes: Synthesis, spectral characterization, phosphate-hydrolysis, antioxidant, DNA interaction and cytotoxic studies

    Science.gov (United States)

    Gurumoorthy, Perumal; Mahendiran, Dharmasivam; Prabhu, Durai; Arulvasu, Chinnasamy; Rahiman, Aziz Kalilur

    2015-01-01

    A series of phenol-based mixed-ligand copper(II) complexes of the type [CuL1-4(diimine)] (1-8), where L1-4 = N1,N2-bis(5-substituted-2-hydroxybenzylidene)-1,2-ethylene/phenylenediimine and diimine = 2,2‧-bipyridyl (bpy) or 1,10-phenanthroline (phen), have been isolated and fully characterized by analytical and spectral techniques. Electronic spectra of complexes suggest Cu(II) cation has a d9 electronic configuration, adopting distorted octahedral geometry with axial elongation, due to Jahn-Teller effect. Electrochemical studies of complexes evidenced one-electron irreversible reduction wave in the cathodic region. The observed rate constant (k) values for the hydrolysis of 4-nitrophenylphosphate (4-NPP) are in the range of 0.25-3.82 × 10-2 min-1. The obtained room temperature magnetic moment values (1.79-1.90 BM) lies within the range observed for octahedral copper(II) complexes. Antioxidant studies revealed that these complexes possess considerable radical scavenging potency against DPPH. The binding studies of complexes with calf thymus DNA (CT-DNA) revealed intercalation with minor-groove binding, and the complex 4 exhibits highest binding activity than the other complexes. The cleavage activity on supercoiled pBR322 DNA revealed the involvement of hydroxyl radical and singlet-oxygen as reactive oxygen species, and complexes encourage binding to minor-groove. Further, the cytotoxicity of complex 4 on human hepatocellular liver carcinoma HepG2 cell line implies the cell death through apoptosis.

  10. Synthesis, spectra and crystal structure of 2-(?[3-(methyl?3-[(2-hydroxybenzylidene)amino]propyl? amino)propyl]imino?methyl)phenol copper(II) complex

    Science.gov (United States)

    Yilmaz, Veysel T.; Degirmencioglu, Ismail; Andac, Omer; Karabocek, Serdar; Slawin, Alexandra M. Z.

    2003-06-01

    A copper(II) complex, [Cu(salenN3], [salenN3H2=2-({[3-(methyl{3-[(2-hydroxybenzylidene)amino]propyl}amino)propyl]imino}methyl)phenol] was synthesized and characterized by elemental analyses, FTIR spectra and single crystal X-ray diffraction. The complex crystallizes in the monoclinic space group P21/ c with a=6.877(3), b=14.109(6), c=20.106(8) Å, β=92.231(14)°, V=1949.5(14) Å 3. The salen ligand loses two phenolic hydrogens being a dianion and coordinates to the copper(II) ion as a pentadentate ligand through its two O and three N atoms. The copper(II) complex is five-coordinate, lying between perfect square pyramidal and trigonal-bipyramidal extremes. Use of the structural index parameter ( τ) for five coordinate metal complexes indicated that the copper(II) complex exhibits a grater tendency toward trigonal-based-pyramidal geometry ( τ>0.5). The individual molecules in the crystal are held together by C-H⋯π and H⋯H interactions. The IR and electronic spectra of the complex were discussed in detail.

  11. Synthesis and Structure of a Ternary Copper(II) Complex with Mixed Ligands of Diethylenetriamine and Picrate: DNA/Protein-Binding Property and In Vitro Anticancer Activity Studies.

    Science.gov (United States)

    Shi, Ya-Ning; Zheng, Kang; Zhu, Ling; Li, Yan-Tuan; Wu, Zhi-Yong; Yan, Cui-Wei

    2015-05-01

    Based on the importance of the design and synthesis of transition metal complexes with noncovalent DNA/protein-binding abilities in the field of metallo pharmaceuticals, a new mononuclear ternary copper(II) complex with mixed ligands of diethylenetriamine (dien) and picrate anion (pic), identified as [Cu(dien)(pic)](pic), was synthesized and characterized by elemental analysis, molar conductivity measurement, infrared spectrum, electronic spectral studies, and single-crystal X-ray diffractometry. The structure analysis reveals that the copper(II) complex crystallizes in the monoclinic space group P21 /c, and the copper(II) ion has a distorted square pyramidal coordination geometry. A two-dimensional supramolecular structure is formed through hydrogen bonds. The DNA/bovine serum albumin (BSA)-binding properties of the complex are explored, indicating that the complex can interact with herring sperm DNA via intercalation mode and bind to BSA responsible for quenching of tryptophan fluorescence by static quenching mechanism. The in vitro anticancer activity shows that the copper(II) complex is active against the selected tumor cell lines. © 2015 Wiley Periodicals, Inc.

  12. Synthesis, crystal structure and biological evaluation of a new dasatinib copper(II) complex as telomerase inhibitor.

    Science.gov (United States)

    Qin, Qi-Pin; Meng, Ting; Tan, Ming-Xiong; Liu, Yan-Cheng; Luo, Xu-Jian; Zou, Bi-Qun; Liang, Hong

    2018-01-01

    A new copper(II) complex of dasatinib (DAS) was synthesized and characterized via ESI-MS, UV-Vis, IR, single-crystal X-ray diffraction analysis, 1 H and 13 C NMR spectroscopy, and elemental analysis. The composition of the new complex (1) was found to be [Cu(DAS + H)(NO 3 ) 2 (H 2 O)]NO 3 ·(H 2 O)·(CH 3 OH). Through MTT assay, it was found that 1 had high cytotoxicity towards A549, HeLa, BEL-7402, Hep-G2, NCI-H460, and MGC80-3 tumor cell lines, with IC 50 values in 4.04-13.04 μM. The Hep-G2 cells were the most sensitive to 1. It is worth noting that compared with DAS and cisplatin, 1 not only had higher in vitro anticancer activity but also exhibited greater selective toxicity towards Hep-G2 cells than for normal HL-7702 cells. Experimental results from cell apoptosis analysis, cellular uptake, TRAP-silver staining assay, RT-PCR, western blot, and transfection assays showed that 1 was most likely a telomerase inhibitor that targeted c-myc G-quadruplex DNA. The high cytotoxicity and biological behaviors of 1 could be correlated with the central copper(II) atom in the coordinated mode with DAS. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  13. Intercalative interaction of asymmetric copper(II) complex with DNA: experimental, molecular docking, molecular dynamics and TDDFT studies.

    Science.gov (United States)

    Hu, Wei; Deng, Suwen; Huang, Jianyin; Lu, Yanmei; Le, Xueyi; Zheng, Wenxu

    2013-10-01

    The intercalative interactions of small molecules with DNA are important in a variety of biological processes including mutagenesis, carcinogenesis, and chemotherapy. A comprehensive research protocol including experiments and calculations was employed to investigate the intercalative interaction between metallointercalator copper(II) complex and DNA. The intercalative binding mode has been validated by UV spectra, fluorescence spectra, CD spectra and viscosity measurements. The classical molecular dynamics simulation was carried out to investigate the intercalative interaction between asymmetric copper(II) complex and DNA. An analytical method was proposed to simulate the dynamically changing absorption spectra of intercalator/DNA system. According to the established model, the changing process of the electronic absorption spectra for intercalator/DNA system can be predicted accurately. A rational explanation for the change law of absorption spectra has been proposed. Moreover, the analyses of the frontier orbital reveal that the red shift of the absorption spectra is due to the increase of π orbital energy caused by the coupling of the π orbital of the intercalated ligand with the π orbital of DNA. This cause of red shift of spectra is completely different from the previous inference. All these insights are of crucial importance for correctly analyzing the absorption spectra of intercalative interaction, as well as for explaining the macroscopic phenomena observed in experiments at the molecular level. © 2013.

  14. Characterisation of the interactions between substrate, copper(II) complex and DNA and their role in rate acceleration in DNA-based asymmetric catalysis.

    Science.gov (United States)

    Draksharapu, Apparao; Boersma, Arnold J; Browne, Wesley R; Roelfes, Gerard

    2015-02-28

    Interactions of the azachalcone derived substrate Aza with copper(II) complexes in the presence and absence of st-DNA were studied in detail by UV/Vis absorption, EPR and Raman and (UV and vis) resonance Raman spectroscopies. The binding of Aza to the Lewis acidic copper(II) complexes, which results in activation of the substrate, was established spectroscopically. It was shown that the binding of Aza differs between Cu(II)dmbpy and Cu(II)terpy, consistent with the observed differences in catalytic asymmetric Diels-Alder reactions with regard to both the rate and enantiomeric preference. Finally, it was shown that DNA has a major beneficial effect on the binding of Aza to the copper(II) complex due to the fact that both bind to the DNA. The result is a high effective molarity of both the copper complexes and the Aza substrate, which leads to a significant increase in binding of Aza to the copper(II) complex. This effect is a key reason for the observed rate acceleration in the catalyzed reactions brought about by the presence of DNA.

  15. Biphenyl derived oxovanadium(IV) and copper(II) salen-type complexes--structure and redox tuning.

    Science.gov (United States)

    Plitt, Patrick; Pritzkow, Hans; Oeser, Thomas; Kraemer, Roland

    2005-05-01

    A series of vanadyl(IV) salen (N,N'-bis(salicylidene)ethylenediaminato)-type complexes (1-4) bearing phenyl or 2-hydroxyphenyl moieties have been prepared and characterized by means of mass spectrometry, infra-red, electron paramagnetic resonance (EPR), UV/Vis spectroscopy, cyclovoltammetry and X-ray crystallography. Their structures have been compared to their copper(II) analogs 5-8. Hydrogen intralinkages have been observed in the crystal structure of 5. The pendant hydroxy groups fine-tune the redox properties of the complexes. The catalytic activity in the oxygenation of ethyl phenyl sulfide to the corresponding sulfoxide was investigated. Results indicate that complex 1 bearing hydroxyphenyl subunits and a phenylene bridge is the most selective under these reaction conditions, with the smallest amount of the over-oxidized product, sulfone.

  16. Anti-cancer activity and mutagenic potential of novel copper(II) quinolinone Schiff base complexes in hepatocarcinoma cells.

    Science.gov (United States)

    Duff, Brian; Thangella, Venkat Reddy; Creaven, Bernadette S; Walsh, Maureen; Egan, Denise A

    2012-08-15

    This study determined the cytotoxic, cyto-selective and mutagenic potential of novel quinolinone Schiff base ligands and their corresponding copper(II) complexes in human-derived hepatic carcinoma cells (Hep-G2) and non-malignant human-derived hepatic cells (Chang). Results indicated that complexation of quinolinone Schiff bases with copper served to significantly enhance cytotoxicity. Here, the complex of (7E)-7-(3-ethoxy-2-hydroxybenzylideamino)-4-methylquinolin-2(1H)-one (TV117-FM) exhibited the lowest IC(50) value (17.9 μM) following 96 h continuous exposure, which was comparable to cisplatin (15.0 μM). However, results revealed that TV117-FM lacked cytoselectivity over non-malignant cells. Additionally, the complex was minimally effluxed from cells via Pglycoprotein (P-gp) and was shown to be non-mutagenic in the Standard Ames test. Furthermore, BrdU incorporation assays showed that it was capable of inhibiting DNA synthesis in a concentrationand time-dependent manner. However, inhibition was not as a consequence of DNA intercalation, as illustrated in electrophoretic mobility shift assays. Interestingly, it was shown that the ligand was capable of inhibiting the action of topoisomerase II, but this was lost following complexation. This indicated that the mechanism of action of the novel copper(II) complex was different from that of the parent ligand and suggests that TV117-FM may have a therapeutic role to play in the treatment of hepatocellular carcinoma. Studies are currently underway to elucidate the exact in vitro mechanism of action of this novel, metal-based anti-cancer agent. Copyright © 2012 Elsevier B.V. All rights reserved.

  17. A Nanostructured Lipid System as a Strategy to Improve the in Vitro Antibacterial Activity of Copper(II Complexes

    Directory of Open Access Journals (Sweden)

    Patricia B. da Silva

    2015-12-01

    Full Text Available The aim of this study was to construct a nanostructured lipid system as a strategy to improve the in vitro antibacterial activity of copper(II complexes. New compounds with the general formulae [CuX2(INH2]·nH2O (X = Cl− and n = 1 (1; X = NCS− and n = 5 (2; X = NCO− and n = 4 (3; INH = isoniazid, a drug widely used to treat tuberculosis derived from the reaction between the copper(II chloride and isoniazid in the presence or absence of pseudohalide ions (NCS− or NCO− were synthesized and characterized by infrared spectrometry, electronic absorption spectroscopy, electron paramagnetic resonance (EPR spectroscopy, elemental analysis, melting points and complexometry with 2,2′,2′′,2′′′-(Ethane-1,2-diyldinitrilotetraacetic acid (EDTA. The characterization techniques allowed us to confirm the formation of the copper(II complexes. The Cu(II complexes were loaded into microemulsion (MEs composed of 10% phase oil (cholesterol, 10% surfactant [soy oleate and Brij® 58 (1:2] and 80% aqueous phase (phosphate buffer pH = 7.4 prepared by sonication. The Cu(II complex-loaded MEs displayed sizes ranging from 158.0 ± 1.060 to 212.6 ± 1.539 nm, whereas the polydispersity index (PDI ranged from 0.218 ± 0.007 to 0.284 ± 0.034. The antibacterial activity of the free compounds and those that were loaded into the MEs against Staphylococcus aureus ATCC® 25923 and Escherichia coli ATCC® 25922, as evaluated by a microdilution technique, and the cytotoxicity index (IC50 against the Vero cell line (ATCC® CCL-81TM were used to calculate the selectivity index (SI. Among the free compounds, only compound 2 (MIC 500 μg/mL showed activity for S. aureus. After loading the compounds into the MEs, the antibacterial activity of compounds 1, 2 and 3 was significantly increased against E. coli (MIC’s 125, 125 and 500 μg/mL, respectively and S. aureus (MICs 250, 500 and 125 μg/mL, respectively. The loaded compounds were less toxic against the Vero

  18. Synthesis and spectral characterization of mono- and binuclear copper(II) complexes derived from 2-benzoylpyridine-N⁴-methyl-3-thiosemicarbazone: crystal structure of a novel sulfur bridged copper(II) box-dimer.

    Science.gov (United States)

    Jayakumar, K; Sithambaresan, M; Aiswarya, N; Kurup, M R Prathapachandra

    2015-03-15

    Mononuclear and binuclear copper(II) complexes of 2-benzoylpyridine-N(4)-methyl thiosemicarbazone (HL) were prepared and characterized by a variety of spectroscopic techniques. Structural evidence for the novel sulfur bridged copper(II) iodo binuclear complex is obtained by single crystal X-ray diffraction analysis. The complex [Cu2L2I2], a non-centrosymmetric box dimer, crystallizes in monoclinic C2/c space group and it was found to have distorted square pyramidal geometry (Addison parameter, τ=0.238) with the square basal plane occupied by the thiosemicarbazone moiety and iodine atom whereas the sulfur atom from the other coordinated thiosemicarbazone moiety occupies the apical position. This is the first crystallographically studied system having non-centrosymmetrical entities bridged via thiolate S atoms with Cu(II)I bond. The tridentate thiosemicarbazone coordinates in mono deprotonated thionic tautomeric form in all complexes except in sulfato complex, [Cu(HL)(SO4)]·H2O (1) where it binds to the metal centre in neutral form. The magnetic moment values and the EPR spectral studies reflect the binuclearity of some of the complexes. The spin Hamiltonian and bonding parameters are calculated based on EPR studies. In all the complexes g||>g⊥>2.0023 and the g values in frozen DMF are consistent with the d(x2-y2) ground state. The thermal stabilities of some of the complexes were also determined. Copyright © 2014 Elsevier B.V. All rights reserved.

  19. Synthesis and spectral characterization of mono- and binuclear copper(II) complexes derived from 2-benzoylpyridine-N4-methyl-3-thiosemicarbazone: Crystal structure of a novel sulfur bridged copper(II) box-dimer

    Science.gov (United States)

    Jayakumar, K.; Sithambaresan, M.; Aiswarya, N.; Kurup, M. R. Prathapachandra

    2015-03-01

    Mononuclear and binuclear copper(II) complexes of 2-benzoylpyridine-N4-methyl thiosemicarbazone (HL) were prepared and characterized by a variety of spectroscopic techniques. Structural evidence for the novel sulfur bridged copper(II) iodo binuclear complex is obtained by single crystal X-ray diffraction analysis. The complex [Cu2L2I2], a non-centrosymmetric box dimer, crystallizes in monoclinic C2/c space group and it was found to have distorted square pyramidal geometry (Addison parameter, τ = 0.238) with the square basal plane occupied by the thiosemicarbazone moiety and iodine atom whereas the sulfur atom from the other coordinated thiosemicarbazone moiety occupies the apical position. This is the first crystallographically studied system having non-centrosymmetrical entities bridged via thiolate S atoms with Cu(II)sbnd I bond. The tridentate thiosemicarbazone coordinates in mono deprotonated thionic tautomeric form in all complexes except in sulfato complex, [Cu(HL)(SO4)]·H2O (1) where it binds to the metal centre in neutral form. The magnetic moment values and the EPR spectral studies reflect the binuclearity of some of the complexes. The spin Hamiltonian and bonding parameters are calculated based on EPR studies. In all the complexes g|| > g⊥ > 2.0023 and the g values in frozen DMF are consistent with the dx2-y2 ground state. The thermal stabilities of some of the complexes were also determined.

  20. Synthesis, Crystal Structure, Spectroscopic Properties and Potential Biological Activities of Salicylate‒Neocuproine Ternary Copper(II Complexes

    Directory of Open Access Journals (Sweden)

    Lenka Kucková

    2015-01-01

    Full Text Available Mixed ligand copper(II complexes containing derivatives of salicylic acid and heterocyclic ligands with nitrogen donor atoms have been the subject of various studies and reviews. In this paper, synthesis and characterization of the ternary copper(II complexes of neocuproine (2,9-dimethyl-1,10-phenanthroline, Neo and salicylate ligands (Sal are reported. In addition, the crystal structures of ([Cu(H2O(5-Cl-Sal(Neo] (1, [Cu(μ-Sal(Neo]2 (2, Cu2(μ-5-Cl-Sal(5-Cl-HSal2(Neo2]·EtOH (3 were determined. In order to compare structural and biological properties of the prepared complexes, spectroscopic and biological studies were performed. Results of X-ray diffraction show that prepared complexes form three types of crystal structures in a given system: monomeric, dimeric and dinuclear complex. The preliminary study on the DNA cleavage activity has shown that the complexes under study behave as the chemical nucleases in the presence of added hydrogen peroxide with slight differences in the activity (1 > 2 > 3. The complexes 1 and 2 exhibited nuclease activity itself indicating the interaction of complexes with the DNA. It has been proposed that the enhanced destructive effect of the complexes 1 and 2 on the DNA is a result of two possible mechanisms of action: (i the conversion of closed circular DNA (form I to the nicked DNA (form II caused by the copper complex itself and (ii damage of DNA by Reactive Oxygen Species (ROS—products of the interaction of copper with hydrogen peroxide by means of Fenton reaction (hydroxyl radicals. Thus the biological activity of the prepared Cu(II complexes containing derivatives of salicylic acid and phenanthroline molecules is substantiated by two independent mechanisms. While derivatives of salicylic acids in the coordination sphere of copper complexes are responsible for radical-scavenging activity (predominantly towards superoxide radical anion, the presence of chelating ligand 2,9-dimethyl-1,10-phenanthroline

  1. Synthesis, micellization behavior, antimicrobial and intercalative DNA binding of some novel surfactant copper(II) complexes containing modified phenanthroline ligands.

    Science.gov (United States)

    Nagaraj, Karuppiah; Ambika, Subramanian; Rajasri, Shanmugasundaram; Sakthinathan, Subramanian; Arunachalam, Sankaralingam

    2014-10-01

    The novel surfactant copper(II) complexes, [Cu(ip)2DA](ClO4)21, [Cu(dpqc)2DA](ClO4)22, [Cu(dppn)2DA](ClO4)23, where ip=imidazo[4,5-f][1,10]phenanthroline, dpqc=dipyrido[3,2-a:2',4'-c](6,7,8,9-tetrahydro)phenazine, dppn=benzo[1]dipyrido[3,2-a':2',3'-c]phenazine and DA-dodecylamine, were synthesized and characterized by physico-chemical and spectroscopic methods. In these complexes 1-3, the geometry of copper metal ions was described as square pyramidal. The critical micelle concentration (CMC) value of these surfactant copper(II) complexes in aqueous solution was found out from conductance measurements. Specific conductivity data at different temperatures served for the evaluation of the temperature-dependent CMC and the thermodynamics of micellization (ΔGm°, ΔHm° and ΔSm°). The binding interaction of these complexes with DNA (calf thymus DNA) in Tris buffer was studied by physico-chemical techniques. In the presence of the DNA UV-vis spectrum of complexes showed red shift of the absorption band along with significant hypochromicity indicating intercalation of our complexes with nucleic acids. Competitive binding study with ethidium bromide (EB) shows that the complexes exhibit the ability to displace the nucleic acid-bound EB indicating that the complexes bind to nucleic acids in strong competition with EB for the intercalative binding site. Observed changes in the circular dichoric spectra of DNA in the presence of surfactant complexes support the strong binding of complexes with DNA. CV results also confirm this mode of binding. Some significant thermodynamic parameters of the binding of the titled complexes to DNA have also been determined. The results reveal that the extent of DNA binding of 3 was greater than that of 1 and 2. The antibacterial and antifungal screening tests of these complexes have shown good results compared to its precursor chloride complexes. Copyright © 2014 Elsevier B.V. All rights reserved.

  2. Bio-affinity of copper(II) complexes with nitrogen and oxygen donor ligands: Synthesis, structural studies and in vitro DNA and HSA interaction of copper(II) complexes.

    Science.gov (United States)

    Jain, Surbhi; Khan, Tanveer A; Patil, Yogesh P; Pagariya, Darshana; Kishore, Nand; Tapryal, Suman; Naik, Anil D; Naik, Sunil G

    2017-09-01

    Reported herein the binding affinity between Human Serum Albumin and the DNA binding and cleavage activity of three copper(II) complexes, [Cu(phen)(o-van)ClO 4 ] (1), [Cu(phen)(gly)]ClO 4 (2) and [Cu(L 1 ) 2 (H 2 O) 2 ] (3) wherein 1 and 2 are synthesized with 1,10-phenanthroline (phen) and co-ligands (o-van: o-vanillin; gly: glycine) and 3 with a ligand 2-hydroxy-3-methoxybenzylidene-4H-1,2,4-triazol-4-amine (H 1 L 1 ). Complex 2 crystallizes in monoclinic (P21/n) space group shows square pyramidal geometry. The complex 3 crystallizes in monoclinic (P21/a) space group. All the three complexes exhibit binding affinity towards the transport protein Human Serum albumin (HSA). Quantitative evaluation of the thermodynamics of interaction and the results obtained from fluorescence spectroscopy suggest that metal coordinated glycynate, o-vanillin and perchlorate groups have a major role to play in the binding process, the latter two being stronger in the binding of complex 1. The coordinated water in complex 3 also plays an important role in the binding, which makes binding of complex 3 with HSA stronger than that of complex 2. Experimental results indicate that the binding affinity of the complexes towards CT-DNA is in the order 1>3>2 implying that complex 1 binds stronger than complex 3 and 2.The DNA cleaving activity of all the three complexes was explored in the presence of reactive oxygen compound, H 2 O 2 . All the three complexes have primarily shown the DNA cleaving activity. Copyright © 2017. Published by Elsevier B.V.

  3. Physico-chemical characterization and anti- microbial activity of copper(II complexes with 2-amino and 2-methylbenzimidazole derivatives

    Directory of Open Access Journals (Sweden)

    Podunavac-Kuzmanović Sanja O.

    2004-01-01

    Full Text Available Copper(II chloride, in warm ethanolic solution, reacted with 2-amino and 2-methylbenzimidazole derivatives to give complexes of the formula CuL2Cl2·nH2O, where L=1-benzyl-2-aminobenzimidazole 1-(4-methylbenzyl-2-aminobenzimidazole, 1-benzyl-2-methylbenzimidazole and 1-(4-methylbenzyl-2-methylbenzimidazole( n=1 or 2. The complexes were characterized by elemental analysis of the metal, molar conductivity magnetic susceptibility measurements and IR spectra. The molar conductivities of copper(IIcomplexes in dimethyl formamide (DMF corresponding to a 1:1 type of electrolyte indicate that in all the complexes one of the coordinated chloride ions has been replaced by DMF molecule. The room temperature effective magnetic moments and IR data of the complexes suggest that all Cu(II complexes have a tetrahedral configuration, which is realized by participation of the pyridine nitrogen of two organic ligand molecules and two chloride anions. The antimicrobial activity of the ligands and their complexes against Pseudomonas aeruginosa, Bacillus sp. Staphylococcus aureus, Sarcina lutea and Saccharomyces cerevisiae was investigated. The effect of copper complexation on the ligand antimicrobial activity is discussed.

  4. Antioxidant, DNA binding and nuclease activities of heteroleptic copper(II) complexes derived from 2-((2-(piperazin-1-yl)ethylimino)methyl)-4-substituted phenols and diimines

    Science.gov (United States)

    Ravichandran, J.; Gurumoorthy, P.; Imran Musthafa, M. A.; Kalilur Rahiman, A.

    2014-12-01

    A series of heteroleptic copper(II) complexes of the type [CuL1-4(diimine)](ClO4)2 (1-8) [L1-4 = 2-((2-(piperazin-1-yl)ethylimino)methyl)-4-substituted phenols, and diimine = 2,2‧-bipyridyl (bpy) or 1,10-phenanthroline (phen)], have been synthesized and characterized by spectroscopic methods. The IR spectra of complexes indicate the presence of uncoordinated perchlorate anions and the electronic spectra revealed the square pyramidal geometry with N4O coordination environment around copper(II) nuclei. Electrochemical studies of the mononuclear complexes evidenced one-electron irreversible reduction wave in the cathodic region. The EPR spectra of complexes with g|| (2.206-2.214) and A|| (154-172 × 10-4 cm-1) values support the square-based CuN3O coordination chromophore and the presence of unpaired electron localized in dx-y ground state. Antioxidant studies against DPPH revealed effective radical scavenging properties of the synthesized complexes. Binding studies suggest that the heteroleptic copper(II) complexes interact with calf thymus DNA (CT-DNA) through minor-groove and electrostatic interaction, and all the complexes display pronounced nuclease activity against supercoiled pBR322 DNA.

  5. Copper(II) complexes with naringenin and hesperetin : cytotoxic activity against A 549 human lung adenocarcinoma cells and investigation on the mode of action

    NARCIS (Netherlands)

    Tamayo, Lenka V.; Gouvea, Ligiane R.; Sousa, Anna C.; Albuquerque, Ronniel M.; Teixeira, Sarah Fernandes; de Azevedo, Ricardo Alexandre; Louro, Sonia R. W.; Ferreira, Adilson Kleber; Beraldo, Heloisa

    Copper(II) complexes [Cu(H (2) O) (2) (L1)(phen)](ClO (4) ) (1) and [Cu(H (2) O)(L2)(phen)](ClO (4) ) (2) (HL1 = naringenin; HL2 = hesperetin) were obtained, in which an anionic flavonoid ligand is attached to the metal center along with 1,10-phenanthroline (phen) as co-ligand. Complexes (1) and (2)

  6. Cytotoxic activity, albumin and DNA binding of new copper(II) complexes with chalcone-derived thiosemicarbazones.

    Science.gov (United States)

    Da Silva, Jeferson G; Recio Despaigne, Angel A; Louro, Sonia R W; Bandeira, Cristiano C; Souza-Fagundes, Elaine M; Beraldo, Heloisa

    2013-07-01

    [Cu(HL)Cl2] complexes of chalcone-derived thiosemicarbazones were obtained with 3-phenyl-1-pyridin-2-ylprop-2-en-1-one thiosemicarbazone (HPyCTPh), complex (1), 3-(4-chlorophenyl)-1-pyridin-2-ylprop-2-en-1-one thiosemicarbazone (HPyCT4ClPh), complex (2), 3-(4-bromophenyl)-1-pyridin-2-ylprop-2-en-1-one thiosemicarbazone (HPyCT4BrPh), complex (3), and 3-(4-nitrophenyl-1-pyridin-2-ylprop-2-en-1-one thiosemicarbazone (HPyCT4NO2Ph), complex (4). 1-3 showed interaction with bovine serum albumin (BSA) and deoxyribonucleic acid from calf thymus (CT-DNA). The cytotoxic activities of the thiosemicarbazones and complexes (1-4) were tested against HL60 (wild type human promyelocytic leukemia), Jurkat (human immortalized line of T lymphocyte), MDA-MB 231 (human breast carcinoma) and HCT-116 (human colorectal carcinoma) tumor cell lineages. Upon coordination to copper(II) cytotoxicity significantly increased in Jurkat, MDA-MB 231 and HCT-116 cells. Unlike the free thiosemicarbazones, 1-4 induced DNA fragmentation in solid tumor cells indicating their pro-apoptotic potential. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

  7. Spectroscopic characterization, antioxidant and antitumour studies of novel bromo substituted thiosemicarbazone and its copper(II), nickel(II) and palladium(II) complexes

    Science.gov (United States)

    Jagadeesh, M.; Lavanya, M.; Kalangi, Suresh K.; Sarala, Y.; Ramachandraiah, C.; Varada Reddy, A.

    2015-01-01

    A new, slightly distorted octahedral complex of copper(II), square planar complexes of nickel(II) and palladium(II) with 2,4‧-dibromoacetophenone thiosemicarbazone (DBAPTSC) are synthesized. The ligand and the complexes are characterized by FT-IR, FT-Raman, powder X-ray diffraction studies. The IR and Raman data are correlated for the presence of the functional groups which specifically helped in the confirmation of the compounds. In addition, the free ligand is unambiguously characterized by 1H and 13C NMR spectroscopy while the copper(II) complex is characterized by electron paramagnetic resonance spectroscopy (EPR). The g values for the same are found to be 2.246 (g1), 2.012 (g2) and 2.005 (g3) which suggested rhombic distortions. The HOMO-LUMO band gap calculations for these compounds are found to be in between 0.5 and 4.0 eV and these compounds are identified as semiconducting materials. The synthesized ligand and its copper(II), nickel(II) and palladium(II) complexes are subjected to antitumour activity against the HepG2 human hepatoblastoma cell lines. Among all the compounds, nickel(II) complex is found to exert better antitumour activity with 57.6% of cytotoxicity.

  8. Ternary complexes of copper(II) and cobalt(II) involving nitrite/pyrazole and tetradentate N4-coordinate ligand: Synthesis, characterization, structures and antimicrobial activity

    Science.gov (United States)

    Solanki, Ankita; Sadhu, Mehul H.; Kumar, Sujit Baran

    2015-12-01

    Five new mononuclear mixed ligand complexes of the type [Cu(NCCH3)(dbdmp)](ClO4)2, [M(ONO)(dbdmp)]ClO4, [M(pz) (dbdmp)](ClO4)2 where M = Cu(II) and Co(II), pz = 3,5-dimethylpyrazole and dbdmp = N,N-diethyl-N‧,N‧-bis((3,5-dimethyl-1H-pyrazol-1-yl)methyl)ethane-1,2-diamine have been synthesized and characterized by physico-chemical and spectroscopy studies. The crystal structures of three copper(II) complexes [Cu(NCCH3)(dbdmp)](ClO4)2, [Cu(ONO)(dbdmp)]ClO4 and [Cu(pz)(dbdmp)](ClO4)2 have been determined by single crystal X-ray diffraction studies. Structural analyses reveal the geometry of [Cu(pz)(dbdmp)](ClO4)2 is distorted square pyramidal and other two copper(II) complexes have distorted trigonal bipyramidal geometry. Molecular composition of cobalt(II) complexes have been determined by mass spectral data. The EPR spectra of copper(II) complexes in frozen acetonitrile solution exhibit axial spectra, characteristic of dx2-y2 ground state. Electrochemical studies of copper(II) complexes using glassy carbon as working electrode in acetonitrile solution show Cu(II)/Cu(I) couple with quasi reversible electron transfer versus Ag/Ag+ reference electrode. Antimicrobial activity of all the synthesized complexes were investigated against two Gram positive and two Gram negative bacterial strains.

  9. Comparison of availability of copper(II) complexes with organic ligands to bacterial cells and to chitin

    Energy Technology Data Exchange (ETDEWEB)

    Vasconcelos, M.T.S.D.; Azenha, M.A.O. [Laquipai, Porto (Portugal). Faculdade de Ciencias do Porto; Cabral, J.P.S. [Inst. de Botanica e Centro de Citologia Experimental U.P., Porto (Portugal)

    1997-10-01

    Bacterial cells or chitin were exposed to solutions with 100 {micro}M total but only 5 {micro}M free copper, due to the presence of a proper concentration of proline, lysine, cysteine, or ethylenediamine tetraacetate (EDTA). The influence of the nature and concentration of the particles and soluble ligands, on the sorption and on the desorption of the copper, at pH 6.50 and 25.0 C, was investigated. The metal sorbed by the particles and that left in the solution were measured by atomic absorption spectrometry, after different periods of contact between particles and solution. The interpretation of the results was based on the copper(II) speciation calculated through equilibrium approaches applied to homogeneous or heterogeneous systems. A significant fraction of copper bound to the organic ligands was displaced to the bacteria or chitin, and the extent of chemical reaction depended on the nature of both the soluble (or leaving) ligands and sites on the particle surface (or entering ligands), as expected by the equilibrium theory. But with chitin, the uptake of copper in the presence of cysteine or EDTA was higher than expected, which may be due to the adsorption of the soluble copper complexes on the particle surface. In consequence of a competition between soluble and particulate ligands (cells or chitin), the free copper(II) concentration decreased in the solution, even in the presence of very strong chelators. The results indicate that copper availability is not a simple function of the initial free copper concentration in the solution. Desorption of the previously fixed copper, originated by free soluble ligands indicated that the sorption of copper was quasireversible for both particles, though a larger dismissal of the equilibrium position occurred for the cells, probably due to their biological activity.

  10. Copper(II), cobalt(II) and nickel(II) complexes of juglone: synthesis, structure, DNA interaction and enhanced cytotoxicity.

    Science.gov (United States)

    Tabrizi, Leila; Fooladivanda, Mahrokh; Chiniforoshan, Hossein

    2016-12-01

    Three novel copper(II), cobalt(II), and nickel(II) complexes of juglone (Jug) containing 1,10-phenanthroline (phen) ligand, [M(Jug) 2 (phen)] (M = Cu(II), 1, Co(II), 2, and Ni(II), 3), have been synthesized and characterized using, elemental analysis and spectroscopic studies. Their interactions with calf thymus DNA were investigated using viscosity measurements, UV-visible and fluorescence spectrophotometric methods. The catalytic activities on DNA cleavage of the complexes 1-3 were studied, which copper complex 1 showed better catalyst activity in the DNA cleavage process than complexes 2 and 3. The in vitro cytotoxic potential of the complexes 1-3 against human cervical carcinoma (HeLa), human liver hepatocellular carcinoma (HepG-2), and human colorectal adenocarcinoma (HT-29) cells indicated their promising antitumor activity with quite low IC 50 values in the range of 0.09-1.89 μM, which are 75 times lower than those of cisplatin.

  11. One novel 1D coordination polymer with parallel dinuclear copper(II) macrocyclic platforms bridged by trans dimeric half-water molecules and two dinuclear copper(II) macrocyclic complexes with different coordination geometry obtained from different solvents

    Science.gov (United States)

    Chu, Zhaolian; You, Wei; Huang, Wei

    2009-02-01

    Three dinuclear copper(II) macrocyclic complexes, formulated as [Cu 2L(N 3) 2(0.5H 2O) 2] n ( 1), [Cu 2L(ClO 4) 2(CH 3CH 2OH)] ( 2) and [Cu 2L(CH 3OH) 2](ClO 4) 2 ( 3) (LH 2 = [2+2] Schiff base macrocyclic ligand condensed from 4-chloro-2,6-diformylphenol and 1,3-diaminopropane), have been prepared and determined by X-ray single-crystal diffraction. Complex 1 shows two six-coordinate Cu(II) centers in which two monodentate N3- anions and two half-water molecules are bonded at the apical positions in the trans configuration. Furthermore, the dimeric half-water molecules serve as a μ2-bridge linking adjacent macrocyclic units together with the multiple O sbnd H…N hydrogen bonds with azide anions, forming a novel 1D chain-like coordination polymer. Complexes 2 and 3 are obtained from different solvents (ethanol and methanol) and they can be converted into each other. The molecular structures and packing mode of 2 and 3 are different where six-coordinate and five-coordinate copper(II) centers are present, respectively.

  12. Copper(II) complex of new non-innocent O-aminophenol-based ligand as biomimetic model for galactose oxidase enzyme in aerobic oxidation of alcohols

    Science.gov (United States)

    Safaei, Elham; Bahrami, Hadiseh; Pevec, Andrej; Kozlevčar, Bojan; Jagličić, Zvonko

    2017-04-01

    Mononuclear copper(II) complex of tetra-dentate o-aminophenol-based ligand (H2LBAPP) has been synthesized and characterized. The three dentate precursor (HLBAP) of the final ligand was synthesized first, while the title four-dentate copper bound ligand was synthesized in situ, isolated only in the final copper species [CuLBAPP]. This copper coordination complex reveals a distorted square-planar geometry around the copper(II) centre by one oxygen and three nitrogen atoms from the coordinating ligand. The ligand is thus twice deprotonated via hydroxy and amine groups. The complex is red, non-typical for copper(II), but the effective magnetic moment of 1.86 B M. and a single isotropic symmetry EPR signal with g 2.059 confirm a S = 1/2 diluted spin system, without copper-copper magnetic coupling. Electrochemical oxidation of this complex yields the corresponding Cu(II)-phenyl radical species. Finally, the title complex CuLBAPP has shown good and selective catalytic activity towards alcohol to aldehyde oxidation, at aerobic room temperature conditions, for a set of different alcohols.

  13. Extended X-ray absorption fine structure study of mixed-ligand copper(II) complexes having analogous structures

    Science.gov (United States)

    Gaur, Abhijeet; Shrivastava, B. D.; Srivastava, Krishna; Prasad, J.

    2013-02-01

    X-ray absorption fine structure spectra have been studied at the Cu K-edge in five mixed-ligand copper(II) complexes, viz., [Cu(L-glu)(bipy)] 1, [Cu(L-glu)(phen) (H2O)].3H2O 2, [Cu(L-tyro)(bipy)(ClO4)].2H2O 3, [Cu(L-phen)(bipy)(H2O)] (ClO4) 4, and [Cu(L-tyro)(phen)(H2O)] (ClO4).1.5H2O 5 (where L-glu = L-glutamate dianion, L-tyro = L-tyrosinate anion, bipy = 2,2'-bipyridine, and phen =1,10-phenanthroline), having essentially the same structure. The crystallographic data are available for all the complexes using which five theoretical models have been generated. Firstly, extended X-ray absorption fine structure (EXAFS) data of each complex has been analyzed using its own theoretical model and the results obtained are found to be comparable with the crystallographic results. Then, the EXAFS data of each complex has been analyzed using the theoretical models of the remaining four of these complexes. For each complex, the structural parameters obtained by fitting EXAFS data with theoretical models of the four remaining complexes have been found to be comparable with those obtained by fitting its own theoretical model. Thus, it has been found that if the crystal structure is not available for a complex, then the crystal structure of similar or analogous complex can be used satisfactorily for generating the theoretical model for the EXAFS data analysis of that complex, even if different ligands are attached to the central metal atom. On the basis of EXAFS data analysis, the coordination geometries around the central metal ions in these complexes have been depicted.

  14. Synthesis and crystal structure of a ternary copper(II) complex of 2,2‧-bipyridine and picrate: Molecular docking, reactivity towards DNA and in vitro anticancer activity

    Science.gov (United States)

    Zheng, Kang; Jiang, Man; Li, Yan-Tuan; Wu, Zhi-Yong; Yan, Cui-Wei

    2014-01-01

    A new mononuclear ternary copper(II) complex with mixed ligands of 2,2‧-bipyridine (bpy) and picrate (pic), namely [Cu(bpy)(pic)2], has been synthesized and characterized by elemental analysis, molar conductivity measurement, IR and electronic spectral studies, and single-crystal X-ray diffraction. The crystal structure analysis reveals the presence of two crystallographic independent molecules in an asymmetric unit. The copper(II) atoms are in elongated octahedral coordination geometries. A three-dimensional supermolecular network is formed through non-classical C-H⋯O hydrogen bonds. The DNA-binding properties of the copper(II) complex are investigated both theoretically and experimentally, revealing that the copper(II) complex can interact with HS-DNA in the mode of intercalation, and the molecular docking of the copper(II) complex with the self-complementary DNA duplex of sequence d(ACCGACGTCGGT)2 facilitates the binding events. The in vitro anticancer activities suggest that the copper(II) complex is active against the selected tumor cell lines.

  15. Copper(II) complexes with 2-pyridineformamide-derived thiosemicarbazones: Spectral studies and toxicity against Artemia salina

    Science.gov (United States)

    Ferraz, Karina O.; Wardell, Solange M. S. V.; Wardell, James L.; Louro, Sonia R. W.; Beraldo, Heloisa

    2009-07-01

    The copper(II) complexes [Cu(H2Am4DH)Cl 2] ( 1), [Cu(H2Am4Me)Cl 2] ( 2), [Cu(H2Am4Et)Cl 2] ( 3) and [Cu(2Am4Ph)Cl] ( 4) with 2-pyridineformamide thiosemicarbazone (H2Am4DH) and its N(4)-methyl (H2Am4Me), N(4)-ethyl (H2Am4Et) and N(4)-phenyl (H2Am4Ph) derivatives were studied by means of infrared and EPR spectral techniques. The crystal structure of 4 was determined. The studied compounds proved to be toxic to Artemia salina, suggesting that they could present cytotoxic activity against solid tumors. Among the free thiosemicarbazones H2Am4Ph presented higher toxicity than all other compounds, which showed comparable effects. In the case of complexes 2 and 3 toxicity is probably attributable to the complex as an entity or to a synergistic effect involving the thiosemicarbazone and copper. H2Am4Ph and complexes 2 and 3 revealed to be the most promising compounds as potential antineoplasic agents.

  16. A rapid extractive spectrophotometric determination of copper(II) in environmental samples, alloys, complexes and pharmaceutical samples using 4-[N,N(dimethyl)amino]benzaldehyde thiosemicarbazone.

    Science.gov (United States)

    Karthikeyan, J; Naik, P Parameshwara; Shetty, A Nityananda

    2011-05-01

    4-[N,N-(Dimethyl)amino]benzaldehyde thiosemicarbazone (DMABT) is proposed as an analytical reagent for the extractive spectrophotometric determination of copper(II). DMABT forms yellow colored complex with copper(II) in the pH range 4.4-5.4. Beer's law is obeyed in the concentration range up to 4.7 μg mL(-1). The optimum concentration range for minimum photometric error as determined by Ringbom plot method is 1.2-3.8 μg mL(-1). The yellowish Cu(II)-DMABT complex shows a maximum absorbance at 420 nm, with molar absorptivity of 1.72 × 10(4)dm(3) mol(-1) cm(-1) and Sandell's sensitivity of the complex obtained from Beer's data is 0.0036 μg cm(-2). The composition of the Cu(II)-DMABT complex is found to be 1:2 (M/L). The interference of various cations and anions in the method were studied. Thus the method can be employed for the determination of trace amount of copper(II) in water, alloys and other natural samples of significant importance.

  17. Synthesis, characterization and catalytic oxidation properties of multi-wall carbon nanotubes with a covalently attached copper(II) salen complex

    Science.gov (United States)

    Salavati-Niasari, Masoud; Bazarganipour, Mehdi

    2009-06-01

    Hydroxyl functionalized copper(II) Schiff-base, N,N'-bis(4-hydroxysalicylidene)-ethylene-1,2-diaminecopper(II), [Cu((OH) 2-salen)], has been covalently anchored on modified MWCNTs. The new modified MWCNTs ([Cu((OH) 2-salen)]-MWCNTs) have been characterized by TEM, thermal analysis, XRD, XPS, UV-vis, DRS, FT-IR spectroscopy and elemental analysis. The modified copper(II) MWCNTs solid was used to affect the catalytic oxidation of ethylbenzene with tert-butylhydroperoxide as the oxidant at 333 K. The system is truly heterogeneous (no leaching observed) and reusable (no decrease in activity) in three consecutive runs. Acetophenone was the major product though small amounts of o- and p-hydroxyacetophenones were also formed revealing that C-H bond activation takes place both at benzylic and aromatic ring carbon atoms. Ring hydroxylation was more over the "neat" complexes than over the encapsulated complexes.

  18. Synthesis, characterization and catalytic oxidation properties of multi-wall carbon nanotubes with a covalently attached copper(II) salen complex

    Energy Technology Data Exchange (ETDEWEB)

    Salavati-Niasari, Masoud, E-mail: salavati@kashanu.ac.ir [Institute of Nano Science and Nano Technology, University of Kashan, Kashan, P.O. Box 87317-51167 (Iran, Islamic Republic of); Department of Chemistry, University of Kashan, Kashan, P.O. Box 87317-51167 (Iran, Islamic Republic of); Bazarganipour, Mehdi [Department of Chemistry, University of Kashan, Kashan, P.O. Box 87317-51167 (Iran, Islamic Republic of)

    2009-06-15

    Hydroxyl functionalized copper(II) Schiff-base, N,N'-bis(4-hydroxysalicylidene)-ethylene-1,2-diaminecopper(II), [Cu((OH){sub 2}-salen)], has been covalently anchored on modified MWCNTs. The new modified MWCNTs ([Cu((OH){sub 2}-salen)]-MWCNTs) have been characterized by TEM, thermal analysis, XRD, XPS, UV-vis, DRS, FT-IR spectroscopy and elemental analysis. The modified copper(II) MWCNTs solid was used to affect the catalytic oxidation of ethylbenzene with tert-butylhydroperoxide as the oxidant at 333 K. The system is truly heterogeneous (no leaching observed) and reusable (no decrease in activity) in three consecutive runs. Acetophenone was the major product though small amounts of o- and p-hydroxyacetophenones were also formed revealing that C-H bond activation takes place both at benzylic and aromatic ring carbon atoms. Ring hydroxylation was more over the 'neat' complexes than over the encapsulated complexes.

  19. Complexes cobalt(II, zinc(II and copper(II with some newly synthesized benzimidazole derivatives and their antibacterial activity

    Directory of Open Access Journals (Sweden)

    S. O. PODUNAVAC-KUZMANOVIC

    1999-05-01

    Full Text Available The preparation and properties of some complexes of cobalt(II, zinc(II and copper(II with several newly synthesized benzimidazole derivatives (L are reported. The complexes, of the general formula [MCl2L2] (M=Co(II, Zn(II and [CuCl2L(H2O], have a tetrahedral structure. The complexes were characterized by elemental analysis, molar conductivity, magnetic susceptibility measurements, IR and absorption electronic spectra. The antibacterial activitiy of the benzimidazoles and their complexes was evaluated against Erwinia carotovora subsp. carotovora and Erwinia amylovora. The complexes were found to be more toxic than the ligands.

  20. Joint toxicity of tetracycline with copper(II) and cadmium(II) to Vibrio fischeri: effect of complexation reaction.

    Science.gov (United States)

    Tong, Fei; Zhao, Yanping; Gu, Xueyuan; Gu, Cheng; Lee, Charles C C

    2015-03-01

    Co-contamination of antibiotic and heavy metals commonly occurs in the environment. Tetracycline (TC), a common antibiotic, can behave as an efficient organic ligand to complex with cations. In this paper, the joint toxicity of TC with two commonly existing metals, copper(II) and cadmium(II), towards a luminescent bacteria, Vibrio fischeri, are investigated. Results showed that coexistence of TC and Cu(II) showed a significant antagonistic effect, while TC and Cd(II) showed a synergistic effect. The aqueous speciation of TC with two metal cations was calculated using a chemical equilibrium software Visual MINTEQ and results indicated that a strong complexation exist between TC and Cu(II), while much weaker interaction between TC and Cd(II). Traditional joint toxicity prediction model based on independent action failed to predict the combined toxicity of TC with metals. A new method based on speciation calculation was used to evaluate the joint toxicity of ligands and cations. It is assumed that the metal-ligand complexes are non-toxic to V. fischeri and the joint toxicity is determined by the sum of toxic unit of free metal-ions and free organic ligands. It explained the joint toxicity of the mixed systems reasonably well. Meanwhile, citric acid (CA) and fulvic acid (FA) were also introduced in this study to provide a benchmark comparison with TC. Results showed it is also valid for mixed systems of CA and FA with metals except for the Cd-CA mixture.

  1. Determination of formal redox potentials in aqueous solution of copper(II) complexes with ligands having nitrogen and oxygen donor atoms and comparison with their EPR and UV-Vis spectral features.

    Science.gov (United States)

    Tabbì, Giovanni; Giuffrida, Alessandro; Bonomo, Raffaele P

    2013-11-01

    Formal redox potentials in aqueous solution were determined for copper(II) complexes with ligands having oxygen and nitrogen as donor atoms. All the chosen copper(II) complexes have well-known stereochemistries (pseudo-octahedral, square planar, square-based pyramidal, trigonal bipyramidal or tetrahedral) as witnessed by their reported spectroscopic, EPR and UV-visible (UV-Vis) features, so that a rough correlation between the measured redox potential and the typical geometrical arrangement of the copper(II) complex could be established. Negative values have been obtained for copper(II) complexes in tetragonally elongated pseudo-octahedral geometries, when measured against Ag/AgCl reference electrode. Copper(II) complexes in tetrahedral environments (or flattened tetrahedral geometries) show positive redox potential values. There is a region, always in the field of negative redox potentials which groups the copper(II) complexes exhibiting square-based pyramidal arrangements. Therefore, it is suggested that a measurement of the formal redox potential could be of great help, when some ambiguities might appear in the interpretation of spectroscopic (EPR and UV-Vis) data. Unfortunately, when the comparison is made between copper(II) complexes in square-based pyramidal geometries and those in square planar environments (or a pseudo-octahedral) a little perturbed by an equatorial tetrahedral distortion, their redox potentials could fall in the same intermediate region. In this case spectroscopic data have to be handled with great care in order to have an answer about a copper complex geometrical characteristics. © 2013.

  2. Electron spin resonance and optical resonance studies on copper(II) complexes with vanadate, molybdate and tungstate anions

    Science.gov (United States)

    Singh, Raghuvir

    1983-09-01

    A series of complexes of the form Cu(An) nL x · yH 2O, where An = vanadate, molybdate or tungstate anion, L = pyridine, α-, β- or γ-picoline, n = 1 or 2; x = 1-4 and y = 0-3, have been synthesized and characterized by electron spin resonance, photoacoustic and electronic spectral studies as well as infrared spectroscopy in the solid and solution state. The different coordination sites of the ligands and anions have been interpreted from infrared and electronic spectral data. Electron spin resonance spectral data show the square planar or distorted octahedral (in a few cases five-coordinate geometry) stereochemistry around copper(II) in these complexes. Parameters such as g∥, g⊥, A∥, A⊥, , , α 2 and β 21 calculated from electron spin resonance data indicate the presence of unpaired electrons in dx2- y2 or dz2 orbitals. The results of electronic and photoacoustic spectral studies are in good accord with ESR data.

  3. Synthesis, electronic and ESR spectral studies on copper(II) nitrate complexes with some acylhydrazines and hydrazones

    Science.gov (United States)

    Singh, Vinod P.

    2008-11-01

    This paper describes the preparation of [Cu(bh) 2(H 2O) 2](NO 3) 2], [Cu(ibh) 2(NO 3) 2], [Cu(ibh) 2(H 2O) 2](NO 3) 2 and [Cu(iinh) 2(NO 3) 2] (bh = benzoyl hydrazine (C 6H 5CONHNH 2); ibh = isonicotinoyl hydrazine (NC 5H 4CONHNH 2); ibh = isopropanone benzoyl hydrazone (C 6H 5CONHN=C(CH 3) 2; iinh = isopropanone isonicotinoyl hydrazone (NC 5H 4CONHN=C(CH 3) 2). These copper(II) complexes are characterized by elemental analyses, molar conductances, dehydration studies, ESR, IR and electronic spectral studies. The electronic and ESR spectra indicate that each complex exhibits a six-coordinate tetragonally distorted octahedral geometry in the solid state and in DMSO solution. The ESR spectra of most of the complexes are typically isotropic type at room temperature (300 K) in solid state as well as in DMSO solution. However, all the complexes exhibit invariably axial signals at 77 K in DMSO solution. The trend g|| > g⊥ > ge, observed in all the complexes suggests the presence of an unpaired electron in the d-y orbital of the Cu(II). The bh and inh ligands bond to Cu(II) through the >C dbnd O and sbnd NH 2 groups whereas, ibh and iinh bond through >C dbnd O and >C dbnd N sbnd groups. The IR spectra of bh and ibh complexes also show H sbnd O sbnd H stretching and bending modes of coordinated water.

  4. Copper(II) complex of methionine conjugated bis-pyrazole based ligand promotes dual pathway for DNA cleavage.

    Science.gov (United States)

    Bhattacharyya, Sudipta; Sarkar, Amrita; Dey, Suman Kr; Jose, Gregor P; Mukherjee, Arindam; Sengupta, Tapas K

    2013-08-28

    Three Cu(II) complexes of bis-pyrazole based ligands have been synthesized and structurally characterized by X-ray crystallography. One of the ligand (L2) contains a methionine ester conjugated to a bis-pyrazole carboxylate through an amide linkage. The binding constant for complexes 1-3 with CT DNA are of the order of 10(4) M(-1). The crystal structure suggests that the axial Cu-O bonds (ca. 2.31(4) Å) are relatively labile and hence during the redox cycle with ascorbic acid and oxygen one or both the axial Cu-O bonds might open to promote copper oxygen reaction and generate ROS. The chemical nuclease activity of complexes 1-3 in dark, show complete relaxation of supercoiled DNA at 100 μM concentration in presence of ascorbic acid (H2A). The mechanistic investigation suggests that the complexes 1 and 2 show involvement of peroxo species whereas 3 shows involvement of both singlet oxygen and peroxo species in DNA cleavage. The singlet oxygen formation in dark is otherwise unfavourable but the presence of methionine as pendant arm in L2 might activate the generation of singlet oxygen from the metal generated peroxo species. The results of DNA cleavage studies suggest that methionine based copper(II) complexes can promote dual pathway for DNA cleavage. Probing the cytotoxic activity of these complexes on MCF-7, human breast cancer cell line shows that 3 is the most effective one with an IC50 of 70(2) μM.

  5. Structure-activity relationships of highly cytotoxic copper(II) complexes with modified indolo[3,2-c]quinoline ligands.

    Science.gov (United States)

    Primik, Michael F; Göschl, Simone; Jakupec, Michael A; Roller, Alexander; Keppler, Bernhard K; Arion, Vladimir B

    2010-12-06

    A number of indolo[3,2-c]quinolines were synthesized and modified at the lactam unit to provide a peripheral binding site able to accommodate metal ions. Potentially tridentate ligands HL(1a)-HL(4a) and HL(1b)-HL(4b) were reacted with copper(II) chloride in isopropanol/methanol to give novel five-coordinate copper(II) complexes [Cu(HL(1a-4a))Cl(2)] and [Cu(HL(1b-4b))Cl(2)]. In addition, a new complex [Cu(HL(5b))Cl(2)] and two previously reported compounds [Cu(HL(6a))Cl(2)] and [Cu(HL(6b))Cl(2)] with modified paullone ligands HL(5b), HL(6a), and HL(6b), which can be regarded as close analogues of indoloquinolines HL(1b), HL(4a), and HL(4b), in which the pyridine ring was formally substituted by a seven-membered azepine ring, were synthesized for comparison. The new ligands and copper(II) complexes were characterized by (1)H and (13)C NMR, IR and electronic absorption spectroscopy, ESI mass spectrometry, magnetic susceptibility measurements in solution at 298 K ([Cu(HL(1a))Cl(2)] and [Cu(HL(4b))Cl(2)]), and X-ray crystallography ([Cu(HL(3b))Cl(2)]·3DMF, [Cu(HL(4b))Cl(2)]·2.4DMF, HL(5b) and [Cu(HL(5b))Cl(2)]·0.5CH(3)OH). All complexes were tested for cytotoxicity in the human cancer cell lines CH1 (ovarian carcinoma), A549 (non-small cell lung cancer), and SW480 (colon carcinoma). The compounds are highly cytotoxic, with IC(50) values ranging from nanomolar to very low micromolar concentrations. Substitution of the seven-membered azepine ring in paullones by a pyridine ring resulted in a six- to nine-fold increase of cytotoxicity in SW480 cells. Electron-releasing or electron-withdrawing substituents in position 8 of the indoloquinoline backbone do not exert any effect on cytotoxicity of copper(II) complexes, whereas copper(II) compounds with Schiff bases obtained from 2-acetylpyridine and indoloquinoline hydrazines are 10 to 50 times more cytotoxic than those with ligands prepared from 2-formylpyridine and indoloquinoline hydrazines.

  6. Examination of the Impact of Copper(II) α-(N)-Heterocyclic Thiosemicarbazone Complexes on DNA Topoisomerase IIα.

    Science.gov (United States)

    Wilson, James T; Jiang, Xiaohua; McGill, Bradley C; Lisic, Edward C; Deweese, Joseph E

    2016-04-18

    Type II DNA topoisomerases resolve topological knots and tangles in DNA that result from routine cellular processes and are effective targets for anticancer therapeutics. To this end, thiosemicarbazones have been identified as having the ability to kill cancer cells from several cell lines. Literature evidence suggests that at least some thiosemicarbazones have an impact on topoisomerase II activity. However, the mechanism is not as clearly defined. Therefore, we set out to analyze the activity of four α-(N)-heterocyclic thiosemicarbazone compounds against topoisomerase IIα. The ligands, acetylpyridine-ethylthiosemicarbazone (APY-ETSC) and acetylpyrazine-methylthiosemicarbazone (APZ-MTSC), and their copper(II) [Cu(II)] complexes [Cu(APY-ETSC)Cl] and [Cu(APZ-MTSC)Cl] were examined for the ability to impact the catalytic cycle of human topoisomerase IIα. Both [Cu(APY-ETSC)Cl] and [Cu(APZ-MTSC)Cl] were more effective at inhibiting DNA relaxation compared with the ligands alone. Further, both [Cu(APY-ETSC)Cl] and [Cu(APZ-MTSC)Cl] increased double-stranded DNA cleavage levels without inhibiting topoisomerase IIα-mediated DNA ligation. The Cu(II) complexes inactivate enzyme activity over time suggesting a critical interaction with the enzyme. Additionally, we found that the Cu(II)-thiosemicarbazone complexes do not significantly impact DNA cleavage by the catalytic core of the enzyme. This evidence is supported by the fact that both [Cu(APY-ETSC)Cl] and [Cu(APZ-MTSC)Cl], and to a lesser extent the ligands, inhibit topoisomerase IIα-mediated ATP hydrolysis. Based upon kinetic analysis, the Cu(II) complexes appear to be noncompetitive inhibitors of the ATPase domain of topoisomerase IIα. Taken together, our results provide evidence that Cu(II) complexes of α-(N)-heterocyclic thiosemicarbazones catalytically inhibit the enzyme through the ATPase domain but also promote double-stranded DNA cleavage by the enzyme.

  7. Anti-thyroid and antifungal activities, BSA interaction and acid phosphatase inhibition of methimazole copper(II) complexes.

    Science.gov (United States)

    Urquiza, Nora M; Islas, María S; Ariza, Santiago T; Jori, Nadir; Martínez Medina, Juan J; Lavecchia, Martín J; López Tévez, Leonor L; Lezama, Luis; Rojo, Teófilo; Williams, Patricia A M; Ferrer, Evelina G

    2015-03-05

    It has been reported that various metal coordination compounds have improved some biological properties. A high activity of acid phosphatase (AcP) is associated to several diseases (osteoporosis, Alzheimer's, prostate cancer, among others) and makes it a target for the development of new potential inhibitors. Anti-thyroid agents have disadvantageous side effects and the scarcity of medicines in this area motivated many researchers to synthesize new ones. Several copper(II) complexes have shown antifungal activities. In this work we presented for a first time the inhibition of AcP and the anti-thyroid activity produced by methimazole-Cu(II) complexes. Cu-Met ([Cu(MeimzH)2(H2O)2](NO3)2·H2O) produces a weak inhibition action while Cu-Met-phen ([Cu(MeimzH)2(phen)(H2O)2]Cl2) shows a strong inhibition effect (IC50 = 300 μM) being more effective than the reported behavior of vanadium complexes. Cu-Met-phen also presented a fairly good anti-thyroid activity with a formation constant value, Kc=1.02 × 10(10)M(-1) being 10(6) times more active than methimazole (Kc = 4.16 × 10(4)M(-1)) in opposition to Cu-Met which presented activity (Kc=9.54 × 10(3)M(-1)) but in a lesser extent than that of the free ligand. None of the complexes show antifungal activity except Cu-phen (MIC = 11.71 μgmL(-1) on Candidaalbicans) which was tested for comparison. Besides, albumin interaction experiments denoted high affinity toward the complexes and the calculated binding constants indicate reversible binding to the protein. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  8. New copper(II) thiohydantoin complexes: Synthesis, characterization, and assessment of their interaction with bovine serum albumin and DNA.

    Science.gov (United States)

    Tishchenko, Ksenia; Beloglazkina, Elena; Proskurnin, Mikhail; Malinnikov, Vladislav; Guk, Dmitriy; Muratova, Marina; Krasnovskaya, Olga; Udina, Anna; Skvortsov, Dmitry; Shafikov, Radik R; Ivanenkov, Yan; Aladinskiy, Vladimir; Sorokin, Ivan; Gromov, Oleg; Majouga, Alexander; Zyk, Nikolay

    2017-10-01

    New copper(II) complexes of 2-alkylthio-5-arylmethylene-4H-imidazolin-4-ones: (5Z)-2-(methylsulfanyl)-3-(prop-2-en-1-yl)-5-(pyridin-2-ylmethylidene)-3,5-dihydro-4H-imidazol-4-one) (1a), (5Z,5'Z)-2,2'-(ethan-1,2-diyldisulfanyldiyl)bis(5-(2-pyridilmethylen)-3-allyl-3,5-dihydo-4Н-imidazole-4-one) (2a) and (5Z,5'Z)-3,3'-hexan-1,6-diylbis[5-(2-pyridilmethylen)-2-methylthiotetrahydro-4Н-imidazole-4-one)] (3a) were synthesized as possible anticancer drugs. Their structures were characterized by 1 H NMR spectroscopy, elemental analysis, and X-ray crystallography. The composition of the complexes were found for 1a (Cu:L=1:1), 2a (Cu:L=2:1), and 3a (Cu:L=2:1). The chelation constants were found by competitive complexation with ethylenediamine tetraacetate: 1a (6.7±0.6)×10 15 M -1 , 2a=(4.9±0.4)×10 19 M -2 , and 3a (5.7±0.5)×10 19 M -2 . Supramolecular binding with calf thymus DNA by competitive ethidium bromide quenching was made for complex 2a as the most promising anticancer model, the Stern-Volmer constants were found to be K SV =(8.0±0.4)×10 6 M -1 , K q =(6.5±0.4)×10 5 M -1 . The binding of the complex 2a to BSA was made by the Scatchard method, the value of the constant is K b =(1.9±0.2)×10 6 M -1 . Copyright © 2017 Elsevier Inc. All rights reserved.

  9. Synthesis, spectral characterization and biological evaluation of copper(II) and nickel(II) complexes with thiosemicarbazones derived from a bidentate Schiff base

    Science.gov (United States)

    Chandra, Sulekh; Bargujar, Savita; Nirwal, Rita; Yadav, Neesha

    2013-04-01

    Complexes of copper(II) and nickel(II) of general composition M(L)2X2, have been synthesized with the ligand 1-Tetralone thiosemicarbazone (where L = 1-Tetralone thiosemicarbazone and X=Cl,1/2SO42-). The molar conductance of the complexes in fresh solution of DMSO lies in the range of 10-20 Ω-1 cm2 mol-1 indicating their non-electrolytic behavior. Thus, the complexes may be formulated as [M(L2)X2]. Ligand was characterized by mass, NMR, IR and single crystallographic studies. All the complexes were characterized by elemental analyses, magnetic moments, IR, electronic and EPR spectral studies. The IR spectral data of ligand indicated the involvement of sulfur and azomethine nitrogen in coordination to the central metal ion. The copper(II) and nickel(II) complexes were found to have magnetic moments1.93-1.96 BM and 2.91-2.94 BM corresponding to one and two unpaired electrons respectively. On the basis of molar conductance, EPR, electronic and infrared spectral studies, a tetragonal geometry has been assigned for Cu(II) chloride complex and trigonal bipyramidal to Cu(II) sulfate complex but an octahedral geometry for Ni(II) complexes. Newly synthesized ligand and its Cu(II) and Ni(II) complexes have also been screened against different bacterial and fungal species.

  10. Synthesis of mononuclear copper(II) complexes of N3O2 and N4O2 donors containing Schiff base ligands: Theoretical and biological observations

    Science.gov (United States)

    Mancha Madha, K.; Gurumoorthy, P.; Arul Antony, S.; Ramalakshmi, N.

    2017-09-01

    A new series of six mononuclear copper(II) complexes were synthesized from N3O2 and N4O2 donors containing Schiff base ligands, and characterized by various spectral methods. The geometry of the complexes was determined using UV-Vis, EPR and DFT calculations. The complexes of N3O2 donors (1-3) adopted square pyramidal geometry and the remaining complexes of N4O2 donors (4-6) show distorted octahedral geometry around copper(II) nuclei. Redox properties of the complexes show a one-electron irreversible reduction process in the cathodic potential (Epc) region from -0.74 to -0.98 V. The complexes show potent antioxidant activity against DPPH radicals. Molecular docking studies of complexes showed σ-π interaction, hydrogen bonding, electrostatic and van der Waals interactions with VEGFR2 kinase receptor. In vitro cytotoxicity of the complexes was tested against human breast cancer (MDA-MB-231) cell lines and one normal human dermal fibroblasts (NHDF) cell line through MTT assay. The morphological assessment data obtained by Hoechst 33258 and AO/EB staining revealed that the complexes induce apoptosis pathway of cell death.

  11. Simultaneous and sensitive analysis of aliphatic carboxylic acids by ion-chromatography using on-line complexation with copper(II) ion.

    Science.gov (United States)

    Kemmei, Tomoko; Kodama, Shuji; Yamamoto, Atsushi; Inoue, Yoshinori; Hayakawa, Kazuichi

    2015-01-02

    A new approach to ion chromatography is proposed to improve the UV detection of aliphatic carboxylic acids separated by anion-exchange chromatography. When copper(II) ion added to the mobile phase, it forms complexes with carboxylic acids that can be detected at 240 nm. The absorbance was found to increase with increasing copper(II) ion concentration. The retention times of α-hydroxy acids were also found to depend on the copper(II) ion concentration. Addition of acetonitrile to the mobile phase improved the separation of aliphatic carboxylic acids. The detection limits of the examined carboxylic acids (formate, glycolate, acetate, lactate, propionate, 3-hydroxypropionate, n-butyrate, isobutyrate, n-valerate, isovalerate, n-caproate) calculated at S/N=3 ranged from 0.06 to 3 μM. The detector signal was linear over three orders of magnitude of carboxylic acid concentration. The proposed method was successfully applied to analyze aliphatic carboxylic acids in rainwater and bread. Copyright © 2014 Elsevier B.V. All rights reserved.

  12. Copper(II) Complexes with Saccharinate and Glutamine as Antitumor Agents: Cytoand Genotoxicity in Human Osteosarcoma Cells.

    Science.gov (United States)

    Cadavid-Vargas, Juan F; Leon, Ignacio E; Etcheverry, Susana B; Santi, Eduardo; Torre, Maria H; Di Virgilio, Ana L

    2017-01-01

    Copper has shown to be useful in disorders with an inflammation origin such as cancer [1-3]. It has previously shown that Casiopeínas® interact with DNA and promote the disruption by a mechanism related to the increase in the level of free radicals [4-6] which confers antineoplastic potential. Objetive: The aim of the present work was to study the antitumor effects of a series of Cu(II) complexes with saccharinate (sac) and glutamate (gln): [Cu(sac)2(H2O)4].2H2O (Cu-sac), [Cu(gln)2] (Cu-gln) and Na2[Cu(sac)2 (gln)2].H2O (Cu-sac-gln). We have investigated the action of these compounds on cell viability on human osteosarcoma cells MG-63. In particular, we pay special attention to the cyto and genotoxicity actions of these complexes and to the association to oxidative stress. The three complexes: Cu-sac, Cu-gln and Cu-sac-gln caused a decline in cell viability. The half-maximal inhibitory concentration in MG-63 cells for Cu-sac-gln is 170 µM, showing the strongest antiproliferative effect. Moreover, only Cu-sac-gln caused a decrease of the mitochondrial activity from 100 µM. Our results indicate that the copper(II) complexes studied here produce DNA damage and suggest that the rise of reactive oxygen species (ROS) is the central mechanism action. Genotoxicity studied by the Cytokinesis-block micronucleus (MN) assay and the Single cell gel electrophoresis (comet assay) could be observed in MG-63 cells treated with Cu-sac-gln from 100 and 50 µM, respectively. Cu-sac and Cu-gln also induced DNA damage; however their effect was definitively weaker. The generation of reactive oxygen species increased from 50 μM of Cu-sac-gln and Cu-sac and only from 250 µM of Cugln, as well as a reduction of the GSH/GSSG ratio from 50 µM. When cells were treated with several concentrations of the complexes in addition to a combination of 50 μM of vitamin C plus 50 µM of vitamin E, a total recovery in cell survival was obtained for Cu-gln in the whole range of tested

  13. Iron(III)- and copper(II) complexes of an asymmetric, pentadentate salen-like ligand bearing a pendant carboxylate group.

    Science.gov (United States)

    Jancsó, Attila; Paksi, Zoltán; Mikkola, Satu; Rockenbauer, Antal; Gajda, Tamás

    2005-07-01

    The equilibrium and solution structural properties of the iron(III) and copper(II) complexes of an asymmetric salen-like ligand (N,N'-bis(2-hydroxybenzyl)-2,3-diamino-propionic acid, H(3)bhbdpa) bearing a pendant carboxylate group were characterized in aqueous solution by potentiometric, pH-dependent electron paramagnetic resonance (EPR) and UV-Vis (UV-Visible) measurements. In the equimolar systems the pentadentate ligand forms very stable, differently protonated mononuclear complexes with both metal ions. In the presence of iron(III) {NH, PhO(-), COO(-)}, {2NH, 2PhO(-), COO(-)} and {2NH, 2PhO(-), COO(-), OH(-)} coordinated complexes are dominant. The EPR titrations reflected the presence of microscopic complex formation pathways, leading to the formation of binding isomers in case of Cu(H(2)bhbdpa)(+), Cu(Hbhbdpa) and Cu(bhbdpa)(-). The {2NH, 2PhO(-)+COO(-)/H(2)O} coordinated Cu(bhbdpa) is the only species between pH 6-11. At twofold excess of metal ion dinuclear complexes were detected with both iron(III) and copper(II). In presence of iron(III) a mu-carboxylato-mu-hydroxo-bridged dinuclear complex (Fe(2)(bhbdpa)(OH)(3)) is formed from Fe(H(2)bhbdpa)(2+) through overlapping proton release processes, providing one of the rare examples for the stabilization of an endogenous carboxylate bridged diiron core in aqueous solution. The complex Cu(2)(bhbdpa)(+) detected in the presence of copper(II) is a paramagnetic (S=1) species with relatively weakly coupled metal ions.

  14. Copper(II) Complexes of Phenanthroline and Histidine Containing Ligands: Synthesis, Characterization and Evaluation of their DNA Cleavage and Cytotoxic Activity.

    Science.gov (United States)

    Leite, Sílvia M G; Lima, Luís M P; Gama, Sofia; Mendes, Filipa; Orio, Maylis; Bento, Isabel; Paulo, António; Delgado, Rita; Iranzo, Olga

    2016-11-21

    Copper(II) complexes have been intensely investigated in a variety of diseases and pathological conditions due to their therapeutic potential. The development of these complexes requires a good knowledge of metal coordination chemistry and ligand design to control species distribution in solution and tailor the copper(II) centers in the right environment for the desired biological activity. Herein we present the synthesis and characterization of two ligands HL1 and H 2 L2 containing a phenanthroline unit (phen) attached to the amino group of histidine (His). Their copper(II) coordination properties were studied using potentiometry, spectroscopy techniques (UV-vis and EPR), mass spectrometry (ESI-MS) and DFT calculations. The data showed the formation of single copper complexes, [CuL1] + and [CuL2], with high stability within a large pH range (from 3.0 to 9.0 for [CuL1] + and from 4.5 to 10.0 for [CuL2]). In both complexes the Cu 2+ ion is bound to the phen unit, the imidazole ring and the deprotonated amide group, and displays a distorted square pyramidal geometry as confirmed by single crystal X-ray crystallography. Interestingly, despite having similar structures, these copper complexes show different redox potentials, DNA cleavage properties and cytotoxic activity against different cancer cell lines (human ovarian (A2780), its cisplatin-resistant variant (A2780cisR) and human breast (MCF7) cancer cell lines). The [CuL2] complex has lower reduction potential (E pc = -0.722 V vs -0.452 V for [CuL1] + ) but higher biological activity. These results highlight the effect of different pendant functional groups (carboxylate vs amide), placed out of the coordination sphere, in the properties of these copper complexes.

  15. Synthesis, Characterization, and Biological Studies of Binuclear Copper(II Complexes of (2E-2-(2-Hydroxy-3-Methoxybenzylidene-4N-Substituted Hydrazinecarbothioamides

    Directory of Open Access Journals (Sweden)

    P. Murali Krishna

    2013-01-01

    Full Text Available Four novel binuclear copper(II complexes [1–4] of (2E-2-(2-hydroxy-3-methoxybenzylidene-4N-substituted hydrazinecarbothioamides, (OH(OCH3C6H4CH=NNHC(SNHR, where R = H (L1, Me (L2, Et (L3, or Ph (L4, have been synthesized and characterized. The FT-IR spectral data suggested the attachment of copper(II ion to ligand moiety through the azomethine nitrogen, thioketonic sulphur, and phenolic-O. The spectroscopic characterization indicates the dissociation of dimeric complex into mononuclear [Cu(LCl] units in polar solvents like DMSO, where L is monoanionic thiosemicarbazone. The DNA binding properties of the complexes with calf thymus (CT DNA were studied by spectroscopic titration. The complexes show binding affinity to CT DNA with binding constant (Kb values in the order of 106 M−1. The ligands and their metal complexes were tested for antibacterial and antifungal activities by agar disc diffusion method. Except for complex 4, all complexes showed considerable activity almost equal to the activity of ciprofloxacin. These complexes did not show any effect on Gram-negative bacteria, whereas they showed moderate activity for Gram-positive strains.

  16. Preparation of CuO nanoparticles by thermal decomposition of double-helical dinuclear copper(II Schiff-base complexes

    Directory of Open Access Journals (Sweden)

    Aliakbar Dehno Khalaji

    2015-12-01

    Full Text Available In this paper, two double helical dinuclear copper(II complexes of bis-N,O-bidentate Schiff base ligands bis(3-methoxy-N-salicylidene-4,4'-diaminodiphenylsulfone (L1 and bis(5-bromo-N-salicylidene-4,4'-diaminodiphenylsulfone (L2 were prepared and characterized by elemental analyses (CHN, as well as thermal analysis. Elemental analyses (CHN suggested that the reaction between ligands and copper salt has been occurred in 1:1 molar ratio. In these complexes the Schiff base ligands behaves as an anionic and bis-bidentate chelate and is coordinated to the copper(II ion via two phenolic oxygen and two iminic nitrogen atoms. In these double helical dinuclear complexes, each copper(II center has a pseudo-tetrahedral coordination sphere two-wrapped ligands. Thermal analysis of ligands and their complexes were studied in the range of room temperature to 750 °C with a heating rate of 10 °C min-1. TG plots show that the ligands and their complexes are thermally decomposed via 2 and 3 thermal steps, respectively. In addition, the complexes thermally decomposed in air at 520 °C for 3 h. The obtained solids characterized by Fourier transform infrared spectroscopy (FT-IR, X-ray powder diffraction (XRD and transmission electron microscopy (TEM. The X-ray pattern result shows that the CuO nanoparticles are pure and single phase. The TEM result shows the as prepared CuO nanoparticles were very small and similar shape with particle size about

  17. In Vitro Activity of Copper(II) Complexes, Loaded or Unloaded into a Nanostructured Lipid System, against Mycobacterium tuberculosis

    Science.gov (United States)

    da Silva, Patricia B.; de Souza, Paula C.; Calixto, Giovana Maria Fioramonti; Lopes, Erica de O.; Frem, Regina C. G.; Netto, Adelino V. G.; Mauro, Antonio E.; Pavan, Fernando R.; Chorilli, Marlus

    2016-01-01

    Tuberculosis (TB) is an infectious disease caused mainly by the bacillus Mycobacterium tuberculosis (Mtb), presenting 9.5 million new cases and 1.5 million deaths in 2014. The aim of this study was to evaluate a nanostructured lipid system (NLS) composed of 10% phase oil (cholesterol), 10% surfactant (soy phosphatidylcholine, sodium oleate), and Eumulgin® HRE 40 ([castor oil polyoxyl-40-hydrogenated] in a proportion of 3:6:8), and an 80% aqueous phase (phosphate buffer pH = 7.4) as a tactic to enhance the in vitro anti-Mtb activity of the copper(II) complexes [CuCl2(INH)2]·H2O (1), [Cu(NCS)2(INH)2]·5H2O (2) and [Cu(NCO)2(INH)2]·4H2O (3). The Cu(II) complex-loaded NLS displayed sizes ranging from 169.5 ± 0.7095 to 211.1 ± 0.8963 nm, polydispersity index (PDI) varying from 0.135 ± 0.0130 to 0.236 ± 0.00100, and zeta potential ranging from −0.00690 ± 0.0896 to −8.43 ± 1.63 mV. Rheological analysis showed that the formulations behave as non-Newtonian fluids of the pseudoplastic and viscoelastic type. Antimycobacterial activities of the free complexes and NLS-loaded complexes against Mtb H37Rv ATCC 27294 were evaluated by the REMA methodology, and the selectivity index (SI) was calculated using the cytotoxicity index (IC50) against Vero (ATCC® CCL-81), J774A.1 (ATCC® TIB-67), and MRC-5 (ATCC® CCL-171) cell lines. The data suggest that the incorporation of the complexes into NLS improved the inhibitory action against Mtb by 52-, 27-, and 4.7-fold and the SI values by 173-, 43-, and 7-fold for the compounds 1, 2 and 3, respectively. The incorporation of the complexes 1, 2 and 3 into the NLS also resulted in a significant decrease of toxicity towards an alternative model (Artemia salina L.). These findings suggest that the NLS may be considered as a platform for incorporation of metallic complexes aimed at the treatment of TB. PMID:27196901

  18. In Vitro Activity of Copper(II Complexes, Loaded or Unloaded into a Nanostructured Lipid System, against Mycobacterium tuberculosis

    Directory of Open Access Journals (Sweden)

    Patricia B. da Silva

    2016-05-01

    Full Text Available Tuberculosis (TB is an infectious disease caused mainly by the bacillus Mycobacterium tuberculosis (Mtb, presenting 9.5 million new cases and 1.5 million deaths in 2014. The aim of this study was to evaluate a nanostructured lipid system (NLS composed of 10% phase oil (cholesterol, 10% surfactant (soy phosphatidylcholine, sodium oleate, and Eumulgin® HRE 40 ([castor oil polyoxyl-40-hydrogenated] in a proportion of 3:6:8, and an 80% aqueous phase (phosphate buffer pH = 7.4 as a tactic to enhance the in vitro anti-Mtb activity of the copper(II complexes [CuCl2(INH2]·H2O (1, [Cu(NCS2(INH2]·5H2O (2 and [Cu(NCO2(INH2]·4H2O (3. The Cu(II complex-loaded NLS displayed sizes ranging from 169.5 ± 0.7095 to 211.1 ± 0.8963 nm, polydispersity index (PDI varying from 0.135 ± 0.0130 to 0.236 ± 0.00100, and zeta potential ranging from −0.00690 ± 0.0896 to −8.43 ± 1.63 mV. Rheological analysis showed that the formulations behave as non-Newtonian fluids of the pseudoplastic and viscoelastic type. Antimycobacterial activities of the free complexes and NLS-loaded complexes against Mtb H37Rv ATCC 27294 were evaluated by the REMA methodology, and the selectivity index (SI was calculated using the cytotoxicity index (IC50 against Vero (ATCC® CCL-81, J774A.1 (ATCC® TIB-67, and MRC-5 (ATCC® CCL-171 cell lines. The data suggest that the incorporation of the complexes into NLS improved the inhibitory action against Mtb by 52-, 27-, and 4.7-fold and the SI values by 173-, 43-, and 7-fold for the compounds 1, 2 and 3, respectively. The incorporation of the complexes 1, 2 and 3 into the NLS also resulted in a significant decrease of toxicity towards an alternative model (Artemia salina L.. These findings suggest that the NLS may be considered as a platform for incorporation of metallic complexes aimed at the treatment of TB.

  19. Synthesis, magnetostructural correlation, and catalytic promiscuity of unsymmetric dinuclear copper(II) complexes: models for catechol oxidases and hydrolases.

    Science.gov (United States)

    Osório, Renata E H M B; Peralta, Rosely A; Bortoluzzi, Adailton J; de Almeida, Vicente R; Szpoganicz, Bruno; Fischer, Franciele L; Terenzi, Hernán; Mangrich, Antonio S; Mantovani, Karen Mary; Ferreira, Dalva E C; Rocha, Willian R; Haase, Wolfgang; Tomkowicz, Zbigniew; dos Anjos, Ademir; Neves, Ademir

    2012-02-06

    Herein, we report the synthesis and characterization, through elemental analysis, electronic spectroscopy, electrochemistry, potentiometric titration, electron paramagnetic resonance, and magnetochemistry, of two dinuclear copper(II) complexes, using the unsymmetrical ligands N',N',N-tris(2-pyridylmethyl)-N-(2-hydroxy-3,5-di-tert-butylbenzyl)-1,3-propanediamin-2-ol (L1) and N',N'-bis(2-pyridylmethyl)-N,N-(2-hydroxybenzyl)(2-hydroxy-3,5-di-tert-butylbenzyl)-1,3-propanediamin-2-ol (L2). The structures of the complexes [Cu(2)(L1)(μ-OAc)](ClO(4))(2)·(CH(3))(2)CHOH (1) and [Cu(2)(L2)(μ-OAc)](ClO(4))·H(2)O·(CH(3))(2)CHOH (2) were determined by X-ray crystallography. The complex [Cu(2)(L3)(μ-OAc)](2+) [3; L3 = N-(2-hydroxybenzyl)-N',N',N-tris(2-pyridylmethyl)-1,3-propanediamin-2-ol] was included in this study for comparison purposes only (Neves et al. Inorg. Chim. Acta2005, 358, 1807-1822). Magnetic data show that the Cu(II) centers in 1 and 2 are antiferromagnetically coupled and that the difference in the exchange coupling J found for these complexes (J = -4.3 cm(-1) for 1 and J = -40.0 cm(-1) for 2) is a function of the Cu-O-Cu bridging angle. In addition, 1 and 2 were tested as catalysts in the oxidation of the model substrate 3,5-di-tert-butylcatechol and can be considered as functional models for catechol oxidase. Because these complexes possess labile sites in their structures and in solution they have a potential nucleophile constituted by a terminal Cu(II)-bound hydroxo group, their activity toward hydrolysis of the model substrate 2,4-bis(dinitrophenyl)phosphate and DNA was also investigated. Double electrophilic activation of the phosphodiester by monodentate coordination to the Cu(II) center that contains the phenol group with tert-butyl substituents and hydrogen bonding of the protonated phenol with the phosphate O atom are proposed to increase the hydrolase activity (K(ass.) and k(cat.)) of 1 and 2 in comparison with that found for complex 3. In fact

  20. Study on potential antitumor mechanism of a novel Schiff base copper(II) complex: synthesis, crystal structure, DNA binding, cytotoxicity and apoptosis induction activity.

    Science.gov (United States)

    Qiao, Xin; Ma, Zhong-Ying; Xie, Cheng-Zhi; Xue, Fei; Zhang, Yan-Wen; Xu, Jing-Yuan; Qiang, Zhao-Yan; Lou, Jian-Shi; Chen, Gong-Jun; Yan, Shi-Ping

    2011-05-01

    A new cytotoxic copper(II) complex with Schiff base ligand [Cu(II)(5-Cl-pap)(OAc)(H(2)O)]·2H(2)O (1) (5-Cl-pap=N-2-pyridiylmethylidene-2-hydroxy-5-chloro-phenylamine), was synthesized and structurally characterized by X-ray diffraction. Single-crystal analysis revealed that the copper atom shows a 4+1 pyramidal coordination, a water oxygen appears in the apical position, and three of the basal positions are occupied by the NNO tridentate ligand and the fourth by an acetate oxygen. The interaction of Schiff base copper(II) complex 1 with DNA was investigated by UV-visible spectra, fluorescence spectra and agarose gel electrophoresis. The apparent binding constant (K(app)) value of 6.40×10(5) M(-1) for 1 with DNA suggests moderate intercalative binding mode. This copper(II) complex displayed efficient oxidative cleavage of supercoiled DNA, which might indicate that the underlying mechanism involve hydroxyl radical, singlet oxygen-like species, and hydrogen peroxide as reactive oxygen species. In addition, our present work showed the antitumor effect of 1 on cell cycle and apoptosis. Flow cytometric analysis revealed that HeLa cells were arrested in the S phase after treatment with 1. Fluorescence microscopic observation indicated that complex 1 can induce apoptosis of HeLa cells, whose process was mediated by intrinsic mitochondrial apoptotic pathway owing to the activation of caspase-9 and caspase-3. Copyright © 2011 Elsevier Inc. All rights reserved.

  1. The interaction of taurine-salicylaldehyde Schiff base copper(II) complex with DNA and the determination of DNA using the complex as a fluorescence probe.

    Science.gov (United States)

    Zhang, Xiaoyan; Wang, Yong; Zhang, Qianru; Yang, Zhousheng

    2010-09-15

    The interaction of taurine-salicylaldehyde Schiff base copper(II) (Cu(TSSB)2(2+)) complex with DNA was explored by using UV-vis, fluorescence spectrophotometry, and voltammetry. In pH 7.4 Tris-HCl buffer solution, the binding constant of the Cu(TSSB)2(2+) complex interaction with DNA was 3.49 x 10(4) L mol(-1). Moreover, due to the fluorescence enhancing of Cu(TSSB)2(2+) complex in the presence of DNA, a method for determination of DNA with Cu(TSSB)2(2+) complex as a fluorescence probe was developed. The fluorescence spectra indicated that the maximum excitation and emission wavelength were 389 nm and 512 nm, respectively. Under optimal conditions, the calibration graphs are linear over the range of 0.03-9.03 microg mL(-1) for calf thymus DNA (CT-DNA), 0.10-36 microg mL(-1) for yeast DNA and 0.01-10.01 microg mL(-1) for salmon DNA (SM-DNA), respectively. The corresponding detection limits are 7 ng mL(-1) for CT-DNA, 3 ng mL(-1) for yeast DNA and 3 ng mL(-1) for SM-DNA. Using this method, DNA in synthetic samples was determined with satisfactory results.

  2. Spectroscopy of Bioactive Manganese(II) and Copper(II) Complexes with Mannich Bases

    Science.gov (United States)

    Harbatsevich, H. I.; Loginova, N. V.; Koval‧chuk, T. V.; Osipovich, N. P.; Gres, A. T.; Azarko, I. I.; Polozov, G. I.

    2015-11-01

    The compositions and geometries of coordination polyhedra in Cu(II) and Mn(II) complexes with Mannich bases were determined using IR, EPR, and electron spectroscopy. It was shown that bidentate ligands were coordinated to the metal ions in these complexes. The coordination polyhedra of mononuclear Cu(II) and Mn(II) complexes consisted of two mono-anionic ligands. Polyhedra of the Mn(II) complexes also contained two water molecules. The Cu(II) complexes had characteristic square-planar [CuN2O2] coordination polyhedra; Mn(II) complexes, [MnN2O4] octahedra.

  3. Spectroscopic properties of some mixed ligand copper(II) complexes of N-(2-aminoethyl)-1,2-ethanediamine and ethanediamine and its alkylated derivatives

    Science.gov (United States)

    Sastry, B. A.; Chary, K. S.; Subramanian, R.; Ponticelli, G.; Puggioni, G.

    1992-04-01

    IR, EPR and electronic spectral studies have been made on a series of complexes with general formula [M(dien)L](BØ 4) 2nH 2O (M = Cu(II), Zn(II), Cd(II), dien = N-(2-aminoethyl)-1,2-ethanediamine, L = ethanediamine (en), Me 4en, Et 2en, Me = methyl, Et = ethyl, BØ 4 = tetraphenylborate, n = 0 or 2] taking copper(II) as a magnetic probe in polycrystalline and solution forms to obtain stereochemical information. A five-coordinate square-based pyramidal (SBP) geometry with CuN 3N' 2 moiety having moderately covalent metal-ligand σ-bonds is found to exist in unalkylated mixed ligand complexes. Among alkylated complexes [Cu/Cd(dien)(Me 4en)](BØ 4) 2 is found to possess two species having tetrahedral and SBP with trigonal bipyramidal distortion geometries unlike the other alkylated complexes which have indicated the presence of one species having SBP coordination geometry with varying degrees of trigonal bipyramidal distortions and metal-ligand σ-bond strengths. EPR studies in dilute dmf and pyridine solutions of copper(II) complexes indicated the presence of solute-solvent interaction.

  4. Synthesis, characterization and catechol oxidase biomimetic catalytic activity of cobalt(II and copper(II complexes containing N2O2 donor sets of imine ligands

    Directory of Open Access Journals (Sweden)

    Mohamed I. Ayad

    2016-11-01

    Full Text Available New tetradentate imine ligands are derived from Schiff base condensation in a 1:2 molar ratio of the 1,2,4,5-tetra-amino benzene with 2-hydroxy benzaldehyde, (L1, 2,4-dihydroxy benzaldehyde (L2 and 2-hydroxy naphthaldehyde (L3. These ligands react with CoCl2 and CuCl2 in refluxing ethanol to yield a series of cobalt(II and copper(II complexes of the type [M2IILn] nH2O. The structure of the obtained ligands and their metal(II complexes were characterized by various physicochemical techniques, viz. elemental analysis, molar conductance, magnetic susceptibility measurements, thermal analysis (TGA & DTG, IR, electronic absorption and ESR spectral studies. Four-coordinate tetrahedral and square–planar structures were proposed for cobalt(II and copper(II complex species respectively. The ability of the synthesized complexes to catalyze the aerobic oxidation of 3,5-di-tert-butylcatechol (3,5-DTBC to the light absorbing 3,5-di-tert-butylquinone (3,5-DTBQ has been investigated. The results obtained show that all complexes catalyze this oxidation reaction and slight variations in the rate were observed. The probable mechanistic implications of the catalytic oxidation reactions are discussed.

  5. Simple Copper(II) Schiff Base Complex as Efficient Heterogeneous Photo-Fenton-like Catalyst

    National Research Council Canada - National Science Library

    Fei, Bao-Li; Wang, Jiang-Hong; Yan, Qing-Ling; Liu, Qing-Bo; Long, Jian-Ying; Li, Yang-Guang; Shao, Kui-Zhan; Su, Zhong-Min; Sun, Wei-Yin

    2014-01-01

    ...) as photo-Fenton-like catalysts. Both 1 and 2 exhibited excellent catalytic performance without an acidification process, and the mononuclear complex 2 functioned better than the dinuclear complex 1...

  6. Copper(II) complexes of mono-anionic glutamate: anionic influence in the variations of molecular and supramolecular structures.

    Science.gov (United States)

    Biswas, Chaitali; Drew, Michael G B; Estrader, Marta; Ghosh, Ashutosh

    2009-07-07

    Three new polynuclear copper(II) complexes of singly deprotonated L-glutamic acid (L-glu), {[Cu(bipy)2][Cu(bipy)(L-glu)H2O]2(BF4)4 x (H2O)3}n (1), {[Cu(bipy)(L-glu)H2O][Cu(bipy)(L-glu)(ClO4)](ClO4) x (H2O)2}n (2) and [Cu(phen)(L-glu)H2O]2(NO3)2 x (H2O)4 (3) (bipy = 2,2-bipyridine, phen = 1,10-phenanthroline), were synthesized in acidic pH (ca. 2.5) and characterized structurally. In all the complexes, L-glutamic acid acts as a bidentate chelating ligand, leaving the protonated carboxylic acid free. Both in 1 and 2, two different types of species [Cu(bipy)2](BF4)2 and [Cu(bipy)(L-glu)H2O]BF4 for 1 and [Cu(bipy)(L-glu)H2O]ClO4 and [Cu(bipy)(L-glu)(ClO4)] for 2 coexist in the solid state. In complex 1, the [Cu(bipy)(L-glu)H2O]+ units are joined together by syn-anti carboxylate bridges to form an enantiopure (M) helical chain and the [Cu(bipy)2]2+ presents a very rare example of the four-coordinate distorted tetrahedral geometry of Cu(II). In complex 2, the [Cu(bipy)(L-glu)(ClO4)] units are joined together by weakly coordinating perchlorate ions to form a 1D polymeric chain while the [Cu(bipy)(L-glu)H2O]+ units remain as mononuclear species. The different coordinating ability of the two counter anions along with their involvement in the H-bonding network seems likely to be responsible for the difference in the final polymeric structures in the two compounds. Variable-temperature (2-300 K) magnetic susceptibility measurements show negligible coupling for both the complexes. The structure of 3 consists of two independent monomeric [Cu(phen)(L-glu)H2O]+ cations, two nitrate anions and four water molecules. The copper atom occupies a five-coordinate square pyramidal environment with a water molecule in the axial position.

  7. Nickel(II) and copper(II) complexes with humic acid anions and their derivatives

    Energy Technology Data Exchange (ETDEWEB)

    Ryabova, I.N. [Kazakh Academy of Science, Karaganda (Kazakhstan)

    2008-01-15

    Complexation of Ni(II) and Cu(II) in aqueous solutions with anions of humic acids, extracted from naturally oxidized coal, and with their hydroxymethyl derivatives is studied spectrophotometrically and potentiometrically. The complexation stoichiometry and the stability constants of the complexes are determined.

  8. A combination of experimental and computational studies on a new oxamido bridged dinuclear copper(II) complex

    Science.gov (United States)

    Bhattacharya, Arnab; Saha, Pinki; Saha, Baptu; Maiti, Debasish; Mitra, Partha; Naskar, Jnan Prakash; Chowdhury, Shubhamoy

    2017-10-01

    Reaction of N,N‧-bis(2-pyridylmethyl)oxamide (H2L), and copper(II)nitrate trihydrate in 1:2 M proportion in methanol generates oxamido bridged dimeric copper(II) compound, [Cu2L(H2O)2(NO3)2]H2O (1a.H2O) in good yield. 1a.H2O has been characterized by C, H and N microanalyses, copper estimation, FT-IR, UV-Vis and room temperature magnetic susceptibility measurements. The X-ray crystal structure of 1a.H2O has been determined. Bond Valence Sum (BVS) analysis was undertaken to assign the oxidation state of each copper center in 1a. Thermal behavior of 1a.H2O has been studied by TGA. Electrochemical studies on 1a.H2O shows single electron two step sequential reductions of Cu(II) to Cu(I) in dimethyl sulphoxide. Our optimized geometry of 1a as obtained through conceptual Density Functional Theory (DFT) corroborates well with that obtained from single crystal X-ray diffraction. TD-DFT method was also adopted to delve into the electronic properties of 1a. We have taken recourse to employ our optimized structure of 1a to investigate systematically the relative stabilities of various dimeric Cu(II) complexes obtained through variation of ligands bearing uni-donor anion through substitution of nitrate in 1a. The in vitro antibacterial potentiality of 1a.H2O was also tested against some bacterial cell lines, pathogenic to mankind.

  9. Variation in DNA binding constants with a change in geometry of ternary copper(II) complexes with N2O donor Schiff base and cyanate or dicyanamide

    Science.gov (United States)

    Jana, Subrata; Santra, Ramesh Chandra; Das, Saurabh; Chattopadhyay, Shouvik

    2014-09-01

    Two new copper(II) complexes, [Cu(L)(OCN)] (1) and [CuL(dca)]n (2), where HL = 2-(-(2-(diethylamino)ethylimino)methyl)naphthalen-1-ol, dca = N(CN)2-, have been synthesized and characterized by elemental analysis, IR, UV-VIS spectroscopy and single crystal X-ray diffraction studies. Complex 1 has square planar and complex 2 square pyramidal geometries in solid state around metal centre. Interactions of the complexes with calf thymus DNA (CT DNA) were studied by UV-VIS spectroscopy. Binding constant and site size of interaction were determined. Binding site size and intrinsic binding constant K revealed complex 1 interacted with calf thymus DNA better than complex 2.

  10. Copper(II and lead(II complexation by humic acid and humic-like ligands

    Directory of Open Access Journals (Sweden)

    IVANA KOSTIĆ

    2011-09-01

    Full Text Available The stability of metal–humate complexes is an important factor determining and predicting speciation, mobility and bioavailability of heavy metals in the environment. A comparative investigation of the complexation of Cu(II and Pb(II with humic acid and humic-like ligands, such as benzoic and salicylic acid, was performed. The analysis was realized at pH 4.0, a temperature of 25 °C and at an ionic strength of 0.01 mol dm-3 (NaCl using the Schubert ion-exchange method and its modified form. The stability constants were calculated from the experimental data by the Schubert method for complexes with benzoic and humic acid. A modified Schubert method was used for the determination of the stability constants of the complexes with salicylic acid. It was found that Cu(II and Pb(II form mononuclear complexes with benzoic and humic acid while with salicylic acid both metals form polynuclear complexes. The results indicate that Pb(II has a higher binding ability than Cu(II to all the investigated ligands. The Cu(II–salicylate and Pb(II–salicylate complexes showed noticeable higher stability constants compared with their complexes with humic acid, while the stabilities of the complexes with benzoic acid differed less. Salicylic and benzoic acids as humic-like ligands can be used for setting the range of stability constants of humic complexes with Cu(II and Pb(II.

  11. Mixed-ligand copper(ii) Schiff base complexes: the role of the co-ligand in DNA binding, DNA cleavage, protein binding and cytotoxicity.

    Science.gov (United States)

    Lian, Wen-Jing; Wang, Xin-Tian; Xie, Cheng-Zhi; Tian, He; Song, Xue-Qing; Pan, He-Ting; Qiao, Xin; Xu, Jing-Yuan

    2016-05-31

    Four novel mononuclear Schiff base copper(ii) complexes, namely, [Cu(L)(OAc)]·H2O (), [Cu(HL)(C2O4)(EtOH)]·EtOH (), [Cu(L)(Bza)] () and [Cu(L)(Sal)] () (HL = 1-(((2-((2-hydroxypropyl)amino)ethyl)imino)methyl)naphthalene-2-ol), Bza = benzoic acid, Sal = salicylic acid), were synthesized and characterized by X-ray crystallography, elemental analysis and infrared spectroscopy. Single-crystal diffraction analysis revealed that all the complexes were mononuclear molecules, in which the Schiff base ligand exhibited different coordination modes and conformations. The N-HO and O-HO inter- and intramolecular hydrogen bonding interactions linked these molecules into multidimensional networks. Their interactions with calf thymus DNA (CT-DNA) were investigated by UV-visible and fluorescence spectrometry, as well as by viscosity measurements. The magnitude of the Kapp values of the four complexes was 10(5), indicating a moderate intercalative binding mode between the complexes and DNA. Electrophoresis results showed that all these complexes induced double strand breaks of pUC19 plasmid DNA in the presence of H2O2 through an oxidative pathway. In addition, the fluorescence spectrum of human serum albumin (HSA) with the complexes suggested that the quenching mechanism of HSA by the complexes was a static process. Moreover, the antiproliferative activity of the four complexes against HeLa (human cervical carcinoma) and HepG-2 (human liver hepatocellular carcinoma) cells evaluated by colorimetric cell proliferation assay and clonogenic assay revealed that all four complexes had improved cytotoxicity against cancer cells. Inspiringly, complex , with salicylic acid as the auxiliary ligand, displayed a stronger anticancer activity, suggesting that a synergistic effect of the Schiff base complex and the nonsteroidal anti-inflammatory drug may be involved in the cell killing process. The biological features of mixed-ligand copper(ii) Schiff base complexes and how acetic auxiliary

  12. Interaction of drug based copper(II) complexes with Herring Sperm DNA and their biological activities

    Science.gov (United States)

    Patel, Mohan N.; Patel, Chintan R.; Joshi, Hardik N.

    2012-11-01

    Square pyramidal Cu(II) complexes with NS donor ligand and ciprofloxacin have been synthesized and characterized using analytical and spectral techniques. The synthesized complexes have been tested for their antimicrobial activity using double dilution technique in terms of minimum inhibitory concentration (MIC) and colony forming unit (CFU). The DNA binding ability of the complexes with Sperm Herring DNA has been performed using absorption titration and viscosity measurement. The nuclease activity of complexes with plasmid DNA (pUC19) has been carried out using agarose gel electrophoresis technique. Synthesized complexes have been tested for their SOD mimic activity using NBT/NADH/PMS system. The cytotoxic properties of metal complexes have been evaluated using brine shrimp lethality bioassay.

  13. Fluorescence and electron paramagnetic resonance studies of norfloxacin and N-donor mixed-ligand ternary copper(II) complexes: Stability and interaction with SDS micelles

    Science.gov (United States)

    Vignoli Muniz, Gabriel S.; Incio, Jimmy Llontop; Alves, Odivaldo C.; Krambrock, Klaus; Teixeira, Letícia R.; Louro, Sonia R. W.

    2018-01-01

    The stability of ternary copper(II) complexes of a heterocyclic ligand, L (L being 2,2‧-bipyridine (bipy) or 1,10-phenanthroline (phen)) and the fluorescent antibacterial agent norfloxacin (NFX) as the second ligand was studied at pH 7.4 and different ionic strengths. Fluorescence quenching upon titration of NFX with the binary complexes allowed to obtain stability constants for NFX binding, Kb, as a function of ionic strength. The Kb values vary by more than two orders of magnitude when buffer concentration varies from 0.5 to 100 mM. It was observed that previously synthesized ternary complexes dissociate in buffer according with the obtained stability constants. This shows that equimolar solutions of NFX and binary complexes are equivalent to solutions of synthesized ternary complexes. The interaction of the ternary copper complexes with anionic SDS (sodium dodecyl sulfate) micelles was studied by fluorescence and electron paramagnetic resonance (EPR). Titration of NFX-loaded SDS micelles with the complexes Cu:L allowed to determine the stability constants inside the micelles. Fluorescence quenching demonstrated that SDS micelles increase the stability constants by factors around 50. EPR spectra gave details of the copper(II) local environment, and demonstrated that the structure of the ternary complexes inside SDS micelles is different from that in buffer. Mononuclear ternary complexes formed inside the micelles, while in buffer most ternary complexes are binuclear. The results show that anionic membrane interfaces increase formation of copper fluoroquinolone complexes, which can influence bioavailability, membrane diffusion, and mechanism of action of the antibiotics.

  14. Oxidative DNA damage induced by a Copper(II)-1,10-phenanthroline-L-serine complex in the presence of rutin.

    Science.gov (United States)

    Wang, Yong; Dai, Panpan; Chen, Fu; Yang, Zhousheng

    2011-07-01

    The capacity of the ternary complex copper(II)-1,10-phenanthroline-L-serine ([Cu-Phen-Ser]) to induce double-strand scission of DNA was explored by agarose-gel electrophoresis. It was found that the complex exhibited remarkable activity to damage DNA in the presence of rutin. Analysis of the UV and fluorescence spectra clearly demonstrated that the complex was bound to DNA by intercalation. Further, the occurrence of 8-hydroxydeoxyguanosine (8-OHdG), a biomarker of oxidative DNA damage, after the treatment of DNA by the complex in presence of rutin was evidenced by an electrochemical method. Finally, the mechanism of oxidative damage to double-stranded DNA by the [Cu-Phen-Ser] complex in the presence of rutin was discussed. Copyright © 2011 Verlag Helvetica Chimica Acta AG, Zürich.

  15. Synthesis, and structural characterization of mixed ligand copper(II) complexes of N,N,N‧,N'-tetramethylethylenediamine incorporating carboxylates

    Science.gov (United States)

    Batool, Syeda Shahzadi; Gilani, Syeda Rubina; Tahir, Muhammad Nawaz; Rüffer, Tobias

    2017-11-01

    Two ternary copper(II) complexes of N,N,N‧,N'-tetramethylethylenediamine (tmen = C6H16N2) with benzoic acid and p-aminobenzoic acid, having the formula [Cu(tmen)(BA)2(H2O)2] (1), and [Cu(tmen)(pABA)2]. 1/2 CH3OH (2) {(Where BA1- = benzoate1- (C6H5CO21-), pABA1- = p-aminobenzoate1- (p-H2NC6H5CO21-)} have been prepared and characterized by elemental combustion analysis, Uv-Visible spectroscopy, FT-IR spectroscopy, thermal, and single crystal X-ray diffraction analyses. The complex 1 is a monomer with distorted octahedral geometry. In its CuN2O4 chromophore, the Cu(II) centre is coordinated by two N atoms of a symmetrically chelating tmen ligand, by two carboxylate-O atoms from two monodentate benzoate1- anions, and by two apical aqua-O atoms, which define the distorted octahedral structure. The complex 2 is a monomer with a distorted square planar coordination geometry. In CuN2O2 chromophore, tmen is coordinated to Cu(II) ion in a chelating bidentate fashion, while the two p-aminobenzoate1- anions coordinate to Cu(II) centre through their carboxylate-O atoms in a monodentate manner, forming a square planar structure. The observed difference between asymmetric ѵas(OCO) and symmetric ѵs(OCO) stretching IR vibrations of the carboxylate moieties for 1 and 2 is 220 cm-1 and 232 cm-1, respectively, which suggests monodentate coordination mode (Δν OCO>200) of the carboxylate groups to Cu(II) ion. Thermogravimetric studies of 1 indicates removal of two water molecules at 171 °C, elimination of a tmen upto 529 °C and of two benzoate groups upto 931 °C. In tga curve of 2, methanol is lost upto 212 °C, while tmen is lost from 212 to 993 °C. The antibacterial activities of these new compounds against various bacterial strains were also investigated.

  16. Zeolite-Encapsulated Copper(II) Amino Acid Complexes: Synthesis, Spectroscopy, and Catalysis

    NARCIS (Netherlands)

    Weckhuysen, B.M.; Verberckmoes, A.A.; Fu, L.; Schoonheydt, R.A.

    1995-01-01

    The spectroscopic properties and catalytic behavior of Cu(AA)n m+ complexes (AA ) amino acid (glycine, lysine, histidine, alanine, serine, proline, tyrosine, phenylalanine, glutamine, glutamic acid, cysteine, tryptophan, leucine, and arginine)) in faujasite-type zeolites have been investigated.

  17. XAFS study of copper(II) complexes with square planar and square pyramidal coordination geometries

    Science.gov (United States)

    Gaur, A.; Klysubun, W.; Nitin Nair, N.; Shrivastava, B. D.; Prasad, J.; Srivastava, K.

    2016-08-01

    X-ray absorption fine structure of six Cu(II) complexes, Cu2(Clna)4 2H2O (1), Cu2(ac)4 2H2O (2), Cu2(phac)4 (pyz) (3), Cu2(bpy)2(na)2 H2O (ClO4) (4), Cu2(teen)4(OH)2(ClO4)2 (5) and Cu2(tmen)4(OH)2(ClO4)2 (6) (where ac, phac, pyz, bpy, na, teen, tmen = acetate, phenyl acetate, pyrazole, bipyridine, nicotinic acid, tetraethyethylenediamine, tetramethylethylenediamine, respectively), which were supposed to have square pyramidal and square planar coordination geometries have been investigated. The differences observed in the X-ray absorption near edge structure (XANES) features of the standard compounds having four, five and six coordination geometry points towards presence of square planar and square pyramidal geometry around Cu centre in the studied complexes. The presence of intense pre-edge feature in the spectra of four complexes, 1-4, indicates square pyramidal coordination. Another important XANES feature, present in complexes 5 and 6, is prominent shoulder in the rising part of edge whose intensity decreases in the presence of axial ligands and thus indicates four coordination in these complexes. Ab initio calculations were carried out for square planar and square pyramidal Cu centres to observe the variation of 4p density of states in the presence and absence of axial ligands. To determine the number and distance of scattering atoms around Cu centre in the complexes, EXAFS analysis has been done using the paths obtained from Cu(II) oxide model and an axial Cu-O path from model of a square pyramidal complex. The results obtained from EXAFS analysis have been reported which confirmed the inference drawn from XANES features. Thus, it has been shown that these paths from model of a standard compound can be used to determine the structural parameters for complexes having unknown structure.

  18. C{sub 2}-symmetric Copper(II) complexes as chiral Lewis acids

    Energy Technology Data Exchange (ETDEWEB)

    Evans, D.A.; Murry, J.A.; Matt, P. von [Harvard Univ., Cambridge, MA (United States)] [and others

    1995-12-01

    Two new Cu(II)-derived Lewis acid catalysts 1 and 2 have been prepared and their utility as catalysts in the Diels-Alder reaction documented. While complex 1 is effective in catalyzing the cycloaddition of unsaturated aldehyde dienophiles with cyclopentadiene complex 2 is optimal for imide dienophiles. This study provides a rational basis for the design of Lewis acids based on the coordinating capacity of cationic Cu(II) complexes which possess sufficient Lewis acidity to catalyze a range of synthetically useful Diels-Alder reactions. In particular, documentation of the importance of counterion structure in the use of cationic metal centers as Lewis acids has been made for the first time.

  19. Two new copper(II) complexes with the shortest (N N) diazine based rigid ligand: Example of unusual tridentate coordination mode

    Science.gov (United States)

    Karmakar, Ruma; Choudhury, Chirantan Roy; Batten, Stuart R.; Mitra, Samiran

    2007-01-01

    Two new five coordinated Cu(II) complexes, Cu(L)Cl 2,CH 3OH ( 1) and Cu(L)Br 2 ( 2) derived from the flexidentate ligand (L), 2-pyridinealdazine, have been synthesised and characterised by spectroscopic and electrochemical studies. Single crystal structures of the complexes were determined. Crystal structures of both the complexes contain monomeric entities of five coordinated copper(II) ions where the Schiff base ligand, 2-pyridinealdazine, acts in a tridentate fashion. The central part of the ligand in complex 2 is disordered over two positions: N8 sbnd N9 make up the major position and N8A sbnd N9A make up the minor position.

  20. Synthesis and structure elucidation of a copper(II) Schiff-base complex: in vitro DNA binding, pBR322 plasmid cleavage and HSA binding studies.

    Science.gov (United States)

    Tabassum, Sartaj; Ahmad, Musheer; Afzal, Mohd; Zaki, Mehvash; Bharadwaj, Parimal K

    2014-11-01

    New copper(II) complex with Schiff base ligand 4-[(2-Hydroxy-3-methoxy-benzylidene)-amino]-benzoic acid (H₂L) was synthesized and characterized by spectroscopic and analytical and single crystal X-ray diffraction studies which revealed that the complex 1 exist in a distorted octahedral environment. In vitro CT-DNA binding studies were performed by employing different biophysical technique which indicated that the 1 strongly binds to DNA in comparison to ligand via electrostatic binding mode. Complex 1 cleaves pBR322 DNA via hydrolytic pathway and recognizes minor groove of DNA double helix. The HSA binding results showed that ligand and complex 1 has ability to quench the fluorescence emission intensity of Trp 214 residue available in the subdomain IIA of HSA. Copyright © 2014 Elsevier B.V. All rights reserved.

  1. Structure and magnetic properties of a new binuclear copper(II) complex of a tripodal oxime

    Science.gov (United States)

    Premužić, Dejan; Korabik, Maria; Hołyńska, Małgorzata

    2014-02-01

    Perchlorate salt of a new binuclear [Cu2] cationic complex (1) with tris(1-propan-2-onyl oxime)amine acting as a ligand is introduced. In each complex cation two Cu2+ cations are linked by oxime groups from two ligands, whereas two remaining oxime groups per ligand remain non-deprotonated and participate in bifurcated O-H⋯O hydrogen bonds. Cu2+ ions are strongly antiferromagnetically coupled with singlet-triplet energy gap of about 2J = -750 cm-1, giving rise to interesting EPR properties.

  2. Copper(II) and lead(II) complexation by humic acid and humic-like ligands

    OpenAIRE

    IVANA KOSTIĆ; TATJANA ANĐELKOVIĆ; RUŽICA NIKOLIĆ; ALEKSANDAR BOJIĆ; MILOVAN PURENOVIĆ; SRĐAN BLAGOJEVIĆ; DARKO ANĐELKOVIĆ

    2011-01-01

    The stability of metal–humate complexes is an important factor determining and predicting speciation, mobility and bioavailability of heavy metals in the environment. A comparative investigation of the complexation of Cu(II) and Pb(II) with humic acid and humic-like ligands, such as benzoic and salicylic acid, was performed. The analysis was realized at pH 4.0, a temperature of 25 °C and at an ionic strength of 0.01 mol dm-3 (NaCl) using the Schubert ion-exchange method and its modified form....

  3. Partial conversion of thioamide into nitrile in a copper(II) complex of 2,6-diacetylpyridine bis(thiosemicarbazone), a drug prototype for Alzheimer's disease.

    Science.gov (United States)

    Vieira, Rafael P; Thompson, John R; Beraldo, Heloisa; Storr, Tim

    2015-06-01

    This work reports the crystal structure of [(Z)-2-((E)-1-{6-[1-({[amino(sulfanidyl-κS)methylidene]amino}imino-κN)ethyl]pyridin-2-yl-κN}ethylidene)-1-cyanohydrazinido-κN(1)]copper(II), [Cu(C11H11N7S)], the first description of a copper(II) complex of 2,6-diacetylpyridine bis(thiosemicarbazone) showing partial conversion of a thioamide group to a nitrile group. The asymmetric ligand coordinates to the metal centre in an N,N',N'',S-tetradentate manner via the pyridine N atom, an imine N atom, the hydrazinide N atom and the sulfanidyl S atom, displaying a square-planar geometry. Ligand coordination results in two five-membered chelate rings and one six-membered chelate ring, and in crystal packing based on N-H···N hydrogen bonds of the cyanohydrazinide and hydrazinecarbothioamidate arms of the ligand. The correlation between the partial conversion upon metal complexation, H2S release and possible effects on the activity of bis(thiosemicarbazone)s as drug prototypes for Alzheimer's disease is also discussed.

  4. DNA binding, cytotoxicity and apoptosis induction activity of a mixed-ligand copper(II) complex with taurine Schiff base and imidazole

    Science.gov (United States)

    Li, Mei; kong, Lin Lin; Gou, Yi; Yang, Feng; Liang, Hong

    2014-07-01

    A novel binuclear copper(II) complex (complex 1) with taurine Schiff base and imidazole has been synthesized and structurally characterized by single crystal X-ray diffraction, elemental analysis, ESI-MS spectrometry, UV-vis and IR spectroscopy. Single-crystal analysis revealed that 1 displays the sulfonate-bridged dinuclear copper(II) centers. Both copper atoms are five-coordinated and exhibit slightly distorted square pyramidal geometries. Each of copper atom is surrounded by three oxygen atoms and one nitrogen atom from different taurine Schiff base ligands, and one nitrogen atom from one imidazole ligand. The interaction between 1 and calf thymus DNA (CT-DNA) was investigated by UV-vis, fluorescence, circular dichroism (CD) spectra and agarose gel electrophoresis. The experimental results indicated that 1 could bind to CT-DNA via an intercalative mode and show efficient cleavage activity. In addition, 1 showed an antitumor effect on cell cycle and apoptosis. Flow cytometric analysis revealed that MGC-803 cells were arrested in the S phase after treatment with 1. Fluorescence microscopic observation indicated that 1 could induce apoptosis of MGC-803 cells.

  5. DNA binding, cytotoxicity and apoptosis induction activity of a mixed-ligand copper(II) complex with taurine Schiff base and imidazole.

    Science.gov (United States)

    Li, Mei; Kong, Lin Lin; Gou, Yi; Yang, Feng; Liang, Hong

    2014-07-15

    A novel binuclear copper(II) complex (complex 1) with taurine Schiff base and imidazole has been synthesized and structurally characterized by single crystal X-ray diffraction, elemental analysis, ESI-MS spectrometry, UV-vis and IR spectroscopy. Single-crystal analysis revealed that 1 displays the sulfonate-bridged dinuclear copper(II) centers. Both copper atoms are five-coordinated and exhibit slightly distorted square pyramidal geometries. Each of copper atom is surrounded by three oxygen atoms and one nitrogen atom from different taurine Schiff base ligands, and one nitrogen atom from one imidazole ligand. The interaction between 1 and calf thymus DNA (CT-DNA) was investigated by UV-vis, fluorescence, circular dichroism (CD) spectra and agarose gel electrophoresis. The experimental results indicated that 1 could bind to CT-DNA via an intercalative mode and show efficient cleavage activity. In addition, 1 showed an antitumor effect on cell cycle and apoptosis. Flow cytometric analysis revealed that MGC-803 cells were arrested in the S phase after treatment with 1. Fluorescence microscopic observation indicated that 1 could induce apoptosis of MGC-803 cells. Copyright © 2014 Elsevier B.V. All rights reserved.

  6. Theoretical study, and infrared and Raman spectra of copper(II) chelated complex with dibenzoylmethane

    DEFF Research Database (Denmark)

    Nekoei, A.-R.; Vakili, M.; Hakimi-Tabar, M.

    2014-01-01

    There are some discrepancies in both the vibrational assignments and in the metal-ligand (M-L) bond strengths predicted in the previous studies on the copper (II) chelated complex of dibenzoylmethane, Cu(dbm)2. Also, there is a lack of theoretical structure, Raman spectrum and full vibrational as...

  7. Anion receptors containing coordinatively unsaturated metal ions: copper(II) complexes with cyclam derivatives

    National Research Council Canada - National Science Library

    Fabbrizzi, Luigi; Fusco, Nadia; Mangano, Carlo; Broglia, Arturo; Boiocchi, Massimo

    2014-01-01

    .... The formation of a five-cordinate complex is favored by the trans-I configuration of the [Cu(Bn 4 cyclam)] 2+ receptor, but it is contrasted by the severe steric repulsions exerted by the benzyl substituents on the macrocyclic framework...

  8. Enantioselectivity Measurements of Copper(II) Amino Acid Complexes Using Isothermal Titration Calorimetry

    NARCIS (Netherlands)

    Bruin, de T.J.M.; Marcelis, A.T.M.; Zuilhof, H.; Sudhölter, E.J.R.

    2000-01-01

    Enantioselectivity experiments for the binding to chiral Cu(II) complexes have been performed for several -amino acids using isothermal titration calorimetry. To a system containing nonionic micelles, Cu(II) ions, and cholesteryl glutamate as chiral selector, either the D- or L-amino acid was

  9. Copper(II) nickel(II), cobalt(II) and oxovanadium(IV) complexes of ...

    Indian Academy of Sciences (India)

    Administrator

    phenyl)-. 1-phenyl-5-(phenyl-methylene)-2-naphthalenecarboxamide (X = H, CH3, OCH3. Cl)] have been prepared and characterized on the basis of elemental analysis, magnetic moments, i.e., EPR and electronic spectra. These metal complexes ...

  10. In vitro DNA and BSA-binding, cell imaging and anticancer activity against human carcinoma cell lines of mixed ligand copper(II) complexes.

    Science.gov (United States)

    Anjomshoa, Marzieh; Torkzadeh-Mahani, Masoud

    2015-01-01

    Binding studies of two water soluble copper(II) complexes of the type [Cu(phen-dion)(diimine)Cl]Cl, where phen-dione is 1,10-phenanthroline-5,6-dione and diimine is 1,10-phenanthroline (1) and 2,2'-bipyridine (2), with fish sperm DNA (FS-DNA) and bovine serum albumin (BSA) have been examined under physiological conditions by a series of experimental methods (UV-Vis absorption, fluorescence, viscosity, cyclic voltammetry (CV) and circular dichroism (CD) spectroscopic techniques). The experimental results indicate that the complexes interact with FS-DNA by electrostatic and partial insertion of pyridyl rings between the base stacks of double-stranded DNA. The complexes could quench the intrinsic fluorescence of BSA with the binding constants (Kbin) of 32×10(5) M(-1) (1) and 1.7×10(5) M(-1) (2) at 290 K. The quenching mechanism, thermodynamic parameters, the number of binding sites and the effect of the Cu(II) complexes on the secondary structure of BSA have been explored. The in vitro anticancer chemotherapeutic potential of two copper(II) complexes against the three human carcinoma cell lines (MCF-7, A-549, and HT-29) and one normal cell line (DPSC) were evaluated by MTT assay. The results of in vitro cytotoxicity indicate that the complex (1) has greater cytotoxicity activity against all of the cell lines, especially HT-29 with IC50 values of 1.8 μM. Based on the IC50 values, these complexes did not display an apparent cyto-selective profile, because it would appear that two complexes are toxic to all four model cell lines. The microscopic analyses of the cancer cells confirm results of cytotoxicity. Copyright © 2015 Elsevier B.V. All rights reserved.

  11. New copper(II) complexes with dopamine hydrochloride and vanillymandelic acid: Spectroscopic and thermal characterization

    Science.gov (United States)

    Mohamed, Gehad G.; Nour El-Dien, F. A.; El-Nahas, R. G.

    2011-10-01

    The dopamine derivatives participate in the regulation of wide variety of physiological functions in the human body and in medication life. Increase and/or decrease in the concentration of dopamine in human body reflect an indication for diseases such as Schizophrenia and/or Parkinson diseases. The Cu(II) chelates with coupled products of dopamine hydrochloride (DO.HCl) and vanillymandelic acid (VMA) with 4-aminoantipyrine (4-AAP) are prepared and characterized. Different physico-chemical techniques namely IR, magnetic and UV-vis spectra are used to investigate the structure of these chelates. Cu(II) forms 1:1 (Cu:DO) and 1:2 (Cu:VMA) chelates. DO behave as a uninegative tridentate ligand in binding to the Cu(II) ion while VMA behaves as a uninegative bidentate ligand. IR spectra show that the DO is coordinated to the Cu(II) ion in a tridentate manner with ONO donor sites of the phenolic- OH, -NH and carbonyl- O, while VMA is coordinated with OO donor sites of the phenolic- OH and -NH. Magnetic moment measurements reveal the presence of Cu(II) chelates in octahedral and square planar geometries with DO and VMA, respectively. The thermal decomposition of Cu(II) complexes is studied using thermogravimetric (TG) and differential thermal analysis (DTA) techniques. The activation thermodynamic parameters, such as, energy of activation, enthalpy, entropy and free energy change of the complexes are evaluated and the relative thermal stability of the complexes are discussed.

  12. Antibacterial, DNA interaction and cytotoxic activities of pendant-armed polyamine macrocyclic dinuclear nickel(II) and copper(II) complexes

    Science.gov (United States)

    Arthi, P.; Haleel, A.; Srinivasan, P.; Prabhu, D.; Arulvasu, C.; Kalilur Rahiman, A.

    2014-08-01

    A series of dinuclear nickel(II) and copper(II) complexes (1-6) of hexaaza macrocycles of 2,6-diformyl-4-methylphenol with three different benzoyl pendant-arms, 2,2‧-benzoyliminodi(ethylamine) trihydrochloride (L), 2,2‧-4-nitrobenzoyliminodi(ethylamine) trihydrochloride (L‧) and 2,2‧-3,5-dinitrobenzoyliminodi(ethylamine) trihydrochloride (L″) have been synthesized and characterized by spectral methods. The electrochemical studies of these complexes depict two irreversible one electron reduction processes around E1pc = -0.62 to -0.76 V and E2pc = -1.21 to -1.31, and nickel(II) complexes (1-3) exhibit two irreversible one electron oxidation processes around E1pa = 1.08 to 1.14 V and E2pa = 1.71 to 1.74 V. The room temperature magnetic moment values (μeff, 1.52-1.54 BM) indicate the presence of an antiferromagnetic interaction in the binuclear copper(II) complexes (4-6) which is also observed from the broad ESR spectra with a g value of 2.14-2.15. The synthesized complexes (1-6) were screened for their antibacterial activity. The results of DNA interaction studies indicate that the dinuclear complexes can bind to calf thymus DNA by intercalative mode and display efficient cleavage of plasmid DNA. Further, the cytotoxic activity of complexes 2, 5 and 6 on human liver adenocarcinoma (HepG2) cell line has been examined. Nuclear-chromatin cleavage has also been observed with PI staining and comet assays.

  13. Synthesis, Characterization and Antimicrobial Activity of Copper(II ...

    African Journals Online (AJOL)

    This study presents the synthesis, characterization and antimicrobial activity of copper(II) complexes of some ortho-substituted aniline Schiff bases (L1–L8). The Schiff bases and their respective copper(II) complexes were characterized by a combination of elemental analysis, infrared and UV/Visible studies. The structures of ...

  14. Synthesis, stereochemistry and antimicrobial activity of copper(II ...

    African Journals Online (AJOL)

    On the basis of the analytical data, magnetic moments and spectral data, a square-planar geometry has been proposed for the nickel(II) and copper(II) complexes with these ligands. Some representative complexes of copper(II) and nickel(II) were found to have remarkable antifungal and antibacterial activity. KEY WORDS: ...

  15. Syntheses, crystal structures and properties of novel copper(II) complexes obtained by reactions of copper(II) sulfate pentahydrate with tripodal ligands.

    Science.gov (United States)

    Zhao, Wei; Fan, Jian; Song, You; Kawaguchi, Hiroyuki; Okamura, Taka-aki; Sun, Wei-Yin; Ueyama, Norikazu

    2005-04-21

    Three novel metal-organic frameworks (MOFs), [Cu(1)SO4].H2O (4), [Cu2(2)2(SO4)2].4H2O (5) and [Cu(3)(H2O)]SO4.5.5H2O (6), were obtained by hydrothermal reactions of CuSO4.5H2O with the corresponding ligands, which have different flexibility. The structures of the synthesized complexes were determined by single-crystal X-ray diffraction analyses. Complex 4 has a 2D network structure with two types of metallacycles. Complex 5 also has a 2D network structure in which each independent 2D sheet contains two sub-layers bridged by oxygen atoms of the sulfate anions. Complex 6 has a 2D puckered structure in which the sulfate anions serve as counter anions, which are different from those in complexes 4 (terminators) and 5 (bridges). The different structures of complexes 4, 5 and 6 indicate that the nature of organic ligands affected the structures of the assemblies greatly. The magnetic behavior of complex 5 and anion-exchange properties of complex 6 were investigated.

  16. Synthesis and Characterization of a Tetramethyl Furanone Functionalized Diiminedioxime, A Potential Ligand for Cu Radiopharmaceuticals, and its Copper(II) and Nickel(II) Complexes.

    Science.gov (United States)

    Kiani, Salma; Staples, Richard J; Treves, S Ted; Packard, Alan B

    2009-03-12

    As part of our on-going effort to develop (64)Cu-based radiopharmaceuticals for PET (positron emission tomography) imaging of multidrug resistance in cancer, we prepared a tetramethylfuranone-functionalized diiminedioxime ligand, TMFPreH (TMFPreH = 4-[3-(4-Hydroxyimino-2,2,5,5-dimethyl-dihydro-furan-3-ylideneamino)-propylimino]-2,2,5,5-tetramethyl-dihydro-furan-3-one oxime) and its Cu(II) and Ni(II) complexes. When the copper(II) complex was prepared from Cu(ClO(4))(2) in ethanol, it was isolated as a Cu(II)-bridged dimer, but when it was prepared from Cu(OAc)(2) and heated in acetone, an unusual example of an acetone adduct of the ligand is formed by reduction of one of the imine double bonds by the solvent. The Ni(II) complex is square pyramidal with the perchlorate counterion at the apex.

  17. Spectrophotometric determination of formation constants of copper(II) complexes with 2,2‧-bipyridyl, 1,10-phenanthroline and their halides in methanol

    Science.gov (United States)

    Segoviano-Garfias, José J. N.; Nájera-Lara, Mónica; Pérez-Arredondo, María de la Luz; López-Ramírez, Varinia; Rubio-Jimenez, C. A.; Ramírez-Vázquez, Juan Antonio; Moreno-Esparza, Rafael

    2017-11-01

    The redox mediator used in dye-sensitized solar cells present several disadvantages; several research groups have theorized the possible use of blue copper proteins as electron mediators, despite their high costs. Copper complexes that mimic blue copper proteins could represent an alternative as electronic transfer agent with lower costs. In this work, we conducted a spectrophotometric study of the speciation of copper(II) complexes with 2,2‧-bipyridyl, 1,10-phenanthroline and their ternary complexes with chloride and bromide, at 303 K. For the copper-2,2‧-bipyridyl complexes, the formation constants obtained are: log β110 = 7.57 ± 0.08, log β120 = 13.26 ± 0.11 and log β130 = 17.21 ± 0.14. For the ternary systems of copper-2,2‧-bipyridyl with chloride or bromide, are: log β111 = 12.06 ± 0.06 and log β111 = 11.23 ± 0.01, respectively. Also, the formation constants obtained for the copper-1,10-phenanthroline complexes are log β110 = 4.21 ± 0.01 and log β120 = 7.24 ± 0.02. For the ternary systems of copper(II) with 1,10-phenanthroline and chloride or bromide, are: log β111 = 6.14 ± 0.04 and log β111 = 7.46 ± 0.03, respectively. Finally, the individual calculated electronic spectra of these species were obtained and compared to other copper complexes mimicking to blue copper proteins.

  18. Unusual saccharin-N,O (carbonyl) coordination in mixed-ligand copper(II) complexes: Synthesis, X-ray crystallography and biological activity

    Science.gov (United States)

    Mokhtaruddin, Nur Shuhada Mohd; Yusof, Enis Nadia Md; Ravoof, Thahira B. S. A.; Tiekink, Edward R. T.; Veerakumarasivam, Abhi; Tahir, Mohamed Ibrahim Mohamed

    2017-07-01

    Three tridentate Schiff bases containing N and S donor atoms were synthesized via the condensation reaction between S-2-methylbenzyldithiocarbazate with 2-acetyl-4-methylpyridine (S2APH); 4-methyl-3-thiosemicarbazide with 2-acetylpyridine (MT2APH) and 4-ethyl-3-thiosemicarbazide with 2-acetylpyridine (ET2APH). Three new, binuclear and mixed-ligand copper(II) complexes with the general formula, [Cu(sac)(L)]2 (sac = saccharinate anion; L = anion of the Schiff base) were then synthesized, and subsequently characterized by IR and UV/Vis spectroscopy as well as by molar conductivity and magnetic susceptibility measurements. The Schiff bases were also spectroscopically characterized using NMR and MS to further confirm their structures. The spectroscopic data indicated that the Schiff bases behaved as a tridentate NNS donor ligands coordinating via the pyridyl-nitrogen, azomethine-nitrogen and thiolate-sulphur atoms. Magnetic data indicated a square pyramidal environment for the complexes and the conductivity values showed that the complexes were essentially non-electrolytes in DMSO. The X-ray crystallographic analysis of one complex, [Cu(sac)(S2AP)]2 showed that the Cu(II) atom was coordinated to the thiolate-S, azomethine-N and pyridyl-N donors of the S2AP Schiff base and to the saccharinate-N from one anion, as well as to the carbonyl-O atom from a symmetry related saccharinate anion yielding a centrosymmetric binuclear complex with a penta-coordinate, square pyramidal geometry. All the copper(II) saccharinate complexes were found to display strong cytotoxic activity against the MCF-7 and MDA-MB-231 human breast cancer cell lines.

  19. Transition metal complexes with thiosemicarbazide-based ligands. Part 60. Reactions of copper(II) bromide with pyridoxal S-methylisothiosemicarbazone (PLITSC). Crystal structure of [Cu(PLITSC–H)H2O]Br·H2O

    National Research Council Canada - National Science Library

    Vukadin M Leovac; Ljiljana S Vojinović-Ješić; Sonja A Ivković; Marko V Rodić; Ljiljana S Jovanović; Berta Holló; Katalin Mészáros Szécsényi

    2014-01-01

    The synthesis and structural characterization of a square-planar copper(II) complex with pyridoxal S-methylisothiosemicarbazone (PLITSC) of the formula [Cu(PLITSC–H)H2O]Br·H2O (1) as the first Cu(II...

  20. Copper(II) selective electrochemical sensor based on Schiff Base complexes.

    Science.gov (United States)

    Singh, Lok P; Bhatnagar, Jitendra M

    2004-10-08

    Plasticized membranes using Schiff Base complexes, derived from 2,3-diaminopyridine and o-vanilin have been prepared and explored as Cu(2+)-selective sensors. Effect of various plasticizers viz., dibutyl phthalate (DBP), dioctylphthalate (DOP), chloronaphthalene (CN), tri-n-butylphosphate (TBP) etc. and anion excluder, sodium tetraphenylborate (NaTPB) was studied in detail and improved performance was observed at several instances. Optimum performance was observed with Schiff Base (B) having a membrane composition of B(1%):PVC(33%):DOP(65%):NaTPB(1%). The sensor works satisfactorily in the concentration range 5.0x10(-6) to 1.0x10(-1)M (detection limit 0.3ppm) with a Nernstian slope of 29.6mV per decade of activity. Wide pH range (1.9-5.2), fast response time (4 months) indicate the vital utility of the proposed sensor. The potentiometric selectivity coefficient values as determined by match potential method (MPM) indicate good response for Cu(2+) in presence of interfering ions. The tolerance level of Hg(2+), which causes serious interference in the determination of Cu(2+) ions (K(Cu(2+)Hg(2+))(Pot)(MPM): 0.45), was determined as a function of Cu(2+) concentration in simulated mixtures. The sensor was also used in the potentiometric titration of Cu(2+) with EDTA.

  1. ROS-mediated cytotoxic effect of copper(II) hydrazone complexes against human glioma cells.

    Science.gov (United States)

    Recio Despaigne, Angel A; Da Silva, Jeferson G; da Costa, Pryscila R; Dos Santos, Raquel G; Beraldo, Heloisa

    2014-10-27

    2-Acetylpyridine acetylhydrazone (H2AcMe), 2-benzoylpyridine acetylhydrazone (H2BzMe) and complexes [Cu(H2AcMe)Cl2] (1) and [Cu(H2BzMe)Cl2] (2) were assayed for their cytotoxicity against wild type p53 U87 and mutant p53 T98 glioma cells, and against MRC-5 fibroblast cells. Compounds 1 and 2 proved to be more active than the corresponding hydrazones against U87, but not against T98 cells. Compound 1 induced higher levels of ROS than H2AcMe in both glioma cell lines. H2AcMe and 1 induced lower levels of ROS in MRC5 than in U87 cells. Compound 2 induced lower levels of ROS in MRC5 than in T98 cells. The cytotoxic effect of 1 in U87 cells could be related to its ability to provoke the release of ROS, suggesting that the cytotoxicity of 1 might be somehow p53 dependent.

  2. ROS-Mediated Cytotoxic Effect of Copper(II Hydrazone Complexes against Human Glioma Cells

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    Angel A. Recio Despaigne

    2014-10-01

    Full Text Available 2-Acetylpyridine acetylhydrazone (H2AcMe, 2-benzoylpyridine acetylhydrazone (H2BzMe and complexes [Cu(H2AcMeCl2] (1 and [Cu(H2BzMeCl2] (2 were assayed for their cytotoxicity against wild type p53 U87 and mutant p53 T98 glioma cells, and against MRC-5 fibroblast cells. Compounds 1 and 2 proved to be more active than the corresponding hydrazones against U87, but not against T98 cells. Compound 1 induced higher levels of ROS than H2AcMe in both glioma cell lines. H2AcMe and 1 induced lower levels of ROS in MRC5 than in U87 cells. Compound 2 induced lower levels of ROS in MRC5 than in T98 cells. The cytotoxic effect of 1 in U87 cells could be related to its ability to provoke the release of ROS, suggesting that the cytotoxicity of 1 might be somehow p53 dependent.

  3. Synthesis and crystal structures of novel copper(II) complexes with glycine and substituted phenanthrolines: reactivity towards DNA/BSA and in vitro cytotoxic and antimicrobial evaluation.

    Science.gov (United States)

    İnci, Duygu; Aydın, Rahmiye; Vatan, Özgür; Sevgi, Tuba; Yılmaz, Dilek; Zorlu, Yunus; Yerli, Yusuf; Çoşut, Bünyemin; Demirkan, Elif; Çinkılıç, Nilüfer

    2017-01-01

    New copper(II) complexes-dimeric-[Cu(nphen)(gly)(H 2 O)] + (1) and [Cu(dmphen)(gly)(NO 3 )(H 2 O)] (2) (nphen = 5-nitro-1,10-phenanthroline, dmphen = 4,7-dimethyl-1,10-phenanthroline, and gly = glycine)-have been synthesized and characterized by CHN analysis, single-crystal X-ray diffraction techniques, FTIR, EPR spectroscopy, and cyclic voltammetry. The CT-DNA-binding properties of these complexes have been investigated by thermal denaturation measurements and both absorption and emission spectroscopy. The DNA cleavage activity of these complexes has been studied on supercoiled pUC19 plasmid DNA by gel electrophoresis experiments in the absence and presence of H 2 O 2 . Furthermore, the interaction of these complexes with bovine serum albumin (BSA) has been investigated using absorption and emission spectroscopy. The thermodynamic parameters, free-energy change (ΔG), enthalpy change (ΔH), and entropy change (ΔS) for BSA + complexes 1 and 2 systems have been calculated by the van't Hoff equation at three different temperatures (293.2, 303.2, and 310.2 K). The distance between the BSA and these complexes has been determined using fluorescence resonance energy transfer (FRET). Conformational changes of BSA have been observed using the synchronous fluorescence technique. In addition, in vitro cytotoxicities of these complexes on tumor cell lines (Caco-2, A549, and MCF-7) and healthy cells (BEAS-2B) have been examined. The antimicrobial activity of the complexes has also been tested on certain bacteria cells. The effect of mono and dimeric in the above complexes is presented and discussed. New copper(II) complexes-dimeric-[Cu(nphen)(gly)(H 2 O)] + (1) and [Cu(dmphen)(gly) (NO 3 )(H 2 O)] (2) (nphen = 5-nitro-1,10-phenanthroline, dmphen = 4,7-dimethyl-1,10-phenanthroline and gly = glycine)-have been synthesized and characterized by CHN analysis, single-crystal X-ray diffraction techniques, FTIR and EPR spectroscopy. They have been tested for their in vitro

  4. Antibacterial susceptibility of new copper(II N-pyruvoyl anthranilate complexes against marine bacterial strains – In search of new antibiofouling candidate

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    Reda F.M. Elshaarawy

    2016-11-01

    Full Text Available Biofouling is a serious problem and very difficult to overcome, since the marine biofilm-producing microorganisms resist the host defense mechanism and antibiotic therapy. Therefore, there is an urgent need to develop potent anti-biofouling agent to effectively eradicate unwanted biofilms. Our work represents antibacterial susceptibility and antibiofilm forming assay of new copper(II N-pyruvoyl anthranilate architectures (4a–d against Staphylococcus aureus and Escherichia coli, marine isolates. The preliminary biofilm susceptibility tests revealed that, the most potent staphylococcalcidal (MIC/MBC = 9.25/10.50 mM and E. coli-cidal (MIC/MBC = 13.25/13.50 mM agent, 4d, exhibits significant biofilm inhibition. Complex 4d can therefore provide an antibiofilm-forming agent candidate to curb the formation of biofilms.

  5. Effect of substituents on prediction of TLC retention of tetra-dentate Schiff bases and their Copper(II) and Nickel(II) complexes.

    Science.gov (United States)

    Stevanović, Nikola R; Perušković, Danica S; Gašić, Uroš M; Antunović, Vesna R; Lolić, Aleksandar Đ; Baošić, Rada M

    2017-03-01

    The objectives of this study were to gain insights into structure-retention relationships and to propose the model to estimating their retention. Chromatographic investigation of series of 36 Schiff bases and their copper(II) and nickel(II) complexes was performed under both normal- and reverse-phase conditions. Chemical structures of the compounds were characterized by molecular descriptors which are calculated from the structure and related to the chromatographic retention parameters by multiple linear regression analysis. Effects of chelation on retention parameters of investigated compounds, under normal- and reverse-phase chromatographic conditions, were analyzed by principal component analysis, quantitative structure-retention relationship and quantitative structure-activity relationship models were developed on the basis of theoretical molecular descriptors, calculated exclusively from molecular structure, and parameters of retention and lipophilicity. Copyright © 2016 John Wiley & Sons, Ltd.

  6. Speciation of copper(II) complexes in an ionic liquid based on choline chloride and in choline chloride/water mixtures.

    Science.gov (United States)

    De Vreese, Peter; Brooks, Neil R; Van Hecke, Kristof; Van Meervelt, Luc; Matthijs, Edward; Binnemans, Koen; Van Deun, Rik

    2012-05-07

    A deep-eutectic solvent with the properties of an ionic liquid is formed when choline chloride is mixed with copper(II) chloride dihydrate in a 1:2 molar ratio. EXAFS and UV-vis-near-IR optical absorption spectroscopy have been used to compare the coordination sphere of the cupric ion in this ionic liquid with that of the cupric ion in solutions of 0.1 M of CuCl(2)·2H(2)O in solvents with varying molar ratios of choline chloride and water. The EXAFS data show that species with three chloride ions and one water molecule coordinated to the cupric ion as well as species with two chloride molecules and two water molecules coordinated to the cupric ion are present in the ionic liquid. On the other hand, a fully hydrated copper(II) ion is formed in an aqueous solution free of choline chloride, and the tetrachlorocuprate(II) complex forms in aqueous choline chloride solutions with more than 50 wt % of choline chloride. In solutions with between 0 and 50 wt % of choline chloride, mixed chloro-aquo complexes occur. Upon standing at room temperature, crystals of CuCl(2)·2H(2)O and of Cu(choline)Cl(3) formed in the ionic liquid. Cu(choline)Cl(3) is the first example of a choline cation coordinating to a transition-metal ion. Crystals of [choline](3)[CuCl(4)][Cl] and of [choline](4)[Cu(4)Cl(10)O] were also synthesized from molecular or ionic liquid solvents, and their crystal structures were determined.

  7. DFT studies of copper(II) complexes of cis-1,2-diaminocyclohexane (Dach) and crystal structure of [Cu(Dach)2(H2O)]Cl2

    Science.gov (United States)

    Nawaz, Sidra; Ghaffar, Abdul; Zierkiewicz, Wiktor; Monim-ul-Mehboob, Muhammad; Khurram; Tahir, Muhammad Nawaz; Isab, Anvarhusein A.; Ahmad, Saeed

    2017-06-01

    A copper(II) complex, [Cu(Dach)2(H2O)]Cl2 (1) (Dach = cis-1,2-Diaminocyclohexane) has been prepared and characterized by IR spectroscopy and X-ray crystallography. The crystal structure of complex 1 is ionic consisting of [Cu(Dach)2(H2O)]2+ cation and two chloride counter ions. The copper atom in the complex ion assumes a distorted square pyramidal geometry with water occupying the apical position. The adjacent molecules are joined by hydrogen bonding to form irregular chains. The structures of [Cu(Dach)2(H2O)]Cl2 (1) and three of its analogues, [Cu(Dach)2Cl]Cl·H2O (2), [Cu(Dach)2(H2O)Cl]Cl (3) and [Cu(Dach)2Cl2]·H2O (4) were predicted by DFT calculations. The DFT results reveal that in the gas phase, the structure 1 is less stable in comparison to the calculated structure, [Cu(Dach)2Cl2]·H2O (4). The additional calculations were performed for the complexes investigated in solution (water) using the polarizable continuum model. According to these calculations, the electronic energies (stabilities) of the complexes 1 and 4 in the solvent are comparable to each other. The atomic charges and second-order interaction energies between orbitals for complexes 1-4 were calculated with natural bond orbital (NBO) analysis.

  8. Biological evaluation of a cytotoxic 2-substituted benzimidazole copper(II) complex: DNA damage, antiproliferation and apoptotic induction activity in human cervical cancer cells.

    Science.gov (United States)

    Qiao, Xin; Ma, Zhong-Ying; Shao, Jia; Bao, Wei-Guo; Xu, Jing-Yuan; Qiang, Zhao-Yan; Lou, Jian-Shi

    2014-02-01

    Exploring novel chemotherapeutic agents is a great challenge in cancer medicine. To that end, 2-substituted benzimidazole copper(II) complex, [Cu(BMA)Cl2]·(CH3OH) (1) [BMA = N,N'-bis(benzimidazol-2-yl-methyl)amine], was synthesized and its cytotoxicity was characterized. The interaction between complex 1 and calf thymus DNA was detected by spectroscopy methods. The binding constant (K b = 1.24 × 10(4 )M(-1)) and the apparent binding constant (K app = 6.67 × 10(6 )M(-1)) of 1 indicated its moderate DNA affinity. Complex 1 induced single strand breaks of pUC19 plasmid DNA in the presence of H2O2 through an oxidative pathway. Cytotoxicity studies proved that complex 1 could inhibit the proliferation of human cervical carcinoma cell line HeLa in both time- and dose-dependent manners. The results of nuclei staining by Hoechst 33342 and alkaline single-cell gel electrophoresis proved that complex 1 caused cellular DNA damage in HeLa cells. Furthermore, treatment of HeLa cells with 1 resulted in S-phase arrest, loss of mitochondrial potential, and up-regulation of caspase-3 and -9 in HeLa cells, suggesting that complex 1 was capable of inducing apoptosis in cancer cells through the intrinsic mitochondrial pathway.

  9. Evaluation of DNA/Protein interactions and cytotoxic studies of copper(II) complexes incorporated with N, N donor ligands and terpyridine ligand.

    Science.gov (United States)

    Tummalapalli, Kiran; C S, Vasavi; Munusami, Punnagai; Pathak, Madhvesh; M M, Balamurali

    2017-02-01

    A series of four new copper(II) heteroleptic complexes, [Cu(2‴-pytpy) (L)] (NO 3 ) 2 ·2H 2 O (1-4), where 2‴-pytpy=4'-(2'''-Pyridyl)-2, 2':6', 2''-terpyridine, L=bipyridyl (bpy), 1, 10 phenanthroline(phen), dipyridoquinoxaline(dpq) and dipyridophenazine (dppz) were synthesized and characterized by spectroscopic techniques. Further, the molecular structure of the complex (2) was confirmed by single crystal X-ray diffraction technique and the data revealed a penta coordinated, distorted square-pyramidal geometry with triclinic system. The interactions of four complexes with calf thymus DNA and bovine serum albumin (BSA) were investigated by electronic absorption, fluorescence and circular dichroism spectroscopy techniques. Spectral studies substantiated an intercalative binding mode of metal complexes with ct-DNA. Significant binding interactions of the complexes with protein have been further revealed from fluorescence studies. Furthermore, all the four complexes show potential cytotoxicity towards the human liver carcinoma cell line (HepG-2). Copyright © 2016 Elsevier B.V. All rights reserved.

  10. Binuclear copper(II) complexes with N4O3 coordinating heptadentate ligand: synthesis, structure, magnetic properties, density-functional theory study, and catecholase activity.

    Science.gov (United States)

    Banerjee, Atanu; Sarkar, Sumana; Chopra, Deepak; Colacio, Enrique; Rajak, Kajal Krishna

    2008-05-19

    The N4O3 coordinating heptadentate ligand afforded binuclear complex [Cu 2(H 2L)(mu-OH)](ClO4)2 (1) and [Cu2(L)(H2O)2]PF6 (2). In complex 1, two copper ions are held together by mu-phenoxo and mu-hydroxo bridges, whereas in complex 2, the copper centers are connected only by a mu-phenoxo bridge. In 1, both the Cu(II) centers have square pyramidal geometry (tau=0.01-0.205), whereas in the case of 2, one Cu(II) center has square pyramidal (tau=0.2517) and other one has square based pyramidal distorted trigonal bipyramidal (tau=0.54) geometry. Complexes 1 and 2 show an strong intramolecular and very weak antiferromagnetic interaction, respectively. Density-functional theory calculations were performed to establish the magneto structural correlation between the two paramagnetic copper(II) centers. Both of the complexes display a couple of one-electron reductive responses near -0.80 and -1.10 V. The complexes show significant catalytic activity at pH 8.5 on the oxidation of 3,5-di- tert-butylcatechol (3,5-DTBC) to 3,5-di- tert-butylquinone (3,5-DTBQ), and the activity measured in terms of kcat=29-37 h(-1).

  11. Non-covalent interactions in 2-methylimidazolium copper(II) complex (MeImH)2[Cu(pfbz)4]: Synthesis, characterization, single crystal X-ray structure and packing analysis

    Science.gov (United States)

    Sharma, Raj Pal; Saini, Anju; Kumar, Santosh; Kumar, Jitendra; Sathishkumar, Ranganathan; Venugopalan, Paloth

    2017-01-01

    A new anionic copper(II) complex, (MeImH)2 [Cu(pfbz)4] (1) where, MeImH = 2-methylimidazolium and pfbz = pentafluorobenzoate has been isolated by reacting copper(II) sulfate pentahydrate, pentafluorobenzoic acid and 2-methylimidazole in ethanol: water mixture in 1:2:2 molar ratio. This complex 1 has been characterized by elemental analysis, thermogravimetric analysis, spectroscopic techniques (UV-Vis, FT-IR) and conductance measurements. The complex salt crystallizes in monoclinic crystal system with space group C2/c. Single crystal X-ray structure determination revealed the presence of discrete ions: [Cu(pfbz)4]2- anion and two 2-methylimidazolium cation (C4H7N2)+. The crystal lattice is stabilized by strong hydrogen bonding and F⋯F interactions between cationic-anionic and the anionic-anionic moieties respectively, besides π-π interactions.

  12. Iron(III and copper(II complexes bearing 8-quinolinol with amino-acids mixed ligands: Synthesis, characterization and antibacterial investigation

    Directory of Open Access Journals (Sweden)

    Saliu A. Amolegbe

    2015-09-01

    Full Text Available Four d-orbital metal complexes with mixed ligands derived from 8-hydroxyquinoline (HQ and amino acids (AA: l-alanine and methionine have been synthesized through a mild reflux in alkaline solution and characterized by elemental analyses, infrared, electronic transition, and temperature dependant magnetic susceptibility. The IR spectroscopy revealed that iron and copper ions coordinated through carbonyl (CO, hydroxyl group (OH of the amino acids, N-pyridine ring of hydroxyquinoline. The elemental analysis measurement with other obtained data suggested an octahedral geometry for the iron(III complexes and tetrahedral geometry for the copper(II complexes. From the molar magnetic susceptibility measurement, the iron(III system (S = 5/2 d5 (non-degenerate 6A1 with χmT = 0.38 cm3 Kmol−1 showed an antiferromagnetic while Cu2+ ions system (S = ½ (2T2g has χmT = 4.77 cm3 Kmol−1 described as paramagnetic behaviour. In vitro antimicrobial investigations of the metal complexes against standard bacteria species gave significant inhibition with, copper complex showing highest inhibitions against Pseudomonas aeruginosa (ATCC27853 of 43 mm at 10 μg/ml signalling its potential as pharmaceutical or chemotherapeutic agents.

  13. Characterization of copper(II) complexes of N4, N4-disubstituted thiosemicarbazones of 2-acetylpyridine by combined evaluation of electronic and ESR parameters

    Science.gov (United States)

    Jain, Satendra K.; Garg, Bhagwan S.; Bhoon, Yudhvir K.

    Copper(II) complexes of 2-acetylpyridine 4,4-dimethyl-3-thiosemicarbazone (L'H) and 2-acetylpyridine 4-(4-methylpiperidinyl)-3-thiosemicarbazone (LH) of the general formula CuLX (where L is a deprotonated ligand and X = F -, Cl -, Br -, I -, OAc - and NO -3) have been synthesized and characterized by elemental analysis, magnetic susceptibility measurements between 93 and 298 K in the polycrystalline state, i.r. spectra, electronic spectra, conductivity measurements and ESR spectra recorded in the polycrystalline state, in chloroform and dimethylformamide solution at room temperature and at 77K. The molar conductivities measured in dimethylformamide for all complexes show them to be non-electrolytes. The terdentate character of the ligands in all the complexes is inferred from i.r. spectral studies. The i.r. spectra also confirm the monodentate nature of the polyatomic anions such as nitrate and acetate. The electronic spectra in Nujol mulls, chloroform or dimethylformamide solution suggest planar geometry for all of the complexes. The calculated ESR parameters show an axial dx2- y2 ground state and suggest coordination through sulphur in agreement with the i.r. results. Little change in the value of g with temperature indicates no significant change in planarity of these four coordinated species. ESR spectra in solution at room temperature and 77 K also suggest a strong covalent environment with strong in-plane sigma and pi bonds provided by the ligands.

  14. Synthesis, DNA interaction and anticancer activity of copper(II) complexes with 4'-phenyl-2,2':6',2″-terpyridine derivatives.

    Science.gov (United States)

    Liang, Jie-Wen; Wang, Yi; Du, Ke-Jie; Li, Guan-Ying; Guan, Rui-Lin; Ji, Liang-Nian; Chao, Hui

    2014-12-01

    Three novel copper(II) complexes CuL(1)Cl2 (1) (L(1)=4'-(3-methoxyphenyl)-2,2':6'- 2″-terpyridine), CuL(2)Cl2 (2) (L(2)=4'-(4-methoxyphenyl)-2,2':6'-2″-terpyridine) and CuL(3)Cl2 (3) (L(3)=4'-(3,5-dimethoxyphenyl)-2,2':6'-2″-terpyridine) have been synthesized and characterized. Absorption spectral titration experiments, ethidium bromide displacement assays, and cyclic voltammetric experiments were carried out and the results suggested that these complexes bound to DNA through an intercalative mode. Moreover, these complexes were found to cleave pBR322 DNA efficiently in the presence of glutathione (GSH), and exhibited good anticancer activity against HeLa, Hep-G2 and BEL-7402 cell lines. Nuclear chromatin cleavage was also observed by acridine orange/ethidium bromide (AO/EB) staining assays and comet assays. These results demonstrated that these three Cu(II) complexes caused DNA damage and induced the apoptosis of HeLa cells. Mechanistic investigations revealed the participation of reactive oxygen species which can be trapped by reactive oxygen species (ROS) radical scavengers and ROS sensors. Copyright © 2014 Elsevier Inc. All rights reserved.

  15. Synthesis, Spectroscopic, and Electrochemical Studies on Some New Copper(II Complexes Containing 2-{[(Z-Phenyl (Pyridine-2-yl Methylidene] Amino}Benzenethiol and Monodentate Ligands

    Directory of Open Access Journals (Sweden)

    S. P. Rawat

    2014-01-01

    Full Text Available Five new mononuclear copper(II complexes, namely, [Cu(L(ImH]·ClO41; [Cu(L(Me-ImH]·ClO42; [Cu(L(Et-ImH]·ClO43; [Cu(L(2-benz-ImH]·ClO44; [Cu(L(benz-ImH]·ClO45, where HL = 2-{[(Z-phenyl (pyridine-2-yl methylidene] amino} benzenethiol; ImH = Imidazole; Me-ImH = Methy-limidazole; Et-ImH = Ethyl-imidazole; 2-benz-ImH = 2-methyl-benzimidazole; benz-ImH = benz-imidazole, have been synthesized and characterized by various physicochemical and spectroscopic techniques. Magnetic moments, electronic spectra, and EPR spectra of the complexes suggested a square planar geometry around Cu(II ion. The synthesized HL ligand behaves as monobasic tridentate Schiff base bound with the metal ion in a tridentate manner, with N2S donor sites of the pyridine-N, azomethine-N, and benzenethiol-S atoms. The redox behaviour of the copper complexes has been studied by cyclic voltammetry. Superoxide dismutase activity of these complexes has been revealed to catalyse the dismutation of superoxide (O2- and IC50 values were evaluated and discussed.

  16. Synthesis, spectroscopy, magnetic and redox behaviors of copper(II) complexes with tert-butylated salen type ligands bearing bis(4-aminophenyl)ethane and bis(4-aminophenyl)amide backbones

    Science.gov (United States)

    Kasumov, Veli T.; Yerli, Yusuf; Kutluay, Aysegul; Aslanoglu, Mehmet

    2013-03-01

    New salen type ligands, N,N'-bis(X-3-tert-butylsalicylidene)-4,4'-ethylenedianiline [(X = H (1), 5-tert-butyl (2)] and N,N'-bis(X-3-tert-butylsalicylidene)-4,4'-amidedianiline [X = H (3), 5-tert (4)] and their copper(II) complexes 5-8, have been synthesized. Their spectroscopic (IR, 1H NMR, UV/vis, ESR) properties, as well as magnetic and redox-reactivity behavior are reported. IR spectra of 7 and 8 indicate the coordination of amide oxygen atoms of 3 and 4 ligands to Cu(II). The solid state ESR spectra of 5-8 exhibits less informative exchange narrowed isotropic or anisotropic signals with weak unresolved low field patterns. The magnetic moments of 5 (2.92 μB per CuII) and 6 (2.79 μB per CuII) are unusual for copper(II) complexes and considerably higher than those for complexes 7 and 8. Cryogenic measurements (300-10 K) show weak antiferromagnetic exchange interactions between the copper(II) centers in complexes 6 and 8. The results of electrochemical and chemical redox-reactivity studies are discussed.

  17. In vitro cytotoxic activities, DNA-, and BSA-binding studies of a new dinuclear copper(II) complex with N-[3-(dimethylamino)propyl]-N'-(2-carboxylatophenyl)-oxamide as ligand.

    Science.gov (United States)

    Jiao, Jing; Jiang, Man; Li, Yan-Tuan; Wu, Zhi-Yong; Yan, Cui-Wei

    2014-02-01

    A new dinuclear copper(II) complex bridged by N-[3-(dimethylamino)propyl]-N'- (2-carbo-xylatophenyl)oxamide (H3 dmapob), and endcapped with 2,2'-diamino-4,4'-bithiazole (dabt), namely [Cu₂(dmapob)(dabt)(CH₃OH)(pic)]·(DMF)₀.₇₅ ·(CH₃OH)₀.₂₅ has been synthesized and characterized by elemental analysis, molar conductivity measurement, infrared and electronic spectra studies, and single-crystal X-ray diffraction. In the crystal structure, both copper(II) ions have square-pyramidal coordination geometries. The Cu···Cu separation through the oxamido bridge is 5.176(9) Å. A two-dimensional supramolecular framework is formed through hydrogen bonds and π-π stacking interactions. The reactivities toward herring sperm DNA and bovine serum albumin (BSA) show that the complex can interact with the DNA via intercalation mode and bind to the BSA responsible for quenching of tryptophan fluorescence by the static quenching mechanism. The in vitro anticancer activities suggest that the copper(II) complex is active against the selected tumor cell lines. The influence of different bridging ligands in dinuclear complexes on the DNA- and BSA-binding properties as well as anticancer activities is preliminarily discussed. © 2013 Wiley Periodicals, Inc.

  18. Crystallographic Characterization of Stepwise Changes in Ligand Conformations as Their Internal Topology Changes and Two Novel Cross-Bridged Tetraazamacrocyclic Copper(II) Complexes.

    Science.gov (United States)

    Hubin, Timothy J.; McCormick, James M.; Alcock, Nathaniel W.; Clase, Howard J.; Busch, Daryle H.

    1999-10-04

    The parallel syntheses of two new cross-bridged tetraazamacrocyclic complexes whose ligands are derived from 1,4,8,11-tetraazacyclotetradecane (cyclam = 14N4) and rac-1,4,8,11-tetraaza-5,5,7,12,12,14-hexamethylcyclotetradecane (tetB = 14N4Me(6)) have been characterized through the crystal structure determination of every stepwise intermediate ligand in the multistep ligand syntheses. These structures show that although the final ligand skeletons are nearly identical, the immediate precursors differ greatly because of the six additional methyl groups of the 14N4Me(6) macrocycle. The inversion from one diastereomer to another of the tetracycle derived from rac-14N4Me(6) has been chemically induced through the successive addition of methyl groups to the reactive tertiary nitrogens, and the novel heterocycles produced have been crystallographically characterized with one showing a conformation not previously known for these systems. The structures of the two copper(II) complexes have significant geometrical differences, and accordingly, their electrochemical and spectroscopic properties are compared. The complexes exhibit remarkable kinetic stability under harsh conditions.

  19. Biologically active Schiff bases containing thiophene/furan ring and their copper(II) complexes: Synthesis, spectral, nonlinear optical and density functional studies

    Science.gov (United States)

    Gündüzalp, Ayla Balaban; Özsen, İffet; Alyar, Hamit; Alyar, Saliha; Özbek, Neslihan

    2016-09-01

    Schiff bases; 1,8-bis(thiophene-2-carboxaldimine)-p-menthane (L1) and 1,8-bis(furan-2-carboxaldimine)-p-menthane (L2) have been synthesized and characterized by elemental analysis, 1Hsbnd 13C NMR, UV-vis, FT-IR and LC-MS methods. 1H and 13C shielding tensors for L1 and L2 were calculated with GIAO/DFT/B3LYP/6-311++G(d,p) methods in CDCl3. The vibrational band assignments, nonlinear optical (NLO) activities, frontier molecular orbitals (FMOs) and absorption spectrum have been investigated by the same basis set. Schiff base-copper(II) complexes have been synthesized and structurally characterized with spectroscopic methods, magnetic and conductivity measurements. The spectroscopic data suggest that Schiff base ligands coordinate through azomethine-N and thiophene-S/furan-O donors (as SNNS and ONNO chelating systems) to give a tetragonal geometry around the copper(II) ions. Schiff bases and Cu(II) complexes have been screened for their biological activities on different species of pathogenic bacteria, those are, Gram positive bacteria: Bacillus subtitilus, Yersinia enterotica, Bacillus cereus, Listeria monocytogenes, Micrococcus luteus and Gram negative bacteria: Escherichia coli, Pseudomonas aeroginosa, Shigella dysenteriae, Salmonella typhi, Klebsiella pseudomonas by using microdilution technique (MIC values in mM). Biological activity results show that Cu(II) complexes have higher activities than parent ligands and metal chelation may affect significantly the antibacterial behavior of the organic ligands.

  20. Synthesis, characterization and antifungal activity of a series of manganese(II) and copper(II) complexes with ligands derived from reduced N,N'-O-phenylenebis(salicylideneimine).

    Science.gov (United States)

    Belaid, Sabrina; Landreau, Anne; Djebbar, Safia; Benali-Baitich, Ouassini; Bouet, Gilles; Bouchara, Jean-Philippe

    2008-01-01

    A series of manganese(II) and copper(II) complexes with reduced Schiff bases derived from o-phenylenediamine has been prepared and characterized by elemental analysis, TG measurements, ESR, magnetic measurements, FTIR, UV-Visible spectra and conductivity. These complexes were found to be [MnL(H2O)n] and [CuL](H2O)n species with n=0-2. Their antifungal activity was evaluated on different human fungi including yeasts of the Candida genus (C. albicans, C. glabrata, C. tropicalis and C. parapsilopsis) some opportunistic moulds belonging to the Aspergillus (A. fumigatus, A. terreus and A. flavus), Scedosporium genus (S. apiospermum and S. prolificans) and some dermatophytes (M. gypseum, M. persicolor, T. mentagrophytes, M. canis and T. tonsurans). The manganese complexes showed a significant growth inhibition of the dermatophytes tested and fungi of the genus Scedosporium. This is very interesting as these fungi are usually poorly susceptible to current antifungal including Amphotericin B and Itraconazole chosen as reference in this study.

  1. Binary and ternary new water soluble copper(II) complexes of L-tyrosine and substituted 1,10-phenanthrolines: Effect of substitution on DNA interactions and cytotoxicities

    Science.gov (United States)

    İnci, Duygu; Aydın, Rahmiye; Vatan, Özgür; Yılmaz, Dilek; Gençkal, Hasene Mutlu; Zorlu, Yunus; Cavaş, Tolga

    2015-06-01

    Binary and ternary water soluble copper(II) complexes - [Cu(nphen)2(H2O)](NO3)2·H2O (1), [Cu(phen)2(H2O)](NO3)2 (2), [Cu(nphen)(L-tyr)(H2O)]NO3·2H2O (3), [Cu(phen)(tyr)(H2O)] NO3·2H2O (4) - and diquarternary salts of nphen and phen (nphen = 5-nitro-1,10-phenanthroline, phen = 1,10-phenanthroline and tyr = L-tyrosine) have been synthesized and characterized by CHN analysis, 1H NMR, 13C NMR and IR spectroscopy, thermal analysis and single crystal X-ray diffraction techniques. The CT-DNA binding properties of these compounds have been investigated by thermal denaturation measurements, absorption and emission spectroscopy. The supercoiled pUC19 plasmid DNA cleavage activity of these compounds has been explored by agarose gel electrophoresis. The cytotoxicity of these compounds against MCF-7, Caco-2, A549 cancer cells and BEAS-2B healthy cells was also studied by using XTT method. The complexes 1-4 exhibit significant high cytotoxicity with low IC50 values in compared with cisplatin. The effect of the substituents of phen and coordinated amino acid in the above complexes are presented and discussed.

  2. Synthesis, characterization, cellular uptake and interaction with native DNA of a bis(pyridyl)-1,2,4-oxadiazole copper(II) complex.

    Science.gov (United States)

    Terenzi, Alessio; Barone, Giampaolo; Piccionello, Antonio Palumbo; Giorgi, Gianluca; Guarcello, Annalisa; Portanova, Patrizia; Calvaruso, Giuseppe; Buscemi, Silvestre; Vivona, Nicolò; Pace, Andrea

    2010-10-14

    The copper(II) complex of 3,5-bis(2'-pyridyl)-1,2,4-oxadiazole was synthesized and characterized. X-Ray crystallography revealed that the complex consists of a discrete [Cu(3,5-bis(2'-pyridyl)-1,2,4-oxadiazole)(2)(H(2)O)(2)](2+) cation and two ClO(4)(-) anions. The Cu(II) coordination sphere has a distorted octahedral geometry and each ligand chelates the copper ion through the N(4) nitrogen of the oxadiazole ring and the nitrogen of one pyridine moiety. The coordinated water molecules are in cis position and each of them is H-bonded to the 5-pyridyl nitrogen of the oxadiazole ligand and to an oxygen of the perchlorate anion. Biological assays showed that, despite the free ligand not being effective, [Cu(3,5-bis(2'-pyridyl)-1,2,4-oxadiazole)(2)(H(2)O)(2)](2+) reduced the vitality of human hepatoblastoma HepG2 and colorectal carcinoma HT29 cells in a dose- and time-dependent manner. The interaction of the cationic copper complex with native DNA was investigated by variable-temperature UV-vis spectroscopy, circular dichroism, viscosity and gel electrophoresis, indicating that it is a groove binder with binding constant K(b) = 2.2 × 10(4) M(-1).

  3. Phosphate diester hydrolysis and DNA damage promoted by new cis-aqua/hydroxy copper(II) complexes containing tridentate imidazole-rich ligands.

    Science.gov (United States)

    Scarpellini, Marciela; Neves, Ademir; Hörner, Rosmari; Bortoluzzi, Adailton J; Szpoganics, Bruno; Zucco, César; Nome Silva, René A; Drago, Valderes; Mangrich, Antônio S; Ortiz, Wilson A; Passos, Wagner A C; de Oliveira, Maurício C B; Terenzi, Hernán

    2003-12-15

    The tridentate Schiff base [(2-(imidazol-4-yl)ethyl)(1-methylimidazol-2-yl)methyl)imine (HISMIMI) and its reduced form HISMIMA were synthesized and characterized, as well their mononuclear cis-dihalo copper(II) complexes 1 and 2, respectively. In addition, the dinuclear [CuII(mu-OH)2CuII](2+) complexes (3) and (4) obtained from complexes 1 and 2, respectively, were also isolated and characterized by several physicochemical techniques, including magnetochemistry, electrochemistry, and EPR and UV-vis spectroscopies. The crystal structures of 1 and 2 were determined by X-ray crystallography and revealed two neutral complexes with their tridentate chelate ligands meridionally coordinated. Completing the coordination spheres of the square-pyramidal structures, a chloride ion occupies the apical position and another is bonded in the basal plane. In addition, complexes 1 and 2 were investigated by infrared, electronic, and EPR spectroscopies, cyclic voltammetry, and potentiometric equilibrium studies. The hydrolytic activity on phosphate diester cleavage of 1 and 2 was investigated utilizing 2,4-BDNPP as substrate. These experiments were carried out at 50 degrees C, and the data treatment was based on the Michaelis-Menten approach, giving the following kinetic parameters (complex 1/complex 2): vmax (mol L(-1) s(-1))=16.4x10(-9)/7.02x10(-9); KM (mol L(-1))=17.3x10(-3)/3.03x10(-3); kcat (s(-1))=3.28x10(-4)/1.40x10(-4). Complex 1 effectively promoted the hydrolytic cleavage of double-strand plasmid DNA under anaerobic and aerobic conditions, with a rate constant of 0.28 h(-1) for the decrease of form I, which represents about a 10(7) rate increase compared with the estimated uncatalyzed rate of hydrolysis.

  4. New cyclic tetranuclear copper(II) complexes containing quadrilateral cores: Synthesis, structure, spectroscopy and their interactions with DNA in aqueous solution

    Science.gov (United States)

    Giri, Gopal C.; Haldar, Shobhraj; Ghosh, Aloke Kumar; Chowdhury, Priyanka; Carrella, Luca; Ghosh, Utpal; Bera, Manindranath

    2017-08-01

    Three new cyclic tetranuclear copper(II) complexes, Tetrakis{3-[(2-pyridylmethyl)-amino]-propionato}(tetrachloro)tetracopper(II)methanolhydrate (1·CH3OH·H2O), Tetrakis{3-[(2-pyridylmethyl)-amino]-propionato}(tetrathiocyanato)tetracopper(II) (2) and Tetrakis{3-[(2-pyridylmethyl)-amino]-propionato}(tetraazido)tetracopper(II) (3) have been synthesized by exploiting the chelating ability and bridging potential of a carboxyamine functionalized tridentate ligand, HL (HL = 3-[(2-Pyridylmethyl)-amino]-propionic acid). Complexes 1, 2 and 3 have been synthesized by carrying out reaction of the ligand HL with stoichiometric amounts of CuCl2·2H2O, CuCl2·2H2O/NH4SCN, and CuCl2·2H2O/NaN3, respectively, in the presence of NMe4OH at ambient temperature. Various analytical techniques have been employed to characterize the complexes, including single crystal X-ray diffraction study of 1. Structures of complexes 2 and 3 have been optimized by DFT calculation at B3LYP/6-311G level. Analysis of X-ray crystal structure reveals that the metallic core of complex 1 contains four distorted square pyramidal Cu(II) ions. The Cu(II) ions in each complex are arranged at the corners of a quadrilateral showing a μ2:η1:η1syn-anti bidentate bridging mode of four carboxylate groups of L- ligands with each bridging between two Cu(II) ions. These complexes represent a new family of 16-MCCuII-4 metallocoronates with repeating -[CuIIsbnd Osbnd Csbnd O]- units. In aqueous solution (pH∼7.5), the interactions of complexes with DNA have been investigated by UV-Vis and fluorescence titration spectroscopy, and viscosity measurements.

  5. Synthesis, CMC Determination, Antimicrobial Activity and Nucleic Acid Binding of A Surfactant Copper(II) Complex Containing Phenanthroline and Alanine Schiff-Base.

    Science.gov (United States)

    Nagaraj, Karuppiah; Sakthinathan, Subramanian; Arunachalam, Sankaralingam

    2014-03-01

    A new water-soluble surfactant copper(II) complex [Cu(sal-ala)(phen)(DA)] (sal-ala = salicylalanine, phen = 1,10-phenanthroline, DA = dodecylamine), has been synthesized and characterized by physico-chemical and spectroscopic methods. The critical micelle concentration (CMC) values of this surfactant-copper(II) complex in aqueous solution were obtained from conductance measurements. Specific conductivity data (at 303, 308, 313. 318 and 323 K) served for the evaluation of the temperature-dependent CMC and the thermodynamics of micellization (ΔG(0)m, ΔH(0)m and ΔS(0)m). The interaction of this complex with nucleic acids (DNA and RNA) has been explored by using electronic absorption spectral titration, competitive binding experiment, cyclic voltammetry, circular dichroism (CD) spectra, and viscosity measurements. Electronic absorption studies have revealed that the complex can bind to nucleic acids by the intercalative binding mode which has been verified by viscosity measurements. The DNA binding constants have also been calculated (Kb = 1.2 × 10(5) M(-1) for DNA and Kb = 1.6 × 10(5) M(-1) for RNA). Competitive binding study with ethidium bromide (EB) showed that the complex exhibits the ability to displace the DNA-bound-EB indicating that the complex binds to DNA in strong competition with EB for the intercalative binding site. The presence of hydrophobic ligands, alanine Schiff-base, phenanthroline and long aliphatic chain amine in the complex were responsible for this strong intercalative binding. The surfactant-copper (II) complex was screened for its antibacterial and antifungal activities against various microorganisms. The results were compared with the standard drugs, amikacin(antibacterial) and ketokonazole(antifungal).

  6. Copper(II) complexes with new polypodal ligands presenting axial-equatorial phenoxo bridges {2-[(bis(2-pyridylmethyl)amino)methyl]-4-methylphenol, 2-[(bis(2-pyridylmethyl)amino)methyl]-4-methyl-6-(methylthio)phenol}: examples of ferromagnetically coupled bi- and trinuclear copper(II) complexes.

    Science.gov (United States)

    Manzur, Jorge; Mora, Hector; Vega, Andrés; Spodine, Evgenia; Venegas-Yazigi, Diego; Garland, María Teresa; El Fallah, M Salah; Escuer, Albert

    2007-08-20

    Two new ligands, 2-[(bis(2-pyridylmethyl)amino)methyl]-4-methylphenol (HL) and 2-[(bis(2-pyridylmethyl)amino)methyl]-4-methyl-6-(methylthio)phenol (HSL), were synthesized and were used to prepare the trinuclear copper(II) complex {[CuSL(Cl)]2Cu}(PF6)2.H2O (1) and the corresponding binuclear complexes [Cu2(SL)2](PF6)2 (2) and [Cu2L2](PF6)2 (3). The crystal structure of 1 shows two different coordination environments: two square base pyramidal centers (Cu1 and Cu1a, related by a C2 axes), acting as ligands of a distorted square planar copper center (Cu2) by means of the sulfur atom of the SCH3 substituent and the bridging phenoxo oxygen atom of the ligand (Cu2-S = 2.294 A). Compounds 2 and 3 show two equivalent distorted square base pyramidal copper(II) centers, bridged in an axial-equatorial fashion by two phenoxo groups, thus defining an asymmetric Cu2O2 core. A long copper-sulfur distance measured in 2 (2.9261(18) A) suggests a weak bonding interaction. This interaction induces a torsion angle between the methylthio group and the phenoxo plane resulting in a dihedral angle of 41.4(5) degrees. A still larger distortion is observed in 1 with a dihedral angle of 74.0(6) degrees. DFT calculations for 1 gave a ferromagnetic exchange between first neighbors interaction, the calculated J value for this interaction being +11.7 cm-1. In addition, an antiferromagnetic exchange for 1 was obtained for the second neighbor interaction with a J value of -0.05 cm-1. The Bleaney-Bowers equation was used to fit the experimental magnetic susceptibility data for 2 and 3; the best fit was obtained with J values of +3.4 and -16.7 cm-1, respectively. DFT calculations for 2 and 3 confirm the nature and the values of the J constants obtained by the fit of the experimental data. ESR and magnetic studies on the reported compounds show a weak exchange interaction between the copper(II) centers. The low values obtained for the coupling constants can be explained in terms of a poor overlap

  7. Transition metal complexes with thiosemicarbazide-based ligands. Part 60. Reactions of copper(II) bromide with pyridoxal S-methylisothiosemicarbazone (PLITSC). Crystal structure of [Cu(PLITSC−H)H2O]Br•H2O

    OpenAIRE

    Leovac Vukadin M.; Vojinović-Ješić Ljiljana S.; Ivković Sonja A.; Rodić Marko V.; Jovanović Ljiljana S.; Holló Berta; Mészáros-Szécsényi Katalin

    2014-01-01

    The synthesis and structural characterization of a square-planar copper(II) complex with pyridoxal S-methylisothiosemicarbazone (PLITSC) of the formula [Cu(PLITSC−H)H2O]Br•H2O (1) as the first Cu(II) complex with monoanionic form of this ligand were described. Complex 1 together with two previously synthesized complexes [Cu(PLITSC)Br2] (2) and [Cu(PLITSC)Br(MeOH)]Br (3) were characterized by elemental analysis, IR and electronic spectra and also by the meth...

  8. Transition metal complexes with thiosemicarbazide-based ligands. Part 60. Reactions of copper(II bromide with pyridoxal S-methylisothiosemicarbazone (PLITSC. Crystal structure of [Cu(PLITSC−HH2O]Br•H2O

    Directory of Open Access Journals (Sweden)

    Leovac Vukadin M.

    2014-01-01

    Full Text Available The synthesis and structural characterization of a square-planar copper(II complex with pyridoxal S-methylisothiosemicarbazone (PLITSC of the formula [Cu(PLITSC−HH2O]Br•H2O (1 as the first Cu(II complex with monoanionic form of this ligand were described. Complex 1 together with two previously synthesized complexes [Cu(PLITSCBr2] (2 and [Cu(PLITSCBr(MeOH]Br (3 were characterized by elemental analysis, IR and electronic spectra and also by the methods of thermal analysis, conductometry and magnetochemistry. [Projekat Pokrajisnkog sekretarijata za nauku i tehnoloski razvoj Vojvodine i Ministarstva nauke Republike Srbije, br. 172014

  9. Host-lattice effects on the electron spin resonance spectra of copper(II) complexes in diluted and undiluted forms

    Science.gov (United States)

    Massacessi, M.; Ponticelli, G.; Ramachary, C.; Krishnan, V. G.

    1980-05-01

    ESR spectra of the Cu 2+ ion, doped in a di-[(2-aminoethyl)amine)]-di-isothiocyanato-cadmate(II) lattice in its single-crystal form, have been investigated. Cd(den) (SCN) 2 has unusual coordination, in that two separate CdN 6 and CdN 4S 2 entities are present in the unit cell. Cu 2+ substitutes predominantly for the CdN 6 structural unit, and spectra recorded at both ambient and liquid-nitrogen temperatures are fitted to a spin-Hamiltonian of orthorhombic symmetry. In contrast, the weak spectral lines corresponding to the Cu 2+ ions which substitute for the CdN 4S 2 structural unit are characteristic of axial symmetry. A single-crystal study was also made on di-[(2-aminoethyl)amine]-di-isothiocyanato- copper(II), in which the Cu 2+ ion has a coordination number of five and "C 2v" point symmetry. A comparison of the spectral features shown in the two lattices was made and some interesting conclusions are drawn.

  10. An X-ray photoelectron spectroscopy and quantum chemical study of copper(II) β-diketonates and Cu(HFA){sub 2} complexes with imidazoline ligands

    Energy Technology Data Exchange (ETDEWEB)

    Kryuchkova, Natalya A., E-mail: knatali@ngs.ru [Nikolaev Institute of Inorganic Chemistry, Siberian Branch, Russian Academy of Sciences, Lavrentyev Av., 3, RU-630090 Novosibirsk (Russian Federation); Novosibirsk State University, Pirogova Street, 2, RU-630090 Novosibirsk (Russian Federation); Stabnikov, Pavel A. [Nikolaev Institute of Inorganic Chemistry, Siberian Branch, Russian Academy of Sciences, Lavrentyev Av., 3, RU-630090 Novosibirsk (Russian Federation); Kalinkin, Alexander V. [Boreskov Institute of Catalysis, Siberian Branch, Russian Academy of Sciences, Lavrentyev Av., 5, RU-630090 Novosibirsk (Russian Federation); Fursova, Elena Yu. [International Tomography Center, Siberian Branch, Russian Academy of Sciences, Institutskaya Street, 3a, RU-630090 Novosibirsk (Russian Federation)

    2016-10-15

    Highlights: • The charge and spin states of Cu(II) β-diketonates and Cu(hfa){sub 2}(imidazoline) are investigated by the XPS and DFT calculations. • The |2p{sup 5}3d{sup 9}> and | 2p{sup 5}3d{sup 10}L> electronic states are asigned to X-ray photoelectron spectra of copper. - Abstract: An X-ray photoelectron spectroscopy study of the charge and spin state of copper(II) β-diketonates and Cu(hfa){sub 2} (hfa–hexafluoroacetylacetonate) complexes with imidazoline ligands is performed with comparison to the data of quantum chemical calculations. It is shown that the structure of the spectra of copper is described by a superposition of the |2p{sup 5}3d{sup 9}> and | 2p{sup 5}3d{sup 10}L> electronic states determined by electron transfer processes between copper and L ligand atoms. It is found that during the coordination of imidazoline ligands to the Cu(hfa){sub 2} complex the spin density is redistributed through the chain of chemical bonds from the ligand nitroxyl group to the copper atom.

  11. Influence of inductive effects and steric encumbrance on the catecholase activities of copper(II) complexes of reduced Schiff base ligands.

    Science.gov (United States)

    Thio, Yude; Yang, Xiandong; Vittal, Jagadese J

    2014-03-07

    A series of copper(ii) complexes derived from reduced Schiff base ligands has been synthesized and characterized by single-crystal X-ray diffraction and spectroscopic analyses. With the exception of [Cu(Ala5NO2)(H2O)] (), which crystallized as a mononuclear repeating unit, [Cu2L2(H2O)x(DMSO)y]·solvent (L = Ala5H (), Ala5OMe (), Ala5Cl (), Ala5Br (), Gly5Br (), Val5Br () and Leu5Br (), x = 1 or 2, y = 0 or 1, solvent = MeOH or DMSO and H2O) crystallized as phenoxo-bridged dinuclear building units containing Cu2O2 cores. In , , , and , the axial positions are occupied by solvent ligands and carboxylate oxygen atoms from adjacent dimers, resulting in the formation of 1D helical coordination polymers. In , a 2D network is constructed by utilizing weak CuO interactions (∼2.7 Å) with carboxylate groups. All complexes have been investigated for their catecholase activities with 3,5-DTBC, and they show significant catalytic activities except for . The catalytic activities are also observed to increase with increasing +I effects, as well as increase with increasing steric bulkiness on the α-carbon of the carboxylate group.

  12. Synthesis, DNA binding, cellular DNA lesion and cytotoxicity of a series of new benzimidazole-based Schiff base copper(II) complexes.

    Science.gov (United States)

    Paul, Anup; Anbu, Sellamuthu; Sharma, Gunjan; Kuznetsov, Maxim L; Koch, Biplob; Guedes da Silva, M Fátima C; Pombeiro, Armando J L

    2015-12-14

    A series of new benzimidazole containing compounds 2-((1-R-1-H-benzimidazol-2-yl)phenyl-imino)naphthol HL(1-3) (R = methyl, ethyl or propyl, respectively) have been synthesized by Schiff base condensation of 2-(1-R-1-H-benzo[d]imidazol-2-yl)aniline and 2-hydroxy-1-naphthaldehyde. The reactions of HL(1-3) with Cu(NO3)2·2.5H2O led to the corresponding copper(II) complexes [Cu(L)(NO3)] 1-3. All the compounds were characterized by conventional analytical techniques and, for 1 and 3, also by single-crystal X-ray analysis. The interactions of complexes 1-3 with calf thymus DNA were studied by absorption and fluorescence spectroscopic techniques and the calculated binding constants (K(b)) are in the range of 3.5 × 10(5) M(-1)-3.2 × 10(5) M(-1). Complexes 1-3 effectively bind DNA through an intercalative mode, as proved by molecular docking studies. The binding affinity of the complexes decreases with the size increase of the N-alkyl substituent, in the order of 1 > 2 > 3, which is also in accord with the calculated LUMO(complex) energies. They show substantial in vitro cytotoxic effect against human lung (A-549), breast (MDA-MB-231) and cervical (HeLa) cancer cell lines. Complex 1 exhibits a significant inhibitory effect on the proliferation of the A-549 cancer cells. The antiproliferative efficacy of 1 has also been analysed by a DNA fragmentation assay, fluorescence activated cell sorting (FACS) and nuclear morphology using a fluorescence microscope. The possible mode for the apoptosis pathway of 1 has also been evaluated by a reactive oxygen species (ROS) generation study.

  13. Halo-substituted thiosemicarbazones and their copper(II), nickel(II) complexes: Detailed spectroscopic characterization and study of antitumour activity against HepG2 human hepatoblastoma cells

    Science.gov (United States)

    Jagadeesh, M.; Kalangi, Suresh K.; Sivarama Krishna, L.; Reddy, A. Varada

    2014-01-01

    Copper(II) and nickel(II) complexes of two different halogen substituted thiosemicarbazone ligands were synthesized. The ligands 3,4-difluoroacetophenone thiosemicarbazone (1) and 2-bromo-4'-chloroacetophenone thiosemicarbazone (2) were characterized and confirmed spectroscopically by FT-IR, FT-Raman, UV-vis and fluorescence spectral analysis, while the respective copper(II) complexes [Cu(C9H9N3F2S)2Cl2] (1a), [Cu(C9H9N3ClBrS)2Cl2] (2a) and nickel(II) complexes [Ni(C9H9N3F2S)2] (1b), [Ni(C9H9N3ClBrS)2] (2b) were characterized by FT-IR, UV-vis and electron paramagnetic spectroscopy (EPR). The EPR spectra of the Cu(II) complexes provided the rhombic octahedral and axial symmetry of the complexes 1a and 2a respectively. For the complex 1a, the g values calculated as g1 = 2.1228, g2 = 2.0706 and g3 = 2.001 between 2900 and 3300 G. While for the complex 2a, a set of two resonance absorptions were observed. The synthesized compounds were tested for antitumor activity and showed that the ability to kill liver cancer cells significantly. Out of all the synthesized compounds, copper(II) complexes 1a and 2a showed high cytotoxic effect on liver cancer cells with 67.51% and 42.77% of cytotoxicity respectively at 100 μM.

  14. Synthesis, structure, and DNA cleavage properties of copper(II) complexes of 1,4,7-triazacyclononane ligands featuring pairs of guanidine pendants.

    Science.gov (United States)

    Tjioe, Linda; Joshi, Tanmaya; Brugger, Joël; Graham, Bim; Spiccia, Leone

    2011-01-17

    Two new ligands, L(1) and L(2), have been prepared via N-functionalization of 1,4,7-triazacyclononane (tacn) with pairs of ethyl- or propyl-guanidine pendants, respectively. The X-ray crystal structure of [CuL(1)](ClO4)2 (C1) isolated from basic solution (pH 9) indicates that a secondary amine nitrogen from each guanidine pendants coordinates to the copper(II) center in addition to the nitrogen atoms in the tacn macrocycle, resulting in a five-coordinate complex with intermediate square-pyramidal/trigonal bipyramidal geometry. The guanidines adopt an unusual coordination mode in that their amine nitrogen nearest to the tacn macrocycle binds to the copper(II) center, forming very stable five-membered chelate rings. A spectrophotometric pH titration established the pK(app) for the deprotonation and coordination of each guanidine group to be 3.98 and 5.72, and revealed that [CuL(1)](2+) is the only detectable species present in solution above pH ∼ 8. The solution speciation of the CuL(2) complex (C2) is more complex, with at least 5 deprotonation steps over the pH range 4-12.5, and mononuclear and binuclear complexes coexisting. Analysis of the spectrophotometric data provided apparent deprotonation constants, and suggests that solutions at pH ∼ 7.5 contain the maximum proportion of polynuclear complexes. Complex C1 exhibits virtually no cleavage activity toward the model phosphate diesters, bis(p-nitrophenyl)phosphate (BNPP) and 2-hydroxypropyl-p-nitrophenyl phosphate (HPNPP), while C2 exhibits moderate activity. For C2, the respective kobs values measured at pH 7.0 (7.24 (± 0.08) × 10(-5) s(-1) (BNPP at 50 °C) and 3.2 (± 0.3) × 10(-5) s(-1) (HPNPP at 25 °C)) are 40- and 10-times faster than [Cu(tacn)(OH2)2](2+) complex. Both complexes cleave supercoiled pBR 322 plasmid DNA, indicating that the guanidine pendants of [CuL(1)](2+) may have been displaced from the copper coordination sphere to allow for DNA binding and subsequent cleavage. The rate of DNA

  15. New binary copper(II) complexes containing intercalating ligands: DNA interactions, an unusual static quenching mechanism of BSA and cytotoxic activities.

    Science.gov (United States)

    İnci, Duygu; Aydın, Rahmiye; Vatan, Özgür; Zorlu, Yunus; Çinkılıç, Nilüfer

    2017-11-24

    New binary copper(II) complexes - [Cu(4-mphen)2(NO3)]NO3·H2O (1), [Cu(5-mphen)2 (NO3)]NO3·H2O (2), the known complex [Cu(dmphen)2(NO3)]NO3 (3) and [Cu(tmphen)2 (NO3)]NO3·H2O (4) - (4-mphen: 4-methyl-1,10-phenanthroline, 5-mphen: 5-methyl-1,10-phenanthroline, dmphen: 4,7-dimethyl-1,10-phenanthroline, tmphen: 3,4,7,8-tetramethyl-1,10-phenanthroline), have been synthesized and characterized by CHN analysis, ESI-MS, FTIR and single-crystal X-ray diffraction techniques. Interaction of these complexes with calf thymus DNA (CT-DNA) has been investigated by absorption spectral titration, ethidium bromide (EB) and Hoechst 33,258 displacement assay and thermal denaturation measurement. These complexes cleaved pUC19 plasmid DNA in the absence and presence of an external agent. Notably, in the presence of H2O2 as an activator, the cleavage abilities of these complexes are obviously enhanced at low concentration. Addition of hydroxyl radical scavengers like DMSO shows significant inhibition of the DNA cleavage activity of these complexes. BSA quenching mechanism was investigated with regard to the type of quenching, binding constant, number of binding locations and the thermodynamic parameters. The experimental results suggested that the probable quenching mechanism was an unusual static process and hydrophobic forces play a dominant role. The CT-DNA and BSA binding efficiencies of these complexes follow the order: 4 > 3 > 1 > 2. Furthermore, in vitro cytotoxicities of these complexes on tumor cells lines (Caco-2, MCF-7 and A549) and healthy cell line (BEAS-2B) showed that these complexes exhibited anticancer activity with low IC50 values. The effect of hydrophobicity of the methyl-substituted phenanthrolines on DNA and protein binding activities of these complexes is discussed.

  16. Synthesis, Characterization, Crystal Structure and Antimicrobial Activity of Copper(II Complexes with the Schiff Base Derived from 2-Hydroxy-4-Methoxybenzaldehyde

    Directory of Open Access Journals (Sweden)

    Elena Pahonțu

    2015-04-01

    Full Text Available A novel Schiff base, ethyl 4-[(E-(2-hydroxy-4-methoxyphenylmethylene-amino]benzoate (HL, was prepared and structurally characterized on the basis of elemental analyses, 1H NMR, 13C NMR, UV-Vis and IR spectral data. Six new copper(II complexes, [Cu(L(NO3(H2O2] (1, [Cu(L2] (2, [Cu(L(OAc] (3, [Cu2 (L2Cl2(H2O4] (4, [Cu(L(ClO4(H2O] (5 and [Cu2(L2S(ClO4(H2O]ClO4·H2O (6 have been synthesized. The characterization of the newly formed compounds was done by IR, UV-Vis, EPR, FAB mass spectroscopy, elemental and thermal analysis, magnetic susceptibility measurements and molar electric conductivity. The crystal structures of Schiff base and the complex [Cu2(L2S(ClO4(H2O]ClO4·H2O (6 have been determined by single crystal X-ray diffraction studies. Both copper atoms display a distorted octahedral coordination type [O4NS]. This coordination is ensured by three phenol oxygen, two of which being related to the µ-oxo-bridge, the nitrogen atoms of the azomethine group and the sulfur atoms that come from the polydentate ligand. The in vitro antimicrobial activity against Escherichia coli ATCC 25922, Salmonella enteritidis, Staphylococcus aureus ATCC 25923, Enterococcus and Candida albicans strains was studied and compared with that of free ligand. The complexes 1, 2, 5 showed a better antimicrobial activity than the Schiff base against the tested microorganisms.

  17. Electrocatalytic Water Oxidation by a Water-Soluble Copper(II) Complex with a Copper-Bound Carbonate Group Acting as a Potential Proton Shuttle.

    Science.gov (United States)

    Chen, Fangfang; Wang, Ni; Lei, Haitao; Guo, Dingyi; Liu, Hongfei; Zhang, Zongyao; Zhang, Wei; Lai, Wenzhen; Cao, Rui

    2017-11-06

    Water-soluble copper(II) complexes of the dianionic tridentate pincer ligand N,N'-2,6-dimethylphenyl-2,6-pyridinedicarboxamidate (L) are catalysts for water oxidation. In [L-Cu II -DMF] (1, DMF = dimethylformamide) and [L-Cu II -OAc] - (2, OAc = acetate), ligand L binds Cu II through three N atoms, which define an equatorial plane. The fourth coordination site of the equatorial plane is occupied by DMF in 1 and by OAc - in 2. These two complexes can electrocatalyze water oxidation to evolve O 2 in 0.1 M pH 10 carbonate buffer. Spectroscopic, titration, and crystallographic studies show that both 1 and 2 undergo ligand exchange when they are dissolved in carbonate buffer to give [L-Cu II -CO 3 H] - (3). Complex 3 has a similar structure as those of 1 and 2 except for having a carbonate group at the fourth equatorial position. A catalytic cycle for water oxidation by 3 is proposed based on experimental and theoretical results. The two-electron oxidized form of 3 is the catalytically active species for water oxidation. Importantly, for these two oxidation events, the calculated potential values of E p,a = 1.01 and 1.59 V vs normal hydrogen electrode (NHE) agree well with the experimental values of E p,a = 0.93 and 1.51 V vs NHE in pH 10 carbonate buffer. The potential difference between the two oxidation events is 0.58 V for both experimental and calculated results. With computational evidence, this Cu-bound carbonate group may act as a proton shuttle to remove protons for water activation, a key role resembling intramolecular bases as reported previously.

  18. Formation constants of copper(II) complexes with tripeptides containing Glu, Gly, and His: potentiometric measurements and modeling by generalized multiplicative analysis of variance.

    Science.gov (United States)

    Khoury, Rima Raffoul; Sutton, Gordon J; Ebrahimi, Diako; Hibbert, D Brynn

    2014-02-03

    We report a systematic study of the effects of types and positions of amino acid residues of tripeptides on the formation constants logβ, acid dissociation constants pKa, and the copper coordination modes of the copper(II) complexes with 27 tripeptides formed from the amino acids glutamic acid, glycine, and histidine. logβ values were calculated from pH titrations with l mmol L(-1):1 mmol L(-1) solutions of the metal and ligand and previously reported ligand pKa values. Generalized multiplicative analysis of variance (GEMANOVA) was used to model the logβ values of the saturated, most protonated, monoprotonated, logβ(CuL) - logβ(HL), and pKa of the amide group. The resulting model of the saturated copper species has a two-term model describing an interaction between the central and the C-terminal residues plus a smaller, main effect of the N-terminal residue. The model supports the conclusion that two copper coordination modes exist depending on the absence or presence of His at the central position, giving species in which copper is coordinated via two or three fused chelate rings, respectively. The GEMANOVA model for pKamide, which is the same as that for the saturated complex, showed that Gly-Gly-His has the lowest pKamide values among the 27 tripeptides. Visible spectroscopy indicated the formation of metal-ligand dimers for tripeptides His-His-Gly and His-His-Glu, but not for His-His-His, and the formation of multiple ligand bis compexes CuL2 and Cu(HL)2 for tripeptides (Glu/Gly)-His-(Glu/Gly) and His-(Glu/Gly)-(Glu/Gly), respectively.

  19. Synthesis, characterization, biological activity, DNA and BSA binding study: novel copper(ii) complexes with 2-hydroxy-4-aryl-4-oxo-2-butenoate.

    Science.gov (United States)

    Joksimović, Nenad; Baskić, Dejan; Popović, Suzana; Zarić, Milan; Kosanić, Marijana; Ranković, Branislav; Stanojković, Tatjana; Novaković, Sladjana B; Davidović, Goran; Bugarčić, Zorica; Janković, Nenad

    2016-09-27

    A serie of novel square pyramidal copper(ii) complexes [Cu(L) 2 H 2 O] (3a-d) with O,O-bidentate ligands [L = ethyl-2-hydroxy-4-aryl-4-oxo-2-butenoate; aryl = 3-methoxyphenyl-2a, (E)-2-phenylvinyl-2b, (E)-2-(4'-hydroxy-3'-methoxyphenyl)vinyl-2c, 3-nitrophenyl-2d, 2-thienyl-2e] were synthesized and characterized by spectral (UV-Vis, IR, ESI-MS and EPR), elemental and X-ray analysis. The antimicrobial activity was estimated by the determination of the minimal inhibitory concentration (MIC) using the broth microdilution method. The most active antibacterial compounds were 3c and 3d, while the best antifungal activity was showed by complexes 3b and 3e. The lowest MIC value (0.048 mg mL -1 ) was measured for 3c against Proteus mirabilis. The cytotoxic activity was tested using the MTT method on human epithelial carcinoma HeLa cells, human lung carcinoma A549 cells and human colon carcinoma LS174 cells. All complexes showed extremely better cytotoxic activity compared to cisplatin at all tested concentrations. Compound 3d expressed the best activity against all tested cell lines with IC 50 values ranging from 7.45 to 7.91 μg mL -1 . The type of cell death and the impact on the cell cycle for 3d and 3e were evaluated by flow cytometry. Both compounds induced apoptosis and S phase cell cycle arrest. The interactions between selected complexes (3d and 3e) and CT-DNA or bovine serum albumin (BSA) were investigated by the fluorescence spectroscopic method. Competitive experiments with ethidium bromide (EB) indicated that 3d and 3e have a propensity to displace EB from the EB-DNA complex through intercalation suggesting strong competition with EB [K sv = (1.4 ± 0.2) and (2.9 ± 0.1) × 10 4 M -1 , respectively]. K sv values indicate that these complexes bind to DNA covalently and non-covalently. The achieved results in the fluorescence titration of BSA with 3d and 3e [K a = (2.9 ± 0.2) × 10 6 and (2.5 ± 0.2) × 10 5 M, respectively] showed that the fluorescence quenching

  20. A curcumin-based TPA four-branched copper(II) complex probe for in vivo early tumor detection

    Energy Technology Data Exchange (ETDEWEB)

    Pi, Zongxin [Department of Chemical and Chemical Engineering, Hefei Normal University, Hefei 230001 (China); Wang, Jiafeng; Jiang, Bo [Department of Pharmacy, Anhui University of Chinese Medicine, Hefei 230038 (China); Cheng, Gang [Department of Chemical and Chemical Engineering, Hefei Normal University, Hefei 230001 (China); Zhou, Shuangsheng, E-mail: zshuangsheng@126.com [Department of Pharmacy, Anhui University of Chinese Medicine, Hefei 230038 (China); Center of Modern Experimental Technology, Anhui University, Hefei 230038 (China)

    2015-01-01

    A multibranched Cu(II) complex CuL{sub 2} curcumin-based was synthesized and characterized by single-crystal X-ray diffraction analysis. The photophysical properties of the complex have been investigated both experimentally and theoretically. The results show that the target complex exhibits higher quantum yield and larger two-photon absorption (TPA) cross-section in the near infrared (NIR) region compared with its free ligand. The cell imaging studies in vitro and in vivo reveal that the complex shows good photostability and excellent tumor targeting capability to tested cancerous cells, which can be potentially used for early tumor detection. - Graphical abstract: A multibranched Cu(II) complex was prepared from curcumin. The photophysical properties of the obtained complex have been investigated. The results exhibit that the complex has high capability to test cancerous cells and can distinguish between the cancerous and noncancerous cells, which should be potentially used for early tumor detection. - Highlights: • A novel multi-branched copper complex was synthesized. • The obtained compounds exhibited obvious TPA in high polar solvents. • The complex is a low toxicity at low-micromolar concentrations. • The complex exhibits larger TPA cross-section and brighter TPF imaging. • The complex has excellent targeting capability to tested cancerous cells.

  1. Electronic, cyclic voltammetry, IR and EPR spectral studies of copper(II) complexes with 12-membered N 4, N 2O 2 and N 2S 2 donor macrocyclic ligands

    Science.gov (United States)

    Chandra, Sulekh; Kumar, Rajiv

    2005-01-01

    A new series of copper(II) complexes have been synthesized with macrocyclic ligands having three different donating atoms in the macrocyclic ring. It has been shown that the stereochemistry of complexes is dependent on the coordinated anions. These complexes are characterized by various physicochemical techniques, viz. elemental analysis, molar conductance, magnetic susceptibility measurements, IR, electronic, 1H NMR and EPR spectral studies. Cyclic voltammetric behavior of the complexes has also been discussed. The observed anisotropic g-values indicate that the chloro and acetato complexes are six-coordinate tetragonal. Whereas the sulfato and nitrato complexes are found to have five-coordinate square-pyramidal and four-coordinate square-planar geometry, respectively.

  2. Synthesis, Characterization and Antimicrobial Studies of a New Mannich Base N-[Morpholino(phenyl)methyl]acetamide and Its Cobalt(II), Nickel(II) and Copper(II) Metal Complexes

    OpenAIRE

    L. Muruganandam; K. Krishnakumar

    2012-01-01

    A new Mannich base N-[morpholino(phenyl)methyl]acetamide (MBA), was synthesized and characterized by spectral studies. Chelates of MBA with cobalt(II), nickel(II) and copper(II) ions were prepared and characterized by elemental analyses, IR and UV spectral studies. MBA was found to act as a bidentate ligand, bonding through the carbonyl oxygen of acetamide group and CNC nitrogen of morpholine moiety in all the complexes. Based on the magnetic moment values and UV-Visible spectral data, tetrac...

  3. Synthesis and crystal structure of binuclear copper(II) complex bridged by N-(2-hydroxyphenyl)-N'-[3-(diethylamino)propyl]oxamide: in vitro anticancer activity and reactivity toward DNA and protein.

    Science.gov (United States)

    Gao, Yang; Li, Yan-Tuan; Wu, Zhi-Yong; Yan, Cui-Wei

    2013-08-01

    A new oxamido-bridged bicopper(II) complex, [Cu2(pdpox)(bpy)(CH3OH)](ClO4), where H3pdpox and bpy stand for N-(2-hydroxyphenyl)-N'-[3-(diethylamino)propyl]oxamide and 2,2'-bipyridine, respectively, has been synthesized and characterized by elemental analyses, molar conductivity measurements, infrared and electronic spectra studies, and X-ray single crystal diffraction. In the crystal structure, the pdpox(3-) ligand bridges two copper(II) ions as cisoid conformation. The inner copper(II) ion has a {N3O} square-planar coordination geometry, while the exo- one is in a {N2O3} square-pyramidal environment. There are two sets of interpenetrating two-dimensional hydrogen bonding networks parallel to the planes (2 1 0) and (21¯0), respectively, to form a three-dimensional supramolecular structure. The bicopper(II) complex exhibits cytotoxic activity against the SMMC7721 and A549 cell lines. The reactivity toward herring sperm DNA and bovine serum albumin revealed that the bicopper(II) complex can interact with the DNA by intercalation mode, and the complex binds to protein BSA responsible for quenching of tryptophan fluorescence by static quenching mechanism. © 2013 Wiley Periodicals, Inc.

  4. Syntheses, crystal structures, magnetic properties, and EPR spectra of tetranuclear copper(II) complexes featuring pairs of "roof-shaped" Cu2X2 dimers with hydroxide, methoxide, and azide bridges.

    Science.gov (United States)

    Graham, B; Hearn, M T; Junk, P C; Kepert, C M; Mabbs, F E; Moubaraki, B; Murray, K S; Spiccia, L

    2001-03-26

    Hydroxo- and methoxo-bridged tetranuclear copper(II) complexes of the tetramacrocyclic ligand 1,2,4,5-tetrakis(1,4,7-triazacyclonon-1-ylmethyl)benzene (Ldur), have been prepared from [Cu4Ldur(H2O)8](ClO4)8.9H2O (1). Addition of base to an aqueous solution of 1 gave [Cu4Ldur(mu2-OH)4](ClO4)4 (2). Diffusion of MeOH into a DMF solution of 2 produces [Cu4Ldur(mu2-OMe)4](ClO4)4.HClO4.2/3MeOH (3), a complex which hydrolyzes on exposure to moisture regenerating 2. The structurally related azido-bridged complex, [Cu4Ldur(mu2-N3)4](PF6)4.4H2O.6CH3CN (4), was produced by reaction of Ldur with 4 molar equiv of Cu(OAc)2.H2O and NaN3 in the presence of excess KPF6. Compounds 2-4 crystallize in the triclinic space group P1 (No. 2) with a = 10.248(1) A, b = 12.130(2) A, c = 14.353(2) A, alpha = 82.23(1) degrees, beta = 80.79(1) degrees, gamma = 65.71(1) degrees, and Z = 1 for 2, a = 10.2985(4) A, b = 12.1182(4) A, c = 13.9705(3) A, alpha = 89.978(2) degrees, beta = 82.038(2) degrees, gamma = 65.095(2) degrees, and Z = 1 for 3, and a = 12.059(2) A, b = 12.554(2) A, c = 14.051(2) A, alpha = 91.85(1) degrees, beta = 98.22(1) degrees, gamma = 105.62(1) degrees, and Z = 1 for 4. The complexes feature pairs of isolated dibridged copper(II) dimers with "roof-shaped" Cu2(mu2-X)2 cores (X = OH-, OMe-, N3-), as indicated by the dihedral angle between the two CuX2 planes (159 degrees for 2, 161 degrees for 3, and 153 degrees for 4). This leads to Cu.Cu distances of 2.940(4) A for 2, 2.962(1) A for 3, and 3.006(5) A for 4. Variable-temperature magnetic susceptibility measurements indicate weak antiferromagnetic coupling (J = -27 cm(-1)) for the hydroxo-bridged copper(II) centers in 2 and very strong antiferromagnetic coupling (J = -269 cm(-1)) for the methoxo-bridged copper(II) centers in 3. Pairs of copper(II) centers in 4 display the strongest ferromagnetic interaction (J = 94 cm(-1)) reported thus far for bis(mu2-1,1-azido)-bridged dicopper units. Spectral measurements on a neat powdered

  5. ANTINFLAMMATORY ACTIVITY OF AN N, N'-DISALICYLIDENEMETHYLENDIAMINE-DERIVED SCHIFF BIS BASE AND ITS COPPER(II) COMPLEX.

    Science.gov (United States)

    Tântaru, Gladiola; Nechifor, M; Apostu, M; Vieriu, Mădălina; Panainte, Alina Diana; Bibire, Nela

    2015-01-01

    The cooper(II) complex combination of N, N'-disalicylidenemethylenediamine and the Schiff bis base were investigated for anti-inflammatory activity. In vivo, the anti-inflammatory activity of the metallic complex in comparison with the activity of the Schiff bis base was tested by the method of Winter and co-workers using the Levy technique. Our study on the anti-inflammatory activity of a new Schiff bis base and its complex cooper(II) combination showed that the Schiff bis bases exhibited significant anti-inflammatory action in acute experimental inflammation when compared to the control group. The copper cation from the complex combination enhanced the anti-inflammatory effect of the Schiff bis base, the effect being stronger at doses of 10 mg/kg cooper(II) complex. The Schiff bis base and its cooper(II) complex had an anti-inflammatory effect comparable to that of indomethacin.

  6. Copper complexes as chemical nucleases

    Indian Academy of Sciences (India)

    Keywords. Copper(II) complexes; nuclease activity; catalytic properties; DNA binding. Abstract. Redox active mononuclear and binuclear copper(II) complexes have been prepared and structurally characterized. ... The cleavage activity of the bis-dpq complex is significantly higher than the bis-phen complex of copper(II).

  7. Copper(II) Chloro Complex Formation Thermodynamics and Structure in Ionic Liquid, 1-Butyl-3-Methylimidazolium Trifluoromethanesulfonate.

    Science.gov (United States)

    Kanzaki, Ryo; Uchida, Shuma; Kodamatani, Hitoshi; Tomiyasu, Takashi

    2017-10-19

    Metal ions in ionic liquids are laid under an unprecedented reaction field. In order to assess the reaction thermodynamics of metal ions in such a situation, Cu(2+)-chloro complex formation was examined with spectroscopic and calorimetric titrations in an ionic liquid, 1-buthyl-3-methylimidazolium trifluoromethanesulfonate (C4mimTfO). In addition, the effect of the structure of the solvated complexes on the complexation mechanism was investigated with the aid of DFT calculations. Chloro complexation successively proceeded and finally provided a [CuCl4](2-) species, which is also the final product in conventional molecular solvents. Their stability constants were comparable to those in molecular solvents. Interestingly, in spite of the charged solvent in the ionic liquid, the entropy profile of the complexation resembled that in the conventional molecular liquids. This indicates that the entropy gain of the released solvent species from the complexes is the main driving force of the chloro complexation in the ionic liquid. In contrast, unlike the major molecular solvents, the total coordination number of Cu(2+) is saturated to 4 in the ionic liquid, and the Cl(-) complexation tends to be accompanied by a 1:1 exchange of the solvent TfO(-) from the complex. In addition, this ligand exchange was almost athermal. This possibly indicates that the coordination number is dominated by the electrostatic hindrance among the ligands including the solvent ions in the primary coordination sphere.

  8. Copper(II) and nickel(II) complexes of benzyloxybenzaldehyde-4-phenyl-3-thiosemicarbazone: Synthesis, characterization and biological activity

    Science.gov (United States)

    Prathima, B.; Subba Rao, Y.; Adinarayana Reddy, S.; Reddy, Y. P.; Varada Reddy, A.

    2010-09-01

    Benzyloxybenzaldehyde-4-phenyl-3-thiosemicarbazone ligand (L) has been synthesized from benzyloxybenzaldehyde and 4-phenyl-3-thiosemicarbazide. Complexes of this ligand with chlorides of Cu(II) and Ni(II) have been prepared. The structure of the ligand (L) is proposed based on elemental analysis, IR and 1H NMR spectra. Its complexes with Cu(II) and Ni(II) ions are characterized from the studies of electronic as well as EPR spectra. On the basis of electronic and EPR studies, rhombically distorted octahedral structure has been proposed for Cu(II) complex while the Ni(II) complex has been found to acquire an octahedral structure. The ligand and their metal complexes have been tested in vitro for their biological effects. Their antibacterial activities against Gram-negative bacteria ( Escherichia coli and Klebsiella pneumoniae) and Gram-positive bacteria ( Staphylococcus aureus and Bacillus subtilis) have been investigated. The prepared metal complexes exhibit higher antibacterial activities than the parent ligand. The in vitro antioxidant activity of free ligand and its metal(II) complexes have also been investigated and the results however reveal that the ligand exhibits greater antioxidant activity than its complexes.

  9. Synthesis, Characterization and Antimicrobial Studies of a New Mannich Base N-[Morpholino(phenylmethyl]acetamide and Its Cobalt(II, Nickel(II and Copper(II Metal Complexes

    Directory of Open Access Journals (Sweden)

    L. Muruganandam

    2012-01-01

    Full Text Available A new Mannich base N-[morpholino(phenylmethyl]acetamide (MBA, was synthesized and characterized by spectral studies. Chelates of MBA with cobalt(II, nickel(II and copper(II ions were prepared and characterized by elemental analyses, IR and UV spectral studies. MBA was found to act as a bidentate ligand, bonding through the carbonyl oxygen of acetamide group and CNC nitrogen of morpholine moiety in all the complexes. Based on the magnetic moment values and UV-Visible spectral data, tetracoordinate geometry for nitrato complexes and hexacoordinate geometry for sulphato complexes were assigned. The antimicrobial studies show that the Co(II nitrato complex is more active than the other complexes.

  10. In vitro antiproliferative and apoptosis-inducing properties of a mononuclear copper(II) complex with dppz ligand, in two genotypically different breast cancer cell lines.

    Science.gov (United States)

    Dhivya, Rajakumar; Jaividhya, Paramasivam; Riyasdeen, Anvarbatcha; Palaniandavar, Mallayan; Mathan, Ganeshan; Akbarsha, Mohammad Abdulkader

    2015-10-01

    In the background that there is concerted effort to discover newer metal-based cancer chemotherapeutic agents that could overcome the limitations in cisplatin and that copper, a biocompatible and redox-active metal, offers potential as alternative to cisplatin, the present study was undertaken to investigate the in vitro anti-proliferative properties of the mononuclear copper(II)complex [Cu(L)(diimine)] + where LH = 2-[(2-dimethylaminoethylimino)methyl]phenol and diimine = dipyrido[3,2-a:2',3'-c]phenazine (dppz) using breast cancer cell lines MCF-7 (ER(+ve) and p53(WT)) and MDA-MB-231(ER(-ve) and p53(mutant)) when cisplatin was used as positive control. The complex affected the viability of both the cell lines in dose-as well as duration-dependent manner as revealed in the MTT assay. The 24 and 48 h IC50 of the complex were several times lesser than those of cisplatin, and within this huge difference the efficacy of the complex was much superior with MCF-7 cell compared to MDA-MB-231 cell. The cell death was preferentially apoptosis, though necrosis also occurred to a certain extent. These inferences were substantiated by AO/EB fluorescent staining, Hoechst staining, assessment of mitochondrial transmembrane potential, comet assay for DNA damage, DCFH assay for reactive oxygen species (ROS) generation and Western blot of apoptosis-related proteins. Thus, the copper(II) dppz complex under investigation is much more efficient than cisplatin in affecting viability of the breast cancer cells. The underlying mechanism appears to be DNA damage-primed (in view of the known intercalation mode of binding of the complex with DNA) and ROS-associated mitochondria-mediated intrinsic apoptosis to a great extent but necrosis also has a role to a certain extent, which may also be a PARP-mediated cell death independent of apoptosis. Within the purview of this conclusion, the results indicate that the ER and/or p53 genotypes have a bearing on the efficacy of the complex as a

  11. Syntheses, crystal structures and properties of one sodium(I) directed three-dimensional coordination polymer and one propeller-like dinuclear copper(II) complex with (1 S,3 R)-3-carbamoyl-2,2,3-trimethylcyclopentane-1-carboxylate

    Science.gov (United States)

    Huang, Wei; Qian, Huifen; Gou, Shaohua; Yao, Cheng

    2005-05-01

    A sodium(I) complex and a propeller-like dinuclear copper(II) complex formulated as [Na 3(L)(OH) 2(H 2O) 2] n ( 1) and [Cu 2(L) 4(H 2O) 2] ( 2) [LH=(1 S,3 R)-3-carbamoyl-2,2,3-trimethylcyclopentane-1-carboxylic acid which is also known as (1 R,3 S)-1-monoamidocamphoric acid and (1 R,3 S)- β-camphoramic acid] have been synthesized and characterized, respectively. X-ray single crystal determinations of 1 and 2 reveal that three types of sodium(I) centers are present in 1 and a 3D framework is constituted with the help of the weak coordinative bonds as well as the hydrogen bonding interactions, while 2 forms a tetrakis( μ2-carboxylic)-bridged dinuclear diaqua copper(II) complex with the Cu-Cu separation 2.601(4) Å. In 2, half of the ligands undergo the configuration inversion. It is deduced that the formation of the robust five-membered coordination ring (Cu 2CO 2) and the α-hydrogen atom of carboxylic group contribute this racemization. In addition, magnetic properties of 2 are also discussed.

  12. Synthesis, structural study and electrochemical properties of copper(II complexes derived from benzene- and p-toluenesulphonylhydrazones

    Directory of Open Access Journals (Sweden)

    A. REGUIG

    2003-02-01

    Full Text Available The synthesis and characterization of benzene- and p-toluenesulphonylhydrazones derived from salicylaldehyde and 2-hydroxy-1-naphthaldehyde and their Cu(II complexes are reported. The compounds were characterized on the basis of elemental analyses, electronic and IR spectra, magnetic moments, and conductance measurements. The electrochemical behavior of the Cu(II complexes was investigated in DMSO by cyclic voltammetry (CV, rotating disc electrode (RDE and coulometry. The oxidative polymerization of the copper complexes on a glassy carbon electrode was carried out in DMSO.

  13. Synthesis and characterization of iron(III), manganese(II), cobalt(II), nickel(II), copper(II) and zinc(II) complexes of salicylidene- N-anilinoacetohydrazone (H 2L 1) and 2-hydroxy-1-naphthylidene- N-anilinoacetohydrazone (H 2L 2)

    Science.gov (United States)

    AbouEl-Enein, S. A.; El-Saied, F. A.; Kasher, T. I.; El-Wardany, A. H.

    2007-07-01

    Salicylidene- N-anilinoacetohydrazone (H 2L 1) and 2-hydroxy-1-naphthylidene- N-anilinoacetohydrazone (H 2L 2) and their iron(III), manganese(II), cobalt(II), nickel(II), copper(II) and zinc(II) complexes have been synthesized and characterized by IR, electronic spectra, molar conductivities, magnetic susceptibilities and ESR. Mononuclear complexes are formed with molar ratios of 1:1, 1:2 and 1:3 (M:L). The IR studies reveal various modes of chelation. The electronic absorption spectra and magnetic susceptibility measurements show that the iron(III), nickel(II) and cobalt(II) complexes of H 2L 1 have octahedral geometry. While the cobalt(II) complexes of H 2L 2 were separated as tetrahedral structure. The copper(II) complexes have square planar stereochemistry. The ESR parameters of the copper(II) complexes at room temperature were calculated. The g values for copper(II) complexes proved that the Cu sbnd O and Cu sbnd N bonds are of high covalency.

  14. Synthesis and characterization of iron(III), manganese(II), cobalt(II), nickel(II), copper(II) and zinc(II) complexes of salicylidene-N-anilinoacetohydrazone (H2L1) and 2-hydroxy-1-naphthylidene-N-anilinoacetohydrazone (H2L2).

    Science.gov (United States)

    AbouEl-Enein, S A; El-Saied, F A; Kasher, T I; El-Wardany, A H

    2007-07-01

    Salicylidene-N-anilinoacetohydrazone (H(2)L(1)) and 2-hydroxy-1-naphthylidene-N-anilinoacetohydrazone (H(2)L(2)) and their iron(III), manganese(II), cobalt(II), nickel(II), copper(II) and zinc(II) complexes have been synthesized and characterized by IR, electronic spectra, molar conductivities, magnetic susceptibilities and ESR. Mononuclear complexes are formed with molar ratios of 1:1, 1:2 and 1:3 (M:L). The IR studies reveal various modes of chelation. The electronic absorption spectra and magnetic susceptibility measurements show that the iron(III), nickel(II) and cobalt(II) complexes of H(2)L(1) have octahedral geometry. While the cobalt(II) complexes of H(2)L(2) were separated as tetrahedral structure. The copper(II) complexes have square planar stereochemistry. The ESR parameters of the copper(II) complexes at room temperature were calculated. The g values for copper(II) complexes proved that the Cu-O and Cu-N bonds are of high covalency.

  15. Binary and ternary copper(II) complexes of a new Schiff base ligand derived from 4-acetyl-5,6-diphenyl-3(2H)-pyridazinone: Synthesis, spectral, thermal, antimicrobial and antitumor studies

    Science.gov (United States)

    Shebl, Magdy; Adly, Omima M. I.; Abdelrhman, Ebtesam M.; El-Shetary, B. A.

    2017-10-01

    A new Schiff base ligand was synthesized by the reaction of 4-acetyl-5,6-diphenyl-3(2H)-pyridazinone with ethylenediamine. A series of binary copper(II) Schiff base complexes have been synthesized by using various copper(II) salts; AcO-, NO3-, ClO4-, Cl- and Br-. Ternary complexes were synthesized by using auxiliary ligands (L‧) [N,O-donor; 8-hydroxyquinoline and glycine or N,N-donor; 1,10-phenanthroline, bipyridyl and 2-aminopyridine]. The structures of the Schiff base and its complexes were characterized by elemental and thermal analyses, IR, electronic, mass, 1H NMR and ESR spectra in addition to conductivity and magnetic susceptibility measurements. The obtained complexes include neutral binuclear complexes as well as neutral and cationic mononuclear complexes according to the anion used and the experimental conditions. The ESR spin Hamiltonian parameters of some complexes were calculated and discussed. The metal complexes exhibited octahedral and square planar geometrical arrangements depending on the nature of the anion. Kinetic parameters (Ea, A, ΔH, ΔS and ΔG) of the thermal decomposition stages were evaluated using Coats-Redfern equations. The antimicrobial activity of the Schiff base and its complexes was screened against Gram-positive bacteria (Staphylococcus aureus and Bacillus subtilis), Gram-negative bacteria (Salmonella typhimurium and Escherichia coli), yeast (Candida albicans) and fungus (Aspergillus fumigatus). The antitumor activity of the Schiff base and some of its Cu(II) complexes was investigated against HepG-2 cell line.

  16. Crystal structure, Hirshfeld surfaces and DNA cleavage investigation of two copper(II) complexes containing polypyridine and salicylide ligands.

    Science.gov (United States)

    Luo, Yang-Hui; Sun, Bai-Wang

    2014-05-21

    Two copper complexes 1 [Cu2(phen)2(salicylaldehyde)2(ClO4)2] and 2 [Cu2 (2,2'-dipyridyl)2(salicylaldehyde)2(ClO4)2] have been synthesized and characterized by elemental analysis and single-crystal X-ray diffraction. These two complexes were display binuclear structure with Cu(II) ions in distorted octahedral environment but antipodal orientation of the binuclear units between them. Molecular Hirshfeld surfaces revealed that the crystal structures of 1 and 2 were supported mainly by H-H, C-H⋯π, π⋯π (C-C), and C-H⋯O intermolecular interactions. DNA cleavage experiments of complexes 1 and 2 revealed that these complexes can intercalation with DNA. Copyright © 2014 Elsevier B.V. All rights reserved.

  17. Copper(II) complexes with 4-hydroxyacetophenone-derived acylhydrazones: Synthesis, characterization, DNA binding and cleavage properties

    Science.gov (United States)

    Gup, Ramazan; Gökçe, Cansu; Aktürk, Selçuk

    2015-01-01

    Two new Cu(II) complexes of Schiff base-hydrazone ligands, hydroxy-N‧-[(1Z)-1-(4-hydroxyphenyl)ethylidene]benzohydrazide [H3L1] and ethyl 2-(4-(1-(2-(4-(2-ethoxy-2-oxoethoxy)benzoyl)hydrazono)ethyl)phenoxy)acetate (HL2) have been synthesized and then characterized by microcopy and spectral studies. X-ray powder diffraction illustrates that [Cu(L2)2] complex is crystalline in nature whereas [Cu(H2L1)2]·2H2O has an amorphous structure. Binding of the copper complexes with Calf thymus DNA (CT-DNA) has been investigated by UV-visible spectra, exhibiting non-covalent binding to CT-DNA. DNA cleavage experiments have been also investigated by agarose gel electrophoresis in the presence and absence of an oxidative agent (H2O2). The effect of complex concentration on the DNA cleavage reaction has been also studied. Both copper complexes show nuclease activity, which significantly depends on concentrations of the complexes, in the presence of H2O2 through oxidative mechanism whereas they slightly cleavage DNA in the absence an oxidative agent.

  18. Binding of copper(II) polypyridyl complexes to DNA and consequences for DNA-based asymmetric catalysis.

    Science.gov (United States)

    Draksharapu, Apparao; Boersma, Arnold J; Leising, Miriam; Meetsma, Auke; Browne, Wesley R; Roelfes, Gerard

    2015-02-28

    The interaction between salmon testes DNA (st-DNA) and a series of Cu(II) polypyridyl complexes, i.e. [Cu(dmbpy)(NO3)2] (1) (dmbpy = 4,4'-dimethyl-2,2'-bipyridine), [Cu(bpy)(NO3)2] (2) (bpy = 2,2'-bipyridine), [Cu(phen)(NO3)2] (3) (phen = phenanthroline), [Cu(terpy)(NO3)2]·H2O (4) (terpy = 2,2':6',2″-terpyridine), [Cu(dpq)(NO3)2] (5) (dpq = dipyrido-[3,2-d:2',3'-f]-quinoxaline) and [Cu(dppz)(NO3)2] (6) (dppz = dipyrido[3,2-a:2',3'-c]phenazine) was studied by UV/Vis absorption, Circular Dichroism, Linear Dichroism, EPR, Raman and (UV and vis) resonance Raman spectroscopies and viscometry. These complexes catalyse enantioselective C-C bond forming reactions in water with DNA as the source of chirality. Complex 1 crystallizes as an inorganic polymer with nitrate ligands bridging the copper ions, which adopt essentially a distorted square pyramidal structure with a fifth bridging nitrate ligand at the axial position. Raman spectroscopy indicates that in solution the nitrate ligands in 1, 2, 3 and 4 are displaced by solvent (H2O). For complex 1, multiple supramolecular species are observed in the presence of st-DNA in contrast to the other complexes, which appear to interact relatively uniformly as a single species predominantly, when st-DNA is present. Overall the data suggest that complexes 1 and 2 engage primarily through groove binding with st-DNA while 5 and 6 undergo intercalation. For complexes 3 and 4 the data indicates that both groove binding and intercalation takes place, albeit primarily intercalation. Although it is tempting to conclude that the groove binders give highest ee and rate acceleration, it is proposed that the flexibility and dynamics in binding of Cu(II) complexes to DNA are key parameters that determine the outcome of the reaction. These findings provide insight into the complex supramolecular structure of these DNA-based catalysts.

  19. Identification of Copper(II) Complexes in Aqueous Solution by Electron Spin Resonance: An Undergraduate Coordination Chemistry Experiment.

    Science.gov (United States)

    Micera, G.; And Others

    1984-01-01

    Background, procedures, and results are provided for an experiment which examines, through electron spin resonance spectroscopy, complex species formed by cupric and 2,6-dihydroxybenzoate ions in aqueous solutions. The experiment is illustrative of several aspects of inorganic and coordination chemistry, including the identification of species…

  20. Multispectroscopic studies on the interaction of a copper(ii) complex of ibuprofen drug with calf thymus DNA.

    Science.gov (United States)

    Shahabadi, Nahid; Shiri, Farshad

    2017-02-01

    The interaction of copper(II)-ibuprofenato complex with calf thymus DNA (ct-DNA) has been explored following, UV-visible spectrophotometry, fluorescence measurement, dynamic viscosity measurements, and circular dichroism spectroscopy. In spectrophotometric studies of ct-DNA it was found that [Cu(ibp) 2 ] 2 can form a complex with double-helical DNA. The association constant of [Cu(ibp) 2 ] 2 with DNA from UV-Vis study was found to be 6.19 × 10 4 L mol -1 . The values of K f from fluorescence measurement clearly underscore the high affinity of [Cu(ibp) 2 ] 2 to DNA. The experimental results showed that the conformational changes in DNA helix induced by [Cu(ibp) 2 ] 2 are the reason for the fluorescence quenching of the DNA-Hoechst system. In addition, the fluorescence emission spectra of intercalated methylene blue (MB) with increasing concentrations of [Cu(ibp) 2 ] 2 represented a significant increase of MB intensity as to release MB from MB-DNA system. The results of circular dichroism (CD) suggested that copper(II)-ibuprofenato complex can change the conformation of DNA. In addition, the results of viscosity measurements suggest that copper(II)-ibuprofenato complex may bind with non-classical intercalative mode. From spectroscopic and hydrodynamic studies, it has been found that [Cu(ibp) 2 ] 2 interacts with DNA by partial intercalation mode which contains intercalation and groove properties.

  1. Structural variety in copper(II) complexes of 3-formylchromone: Synthesis, spectral, thermal, molecular modeling and biological studies

    Science.gov (United States)

    Shebl, Magdy; Adly, Omima M. I.; Taha, A.; Elabd, N. N.

    2017-11-01

    The compound in the title (L) was synthesized and reacted with Cu(II) metal ion with different anions (OAc-, NO3-, SO42-, ClO4-, Cl- and Br-) in absence and presence of auxiliary ligands (L‧); N,O-donor; or N,N-donor; to form binary and ternary Cu(II)-chelates. The metal complexes were fully characterized by analytical and spectral techniques in addition to thermal, conductivity and magnetic susceptibility measurements. The obtained results showed that the ligand behaves as a neutral bidentate, forming chelates with molar ratios: 1:1, 1:2 and 1:3; M:L for binary and 1:2:1 and 1:1:1; M:L:L‧ for ternary complexes, which can be formulated as: [LmCuXn(H2O)y]·zH2O, m = 1 or 2, n = 0, 1 or 2, X = OAc-, SO42-, Cl- or Br-, y = 0 or 2, z = 0 or 0.5; [LmCu(H2O)n]X2·zMeOH, m = 2 or 3, n = 0 or 2, X = ClO4- or NO3-, z = 0 or 1 and [Lm L'Cu(H2O)n](NO3)x·yS, m = 1 or 2, n = 0 or 2, X = 1 or 2, y = 0.5 or 4, S = H2O or MeOH. The ESR spin Hamiltonian parameters of some complexes were calculated. Kinetic parameters (Ea, A, ΔH, ΔS and ΔG) of the thermal decomposition stages have been evaluated using Coats-Redfern equations. The structural parameters of the ligand and its metal complexes have been calculated and correlated with the experimental data. The metal complexes exhibited octahedral and square planar geometrical arrangements according to the nature of the anion. The ligand and its metal complexes showed antibacterial activity towards Gram-positive bacteria, Gram-negative bacteria, yeast and fungus.

  2. Binding of copper(II) polypyridyl complexes to DNA and consequences for DNA-based asymmetric catalysis

    NARCIS (Netherlands)

    Draksharapu, Apparao; Boersma, Arnold J; Leising, Miriam; Meetsma, Auke; Browne, Wesley R; Roelfes, Gerard

    2015-01-01

    The interaction between salmon testes DNA (st-DNA) and a series of Cu-II polypyridyl complexes, i.e. [Cu(dmbpy)(NO3)(2)] (1) (dmbpy = 4,4'-dimethyl-2,2'-bipyridine), [Cu(bpy)(NO3)(2)] (2) (bpy = 2,2'-bipyridine), [Cu(phen)(NO3)(2)] (3) (phen = phenanthroline), [Cu(terpy)(NO3)(2)]center dot H2O (4)

  3. Dinuclear Silver(I) and Copper(II) Complexes of Hexadentate Macrocyclic Ligands Containing p-Xylyl Spacers

    DEFF Research Database (Denmark)

    McKenzie, Christine J.; Nielsen, Lars Preuss; Søtofte, Inger

    1998-01-01

    The cyclocondensation of terephthalic aldehyde with N,N-bis(3-aminopropyl)-methylamine in the presence of silver(I) gives the dinuclear tetramine Schiff base macrocyclic complex, [Ag2L1](NO3)2 (L1=7,22-N,N'-dimethyl-3,7,11,18, 22,26-hexaazatricyclo[26.2.21.18.213.16]-tetratricosa-2,11,13,15,1 7...

  4. Novel aminonaphthoquinone mannich bases derived from lawsone and their copper(II) complexes: synthesis, characterization and antibacterial activity

    Energy Technology Data Exchange (ETDEWEB)

    Neves, Amanda P.; Barbosa, Claudia C.; Greco, Sandro J.; Vargas, Maria D. [Universidade Federal Fluminense (UFF), Niteroi, RJ (Brazil). Inst. de Quimica; Visentin, Lorenzo C. [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Inst. de Quimica; Pinheiro, Carlos B. [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Dept. de Fisica; Mangrich, Antonio S. [Universidade Federal do Parana (UFPR), Curitiba, PR (Brazil). Centro Politecnico. Dept. de Quimica; Barbosa, Jussara P.; Costa, Gisela L. da [Instituto Oswaldo Cruz, Rio de Janeiro, RJ (Brazil)

    2009-07-01

    A series of novel Mannich bases (HL1-HL13) derived from 2-hydroxy-1,4-naphthoquinone (lawsone), substituted benzaldehydes [C{sub 6}H{sub 2}R{sup 1}R{sup 2}R{sup 3}C(O)H] and various primary amines (NH{sub 2}R{sup 4}, R{sup 4} = n-butyl, benzyl, allyl, 2-furfuryl), and their Cu{sup 2+} complexes, [Cu(L1){sub 2}]-[Cu(L13){sub 2}], have been synthesized and fully characterized by analytical and spectroscopic methods. The structures of complexes 1 (R{sup 1} R{sup 2} = R{sup 3} = H; R{sup 4} = Bu), 2 (R{sup 1} = R{sup 3} = H; R{sup 2} = NO{sub 2}; R{sup 4}= Bu) and 7 (R{sup 1} OH; R{sup 2} = R{sup 3} = H; R{sup 4}= Bu) were determined by single crystal X-ray diffraction studies. All complexes crystallize in centrosymmetric space groups, with a copper atom in the inversion centre. Two L. coordinate through the naphthalen-2-olate oxygen and secondary amine-N atoms, forming six membered chelate rings around the copper atom in a trans-N{sub 2}O{sub 2} environment; spectroscopic data confirm that the other complexes exhibit similar molecular arrangement. The antimicrobial activity of all compounds has been tested on seven different strains of bacteria: Bacillus cereus, Bacillus subtilis, Escherichia coli, Enterococcus faecalis, Klebsiella pneumoniae, Pseudomonas aeruginosa and Staphylococcus aureus. In general, Mannich bases were more active than complexes, HL11 (R{sup 1} = OH; R{sup 2} =H; R{sup 3} = Me; R{sup 4}= Bn) and HL13 (R{sup 1} = OH; R{sup 2} = H; R{sup 3} = Br; R{sup 4}= Bn) being the most potent inhibitors. The MIC for the most active compound HL11 against S. Coli was 20 {mu}mol L{sup -1} (8 {mu}g mL{sup -1}), better than Chloramphenicol (90 {mu}mol L{sup -1}) and well below most values reported for other naphthoquinones. (author)

  5. Synthesis and X-ray crystal structure determination of the first Copper(II) complexes of tetraazamacrocycle-glyoxal condensates.

    Science.gov (United States)

    Hubin, Timothy J; Alcock, Nathaniel W; Seib, Lawrence L; Busch, Daryle H

    2002-12-30

    Novel Cu(II) complexes CuLCl(2) (L = 1-4) have been synthesized containing the metal bound to a well-known type of tetracyclic bisaminal formed from the condensation of glyoxal and tetraazamacrocycles (1 = cyclam-glyoxal condensate, 2 = [13]aneN4-glyoxal condensate, 3 = cyclen-glyoxal condensate, 4 = isocyclam-glyoxal condensate). The four-coordinate complexes were characterized by X-ray crystallography, electronic spectroscopy, solid-state magnetic moments, and electron spin resonance spectroscopy. The tetracyclic bisaminals, although having four potential donor atoms, are bound in a cis-bidentate fashion to Cu(II) with two additional cis-chloride donors. The ligands take up folded conformations, and with the exception of ligand 4, only nonadjacent nitrogen atoms coordinate. As expected, ligand 2 in Cu(2)Cl(2) has a folded structure similar to those of the previously characterized 1 and 3. The conformation of 4 in the complex Cu(4)Cl(2) differs from 1-3 in that three nitrogens direct their lone pairs to one side of the folded tetracycle, with adjacent nitrogen atoms coordinated to Cu(II). This difference is probably caused by the presence of the more flexible seven-membered ring rather than the five- to six-membered rings in 1-3. Air oxidation of Cu(I) in the presence of 1 or 3 results in bis(mu-hydroxo) dimers as characterized by X-ray crystal structures, suggesting dioxygen binding, followed by O-O bond splitting to give the Cu(2)O(2) diamond core.

  6. In vitro DNA binding studies of the sweetening agent saccharin and its copper(II) and zinc(II) complexes.

    Science.gov (United States)

    Icsel, Ceyda; Yilmaz, Veysel T

    2014-01-05

    The interactions of fish sperm DNA (FS-DNA) with the sodium salt of sweetener saccharin (sacH) and its copper and zinc complexes, namely [M(sac)2(H2O)4]·2H2O (M=Cu(II) or Zn(II)) were studied by using UV-Vis titration, fluorometric competition, thermal denaturation, viscosity and gel electrophoresis measurements. The intrinsic binding constants (Kb) obtained from absorption titrations were estimated to be 2.86 (±0.06)×10(4)M(-1) for Na(sac), 6.67 (±0.12)×10(4)M(-1) for Cu-sac and 4.01 (±0.08)×10(4)M(-1) for Zn-sac. The Cu-sac complex binds to FS-DNA via intercalation with a KA value of 50.12 (±0.22)×10(4)M(-1) as evidenced by competitive binding studies with ethidium bromide. Moreover, competition experiments with Hoechst 33258 are indicative of a groove binding mode of Na(sac) and Zn-sac with binding constants of 3.13 (±0.16)×10(4)M(-1) and 5.25 (±0.22)×10(4)M(-1), respectively. The spectroscopic measurements indicate a moderate DNA binding affinity of Na(sac) and its metal complexes. The suggested binding modes are further confirmed by the thermal denaturation and viscosity measurements. In addition, Cu-sac and Zn-sac show weak ability to damage to pBR322 supercoiled plasmid DNA. Copyright © 2013 Elsevier B.V. All rights reserved.

  7. Pocket Semiquinonate Complexes of Cobalt(II), Copper(II), and Zinc(II) Prepared with the Hydrotris(cumenylmethylpyrazolyl)borate Ligand.

    Science.gov (United States)

    Ruf, Michael; Noll, Bruce C.; Groner, Markus D.; Yee, Gordon T.; Pierpont, Cortlandt G.

    1997-10-08

    3,5-Di-tert-butyl-1,2-semiquinonate (3,5-DBSQ) complexes of Co(II), Cu(II), and Zn(II) have been prepared that contain the hydrotris(cumenylmethyl-pyrazolyl)borate (Tp(Cum,Me)) coligand. Tp(Cum,Me)Zn(3,5-DBSQ) and Tp(Cum,Me)Cu(3,5-DBSQ) were prepared by treating the parent hydroxide, Tp(Cum,Me)M(OH), M = Cu and Zn, with 3,5-di-tert-butylcatechol. Tp(Cum,Me)Co(3,5-DBSQ) was prepared by a reaction between (Tp(Cum,Me))(2)Co and 3,5-DBCat. The identity of (Tp(Cum,Me))(2)Co in this reaction was confirmed by a structure determination [(Tp(Cum,Me))(2)Co: orthorhombic, Pbcn, a = 17.7189(4) Å, b = 17.4806(3) Å, c = 25.7123(6) Å, V = 7964.1(3) Å(3), Z = 4, R(F) = 0.054]. Intersecting cumenyl substituents of the pyrazolylborate ligand encapsulate the Co(II) ion. Structural characterization on all three members of the Tp(Cum,Me)M(3,5-DBSQ) series has been carried out. The complexes of Co(II) and Zn(II) are isomorphous and isostructural [Tp(Cum,Me)Co(3,5-DBSQ): triclinic, P&onemacr;, a = 14.4631(2) Å, b = 18.5438(3) Å, c = 21.6142(2) Å, alpha = 79.8430(10) degrees, beta = 90.0900(10) degrees, gamma = 84.9900(10) degrees, V = 5683.45(13) Å(3), Z = 4, R(F) = 0.072; Tp(Cum,Me)Zn(3,5-DBSQ), triclinic, P&onemacr;, a = 14.261(3) Å, b = 18.760(7) Å, c = 21.710(4) Å, alpha = 80.049(12) degrees, beta = 89.853(8) degrees, gamma = 85.542(12) degrees, V = 5703(3) Å(3), Z = 4, R(F) = 0.064]. Tp(Cum,Me)Cu(3,5-DBSQ) [monoclinic, P2(1)/c, a = 19.3081(3) Å, b = 13.0291(2) Å, c = 21.4783(4) Å, beta = 102.8420(10) degrees, V = 5268.1(2) Å(3), Z = 4, R(F) = 0.071] has a distorted square pyramidal structure, the complexes of Zn and Co have structures that are closer to a trigonal bipyramid. Parent catecholate complexes of all three metals are unusually stable in air but undergo slow oxidation in solution to give the semiquinonate products characterized structurally. Copper(II) and SQ spins of Tp(Cum,Me)Cu(3,5-DBSQ) are located in orthogonal orbitals, and the complex has a S = 1 spin

  8. Insertion of a hydroxido bridge into a diphenoxido dinuclear copper(II) complex: drastic change of the magnetic property from strong antiferromagnetic to ferromagnetic and enhancement in the catecholase activity.

    Science.gov (United States)

    Biswas, Apurba; Das, Lakshmi Kanta; Drew, Michael G B; Diaz, Carmen; Ghosh, Ashutosh

    2012-10-01

    A diphenoxido-bridged dinuclear copper(II) complex, [Cu(2)L(2)(ClO(4))(2)] (1), has been synthesized using a tridentate reduced Schiff base ligand, 2-[[2-(diethylamino)ethylamino]methyl]phenol (HL). The addition of triethylamine to the methanolic solution of this complex produced a novel triple bridged (double phenoxido and single hydroxido) dinuclear copper(II) complex, [Cu(2)L(2)(OH)]ClO(4) (2). Both complexes 1 and 2 were characterized by X-ray structural analyses, variable-temperature magnetic susceptibility measurements, and spectroscopic methods. In 1, the two phenoxido bridges are equatorial-equatorial and the species shows strong antiferromagnetic coupling with J = -615.6(6.1) cm(-1). The inclusion of the equatorial-equatorial hydroxido bridge in 2 changes the Cu···Cu distance from 3.018 Å (avg.) to 2.798 Å (avg.), the positions of the phenoxido bridges to axial-equatorial, and the magnetic coupling to ferromagnetic with J = 50.1(1.4) cm(-1). Using 3,5-di-tert-butylcatechol as the substrate, the catecholase activity of the complexes has been studied in a methanol solution; compound 2 shows higher catecholase activity (k(cat) = 233.4 h(-1)) than compound 1 (k(cat) = 93.6 h(-1)). Both complexes generate identical species in solution, and they are interconvertible simply by changing the pH of their solutions. The higher catecholase activity of 2 seems to be due to the presence of the OH group, which increases the pH of its solution.

  9. Synthesis of Two Potentially Heptadentate (N4O3 Schiff-base Ligands Derived from Condensation of Tris(3-aminopropyl-amine and Salicylaldehyde or 4-Hydroxysalicylaldehyde. Nickel(II and Copper(II Complexes of the Former Ligand

    Directory of Open Access Journals (Sweden)

    R. V. Parish

    2002-02-01

    Full Text Available Two potentially heptadentate (N4O3 tripodal Schiff-base ligands: tris(3-(salicylideneiminopropylamine (H3L1 and tris(3-(4’-hydroxysalicylideneimino-propylamine (H3L2 have been prepared and characterized by various spectroscopic methods (IR, FAB-MS, NMR. They are derived from the condensation reactions of tris(3-aminopropylamine (tpt, with 3 equivalents of either salicylaldehyde or the ringsubstituted salicylaldehyde, 4-hydroxysalicylaldehyde. The nickel(II and copper(II complexes of H3L1 were obtained from the its reactions Ni(II and Cu(II salts in absolute methanol. These complexes were studied by IR and FAB-Mass spectrometry.

  10. Synthesis and Characterization of Copper(II), Zinc(II), and Potassium Complexes of a Highly Fluorinated Bis(pyrazolyl)borate Ligand.

    Science.gov (United States)

    Dias, H. V. Rasika; Gorden, John D.

    1996-01-17

    Highly fluorinated, dihydridobis(3,5-bis(trifluoromethyl)pyrazolyl)borate ligand, [H(2)B(3,5-(CF(3))(2)Pz)(2)](-) has been synthesized and characterized as its potassium salt. The copper(II) and zinc(II) complexes, [H(2)B(3,5-(CF(3))(2)Pz)(2)](2)Cu and [H(2)B(3,5-(CF(3))(2)Pz)(2)](2)Zn, have been prepared by metathesis of [H(2)B(3,5-(CF(3))(2)Pz)(2)]K with Cu(OTf)(2) and Zn(OTf)(2), respectively. All the new metal adducts have been characterized by X-ray diffraction. The potassium salt is polymeric and shows several K.F interactions. The Cu center of [H(2)B(3,5-(CF(3))(2)Pz)(2)](2)Cu adopts a square planar geometry, whereas the Zn atom in [H(2)B(3,5-(CF(3))(2)Pz)(2)](2)Zn displays a tetrahedral coordination. Bis(pyrazolyl)borate ligands in the Zn adduct show a significantly distorted boat conformation. The nature and extent of this distortion is similar to that observed for the methylated analog, [H(2)B(3,5-(CH(3))(2)Pz)(2)](2)Zn. This ligand allows a comparison of electronic effects of bis(pyrazolyl)borate ligands with similar steric properties. Crystallographic data for [H(2)B(3,5-(CF(3))(2)Pz)(2)]K: triclinic, space group P&onemacr;, with a = 8.385(1) Å, b = 10.097(2) Å, c = 10.317(1) Å, alpha = 104.193(9) degrees, beta = 104.366(6) degrees, gamma = 91.733(9) degrees, V = 816.5(3) Å(3), and Z = 2. [H(2)B(3,5-(CF(3))(2)Pz)(2)](2)Cu is monoclinic, space group C2/c with a = 25.632(3) Å, b = 9.197(1) Å, c = 17.342(2) Å, beta = 129.292(5) degrees, V = 3164.0(6) Å(3), and Z = 4. [H(2)B(3,5-(CF(3))(2)Pz)(2)](2)Zn is triclinic, space group P&onemacr;, with a = 9.104(1) Å, b = 9.278(1) Å, c = 18.700(2) Å, alpha = 83.560(6) degrees, beta = 88.200(10) degrees, gamma = 78.637(9) degrees, V = 1538.8(3) Å(3), and Z = 2. [H(2)B(3,5-(CH(3))(2)Pz)(2)](2)Zn is monoclinic, space group C2/c with a = 8.445(1) Å, b = 14.514(2) Å, c = 19.983(3) Å, beta = 90.831(8) degrees, V = 2449.1(6) Å(3), and Z = 4.

  11. Cobalt(II), nickel(II), copper(II), zinc(II) and hafnium(IV) complexes of N'-(furan-3-ylmethylene)-2-(4-methoxyphenylamino)acetohydrazide.

    Science.gov (United States)

    Emam, Sanaa M; El-Saied, Fathy A; Abou El-Enein, Saeyda A; El-Shater, Heba A

    2009-03-01

    Cobalt(II), nickel(II), copper(II), zinc(II) and hafnium(IV) complexes of furan-2-carbaldehyde 4-methoxy-N-anilinoacetohydrazone were synthesized and characterized by elemental and thermal (TG and DTA) analyses, IR, UV-vis and (1)H NMR spectra as well as magnetic moment and molar conductivity. Mononuclear complexes are obtained with 1:1 molar ratio except complexes 3 and 9 which are obtained with 1:2 molar ratios. The IR spectra of ligand and metal complexes reveal various modes of chelation. The ligand behaves as a neutral bidentate one and coordination occurs via the carbonyl oxygen atom and azomethine nitrogen atom. The ligand behaves also as a monobasic tridentate one and coordination occurs through the enolic oxygen atom, azomethine nitrogen atom and the oxygen atom of furan ring. Moreover, the ligand behaves as a neutral tridentate and coordination occurs via the carbonyl oxygen, azomethine nitrogen and furan oxygen atoms as well as a monobasic bidentate and coordination occurs via the enolic oxygen atom and azomethine nitrogen atom. The electronic spectra and magnetic moment measurements reveal that all complexes possess octahedral geometry except the copper complex 10 possesses a square planar geometry. The thermal studies showed the type of water molecules involved in metal complexes as well as the thermal decomposition of some metal complexes.

  12. Antioxidant, DNA interaction, VEGFR2 kinase, topoisomerase I and in vitro cytotoxic activities of heteroleptic copper(II) complexes of tetrazolo[1,5-a]pyrimidines and diimines.

    Science.gov (United States)

    Haleel, A; Mahendiran, D; Veena, V; Sakthivel, N; Rahiman, A Kalilur

    2016-11-01

    A series of heteroleptic mononuclear copper(II) complexes of the type [Cu(L(1-3))(diimine)]ClO4 (1-6) containing three tetrazolo[1,5-a]pyrimidine core ligands, ethyl 5-methyl-7-(2-hydroxyphenyl)-4,7-dihydrotetrazolo[1,5-a]pyrimidine-6-carboxylate (HL(1)), ethyl 5-methyl-7-(4-diethylamino-2-hydroxyphenyl)-4,7-dihydrotetrazolo[1,5-a]pyrimidine-6-carboxylate (HL(2)) or ethyl 5-methyl-7-(2-hydroxy-4-nitrophenyl)-4,7-dihydrotetrazolo[1,5-a]pyrimidine-6-carboxylate (HL(3)), and two diimine coligands, 2,2'-bipyridyl (bpy) or 1,10-phenanthroline (phen) have been synthesized and characterized by spectral methods. The geometry of complexes have been determined with the help of electronic absorption and EPR splitting patterns, which suggest four coordinated square planar geometry around copper(II) ion. The lowering of HOMO-LUMO band gap value of complex 4 implies its higher biological activity compared to other complexes. Antioxidant studies revealed that the complexes possess considerable radical scavenging potency against DPPH. The binding studies of the complexes with calf thymus DNA (CT-DNA) revealed groove mode of binding, which was further supported by docking simulation. The complexes 3 and 4 strongly inhibit the topoisomerase I, and also strongly interact with VEGFR2 kinase receptor via π-π, σ-π and hydrogen bonding interaction. Gel electrophoresis experiments demonstrated the ability of the complexes to cleave plasmid DNA in the absence of activators. In vitro cytotoxic activities of the complexes were examined on three cancerous cell lines such as human lung (A549), cervical (HeLa) and colon (HCT-15), and two normal cells such as human embryonic kidney (HEK) and peripheral blood mononuclear cells (PBMCs). The live cell and fluorescent imaging of cancer cells were observed with acridine orange/ethidium bromide staining assay. All encouraging chemical and biological findings indicate that the complex 4 is a suitable candidate for drug target. Copyright © 2016

  13. Preparation, crystal structure and magnetic properties of di-2-pyridylamine (dpa) copper(II) complexes [Cu(dpa)(N 3) 2] n and [Cu 2(dpa) 2(NCO) 4

    Science.gov (United States)

    Carranza, José; Sletten, Jorunn; Lloret, Francesc; Julve, Miguel

    2008-11-01

    The preparation, crystal structures and magnetic properties of two copper(II) complexes with di-2-pyridylamine (dpa) as end-cap ligand and azide ( 1) and cyanate ( 2) as bridging groups, [Cu(dpa)(N 3) 2] n ( 1) and [Cu 2(dpa) 2(NCO) 4] ( 2), are reported. Compound 1 consists of uniform chains of copper(II) ions bridged by single μ-1,1-azido groups whereas that of compound 2 is made up of centrosymmetric dicopper(II) units with double μ-1,1- N-cyanate bridges, the other two cyanate groups acting as terminal ligands. The copper atoms in 1 and 2 are five-coordinated with two nitrogen atoms of a bidentate dpa ligand ( 1 and 2), one nitrogen atom from a terminally bound azide ( 1)/cyanate ( 2) and two other nitrogens from two azide ( 1)/cyanate ( 2) bridges building intermediate square pyramidal/trigonal bipyramidal ( 1) and distorted square pyramidal ( 2) surroundings. The values of the copper-copper separation through the double end-on azido ( 1) and cyanato ( 2) bridges are 3.8556(4) and 3.5154(5) Å, respectively. Variable-temperature magnetic susceptibility measurements show the occurrence of weak magnetic interactions in both complexes being antiferromagnetic in 1 [ J = -4.60 cm -1, the Hamiltonian is defined as Hˆ=-J∑iS·S] and ferromagnetic in 2 [ J = +3.14 cm -1 with Hˆ=-JS·S]. The magnitude and nature of these magnetic interactions are discussed in the light of the respectives structures and they are compared with those reported for related systems.

  14. Synthesis, spectroscopic characterization and antimicrobial activity of binuclear metal complexes of a new asymmetrical Schiff base ligand: DNA binding affinity of copper(II) complexes.

    Science.gov (United States)

    Shebl, Magdy

    2014-01-03

    The 1:1 condensation of o-acetoacetylphenol and 1,2-diaminopropane under condition of high dilution gives the mono-condensed Schiff base, (E)-3-(1-aminopropan-2-ylimino)-1-(2-hydroxyphenyl)butan-1-one. The mono-condensed Schiff base has been used for further condensation with isatin to obtain the new asymmetrical dicompartmental Schiff base ligand, (E)-3-(2-((E)-4-(2-hydroxyphenyl)-4-oxobutan-2-ylideneamino) propylimino)indolin-2-one (H3L) with a N2O3 donor set. Reactions of the ligand with metal salts give a series of new binuclear complexes. The ligand and its metal complexes were characterized by elemental analyses, IR, (1)H and (13)C NMR, electronic, ESR and mass spectra, conductivity and magnetic susceptibility measurements as well as thermal analyses. The analytical and spectroscopic tools showed that the complexes can be formulated as: [(HL)(VO)2(SO4)(H2O)]·4H2O, [(HL)Fe2Cl4(H2O)3]·EtOH, [(HL)Fe2(ox)Cl2(H2O)3]·2H2O, [(L)M2(OAc)(H2O)m]·nH2O; M=Co, Ni or Cu, m=4, 0 and n=2, 3, [(HL)Cu2Cl]Cl·6H2O and [(L)(UO2)2(OAc)(H2O)3]·6H2O. The metal complexes exhibited octahedral geometrical arrangements except copper complexes that exhibited tetrahedral geometries and uranyl complex in which the metal ion is octa-coordinated. The Schiff base and its metal complexes were evaluated for antimicrobial activity against Gram positive bacteria (Staphylococcus aureus), Gram negative bacteria (Escherichia coli) and fungi (Candida albicans and Aspergillus flavus). The ligand and some of its complexes were found to be biologically active. The DNA-binding properties of the copper complexes (6 and 7) have been investigated by electronic absorption, fluorescence and viscosity measurements. The results obtained indicate that these complexes bind to DNA via an intercalation binding mode with an intrinsic binding constant, Kb of 1.34×10(4) and 2.5×10(4) M(-1), respectively. Copyright © 2013 Elsevier B.V. All rights reserved.

  15. Preconcentration and extraction of copper(II) on activated carbon ...

    African Journals Online (AJOL)

    Activated carbon modified method was used for the preconcentration and determination of copper content in real samples such as tap water, wastewater and a synthetic water sample by flame atomic absorption spectrometry. The copper(II) was adsorbed quantitatively on activated carbon due to its complexation with ...

  16. Copper(II) complex with 6-methylpyridine-2-carboxyclic acid: Experimental and computational study on the XRD, FT-IR and UV-Vis spectra, refractive index, band gap and NLO parameters.

    Science.gov (United States)

    Altürk, Sümeyye; Avcı, Davut; Başoğlu, Adil; Tamer, Ömer; Atalay, Yusuf; Dege, Necmi

    2018-02-05

    Crystal structure of the synthesized copper(II) complex with 6-methylpyridine-2-carboxylic acid, [Cu(6-Mepic)2·H2O]·H2O, was determined by XRD, FT-IR and UV-Vis spectroscopic techniques. Furthermore, the geometry optimization, harmonic vibration frequencies for the Cu(II) complex were carried out by using Density Functional Theory calculations with HSEh1PBE/6-311G(d,p)/LanL2DZ level. Electronic absorption wavelengths were obtained by using TD-DFT/HSEh1PBE/6-311G(d,p)/LanL2DZ level with CPCM model and major contributions were determined via Swizard/Chemissian program. Additionally, the refractive index, linear optical (LO) and non-nonlinear optical (NLO) parameters of the Cu(II) complex were calculated at HSEh1PBE/6-311G(d,p) level. The experimental and computed small energy gap shows the charge transfer in the Cu(II) complex. Finally, the hyperconjugative interactions and intramolecular charge transfer (ICT) were studied by performing of natural bond orbital (NBO) analysis. Copyright © 2017 Elsevier B.V. All rights reserved.

  17. Comparisons in the behavior of stable copper(II), silver(II), and gold(II) complexes in the gas phase: are there implications for condensed-phase chemistry?

    Science.gov (United States)

    Walker, N R; Wright, R R; Barran, P E; Murrell, J N; Stace, A J

    2001-05-09

    Experiments conducted in the gas phase have led to the formation of a series of stable gold(II) complexes with nitrogen- and oxygen-containing ligands. Such complexes are very rare in condensed-phase chemistry. However, there is also a significant group of potential ligands, for example, H2O and NH3, for which stable complexes could not be formed. There are strong similarities between these observations and earlier results presented for silver(II), but both metal ions behave markedly different from copper(II). As a group the majority of successful gold(II) ligands are characterized by being good sigma donor-pi acceptor molecules; however, it is also possible to understand the ability of individual ligands to stabilize the metal ion in terms of a simple electrostatic model. Application of the latter reveals a semiquantitative trend between the physical properties of a ligand, e.g. ionization energy, dipole moment, and polarizability, and the ligand's ability to stabilize either Cu(II), Ag(II), or Au(II). The model successfully accounts for the preference of Cu(II) for aqueous chemistry, in comparison to the complete absence of such behavior on the part of Ag(II) and Au(II). Ligands from recent examples of stable condensed-phase gold(II) complexes appear to meet at least one of the criteria identified from the model.

  18. Crystal structures of a copper(II and the isotypic nickel(II and palladium(II complexes of the ligand (E-1-[(2,4,6-tribromophenyldiazenyl]naphthalen-2-ol

    Directory of Open Access Journals (Sweden)

    Souheyla Chetioui

    2016-08-01

    Full Text Available In the copper(II complex, bis{(E-1-[(2,4,6-tribromophenyldiazenyl]naphthalen-2-olato}copper(II, [Cu(C16H8Br3N2O2], (I, the metal cation is coordinated by two N atoms and two O atoms from two bidentate (E-1-[(2,4,6-tribromophenyldiazenyl]naphthalen-2-olate ligands, forming a slightly distorted square-planar environment. In one of the ligands, the tribromobenzene ring is inclined to the naphthalene ring system by 37.4 (5°, creating a weak intramolecular Cu...Br interaction [3.134 (2 Å], while in the other ligand, the tribromobenzene ring is inclined to the naphthalene ring system by 72.1 (6°. In the isotypic nickel(II and palladium(II complexes, namely bis{(E-1-[(2,4,6-tribromophenyldiazenyl]naphthalen-2-olato}nickel(II, [Ni(C16H8Br3N2O2], (II, and bis{(E-1-[(2,4,6-tribromophenyldiazenyl]naphthalen-2-olato}palladium(II, [Pd(C16H8Br3N2O2], (III, respectively, the metal atoms are located on centres of inversion, hence the metal coordination spheres have perfect square-planar geometries. The tribromobenzene rings are inclined to the naphthalene ring systems by 80.79 (18° in (II and by 80.8 (3° in (III. In the crystal of (I, molecules are linked by C—H...Br hydrogen bonds, forming chains along [010]. The chains are linked by C—H...π interactions, forming sheets parallel to (011. In the crystals of (II and (III, molecules are linked by C—H...π interactions, forming slabs parallel to (10-1. For the copper(II complex (I, a region of disordered electron density was corrected for using the SQUEEZE routine in PLATON [Spek (2015. Acta Cryst. C71, 9–18]. The formula mass and unit-cell characteristics of the disordered solvent molecules were not taken into account during refinement.

  19. DNA binding, oxidative DNA cleavage, cytotoxicity, and apoptosis-inducing activity of copper(II) complexes with 1,4-tpbd (N,N,N',N'-tetrakis(2-yridylmethyl)benzene-1,4-diamine) ligand.

    Science.gov (United States)

    Li, Dong-Dong; Tian, Jin-Lei; Gu, Wen; Liu, Xin; Zeng, Hui-Hui; Yan, Shi-Ping

    2011-06-01

    Three new binuclear copper(II) complexes have been synthesized and structurally characterized by X-ray crystallography, [Cu(2)(1,4-tpbd)(dafo)(2)(MeOH)(2)](ClO(4))(4)·2.5H(2)O (1), [Cu(2)(1,4-tpbd) (DMSO)(2)(ClO(4))(2)](OH)(2)·6H(2)O (2) and [Cu(2)(1,4-tpbd)(OAC)(2)(ClO(4))(2)]·5H(2)O (3) (1,4-tpbd=N,N,N',N'-tetrakis(2-pyridylmethyl)benzene-1,4-diamine). Complex 1 to 3 shows similar binuclear structure and each Cu atom adopts five-coordinated square-pyramidal geometry. The interactions of the three complexes with CT-DNA (Calf-thymus DNA) have been investigated by UV absorption, fluorescence spectroscopy, circular dichroism spectroscopy and viscosity. Furthermore, the three complexes display oxidative cleavage of supercoiled DNA in the presence of external agents. Complex 3 shows higher DNA affinity and nuclease activity may be attributed to its cis structural configuration and labile acetate and perchlorate anions. The cleavage mechanisms between the complexes and plasmid DNA are likely to involve singlet oxygen or singlet oxygen-like entity as reactive oxygen species. In addition, in vitro cytotoxicity studies on the Hela cell line show that the IC(50) values of complexes 1-3 are 14.75, 13.67 and 16.58 μM, respectively. The apoptosis-inducing activity was also assessed by AO/EB (Acridine Orange/Ethidium bromide) staining assay, indicating they have the potential to act as effective metal-based anticancer drugs. Copyright © 2011 Elsevier Inc. All rights reserved.

  20. Copper(II) complexes with 4-(1H-1, 2, 4-trizol-1-ylmethyl) benzoic acid: Syntheses, crystal structures and antifungal activities

    Energy Technology Data Exchange (ETDEWEB)

    Xiong, Pingping [Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of Ministry of Education, College of Chemistry and Materials Science, Northwest University, Xi' an 710069 (China); Li, Jie [Key Laboratory of Resource Biology and Biotechnology in Western China (Ministry of Education), Shaanxi Provincial Key Laboratory of Biotechnology, Xi' an 710069 (China); Bu, Huaiyu, E-mail: 7213792@qq.com [Key Laboratory of Resource Biology and Biotechnology in Western China (Ministry of Education), Shaanxi Provincial Key Laboratory of Biotechnology, Xi' an 710069 (China); Wei, Qing [Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of Ministry of Education, College of Chemistry and Materials Science, Northwest University, Xi' an 710069 (China); Zhang, Ruolin [Key Laboratory of Resource Biology and Biotechnology in Western China (Ministry of Education), Shaanxi Provincial Key Laboratory of Biotechnology, Xi' an 710069 (China); Chen, Sanping, E-mail: sanpingchen@126.com [Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of Ministry of Education, College of Chemistry and Materials Science, Northwest University, Xi' an 710069 (China)

    2014-07-01

    Reaction of Cu(II) with an asymmetric semi-rigid organic ligand 4-(1H-1, 2, 4-trizol-1-ylmethyl) benzoic acid (HL), yielded five compounds, [Cu{sub 0.5}L]{sub n} (1), [Cu(HL){sub 2}Cl{sub 2}]{sub n} (2), [Cu(HL){sub 2}Cl{sub 2}(H{sub 2}O)] (3), [Cu(L){sub 2}(H{sub 2}O)]{sub n} (4) and [Cu(L)(phen)(HCO{sub 2})]{sub n} (5), which have been fully characterized by infrared spectroscopy, elemental analysis, and single-crystal X-ray diffraction. As for compounds 1, 2 and 5, Cu(II) is bridged through HL, Cl{sup -}, and formic acid, respectively, featuring 1D chain-structure. In compound 3, Cu(II) with hexahedral coordination sphere is assembled through hydrogen-bonding into 3D supramolecular framework. In compound 4, 1D chain units –Cu–O–Cu–O– are ligand-bridged into a 3D network. All compounds were tested on fungi (Fusarium graminearum, Altemaria solani, Macrophoma kawatsukai, Alternaria alternata and Colletotrichum gloeosporioides). Compound 1 exhibits a better antifungal effect compared to other compounds. An effect of structure on the antifungal activity has also been correlated. - Graphical abstract: Copper(II) compounds with 4-(1H-1, 2, 4-trizol-1-ylmethyl) benzoic acid, were prepared, structurally characterized and investigated for antifungal activity. - Highlights: • The title compounds formed by thermodynamics and thermokinetics. • The five compounds show higher inhibition percentage than reactants. • The structure effect on the antifungal activity.

  1. Unusual trinuclear complex of copper(II) containing a 4‧-(3-methyl-2-thienyl)-4,2‧:6‧,4″-terpyridine ligand. Structural, spectroscopic, electrochemical and magnetic properties

    Science.gov (United States)

    Toledo, Dominique; Ahumada, Guillermo; Manzur, Carolina; Roisnel, Thierry; Peña, Octavio; Hamon, Jean-René; Pivan, Jean-Yves; Moreno, Yanko

    2017-10-01

    We report the synthesis, characterization, crystal and molecular structure as well as the spectroscopic, electrochemical and magnetic properties of an unexpected trinuclear copper(II) complex (1), made of three Cu(2-TTA)2 units (2-TTA = 2-thenoyltrifluoroacetone) bridged by two 4'-(3-methyl-2-thienyl)-4,2‧:6‧,4″-terpyridine (4-stpy) ligands. The central Cu(II) atom shows an octahedral geometry, while the lateral metal centers present a slightly distorted square pyramidal coordination sphere. It is suggested that the introduction of the relatively bulky substituent groups (2-thienyl and sbnd CF3) in the 2-TTA ligand are responsible of this uncommon coordination mode. The magnetic behavior of 1 is reported in terms of a combination of monomer and dimer units, leading to weak antiferromagnetic interaction (J = -1.93 cm-1). The cyclovoltammogram of 1 exhibits, in the cathodic potential region, three redox events due to Cu2+/Cu+ and Cu+/Cu0 redox couples and to the mono-electronic reduction of the 4-stpy ligand.

  2. Syntheses and structural comparisons of two copper(II) complexes with the same formula having D-(+)- and D, L-1,2,2-trimethylcyclopentane-1,3-diamine ligands

    Science.gov (United States)

    Qian, Huifen; Chu, Zhaolian; Huang, Wei; Liu, Jianlan

    2007-09-01

    Two five-coordinate copper(II) complexes, formulated as [Cu(L a) 2Cl]BF 4 (1) and [Cu(L b) 2Cl]BF 4 (2) having D-(+)-1,2,2-trimethylcyclopentane-1,3-diamine (L a) and D, L-1,2,2-trimethylcyclopentane-1,3-diamine (L b) ligands, have been synthesized and characterized. X-ray diffraction studies of 1 and 2 demonstrate that they crystallize in the different space groups ( P2 12 12 1 for 1 and Pnma for 2), although they have identical unit cell volumes, due to the use of enantiomeric and racemic diamine ligands. One dimensional (1D) hydrogen-bond-sustained dimeric zigzag chains are formed by means of eight-membered N 2H 2CuBF 2 as well as 10-membered N 2H 4ClBF 2 hydrogen-bonded cycles. Thermal analyses for 1 and 2 are also described herein.

  3. Cobalt(II), nickel(II) and copper(II) complexes of a hexadentate pyridine amide ligand. Effect of donor atom (ether vs. thioether) on coordination geometry, spin-state of cobalt and M(III)-M(II) redox potential.

    Science.gov (United States)

    Pandey, Sharmila; Das, Partha Pratim; Singh, Akhilesh Kumar; Mukherjee, Rabindranath

    2011-10-28

    Using an acyclic hexadentate pyridine amide ligand, containing a -OCH(2)CH(2)O- spacer between two pyridine-2-carboxamide units (1,4-bis[o-(pyrydine-2-carboxamidophenyl)]-1,4-dioxabutane (H(2)L(9)), in its deprotonated form), four new complexes, [Co(II)(L(9))] (1) and its one-electron oxidized counterpart [Co(III)(L(9))][NO(3)]·2H(2)O (2), [Ni(II)(L(9))] (3) and [Cu(II)(L(9))] (4), have been synthesized. Structural analyses revealed that the Co(II) centre in 1 and the Ni(II) centre in 3 are six-coordinate, utilizing all the available donor sites and the Cu(II) centre in 4 is effectively five-coordinated (one of the ether O atoms does not participate in coordination). The structural parameters associated with the change in the metal coordination environment have been compared with corresponding complexes of thioether-containing hexadentate ligands. The μ(eff) values at 298 K of 1-4 correspond to S = 3/2, S = 0, S = 1 and S = 1/2, respectively. Absorption spectra for all the complexes have been investigated. EPR spectral properties of the copper(II) complex 4 have been investigated, simulated and analyzed. Cyclic voltammetric experiments in CH(2)Cl(2) reveal quasireversible Co(III)-Co(II), Ni(III)-Ni(II) and Cu(II)-Cu(I) redox processes. In going from ether O to thioether S coordination, the effect of the metal coordination environment on the redox potential values of Co(III)-Co(II) (here the effect of spin-state as well), Ni(III)-Ni(II) and Cu(II)-Cu(I) processes have been systematically analyzed.

  4. Theoretical studies of the tautomerism in 3-(2-R-Phenylhydrazono)-naphthalene- 1,2,4-triones: synthesis of copper(II) complexes and studies of antibacterial and antitumor activities

    Energy Technology Data Exchange (ETDEWEB)

    Francisco, Acacio I.; Vargas, Maria D.; Fragoso, Thais P.; Carneiro, J. Walkimar de M.; Silva, Fernando de C. da; Ferreira, Vitor F., E-mail: mdvargas@vm.uff.b [Universidade Federal Fluminense (UFF), Niteroi, RJ (Brazil). Inst. de Quimica; Casellato, Annelise [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Inst. de Quimica; Barbosa, Jussara P. [Instituto Oswaldo Cruz (FIOCRUZ), Rio de Janeiro, RJ (Brazil); Pessoa, Claudia; Costa-Lotufo, Leticia V.; Marinho Filho, Jose D.B.; Moraes, Manoel O. de [Universidade Federal do Ceara (UFC), Fortaleza, CE (Brazil). Dept. de Fisiologia e Farmacologia; Mangrich, Antonio S. [Universidade Federal do Parana (UFPR), Curitiba, PR (Brazil). Dept. de Quimica

    2010-07-01

    DFT calculations using the B3LYP and PBE1PBE functionals with the standard 6-31G(d) and 6-311+G(2d,p) basis sets were carried out for the 3-(2-phenylhydrazone)-naphthalene-1,2,4-trione system in solution (dmso) and in the gas phase, and showed the keto-hydrazone forms (rotamers Ia and Ib) to be more stable than the enol-azo forms (rotamers IIa and IIb, by about 14 kcal mol-1) and III (by approximately 6 kcal mol-1), independently of the nature of the substituent in the phenylene ring. These results were confirmed by spectroscopic data on the derivatives HL1-HL13, obtained from 2-hydroxy-1,4-naphthoquinone and arylamines (R = 4-OMe, 4-N{sub 2}-C{sub 6}H{sub 5}, 4-Cl, 4-I, 3-I, 2-I, 4-COOH, 3-COOH, 4-CN, 3-CN, 4-NO{sub 2}, 3-NO{sub 2}, 2-NO{sub 2}). The in vitro antitumor (against SF-295, HCT-8, MDAMB-435 and HL-60 cancer cell lines) and antibacterial activities (Bacillus cereus, Bacillus subtilis, Enterococcus faecalis, Staphylococcus aureus, Escherichia coli, Klebsiella pneumonia and Pseudomonas aeruginosa) of compounds HL1-HL13 and of their respective copper(II) complexes, [Cu(L1-13){sub 2}], were tested. In general, these compounds exhibited low antibacterial activity, except for HL5 (R 3-I), more active than the control; however, the corresponding complex was inactive. In contrast, increased cytotoxicity was observed upon complexation. Complex [Cu(L13){sub 2}] (R = 3-NO{sub 2}) presented moderate cytotoxicity against human leukemia (HL-60). (author)

  5. Losartan and its interaction with copper(II): biological effects.

    Science.gov (United States)

    Etcheverry, Susana B; Ferrer, Evelina G; Naso, Luciana; Barrio, Daniel A; Lezama, Luis; Rojo, Teófilo; Williams, Patricia A M

    2007-10-01

    Losartan, the potassium salt of 2-n-butyl-4-chloro-5-hydroxymethyl-1-[(2'-(1H-tetrazol-5-yl)biphenyl-4-yl)methyl]imidazol, is an efficient antihypertensive drug. The vibrational FTIR and Raman spectra of Losartan (its anionic and protonated forms) are discussed. In addition, the copper(II) complex of Losartan was obtained and characterized as a microcrystalline powder. The metal center is bound to the ligand through the nitrogen atoms of the tetrazolate moiety as determined by vibrational spectroscopy. The compound is a dimer with the metal centers in a tetragonal distorted environment but the presence of a monomeric impurity has been determined by EPR spectroscopy. The antioxidant properties of the complex (superoxide dismutase mimetic activity) and its effect on the proliferation and morphology of two osteoblast-like cells in culture are reported. The new compound exerted more toxic effects on tumoral cells than the copper(II) ion and Losartan.

  6. Co(II)-Ni(II) heteropolynuclear coordination compound obtained through the reaction of 1,2-propanediol with metallic nitrates as precursor for mixed oxide of spinel type NiCo{sub 2}O{sub 4}

    Energy Technology Data Exchange (ETDEWEB)

    Niculescu, M., E-mail: mniculescuro@yahoo.com [University ' Politehnica' of Timisoara, Faculty for Industrial Chemistry and Environmental Engineering, Piata Victoriei 2, 300223 Timisoara (Romania); Birzescu, M.; Dumitru, Raluca [University ' Politehnica' of Timisoara, Faculty for Industrial Chemistry and Environmental Engineering, Piata Victoriei 2, 300223 Timisoara (Romania); Sisu, E. [Chemistry Institute of Romanian Academy, Bdul Mihai Viteazul 24, 300223 Timisoara (Romania); University of Medicine and Pharmacy ' Victor Babes' , Pta Eftimie Murgu No. 2, 300041 Timisoara (Romania); Budrugeac, P. [National Institute for Research and Development in Electrical Engineering ICPE, CA, Splaiul Unirii 313, 030138 Bucharest (Romania)

    2009-09-10

    In this paper the authors present the experimental results of the thermal analysis of heteropolynuclear coordination compound [Co{sub 2}NiL{sub 3}(OH){sub 3}(H{sub 2}O){sub 3}]{sub n}, where L is lactate anion, obtained by a new method, through the reaction of 1,2-propanediol with M(NO{sub 3}){sub 2}.6H{sub 2}O (M: Co, Ni). The reaction between 1,2-propanediol and M(NO{sub 3}){sub 2}.6H{sub 2}O (M: Co, Ni) occurs with the oxidation of 1,2-propanediol to the lactate anion (L), coordinated to M(II). The thermal properties of the synthesized polynuclear coordination compound, [Co{sub 2}NiL{sub 3}(OH){sub 3}(H{sub 2}O){sub 3}]{sub n}, have been investigated by TG, DTG and DTA. The mixed oxide of spinel type, NiCo{sub 2}O{sub 4}, impurified with NiO, obtained by thermal decomposition of heteropolynuclear coordination compound was characterized by IR spectroscopy, X-ray powder diffraction (XRD) and elemental analysis.

  7. Comparison of the binding behavior of several histidine-containing proteins with immobilized copper(II) complexes of 1,4,7-triazacyclononane and 1,4-bis(1,4,7-triazacyclononan-1-yl)butane.

    Science.gov (United States)

    Graham, Bim; Spiccia, Leone; Hearn, Milton T W

    2011-04-15

    The protein binding characteristics of the immobilized binucleating chelate system, 1,4-bis(1,4,7-triazacyclononan-1-yl)butane (tacn(2)butane), complexed with Cu(2+) ions have been investigated with hen egg white lysozyme, horse skeletal muscle myoglobin and horse heart cytochrome C, as well as three histidine-rich proteins, serum albumin, transferrin, and α(2)-macroglobulin, present in partially fractionated human serum. The effects of pH, ionic strength and elution buffers on protein binding have been examined and compared with those of the analogous immobilized mononuclear copper complex of 1,4,7-triazacyclononane (tacn). The Cu(2+)-tacn(2)butane system was generally found to exhibit higher protein binding affinities than the Cu(2+)-tacn system, suggesting that the presence of immobilized binuclear copper(II) species leads to enhanced coordinative interaction with surface-exposed amino acid residues of the studied proteins. However, under some buffer conditions the dependencies of protein binding and elution on pH and ionic strength with these immobilized metal ion affinity chromatographic (IMAC) systems were consistent with electrostatic, hydrophobic and π-bonding interactions playing a significant secondary role in addition to the dominant coordinative interactions. As such, the results indicated that the selectivities were not solely dependent on the histidine content of the protein. In accord with this conclusion, differences in the selectivities of the Cu(2+)-tacn and Cu(2+)-tacn(2)butane adsorbents for serum albumin, transferrin, and α(2)-macroglobulin were observed depending on the choice of elution buffer. This attribute suggests that additional selectivity features can be realised for the separation of specific proteins with this new class of adsorbent. Copyright © 2011. Published by Elsevier B.V.

  8. Cobalt(II), nickel(II), copper(II), and zinc(II) complexes with [3(5)]adamanzane, 1,5,9,13-tetraazabicyclo[7.7.3]nonadecane and [(2.3)(2).2(1)]adamanzane, 1,5,9,12-tetraazabicyclo[7.5.2]hexadecane

    DEFF Research Database (Denmark)

    Broge, Louise; Pretzmann, Ulla; Jensen, Nicolai

    2001-01-01

    Isolation of the free bicyclic tetraamine, [3(5)]adamanzane .H2O (1,5,9,13-tetraazabicyclo[7.7.3]nonadecane .H2O), is reported along with the synthesis and characterization of a copper(II) complex of the smaller macrocycle [(2.3)(2).2(1)]-adamanzane (1,5,9,12-tetraazabicyclo[7.5.2]hexadecane......) and of three cobalt(II), four nickel(II), one copper(II), and two zinc(II) complexes with [3(5)]adamanzane. For nine of these compounds (2-8, 10b, and 12) the single-crystal X-ray structures were determined. The coordination geometry around the metal ion is square pyramidal in [Cu([(2.3)(2).2(1)]adz)Br]ClO4 (2...... in the region 2-10 M(-1)for the halide complexes and 30-65 M(-1)for the nickel(II) nitrate complex (4). Rate constants for the dissociation of the macrocyclic ligand from the metal ions in 5 M HCl were determined for complexes 2, 3, 5, 8, 10, and 12. The reaction rates vary from half-lives at 40 degreesC of 14...

  9. Tetradentate bis(o-iminobenzosemiquinonate(1-)) pi radical ligands and their o-aminophenolate(1-) derivatives in complexes of nickel(II), palladium(II), and copper(II).

    Science.gov (United States)

    Min, Kil Sik; Weyhermüller, Thomas; Bothe, Eberhard; Wieghardt, Karl

    2004-05-03

    The coordination chemistries of the potential tetradentate ligands N,N'-bis(3,5-di-tert-butyl-2-hydroxyphenyl)ethylenediamine, H4[L1], the unsaturated analogue glyoxal-bis(2-hydroxy-3,5-di-tert-butylanil), H2[L2], and N,N'-bis(2-hydroxy-3,5-di-tert-butylphenyl)-2,2-dimethylpropylenediamine, H4[L3], have been investigated with nickel(II), palladium(II), and copper(II). The complexes prepared and characterized are [Ni(II)(H3L1)2] (1), [Ni(II)(HL2)2].5/8CH2Cl2 (2), [Ni(II)(L3**)] (3), [Pd(II)(L3**)][Pd(II)(H2L3) (4), and [Cu(II)(H2O)(L4)] (5), where (L4)2- is the oxidized diimine form of (L3)4- and (L3**)2- is the bis(o-iminosemiquinonate) diradical form of (L3)4-. The structures of compounds 1-5 have been determined by single crystal X-ray crystallography. In complexes 1 and 2, the ligands (H3L1)- and (HL2)- are tridentate and the nickel ions are in an octahedral ligand environment. The oxidation level of the ligands is that of an aromatic o-aminophenol. 1 and 2 are paramagnetic (mu(eff) approximately 3.2 mu(B) at 300 K), indicating an S = 1 ground state. The diamagnetic, square planar, four-coordinate complexes 3 and [Pd(II)(L3**)] in 4 each contain two antiferromagnetically coupled o-iminobenzosemiquinonate(1-) pi radicals. Diamagnetic [Pd(II)(H2L3)] in 4 forms an eclipsed dimer via four N-H.O hydrogen bonding contacts which yields a nonbonding Pd.Pd contact of 3.0846(4) A. Complex 5 contains a five-coordinate Cu(II) ion and two o-aminophenolate(1-) halves in (L4)2-. The electrochemistries of complexes 3 and 4a ([Pd(II)(L3**)] of 4) have been investigated, and the EPR spectra of the monocations and -anions are reported.

  10. Effect of substituent of terpyridines on the in vitro antioxidant, antitubercular, biocidal and fluorescence studies of copper(II) complexes with clioquinol

    Science.gov (United States)

    Kharadi, G. J.

    2014-01-01

    An octahedral complexes of copper with clioquinol(CQ) and substituted terpyridine have been synthesized. The Cu(II) complexes have been characterized by elemental analyses, thermogravimetric analyses, magnetic moment measurements, FT-IR, electronic, 1H NMR and FAB mass spectra. Antimycobacterial screening of ligand and its copper compound against Mycobacterium tuberculosis shows clear enhancement in the antitubercular activity upon copper complexation. Ferric-reducing anti-oxidant power of all complexes were measured. The fluorescence spectra of complexes show red shift, which may be due to the chelation by the ligands to the metal ion. It enhances ligand ability to accept electrons and decreases the electron transition energy. The antimicrobial efficiency of the complexes were tested on five different microorganisms and showed good biological activity.

  11. DNA cleavage, structural elucidation and anti-microbial studies of three novel mixed ligand Schiff base complexes of copper(II

    Directory of Open Access Journals (Sweden)

    N. RAMAN

    2007-10-01

    Full Text Available Three new copper complexes of mixed ligands derived from Schiff bases (condensation of p-aminoacetanilide and substituted benzaldehydes with 1,10-phenanthroline have been synthesized and characterized by elemental analysis, IR, UV–Vis, magnetic moments, conductivity and electrochemical measurements. The spectral techniques suggest that all the copper complexes exhibit octahedral geometry. The low electrical conductance of the complexes supports their neutral nature. The monomeric nature of the complexes was assessed from their magnetic susceptibility values. The in vitro biological screening effects of the investigated compounds were tested against the bacteria Escherichia coli, Staphylococcus aureus, and Salmonella typhi and the fungi Rhizopus stolonifer and Candida albicans by the serial dilution method. A comparative study of the MIC values of the Schiff bases and their copper complexes indicates that the metal complexes exhibited higher antibacterial activity than the free ligands. The DNA cleavage ability of the complexes was monitored by the gel electrophoresis technique. It was found that electron withdrawing group substituted copper complex had higher DNA cleavage activity than the other copper complexes.

  12. Design, synthesis, spectral characterization, DNA interaction and biological activity studies of copper(II), cobalt(II) and nickel(II) complexes of 6-amino benzothiazole derivatives

    Science.gov (United States)

    Daravath, Sreenu; Kumar, Marri Pradeep; Rambabu, Aveli; Vamsikrishna, Narendrula; Ganji, Nirmala; Shivaraj

    2017-09-01

    Two novel Schiff bases, L1 = (2-benzo[d]thiazol-6-ylimino)methyl)-4,6-dichlorophenol), L2 = (1-benzo[d]thiazol-6-ylimino)methyl)-6-bromo-4-chlorophenol) and their bivalent transition metal complexes [M(L1)2] and [M(L2)2], where M = Cu(II), Co(II) and Ni(II) were synthesized and characterized by elemental analysis, NMR, IR, UV-visible, mass, magnetic moments, ESR, TGA, SEM, EDX and powder XRD. Based on the experimental data a square planar geometry around the metal ion is assigned to all the complexes (1a-2c). The interaction of synthesized metal complexes with calf thymus DNA was explored using UV-visible absorption spectra, fluorescence and viscosity measurements. The experimental evidence indicated that all the metal complexes strongly bound to CT-DNA through an intercalation mode. DNA cleavage experiments of metal(II) complexes with supercoiled pBR322 DNA have also been explored by gel electrophoresis in the presence of H2O2 as well as UV light, and it is found that the Cu(II) complexes cleaved DNA more effectively compared to Co(II), Ni(II) complexes. In addition, the ligands and their metal complexes were screened for antimicrobial activity and it is found that all the metal complexes were more potent than free ligands.

  13. Interaction of DNA with Simple and Mixed Ligand Copper(II Complexes of 1,10-Phenanthrolines as Studied by DNA-Fiber EPR Spectroscopy

    Directory of Open Access Journals (Sweden)

    Makoto Chikira

    2015-09-01

    Full Text Available The interaction of simple and ternary Cu(II complexes of 1,10-phenanthrolines with DNA has been studied extensively because of their various interesting and important functions such as DNA cleavage activity, cytotoxicity towards cancer cells, and DNA based asymmetric catalysis. Such functions are closely related to the DNA binding modes of the complexes such as intercalation, groove binding, and electrostatic surface binding. A variety of spectroscopic methods have been used to study the DNA binding mode of the Cu(II complexes. Of all these methods, DNA-fiber electron paramagnetic resonance (EPR spectroscopy affords unique information on the DNA binding structures of the complexes. In this review we summarize the results of our DNA-fiber EPR studies on the DNA binding structure of the complexes and discuss them together with the data accumulated by using other measurements.

  14. Interaction of DNA with Simple and Mixed Ligand Copper(II) Complexes of 1,10-Phenanthrolines as Studied by DNA-Fiber EPR Spectroscopy

    Science.gov (United States)

    Chikira, Makoto; Ng, Chew Hee; Palaniandavar, Mallayan

    2015-01-01

    The interaction of simple and ternary Cu(II) complexes of 1,10-phenanthrolines with DNA has been studied extensively because of their various interesting and important functions such as DNA cleavage activity, cytotoxicity towards cancer cells, and DNA based asymmetric catalysis. Such functions are closely related to the DNA binding modes of the complexes such as intercalation, groove binding, and electrostatic surface binding. A variety of spectroscopic methods have been used to study the DNA binding mode of the Cu(II) complexes. Of all these methods, DNA-fiber electron paramagnetic resonance (EPR) spectroscopy affords unique information on the DNA binding structures of the complexes. In this review we summarize the results of our DNA-fiber EPR studies on the DNA binding structure of the complexes and discuss them together with the data accumulated by using other measurements. PMID:26402668

  15. Synthesis, characterization, X-ray crystal structure, DFT calculation, DNA binding, and antimicrobial assays of two new mixed-ligand copper(II) complexes

    Science.gov (United States)

    Ebrahimipour, S. Yousef; Sheikhshoaie, Iran; Mohamadi, Maryam; Suarez, Sebastian; Baggio, Ricardo; Khaleghi, Moj; Torkzadeh-Mahani, Masoud; Mostafavi, Ali

    2015-05-01

    Two new Cu(II) complexes, [Cu(L)(phen)] (1), [Cu(L)(bipy)] (2), where L2- = (3-methoxy-2oxidobenzylidene)benzohydrazidato, phen = 1,10 phenanthroline, and bipy = 2,2‧ bipyridine, were prepared and fully characterized using elemental analyses, FT-IR, molar conductivity, and electronic spectra. The structures of both complexes were also determined by X-ray diffraction. It was found that, both complexes possessed square pyramidal coordination environment in which, Cu(II) ions were coordinated by donor atoms of HL and two nitrogens of heterocyclic bases. Computational studies were performed using DFT calculations at B3LYP/6-311+G(d,p) level of theory. DNA binding activities of these complexes were also investigated using electronic absorption, competitive fluorescence titration and cyclic voltammetry studies. The obtained results indicated that binding of the complexes to DNA was of intercalative mode. Furthermore, antimicrobial activities of these compounds were screened against microorganisms.

  16. Synthesis and Characterization of the Adducts of Morpholinedithioccarbamate Complexes of Oxovanadium (IV, Nickel(II, and Copper(II with Piperidine and Morpholine

    Directory of Open Access Journals (Sweden)

    Mousami Sharma

    2012-01-01

    Full Text Available A series of 1:1 adducts of bis(morpholinedithiocarbamato complex of VO(IV, 1:1 and 1:2 adducts of bis(morpholinedithiocarbamato complexes of Ni(II and Cu(II with piperidine and morpholine have been synthesized and characterized by elemental analysis, molar conductance, magnetic susceptibility, IR, UV-Vis, and TGA/DTA techniques. Analytical data reveals that VO(IV complex forms only 1:1 adducts with the formula [VO(morphdtc2L].H2O while Ni(II and Cu(II complexes form both 1:1 and 1:2 adducts with 1:1 adducts having general formula Ni(morphdtc2.L and Cu(morphdtc2.L and 1:2 adducts having general formula Ni(morphdtc2.L2 and Cu(morphdtc2.L2 (morphdtc = morpholinedithiocarbamate, L = morpholine and piperidine. Antifungal activity of some complexes has been carried out against the fungal strain Fusarium oxysporium. Thermal studies indicate a continuous weight loss. A square pyramidal geometry has been proposed for the 1:1 adducts of Ni(II and Cu(II complexes while an octahedral geometry has been proposed for the 1:1 adducts of VO(IV and for the 1:2 adducts of Ni(II and Cu(II complexes.

  17. A new ternary copper(II) complex derived from 2-(2'-pyridyl)benzimidazole and glycylglycine: synthesis, characterization, DNA binding and cleavage, antioxidation and HSA interaction.

    Science.gov (United States)

    Fu, Xia-Bing; Lin, Zi-Hua; Liu, Hai-Feng; Le, Xue-Yi

    2014-03-25

    A new ternary copper(II)-dipeptide complex [Cu(glygly)(HPB)(Cl)]⋅2H2O (glygly=glycylglycine anion, HPB=2-(2'-pyridyl)benzimidazole) has been synthesized and characterized. The DNA interaction of the complex was studied by spectroscopic methods, viscosity, and electrophoresis measurements. The antioxidant activity was also investigated using the pyrogallol autoxidation assay. Besides, the interaction of the complex with human serum albumin (HSA) in vitro was examined by multispectroscopic techniques. The complex partially intercalated to CT-DNA with a high binding constant (Kb=7.28×10(5) M(-1)), and cleaved pBR322 DNA efficiently via an oxidative mechanism in the presence of Vc, with the HO· and O2(-) as the active species, and the SOD as a promoter. Furthermore, the complex shows a considerable SOD-like activity with the IC50 value of 3.8386 μM. The complex exhibits desired binding affinity to HSA, in which hydrogen bond or vander Waals force played a major role. The alterations of HSA secondary structure induced by the complex were confirmed by UV-visible, CD, synchronous fluorescence and 3D fluorescence spectroscopy. Copyright © 2013 Elsevier B.V. All rights reserved.

  18. A new ternary copper(II) complex derived from 2-(2";-pyridyl)benzimidazole and glycylglycine: Synthesis, characterization, DNA binding and cleavage, antioxidation and HSA interaction

    Science.gov (United States)

    Fu, Xia-Bing; Lin, Zi-Hua; Liu, Hai-Feng; Le, Xue-Yi

    2014-03-01

    A new ternary copper(II)-dipeptide complex [Cu(glygly)(HPB)(Cl)]ṡ2H2O (glygly = glycylglycine anion, HPB = 2-(2";-pyridyl)benzimidazole) has been synthesized and characterized. The DNA interaction of the complex was studied by spectroscopic methods, viscosity, and electrophoresis measurements. The antioxidant activity was also investigated using the pyrogallol autoxidation assay. Besides, the interaction of the complex with human serum albumin (HSA) in vitro was examined by multispectroscopic techniques. The complex partially intercalated to CT-DNA with a high binding constant (Kb = 7.28 × 105 M-1), and cleaved pBR322 DNA efficiently via an oxidative mechanism in the presence of Vc, with the HO· and O2-rad as the active species, and the SOD as a promoter. Furthermore, the complex shows a considerable SOD-like activity with the IC50 value of 3.8386 μM. The complex exhibits desired binding affinity to HSA, in which hydrogen bond or vander Waals force played a major role. The alterations of HSA secondary structure induced by the complex were confirmed by UV-visible, CD, synchronous fluorescence and 3D fluorescence spectroscopy.

  19. Synthesis, characterization and biological activities of copper(II) complex of 2-Benzimidazolyl-urea and the nitrate salt of 2-Benzimidazolyl-urea

    Science.gov (United States)

    Poyraz, Mehmet; Sari, Musa; Banti, Christina N.; Hadjikakou, Sotiris K.

    2017-10-01

    The synthesis of the complex {[Cu(BZIMU)2](NO3)2} (1) (BZIMU = 2-Benzimidazolyl-urea) is reported here. The complex 1 was characterized by elemental analysis, FT-IR, magnetic susceptibility and molar conductance measurements. The crystal structures of 1 and of the nitrate salt of [(BZIMUH+)(NO3)-] (2) were determined by X-ray diffraction analysis. The copper complex 1 and [(BZIMUH+)(NO3)-] (2) were evaluated for their in vitro cytotoxic activity (cell viability) against human cervix adenocarcinoma (HeLa) and human breast adenocarcinoma (MCF-7) cell line and normal human fetal lung fibroblast cells (MRC-5) with SRB assay.

  20. DNA binding, DNA cleavage and cytotoxicity studies of a new water soluble copper(II) complex: the effect of ligand shape on the mode of binding.

    Science.gov (United States)

    Kashanian, Soheila; Khodaei, Mohammad Mehdi; Roshanfekr, Hamideh; Shahabadi, Nahid; Mansouri, Ghobad

    2012-02-01

    The interaction of native calf thymus DNA (CT-DNA) with [Cu(ph(2)phen)(phen-dione)Cl]Cl was studied at physiological pH by spectrophotometric, spectrofluorometric, circular dichroism, and viscometric techniques. Considerable hypochromicity and red shift are observed in the UV absorption band of the Cu complex. Binding constants (K(b)) of DNA with the complex were calculated at different temperatures. Thermodynamic parameters, enthalpy and entropy changes were calculated according to Van't Hoff equation, which indicated that reaction is predominantly enthalpically driven. All these results indicate that Cu(II) complex interacts with CT-DNA via intercalative mode. Also, this new complex induced cleavage in pUC18 plasmid DNA as indicated in gel electrophoresis and showed excellent antitumor activity against K562 (human chronic myeloid leukemia) and human T lymphocyte carcinoma-Jurkat cell lines. Copyright © 2011 Elsevier B.V. All rights reserved.

  1. Nuclease Activity via Self-Activation and Anticancer Activity of Mononuclear Copper(II) Complex: Novel Role of Tertiary Butyl Group in the Ligand Frame

    OpenAIRE

    Ghosh, Kaushik; Kumar, Pramod; Mohan, Varun; Singh, Udai P.; Kasiri, Sahba; Mandal, Subhrangsu S.

    2012-01-01

    Copper complex [Cu(tBuPhimp)(Cl)] (1) derived from tridentate ligand tBuPhimpH having N2O donors was synthesized and molecular structure was determined. Phenoxyl radical complex was generated in solution at room temperature using Ce(IV) salt. Nuclease activity and anticancer activity of 1 was investigated. Roles of tert-butyl group and singlet oxygen in DNA cleavage activity were also discussed.

  2. Synthesis, Characterization, and Cytotoxic Activities of a Schiff Base Ligand and Its Binuclear Copper(II and Manganese(III Complexes

    Directory of Open Access Journals (Sweden)

    Zafer Uyar

    2017-09-01

    Full Text Available A novel symmetrical N2O2 type Schiff base (1 and its copper (II (2 and manganese (III (3 complexes were synthesized and characterized by spectroscopic, analytical, and magnetic susceptibility studies. Spectroscopic and magnetic susceptibility studies suggested that copper and manganese ions are in 2+ and 3+ states and their complexes have a binuclear double stranded helical structure in the form of 2:2 (metal to ligand stoichiometry. Cytotoxic effects of the ligand and its metal complexes against MCF-7 (human breast cancer cell line, DLD-1 (human colorectal cancer cell line, ECC-1 (human endometrium cancer cell line, DU-145 (human prostate cancer line, MDA-MB231 (human breast cancer cell line, PC-3 (human prostate cancer line and HEK293 (normal cells were evaluated by determining their cellular viability using the colorimetric 3-(4,5- dimethylthiazole-2-yl-2,5-biphenyl tetrazolium bromide (MTT assay. It has been found that cytotoxicity of the ligand was significantly enhanced towards cancer cells and declined towards normal HEK293 cells by metal chelation. Copper complex yielded better results in comparison with manganese complex. Particularly, copper complex showed a selective cytotoxicity, harming the cancerous cell lines while not impairing the normal cells, which is considered as the key to the future of cytotoxic therapy.

  3. Rational design and structural diversity of copper(II) complexes assembled from 3-sulfobenzoate and 2,2‧-bipyridine

    Science.gov (United States)

    Miao, Xiao-He; Zhu, Long-Guan

    2008-04-01

    Three new Cu II/3-sb/2,2'-bipy complexes, [Cu(2,2'-bipy) 2(3-sb)]·4 H 2O ( 1), {[Cu(2,2'-bipy)(3-sb)(H 2O) 2]·2. 5H 2O} n ( 2), and {[Cu(2,2'-bipy)(3-sb)(H 2O)]·2H 2O} n ( 3), in addition to the our previously reported {[Cu(2,2'-bipy)(3-sb)(H 2O)](H 2O)} n ( 4) and [Cu(2,2'-bipy) 2Cl](3-Hsb)·3H 2O ( 5) [3-sb = 3-sulfobenzoate dianion; 2,2'-bipy = 2,2'-bipyridine], have been synthesized by hydrothermal reactions or the combination of hydrothermal reactions and solution evaporation. The molecular structure of complex 1 is a monomer in which the 3-sb monodentately coordinates to the Cu II ion. Complexes 2- 4 exhibit one-dimensional infinite chain structures in which the 3-sb ligands serve as bridges. Complex 5 is a cation-anion species in which the 3-Hsb is non-coordinating. Five complexes exhibit four coordination geometries, irregular geometry between square pyramid and trigonal bipyramid in 1, distorted octahedron in 2, square pyramid in 3- 4, and trigonal bipyramid in 5. These complexes contain lattice and/or coordinated water molecules, therefore extensive hydrogen bonds occur. The extended hydrogen-bonding architectures are 1-D chains for 4 and 5, 2-D layers for 1 and 3, and 3-D network for 2. Complexes 3 and 4 have same crystal system and space group, and afford similar 1-D frameworks but have different lattice water molecules, therefore the addition lattice water molecule in complex 3 leads to more compact packing, longer metal-lattice water distance, and shorter Cu⋯Cu separation by 3-sb compared to those in complex 4. The fluorescent emissions of complexes 1- 3 are stronger than those of ligands, indicating the coordination of 3-sb and 2,2'-bipyridine can enhance the emissions.

  4. Studies on the mixed ligand complexes of copper(II involving a sulfa drug and some potentially bi or tridentate ligands under physiological conditions

    Directory of Open Access Journals (Sweden)

    S. Regupathy

    2014-12-01

    Full Text Available The stability constants of mixed ligand complexes formed in the Cu(II-sulfathiazole(stz(A-glycine(gly, dl-2-aminobutanoic acid(2aba, dl-3-aminobutanoic acid(3aba, 1,2-diaminopropane(dp, 1,3-diaminopropane(tp, dl-2,3-diaminopropanoic acid(dapa, dl-2,4-diaminobutanoic acid(daba, dl-2,5-diaminopentanoic acid(ornithine, orn(B systems have been determined pH-metrically at 37 °C and I = 0.15 mol dm−3 (NaClO4 using SCOGS program. Analysis of experimental data indicates the presence of CuABH, CuAB, CuAB2H2 or CuAB2 species. The Δlog K values demonstrate higher stabilities for the mixed ligand complexes compared to the binary analogues. The CuAB complexes with B = gly, 2aba, dapa & orn systems were isolated and characterized using micro analytical, magnetic moment, ESR, electrochemical studies, TG/DTA, power XRD and SEM analysis. Magnetic susceptibility and electronic spectral studies suggest square planar geometry for the CuAB complexes. The g values indicate that the unpaired electron lies in thedx2-y2 orbital. The TG/DTA studies reveal that the complexes are non hydrated and possesses high thermal stability. The powder XRD data suggest that the complex is microcrystalline. The antimicrobial activity and CT DNA cleavage studies of the complexes are also reported.

  5. Varying coordination modes and magnetic properties of copper(II) complexes with diazamesocyclic ligands by altering additional donor pendants on 1,5-diazacyclooctane.

    Science.gov (United States)

    Bu, X H; Du, M; Shang, Z L; Zhang, R H; Liao, D Z; Shionoya, M; Clifford, T

    2000-09-18

    A series of new diazamesocyclic ligands based on a diazamesocycle, 1,5-diazacyclooctane (DACO), functionalized by additional donor groups--1,5-bis(N-1-methylimidazol-2-ylmethyl)-1,5- diazacyclooctane (L1), 1-(2-hydroxybenzyl)-1,5-diazacyclooctane (HL2), 1,5-bis(2-hydroxybenzyl)-1,5-diazacyclooctane (H2L3), and 1-(N-1-methylimidazol-2-ylmethyl)-1,5-diazacyclooctane (L4)--and their Cu(II) complexes have been synthesized and characterized. Single-crystal X-ray diffraction analysis of the four Cu(II) complexes revealed that L1 forms a five-coordinate mononuclear complex, HL2 a N3- mu-bridged binuclear complex, H2L3 an oxygen mu-bridged trinuclear complex, and L4 a one-dimensional zigzag coordination polymeric complex with Cu(II). [CuL1ClO4](ClO4) (I): a = 12.194(2) A, b = 13.351(3) A, c = 14.473(3) A, beta = 107.10(3) degrees, Z = 4. [CuL2(N3)]2 (II): a = 8.1864(6) A, b = 18.141(2) A, c = 9.3307(7) A, beta = 103.662(6) degrees, Z = 2. [Cu3(L3)2Cl2] (III): a = 10.7296(13) A, b = 13.7707(17) A, c = 13.5523(17) A, beta = 106.350(3) degrees, Z = 2. ([CuL4Cl]2ClO4) infinity (IV): a = 7.279(1) A, b = 23.695(5) A, c = 19.308(4) A, beta = 100.28(3) degrees, Z = 8. All four complexes crystallize in the monoclinic crystal system with the P2(1)/c space group, and each Cu(II) center coordinated with DACO is pentacoordinated with a distorted square-pyramidal or trigonal-bipyrimidal coordination environment. In complex IV, the binuclear cation unit [CuL4Cl]2(2+) constitutes the fundamental building block of an infinite alternating zigzag chain structure, and the binuclear unit contains two types of geometries around the Cu(II) centers: the Cu(1) center is a distorted square-pyramidal environment, while the Cu(2) is a distorted trigonal-bipyramidal coordination environment. To the best of our knowledge, this is the first Cu(II) complex of a diazamesocyclic ligand with an infinite polymeric structure. The magnetic properties of complexes II, III, and IV have been investigated by

  6. Synthesis and characterization of a tetraaza macrocyclic ligand and its cobalt(II, nickel(II and copper(II complexes

    Directory of Open Access Journals (Sweden)

    SULEKH CHANDR

    2010-07-01

    Full Text Available Co(II, Ni(II, and Cu(II complexes with a tetradentate nitrogen donor [N4] macrocyclic ligand, viz. 6,15-dimethyl-8,17diphenyl-7,16-dihydrodibenzo[b,i][1.4.8.11]tetraazacyclotetradecine, were synthesized. Their structures were determined based on elemental analyses, molar conductance and magnetic susceptibility measurements, and IR, 1H-NMR (ligand and electronic spectral studies. Based on analytical and molar conductance data, the complexes may be formulated as [M(LCl2] and [M’(L]Cl2 (where M = Co(II and Cu(II, and M’ = Ni(II due to their non-electrolytic and 1:2 electrolytic nature. Based on spectral studies, an octahedral geometry was assigned for the Co(II complex, whereas square-planar and tetragonal geometry were proposed for the Ni(II and Cu(II complexes, respectively. The synthesized ligand and its complexes were screened for fungicidal activity against two pathogenic fungi (i.e., Fusarium moniliformae and Rhizoctonia solani to assess their growth inhibiting potential.

  7. Efficient Synthesis and Characterization of Some Novel Nitro-Schiff Bases and Their Complexes of Nickel(II and Copper(II

    Directory of Open Access Journals (Sweden)

    Hossein Naeimi

    2013-01-01

    Full Text Available Synthesis and characterization of some new Schiff base ligands derived from various diamines and nitrosalicylaldehyde and their complexes of Ni(II and Cu(II are reported. Several spectral techniques such as UV-Vis, FT-IR, and NMR spectra were used to identify the chemical structures of the reported ligands and their complexes. The ligands are found to be bound to the metal atom through the oxygen atoms of the hydroxyl groups and nitrogen atoms of imine groups, which is also supported by spectroscopic techniques. The results obtained by FT-IR and NMR showed that the Schiff base complexes of transition metal (II have square-planar geometry.

  8. Cobalt(II), nickel(II), copper(II), and zinc(II) complexes with [3(5)]adamanzane, 1,5,9,13-tetraazabicyclo[7.7.3]nonadecane and [(2.3)(2).2(1)]adamanzane, 1,5,9,12-tetraazabicyclo[7.5.2]hexadecane

    DEFF Research Database (Denmark)

    Broge, Louise; Pretzmann, Ulla; Jensen, Nicolai

    2001-01-01

    Isolation of the free bicyclic tetraamine, [3(5)]adamanzane .H2O (1,5,9,13-tetraazabicyclo[7.7.3]nonadecane .H2O), is reported along with the synthesis and characterization of a copper(II) complex of the smaller macrocycle [(2.3)(2).2(1)]-adamanzane (1,5,9,12-tetraazabicyclo[7.5.2]hexadecane......) and of three cobalt(II), four nickel(II), one copper(II), and two zinc(II) complexes with [3(5)]adamanzane. For nine of these compounds (2-8, 10b, and 12) the single-crystal X-ray structures were determined. The coordination geometry around the metal ion is square pyramidal in [Cu([(2.3)(2).2(1)]adz)Br]ClO4 (2......) and trigonal bipyramidal in the isostructural structures [Cu([3(5)]adz)Br]Br (3), [Ni-([3(5)]adz)Cl]Cl (5), [Ni([3(5)]adz)Br]Br (6), and [Co([3(5)]adz)Cl]Cl (8). In [Ni([3(5)]adz)(NO3)]NO3 (4) and [Ni([3(5)]-adz)(ClO4)]ClO4 (7) the coordination geometry around nickel(II) is a distorted octahedron...

  9. Synthesis, Spectroscopic, and Biological Studies of Chromium(III), Manganese(II), Iron(III), Cobalt(II), Nickel(II), Copper(II), Ruthenium(III), and Zirconyl(II) Complexes of N{sup 1},N{sup 2}-Bis(3-((3-hydroxynaphthalen-2-yl)methylene-amino)propyl) phthalamide

    Energy Technology Data Exchange (ETDEWEB)

    Al-Hakimi, Ahmed N. [Faculty of science, Ibb University, Ibb (Yemen); Shakdofa, Mohamad M. E.; El-Seidy, Ahemd M. A. [Inorganic Chemistry Department, National Research Center, Cairo (Egypt); El-Tabl, Abdou S. [El-Menoufia University, El-Kom (Egypt)

    2011-06-15

    Novel chromium(III), manganese(II), iron(III), cobalt(II), nickel(II), copper(II), ruthenium(III), and zirconyl(II) complexes of N{sup 1},N{sup 2}-bis(3-((3-hydroxynaphthalen-2-yl)methylene-amino)propyl)phthalamide (H{sub 4}L, 1) have been synthesized and characterized by elemental, physical, and spectral analyses. The spectral data showed that the ligand behaves as either neutral tridentate ligand as in complexes 2-5 with the general formula [H{sub 4}LMX{sub 2}(H{sub 2}O)]·nH{sub 2}O (M=Cu(II), Ni(II), Co(II), X = Cl or NO{sub 3}), neutral hexadentate ligand as in complexes 10-12 with the general formula [H{sub 4}LM{sub 2}Cl{sub 6}]·nH{sub 2}O (M=Fe(III), Cr(III) or Ru(III)), or dibasic hexadentate ligand as in complexes 6-9 with the general formula [H{sub 2}LM{sub 2}Cl{sub 2}(H{sub 2}O){sub 4}]·nH{sub 2}O (M = Cu(II), Ni(II), Co(II) or Mn(II), and 13 with general formula [H{sub 4}L(ZrO){sub 2}Cl{sub 2}]·8H{sub 2}O. Molar conductance in DMF solution indicated the non-ionic nature of the complexes. The ESR spectra of solid copper(II) complexes 2, 5, and 6 showed g{sub ||}>g>g{sub e}, indicating distorted octahedral structure and the presence of the unpaired electron in the d{sub x} {sup 2}{sub -y}{sup 2} orbital with significant covalent bond character. For the dimeric copper(II) complex [H{sub 2}LCu{sub 2}Cl{sub 2}(H{sub 2}O){sub 4}]·3H{sub 2}O, the distance between the two copper centers was calculated using field zero splitting parameter for the parallel component that was estimated from the ESR spectrum. The antibacterial and antifungal activities of the compounds showed that, some of metal complexes exhibited a greater inhibitory effect than standard drug as tetracycline (bacteria) and Amphotricene B (fungi)

  10. Spectroscopic approach in characterization of chromium(III), manganese(II), iron(III) and copper(II) complexes with a nitrogen donor tetradentate, 14-membered azamacrocyclic ligand.

    Science.gov (United States)

    Chandra, Sulekh; Gupta, Lokesh Kumar

    2005-07-01

    The complexes of Cr(III), Mn(II), Fe(III) and Cu(II) were synthesized with the macrocyclic ligand i.e. 2,3,9,10-tetraketo-1,4,8,11-tetraazacyclotetradecane. The ligand was prepared by the [2 + 2] condensation reaction of diethyloxalate and 1,3-diamino propane. These complexes were found to have the general composition M(L)X3 and M'(L)X2 [where M = Mn(II) and Cu(II), M' = Cr(III) and Fe(III), L = ligand (N4) and X = Cl-, NO3-, 1/2SO4(2-) and [CH3COO-]. The ligand and its transition metal complexes were characterized by the elemental analyses, molar conductance, magnetic susceptibility, mass, IR, electronic, and EPR spectral studies. On the basis of IR, electronic and EPR spectral studies an octahedral geometry has been assigned for Cr(III), Mn(II) and Fe(III) and a tetragonal geometry for Cu(II) complexes.

  11. Bimetallic Oxidation Catalysts. Synthesis, X-ray Analysis, and Reactivity of a Binuclear p-Hydroquinone-Containing Copper(II) Complex

    NARCIS (Netherlands)

    Gelling, Onko Jan; Meetsma, Auke; Feringa, Bernard

    1990-01-01

    The new pentadentate ligand 1,3-bis[N-2-(2'-pyridylethyl)formimidoyl]-2,5-dihydroxybenzene (1) was prepared in five steps from 2,6-dimethylphenol in 21% overall yield. Reaction of 1 with CuII(ClO4)2·6H2O gave the unexpectedly stable hydroquinone-containing binuclear Cu(II) complex

  12. Square pyramidal copper(II) complexes with forth generation fluoroquinolone and neutral bidentate ligand: structure, antibacterial, SOD mimic and DNA-interaction studies.

    Science.gov (United States)

    Patel, Mohan N; Parmar, Pradhuman A; Gandhi, Deepen S

    2010-02-01

    Coordination of neutral bidentate ligand to copper ion in combination with gatifloxacin have been focused in this article. The effect of complexation reflects antibacterial activity, DNA interaction and SOD mimic activity of individual greatly. The geometry at the central metal ion provides a site for binding of superoxide anion responsible for better SOD mimic behaviour. Copyright (c) 2009 Elsevier Ltd. All rights reserved.

  13. Spectroscopic approach in characterization of chromium(III), manganese(II), iron(III) and copper(II) complexes with a nitrogen donor tetradentate, 14-membered azamacrocyclic ligand

    Science.gov (United States)

    Chandra, Sulekh; Gupta, Lokesh Kumar

    2005-07-01

    The complexes of Cr(III), Mn(II), Fe(III) and Cu(II) were synthesized with the macrocyclic ligand i.e. 2,3,9,10-tetraketo-1,4,8,11-tetraazacyclotetradecane. The ligand was prepared by the [2 + 2] condensation reaction of diethyloxalate and 1,3-diamino propane. These complexes were found to have the general composition M(L)X 3 and M'(L)X 2 [where M = Mn(II) and Cu(II), M' = Cr(III) and Fe(III), L = ligand (N 4) and X = Cl -, NO 3-, 1/2SO 42- and [CH 3COO -]. The ligand and its transition metal complexes were characterized by the elemental analyses, molar conductance, magnetic susceptibility, mass, IR, electronic, and EPR spectral studies. On the basis of IR, electronic and EPR spectral studies an octahedral geometry has been assigned for Cr(III), Mn(II) and Fe(III) and a tetragonal geometry for Cu(II) complexes.

  14. DNA binding, DNA cleavage and BSA interaction of a mixed-ligand copper(II) complex with taurine Schiff base and 1,10-phenanthroline.

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    Li, Lianzhi; Guo, Qiong; Dong, Jianfang; Xu, Tao; Li, Jinghong

    2013-08-05

    The DNA-binding properties and DNA-cleavage activities of a Cu(II) complex, [Cu(sal-tau(phen)]·1.5H2O (sal-tau=a Schiff base derived from salicylaldehyde and taurine, phen=1,10-phenanthroline), have been investigated by using UV-Vis absorption, fluorescence, circular dichroism (CD) spectra and agarose gel electrophoresis. Results indicated that this Cu(II) complex can bind to calf thymus DNA (CT-DNA) via an intercalative mode and shows efficient cleavage activity in the absence and presence of reducer. Its intrinsic binding constant Kb (1.66×10(4)M(-1)) was calculated by absorption spectra and its linear Stern-Volmer quenching constant K(sq) (3.05) was obtained from florescence spectroscopy, as well as the cleaving reaction rate constant k1 (2.0×10(-4)s(-1)) was acquired from agarose gel electrophoresis. Meanwhile, the interactions of the complex with BSA have also been studied by spectroscopy. Results showed that the complex could quench the intrinsic fluorescence of bovine serum albumin (BSA) remarkably through a static quenching process, and induce a conformational change with the loss of helical stability of protein. Copyright © 2013 Elsevier B.V. All rights reserved.

  15. DNA and protein binding, double-strand DNA cleavage and cytotoxicity of mixed ligand copper(II) complexes of the antibacterial drug nalidixic acid.

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    Loganathan, Rangasamy; Ganeshpandian, Mani; Bhuvanesh, Nattamai S P; Palaniandavar, Mallayan; Muruganantham, Amsaveni; Ghosh, Swapan K; Riyasdeen, Anvarbatcha; Akbarsha, Mohammad Abdulkader

    2017-09-01

    The water soluble mixed ligand complexes [Cu(nal)(diimine)(H 2 O)](ClO 4 ) 1-4, where H(nal) is nalidixic acid and diimine is 2,2'-bipyridine (1), 1,10-phenanthroline (2), 5,6-dimethyl-1,10-phenanthroline (3), and 3,4,7,8-tetramethyl-1,10-phenanthroline (4), have been isolated. The coordination geometry around Cu(II) in 1 and that in the Density Functional Theory optimized structures of 1-4 has been assessed as square pyramidal. The trend in DNA binding constants (K b ) determined using absorption spectral titration (K b : 1, 0.79±0.1DNA base pair. In contrast, 3 and 4 are involved in intimate hydrophobic interaction with DNA through the methyl substituents on phen ring, which is supported by viscosity and protein binding studies. DNA docking studies imply that 4 is involved preferentially in DNA major groove binding while 1-3 in minor groove binding and that all the complexes, upon removing the axially coordinated water molecule, bind in the major groove. Interestingly, 3 and 4 display prominent double-strand DNA cleavage while 1 and 2 effect only single-strand DNA cleavage in the absence of an activator. The complexes 3 and 4 show cytotoxicity higher than 1 and 2 against human breast cancer cell lines (MCF-7). The complex 4 induces apoptotic mode of cell death in cancer cells. Copyright © 2017 Elsevier Inc. All rights reserved.

  16. Synthesis, crystal structure, spectroscopic investigations and DFT calculations of the copper(II) complex of 4-(Trifluoromethyl)pyridine-2-carboxylic acid

    Science.gov (United States)

    Vural, Hatice; Orbay, Metin

    2017-10-01

    A novel polymeric complex of Cu(II) ion, [Cu(tfpc)2]n [tfpc: 4-(Trifluoromethyl)pyridine-2-carboxylate] has been prepared and characterized spectroscopically (by FT-IR) and structurally (by single-crystal XRD). The geometry around the Cu(II) center can be described as square planar made by tfpc ligand having nitrogen and oxygen atoms. Additionally, the Cu(II) complex has a one-dimensional double-bridged polymeric structure in which Cu(II) ions are bridged by two oxygen atoms of adjacent planes. The crystal packing has been stabilized by Csbnd H⋯O intra and intermolecular hydrogen bonds. The molecular structure of the Cu(II) complex has been optimized using the Density Functional Theory (DFT) B3LYP, B3PW91 and PBEPBE levels with 6-311+G(d,p) basis set. The calculated electronic spectra have been explained using the time dependent DFT (TD-DFT) method by applying the polarized continuum model (PCM). The vibrational spectral data have been calculated and compared with experimental ones. The non-linear optical (NLO) properties of the title compound have been investigated using the DFT method with three different levels. Natural Bond Orbital (NBO) property of the Cu(II) complex has been performed by the B3LYP density functional and the 6-311+G(d,p) basis set.

  17. Copper(II Complexes with Ligands Derived from 4-Amino-2,3-dimethyl-1-phenyl-3-pyrazolin-5-one: Synthesis and Biological Activity

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    Raluca Cernat

    2006-11-01

    Full Text Available The synthesis of Cu(II complexes derived from Schiff base ligands obtainedby the condensation of 2-hydroxybenzaldehyde or terephtalic aldehyde with 4-amino-antipyrine (4-amino-2,3-dimethyl-1-phenyl-3-pyrazolin-5-one is presented. The newlyprepared compounds were characterized by 1H-NMR, UV-VIS, IR and ESRspectroscopy. The determination of the antimicrobial activity of the ligands and of thecomplexes was carried out on samples of Escherichia coli, Klebsiella pneumoniae,Acinetobacter boumanii, Pseudomonas aeruginosa, Staphylococcus aureus and Candidasp. The qualitative and quantitative antimicrobial activity test results proved that all theprepared complexes are very active, especially against samples of Ps. aeruginosa, A.Boumanii, E. coli and S. aureus.

  18. Synthesis and Crystal Structure of a Five-Coordinate Complex of Copper(II) with 4-Nitrobenzenesulfonate and 2, 2'-Bipyridine.

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    Sharif, Mahboubeh A; Tabatabaee, Masoumeh; Beik, Vahideh; Khavasi, Hamid Reza

    2012-06-01

    [Cu(bipy)2Cl](nbs) (1) (bipy = 2,2'-bipyridine, nbs = 4-nitrobenzenesulfonate) was obtained from the reaction of 4-nitrobenzenesulfonyl chloride and 2-amine-4-methylopyridine with CuCl2 in the presence of 2,2'-bipyridine and characterized by elemental analysis, IR spectra and X-ray single-crystal diffraction. The asymmetric unit of (1) contains the cationic complex [Cu(bipy)2Cl]+ and, in the outer coordination sphere, an (nbs)- counter ion.

  19. A new mixed-ligand copper(II) complex of (E)-N";-(2-hydroxybenzylidene) acetohydrazide: Synthesis, characterization, NLO behavior, DFT calculation and biological activities

    Science.gov (United States)

    Yousef Ebrahimipour, S.; Sheikhshoaie, Iran; Crochet, Aurelien; Khaleghi, Moj; Fromm, Katharina M.

    2014-08-01

    A tridentate hydrazone Schiff base ligand, (E)-N";-(2-hydroxybenzylidene)acetohydrazide [HL], and its mixed-ligand Cu(II) complex [CuL(phen)], have been synthesized and characterized by elemental analyses, FT-IR, molar conductivity, UV-Vis spectroscopy. The structure of the complex has been determined by X-ray diffraction. This complex has square pyramidal geometry and the positions around central atom are occupied with donor atoms of Schiff base ligand and two nitrogens of 1,10-phenanthroline. Computational studies of compounds were performed by using DFT calculations. The linear polarizabilities and first hyperpolarizabilities of the studied molecules indicate that these compounds can be good candidates of nonlinear optical materials. It is in accordance with experimental data. In addition, invitro antimicrobial results show that these compounds specially [CuL(phen)] have great potential of antibacterial activity against Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, Listeria monocytogenes bacteria and antifungal activity against Candida Albicans in comparison to some standard drugs.

  20. Simultaneous determination of alcohols including diols and triols by HPLC with ultraviolet detection based on the formation of a copper(II) complex.

    Science.gov (United States)

    Tanaka, Sohei; Dohi, Takumi; Aizawa, Sen-Ichi; Kemmei, Tomoko; Terashima, Hiroyuki; Taga, Atsushi; Yamamoto, Atsushi; Kodama, Shuji

    2017-08-29

    We developed a reversed-phase high-performance liquid chromatography method with ultraviolet detection using on-line complexation with Cu(II) ion for analysis of five alcohols including diols and triol (methanol, ethanol, 1,2-propanediol, 1,3-propanediol, and glycerol). The Cu(II) ion concentration in the mobile phase had a great influence on the peak areas of these alcohols, but not on their retention times. Column temperature (25-40°C) and pH of the mobile phase did not affect the separation of analytes. The optimum separation conditions were determined as 5 mM CuSO4 , 3 mM H2 SO4 , and 3 mM NaOH at 30°C. The ratio of the peak areas for three alcohols (methanol, 1,2-propanediol, and glycerol) was in good agreement with that calculated from the obtained stability constants, molar absorption coefficients for the 1:1 Cu(II) complexes with the three alcohols, and the injected molar quantities. This fact strongly suggests that the observed high-performance liquid chromatography signals resulted from formation of the 1:1 Cu(II)-alcohol complexes. Using the proposed method, these five alcohols in spirit, liquid for electronic cigarette, mouthwash, and nail enamel remover samples were successfully analyzed with only a simple pretreatment. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Synthesis, structure, and nuclease properties of several binary and ternary complexes of copper(II) with norfloxacin and 1,10 phenantroline.

    Science.gov (United States)

    Ruíz, P; Ortiz, R; Perelló, L; Alzuet, G; González-Alvarez, M; Liu-González, M; Sanz-Ruíz, F

    2007-05-01

    Three new binary Cu(II) complexes of norfloxacin have been synthesized and characterized. We also report the synthesis, characterization and X-ray crystallographic structures of a new binary compound, [Cu(HNor)(2)]Cl(2).2H(2)O (2) and two new ternary complexes norfloxacin-copper(II)-phen, [Cu(Nor)(phen)(H(2)O)](NO(3)).3H(2)O (4), and [Cu(HNor)(phen)(NO(3))](NO(3)).3H(2)O (5). The structure of 2 consists of two crystallographically independent cationic monomeric units of [Cu(HNor)(2)](2+), chloride anions, and uncoordinated water molecules. The Cu(II) ion is placed at a center of symmetry and is coordinated to two norfloxacin ligands which are related through the inversion center. The structures of 4 and 5 consist of cationic units ([Cu(Nor)(phen)(H(2)O)](+) for 4 and [Cu(HNor)(phen)(NO(3))](+) for 5), nitrate counteranions, and lattice water molecules that provide crystalline stability through a network of hydrogen-bond interactions. The complexes exhibit a five coordinated motif in a square pyramidal environment around the metal center. The ability of compounds 4 and 5 to cleave DNA has also been studied. Mechanistic studies with different inhibiting reagents reveal that hydroxyl radicals, singlet oxygen, and superoxide radicals are all involved in the DNA scission process mediated by these compounds.

  2. Heterobridged dinuclear, tetranuclear, dinuclear-based 1-d, and heptanuclear-based 1-D complexes of copper(II) derived from a dinucleating ligand: syntheses, structures, magnetochemistry, spectroscopy, and catecholase activity.

    Science.gov (United States)

    Majumder, Samit; Sarkar, Sohini; Sasmal, Sujit; Sañudo, E Carolina; Mohanta, Sasankasekhar

    2011-08-15

    The work in this paper presents syntheses, characterization, crystal structures, variable-temperature/field magnetic properties, catecholase activity, and electrospray ionization mass spectroscopic (ESI-MS positive) study of five copper(II) complexes of composition [Cu(II)(2)L(μ(1,1)-NO(3))(H(2)O)(NO(3))](NO(3)) (1), [{Cu(II)(2)L(μ-OH)(H(2)O)}(μ-ClO(4))](n)(ClO(4))(n) (2), [{Cu(II)(2)L(NCS)(2)}(μ(1,3)-NCS)](n) (3), [{Cu(II)(2)L(μ(1,1)-N(3))(ClO(4))}(2)(μ(1,3)-N(3))(2)] (4), and [{Cu(II)(2)L(μ-OH)}{Cu(II)(2)L(μ(1,1)-N(3))}{Cu(II)(μ(1,1)-N(3))(4)(dmf)}{Cu(II)(2)(μ(1,1)-N(3))(2)(N(3))(4)}](n)·ndmf (5), derived from a new compartmental ligand 2,6-bis[N-(2-pyridylethyl)formidoyl]-4-ethylphenol, which is the 1:2 condensation product of 4-ethyl-2,6-diformylphenol and 2-(2-aminoethyl)pyridine. The title compounds are either of the following nuclearities/topologies: dinuclear (1), dinuclear-based one-dimensional (2 and 3), tetranuclear (4), and heptanuclear-based one-dimensional (5). The bridging moieties in 1-5 are as follows: μ-phenoxo-μ(1,1)-nitrate (1), μ-phenoxo-μ-hydroxo and μ-perchlorate (2), μ-phenoxo and μ(1,3)-thiocyanate (3), μ-phenoxo-μ(1,1)-azide and μ(1,3)-azide (4), μ-phenoxo-μ-hydroxo, μ-phenoxo-μ(1,1)-azide, and μ(1,1)-azide (5). All the five compounds exhibit overall antiferromagnetic interaction. The J values in 1-4 have been determined (-135 cm(-1) for 1, -298 cm(-1) for 2, -105 cm(-1) for 3, -119.5 cm(-1) for 4). The pairwise interactions in 5 have been evaluated qualitatively to result in S(T) = 3/2 spin ground state, which has been verified by magnetization experiment. Utilizing 3,5-di-tert-butyl catechol (3,5-DTBCH(2)) as the substrate, catecholase activity of all the five complexes have been checked. While 1 and 3 are inactive, complexes 2, 4, and 5 show catecholase activity with turn over numbers 39 h(-1) (for 2), 40 h(-1) (for 4), and 48 h(-1) (for 5) in dmf and 167 h(-1) (for 2) and 215 h(-1) (for 4) in acetonitrile

  3. A unique discrete tetranuclear Cu'-Cu(N-N)2Cu-Cu' copper(II) complex, built from a μ3-1,2,4-triazolato-μ-carboxylato ligand, as an effective DNA cleavage agent.

    Science.gov (United States)

    Hernández-Gil, Javier; Ferrer, Sacramento; Castiñeiras, Alfonso; Lloret, Francesc

    2012-09-17

    The title compound, characterized by means of an X-ray structure analysis, represents an easy example of a noncatena "1 + 2 + 1" tetranuclear copper(II) μ(3)-triazolate compound. [Cu(4)(atc)(2)(dien)(4)(ClO(4))(2)](ClO(4))(2)·2H(2)O (1), where H(2)atc = 5-amino-l,2,4-triazole-3-carboxylic acid and dien = diethylenetriamine = 1,4,7-triazaheptane, contains two copper atoms linked by a double diazinic bridge, each of which is further connected to a third and fourth copper atom (Cu') through the triply bridging triazolato ring and the bidentate carboxylato group of the atc(2-) ligands. The copper-copper distances within the tetranuclear unit are Cu-Cu = 4.059 Å, Cu-Cu' = 5.686 and 6.370 Å, and Cu'-Cu' = 11.373 Å. The compound self-assembles into a tridimensional hydrogen-bonded network to generate a MOF. 1 exhibits antiferromagnetic behavior with g = 2.10(1), J = -34.1(2) cm(-1) and j = -5.50(3) cm(-1), where J is the coupling constant of the central Cu-Cu pair and j the coupling constant of the two Cu-Cu' (Cu(central)-Cu(pheripheral)) pairs, as defined by H = -JS(2)S(2a) - j (S(1)S(2) + S(2a)S(1a)). Complex 1 has been tested as nuclease mimic. It shows good binding propensity to calf thymus DNA, with a binding constant value of 6.20 × 10(6) M(-1) (K(app)) and ΔT(m) = 18.3 °C. Moreover, the compound displays efficient oxidative cleavage of pUC18 DNA, even at low concentration, in the presence of a mild reducing agent (ascorbate), with a rate constant for the conversion of supercoiled to nicked DNA (k(obs)) of ~0.126 min(-1). The good reactivity of 1 toward DNA is explained from the electrostatic interactions of the cationic species produced in solution.

  4. A new copper(II) chelate complex with tridentate ligand: Synthesis, crystal and molecular electronic structure of aqua-(diethylenetriamine-N, N‧, N‧‧)-copper(II) sulfate monohydrate and its fire retardant properties

    Science.gov (United States)

    Lavrenyuk, H.; Mykhalichko, O.; Zarychta, B.; Olijnyk, V.; Mykhalichko, B.

    2015-09-01

    The crystals of a new aqua-(diethylenetriamine-N, N‧, N‧‧)-copper(II) sulfate monohydrate have been synthesized by direct interaction of solid copper(II) sulfate pentahydrate with diethylenetriamine (deta). The crystal structure of [Cu(deta)H2O]SO4ṡH2O (1) has been determined by X-ray diffraction methods at 100 K and characterized using X-ray powder diffraction pattern: space group P 1 bar, a = 7.2819(4), b = 8.4669(4), c = 8.7020(3) Å, α = 83.590(3), β = 89.620(4), γ = 84.946(4)°, Z = 2. The environment of the Cu(II) atom is a distorted, elongated square pyramid which consists of three nitrogen atoms of the deta molecule and oxygen atom of the water molecule in the basal plane of the square pyramid (the average lengths of the in-plane Cu-N and Cu-O bonds are 2.00 Å). The apical position of the coordination polyhedron is occupied by complementary oxygen atom of the sulfate anion (the length of the axial Cu-O bond is 2.421(1) Å). The crystal packing is governed by strong hydrogen bonds of O-H⋯O and N-H⋯O types. The ab initio quantum-chemical calculations have been performed by the restricted Hartree-Fock method with a basis set 6-31∗G using the structural data of [Cu(deta)H2O]SO4ṡH2O. It has been ascertained that the degenerate d-orbitals of the Cu2+ ion split under the co-action of both the square-pyramidal coordination and the chelation. It is significant that visually observed crystals color (blue-violet) of the [Cu(deta)H2O]SO4ṡH2O complex is in good agreement with the calculated value of wavelength of visible light (λ = 5735 Å) which is closely related to the energy of the absorbed photon (Δ = 2.161 eV). Furthermore, the stereo-chemical aspect of influence of the CuSO4 upon combustibility of modified epoxy-amine polymers has been scrutinized.

  5. Synthesis, spectroscopy, and electrochemistry of copper(II) complexes with N, N'-bis(3,5-di- t-butylsalicylideneimine)polymethylenediamine ligands

    Science.gov (United States)

    Kasumov, Veil T.; Köksal, Fevzi

    2005-01-01

    Bulky salen CuL x derived from aliphatic polymethylene diamines, H 2N(CH 2) xNH 2, where n=2-6, and 3,5-di- t-butylsalicylaldehyde (H 2L x) and some corresponding tetrahydrosalan complexes (CuL x') have been synthesized and characterized by their IR, UV-vis absorption and EPR spectra, by magnetic moments and by cyclic voltammetry in acetonitrile (for H 2L x) and DMF (for CuL x). Complexes CuL x and CuL x' are magnetically normal ( μexp=1.83-1.91 μB). EPR spectra CuL x characterized by the axial g and ACu tensors with g||> g⊥ and without 14N-shf resolution in CHCl 3/toluene at 300 and 150 K. The CV studies on acetonitrile solutions of H 2L x revealed a well-defined quasi-reversible redox wave at E1/2=0.95-1.15 V versus Ag/AgCl but CV of the CuL x complexes in DMF exhibit weak pronounced irreversible oxidation waves at Epa1=0.51-0.98 V and Epa2=1.16-1.33 V attributable to metal centered Cu(II/III) and ligand centered CuL x/CuL xrad + couples, respectively. A poorly defined wave was observed for the quasi-reversible reduction Cu(II)/Cu(I) at potentials less than -1.0 V.

  6. Synthesis, characterization, electrochemical studies and X-ray structures of mixed-ligand polypyridyl copper(II complexes with the acetate

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    Adekunle Oluwafunmilayo F.

    2016-01-01

    Full Text Available [Cu(phen2(CH3COO](ClO4.2H2O (1 and [Cu(bipy2(CH3COO]-(ClO4.H2O (2 {phen = 1,10-phenanthroline, bipy = 2,2’-bipyridine}were synthesized and characterized. The complexes were characterized by employying elemental analyses, infrared and UV-Visible spectroscopy, room temperature magnetic measurements and the crystal structures elucidated using X-ray diffraction experiment. The redox properties of the complexes were also investigated. Both structures have a square pyramidal CuN4O chromophore which exhibit significant distortions due to long Cu-O [2.217(3 Å for (1 and 2.179 (1 for (2] and Cu-N [2.631(2 Å for (1 and 2.714(1 Å for (2] bonds. This distortion if further shown by the O-Cu-N bond angles [147.71(8 o for (1 and 153.40(5 o for (2]. The elemental analyses further support the structural details unveiled by the single crystal X-ray diffraction analysis. The infrared spectra shows the acetate vibrational frequencies at 1587 cm-1,1428 cm-1, 1314 cm-1 for (1 and 1571 cm-1, 1441 cm-1, 1319c m-1 for (2 and the perchlo-rate bands at 1059 cm-1, 720 cm-1 (1 and 1080 cm-1,768 cm-1 (2. The broad d-d bands for the copper ion at 14,514 cm-1(1 and 14,535 cm-1(2 support the adoption of square pyramid geometries. The magnetic moments for the two complexes are 1.83 B.M for (1 and 1.72 B.M for (2. The peak to peak values of the two complexes show that the electrode reactions are quasi-reversibile with ΔEp = 0.023V (1 and 0.025V for (2. In both structures, there are π-π intermolecular interactions in addition to hydrogen bonding between the units.

  7. In Vitro DNA-Binding, Anti-Oxidant and Anticancer Activity of Indole-2-Carboxylic Acid Dinuclear Copper(II Complexes

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    Xiangcong Wang

    2017-01-01

    Full Text Available Indole-2-carboxylic acid copper complex (ICA-Cu was successfully prepared and characterized through elemental analysis, IR, UV-Vis, 1H-NMR, TG analysis, and molar conductance, and its molecular formula was [Cu2(C9H6O2N4(H2O2]·2H2O. The binding ability of ICA-Cu to calf thymus DNA (CT-DNA was examined by fluorescence spectrometry and the viscosity method. The results indicated that, upon the addition of increasing amounts of CT-DNA, the excitation and emission intensity of ICA-Cu decreased obviously and the excitation spectra shifted towards a long wavelength. ICA-Cu could displace ethidium bromide (EB from the EB-DNA system, making the fluorescence intensity of the EB-DNA system decrease sharply; the quenching constant KSV value was 3.99 × 104 M−1. The emission intensity of the ICA-Cu-DNA system was nearly constant, along with the addition of Na+ in a series of concentrations. The fluorescence of the complex could be protected after the complex interacted with DNA. A viscosity measurement further supported the result that the ICA-Cu complex may interact with DNA in an intercalative binding mode. The antioxidant activities of ICA-Cu were evaluated by a 2,2-diphenyl-1-picrylhydrazyl (DPPH assay, a hydroxyl radical (OH scavenging assay, and a 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid (ABTS assay. The ICA-Cu exhibited the highest inhibitory effects on the ABTS radical (94% inhibition at 60 µM, followed by OH and DPPH radicals (the degrees of inhibition being 71% and 56%, respectively. The in vitro cytotoxicity activity of ICA-Cu against two human breast cancer cell lines, MDA-MB-231 and MCF-7, was investigated by 3-[4,5-dimethyltiazol2-yl]-2.5-diphenyl-tetrazolium bromide (MTT assay and cellular morphological analysis. The results showed that, upon increasing the concentration of ICA-Cu, an increase was observed in growth-inhibitory activity and the inhibition percentage were greater than 90% at 20 µM in both cell lines. Also

  8. In Vitro DNA-Binding, Anti-Oxidant and Anticancer Activity of Indole-2-Carboxylic Acid Dinuclear Copper(II) Complexes.

    Science.gov (United States)

    Wang, Xiangcong; Yan, Maocai; Wang, Qibao; Wang, Huannan; Wang, Zhengyang; Zhao, Jiayi; Li, Jing; Zhang, Zhen

    2017-01-20

    Indole-2-carboxylic acid copper complex (ICA-Cu) was successfully prepared and characterized through elemental analysis, IR, UV-Vis, ¹H-NMR, TG analysis, and molar conductance, and its molecular formula was [Cu₂(C₉H₆O₂N)₄(H₂O)₂]·2H₂O. The binding ability of ICA-Cu to calf thymus DNA (CT-DNA) was examined by fluorescence spectrometry and the viscosity method. The results indicated that, upon the addition of increasing amounts of CT-DNA, the excitation and emission intensity of ICA-Cu decreased obviously and the excitation spectra shifted towards a long wavelength. ICA-Cu could displace ethidium bromide (EB) from the EB-DNA system, making the fluorescence intensity of the EB-DNA system decrease sharply; the quenching constant K SV value was 3.99 × 10⁴ M -1 . The emission intensity of the ICA-Cu-DNA system was nearly constant, along with the addition of Na⁺ in a series of concentrations. The fluorescence of the complex could be protected after the complex interacted with DNA. A viscosity measurement further supported the result that the ICA-Cu complex may interact with DNA in an intercalative binding mode. The antioxidant activities of ICA-Cu were evaluated by a 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay, a hydroxyl radical (OH) scavenging assay, and a 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid (ABTS) assay. The ICA-Cu exhibited the highest inhibitory effects on the ABTS radical (94% inhibition at 60 µM), followed by OH and DPPH radicals (the degrees of inhibition being 71% and 56%, respectively). The in vitro cytotoxicity activity of ICA-Cu against two human breast cancer cell lines, MDA-MB-231 and MCF-7, was investigated by 3-[4,5-dimethyltiazol2-yl]-2.5-diphenyl-tetrazolium bromide (MTT) assay and cellular morphological analysis. The results showed that, upon increasing the concentration of ICA-Cu, an increase was observed in growth-inhibitory activity and the inhibition percentage were greater than 90% at 20 µM in both cell

  9. Syntheses, structural properties and catecholase activity of copper(II) complexes with reduced Schiff base N-(2-hydroxybenzyl)-amino acids.

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    Yang, Chang-Tong; Vetrichelvan, Muthalagu; Yang, Xiandong; Moubaraki, Boujemaa; Murray, Keith S; Vittal, Jagadese J

    2004-01-07

    A number of dicopper(II) complexes of reduced Schiff base ligands, N-(2-hydroxybenzyl)-amino acids [Cu2L2(H2O)x].yH2O (L = Sgly (1), D-Sala (2), L-Sala (3), DL-Sala (4), Sab2 (5), Sbal (6), Sab4 (7), Sval (8), Shis (9), Styr (10) and Stryp (11), x= 0-2 & y= 0-2) have been synthesized, and the solid-state structures of, and have been determined. The compounds and are binuclear in which the Cu(II) centres have square-pyramidal geometry with apical sites occupied by aqua ligands. In and one axial site is occupied by water and the other by an oxygen atom of the carboxylate group from the adjacent dimer through oxygen atoms to form 1D helical polymer. Variable temperature magnetic measurements of the dimer and helical polymer showed that they are typical for moderately strong antiferromagnetic coupling. All the complexes show significant catalytic activity on the oxidation of 3,5-di-tert-butylcatechol. The activity measured in terms of Kcat in the range 199-3800 h(-1) has been found to follow the order: 7>6>8>3>5 approximately 2 approximately 1>4 >10 >9 >11. The catalytic activity is found to increase with increasing the length of the methylene side chain of the amino acid in the reduced Schiff base ligands.

  10. SYNTHESIS AND STUDY OF COMPLEXES OF COPPER(II, ZINC, COBALT(II AND NICKEL(II WITH NITROFLUORENYLIDENE-9-AMINO(IMINO DERIVATIVES

    Directory of Open Access Journals (Sweden)

    S.B. Strashnova

    2009-12-01

    Full Text Available The complexes of general formula MCl2∙L1-4∙nH2O (where L1 - N-(2,4,7-trinitrofluorenilidene-9-p-dimethyl-aminoanilin, L2 - N-(2,4,5,7-tetranitrofluorenilidene-9-p-dimethylaminoaniline, L3 - N-(2,4,7-trinitrofluorenilidene-N-(p-dimethylaminophenylhydroxylamine, L4 - N-(2,4,5,7-tetranitrofluorenilidene-9-N-(p-dimethylaminophenyl-hydroxylamine; M=Cu, Co, Ni, Zn; n= 1-3 have been synthesized and investigated by different methods. Spectral criteria of co-ordination of the molecules L1 –L4 in electronic adsorption spectra were detected.

  11. Synthesis, crystal structure, EPR properties, and anti-convulsant activities of binuclear and mononuclear 1,10-phenanthroline and salicylate ternary copper(II) complexes.

    Science.gov (United States)

    Lemoine, Pascale; Viossat, Bernard; Morgant, Georges; Greenaway, Frederick T; Tomas, Alain; Dung, Nguyen Huy; Sorenson, John R J

    2002-04-10

    Two ternary Cu(II) complexes of 1,10-phenanthroline (phen) and singly (Hsal(-)) or dideprotonated (sal(2-)) salicylate ligands were synthesized, their X-ray crystal structure and electron paramagnetic resonance spectral characteristics determined, and evaluated for anti-convulsant activities in the maximal electroshock (MES) and Metrazol models of seizure and Rotorod toxicity. The X-ray crystal structure of [bis(1,10-phenanthroline)-mu-bis(salicylato-O,O')dicopper(II)] dihydrate, 1, ([Cu(II)(2)(phen)(2)(sal)(2)].2[H(2)O]), shows it to be binuclear. This dimer consists of two centrosymmetrically related pseudo-five coordinate Cu(II) atoms 3.242(2) A apart and bridged by two dideprotonated salicylate ligands. The X-ray crystal structure of [bis(1,10-phenanthroline)(salicylato)copper(II)][salicylate] monohydrate, 2, ([Cu(II)(phen)(2)(Hsal)](+)[Hsal](-)[H(2)O]), shows it to be mononuclear. This complex cation exhibits a highly irregular distorted square pyramidal geometry about the Cu(II) atom, (4+1+1*). Each salicylate is singly deprotonated and one of them is ligand bonded in an asymmetric chelating mode. EPR results for 2 indicate that in concentrated DMF solution phen remains bonded to copper but salicylate is likely monodentate in contrast to the situation for 1. However, in dilute DMF solution, both 1 and 2 form the same species, which accounts for the similarity in anti-convulsant activity of the two compounds. Both 1 and 2 were found to be effective in preventing MES-induced seizures and ineffective in preventing Metrazol-induced seizures. Rotorod toxicity, consistent with central nervous system depression, paralleled the observed anti-convulsant activity. It is suggested that the observed anti-convulsant activity is consistent with central nervous system depression as a physiological mechanism in overcoming MES-induced seizures due to MES-induced brain inflammatory disease.

  12. Interesting properties of some iron(II), copper(I) and copper(II ...

    Indian Academy of Sciences (India)

    Administrator

    Tridendate ligands with nitrogen centers, generally well-known as the tripod ligands, have been of considerable interest to inorganic chemists dealing with the preparation of model compounds for hemocyanin, tyrosinase etc. We have found that such ligands when complexed with iron(II) and copper(II) and copper(I) ions ...

  13. Ion Flotation of Copper(II) and Lead(II) from Environmental Water ...

    African Journals Online (AJOL)

    The present study aims to develop a simple, rapid and economic procedure for copper(II) and lead(II) removal under the optimum conditions investigated. It is based on the complex formation between Cu2+ and Pb2+ ions and diphenylcarbazone (HDPC) followed by flotation with oleic acid (HOL) surfactant. The different ...

  14. Mechanisms for biosorption of chromium(III), copper(II) and mercury ...

    African Journals Online (AJOL)

    This shows that the softer metal ions, copper(II) and mercury(II), form complexes with oxygen and/or nitrogen donor ligands in the MO extracts, while the harder and more highly charged chromium(III) ion becomes hydrolysed. The study therefore suggests that the successful biosorption of heavy metals by Moringa, ...

  15. Copper(ii) complexes of a polydentate imidazole-based ligand. pH effect on magnetic coupling and catecholase activity.

    Science.gov (United States)

    Mijangos, Edgar; Reedijk, Jan; Gasque, Laura

    2008-04-14

    A potentially dodecadentate N8O4-donor ligand obtained from 2,2'-biimidazole and l-valine and its tetranuclear Cu(ii) complexes in different degrees of protonation were characterized by chemical and spectroscopic methods. The extensive solution studies performed reveal that the rise in pH media leads successively to the formation of imidazolato (pKa(1) and pKa(2) and hydroxido (pKa(3) and pKa(4)) bridges. A frozen solution EPR study shows a decrease in the signal intensity until an EPR silent spectrum is observed, upon increasing the basicity of the solution. The catalytic performance of the oxidation of 3,5-di-tert-butylcatechol to its corresponding quinone was studied using UV-Vis-NIR absorption spectroscopic methods in CH3CN-H2O and in CH3OH-H2O at pH = 7.5, 8.0 and 8.5. A marked increase in activity, consistent with the formation of the hydroxide bridged species, is observed at pH = 8.5 in both solvent mixtures, but the activity is significantly higher in CH3OH-H2O.

  16. Photocleavage of DNA by copper (II) complexes

    Indian Academy of Sciences (India)

    The chemistry of ternary and binary copper(II) complexes showing efficient visible lightinduced DNA cleavage activity is summarized in this article. The role of the metal in photo-induced DNA cleavage reactions is explored by designing complex molecules having a variety of ligands. Ternary copper(II) complexes with amino ...

  17. The ligational behavior of an isatinic quinolyl hydrazone towards copper(II- ions

    Directory of Open Access Journals (Sweden)

    Mousa Marwa A

    2011-04-01

    Full Text Available Abstract Background The importance of the isatinic quinolyl hydrazones arises from incorporating the quinoline ring with the indole ring. Quinoline ring has therapeutic and biological activities whereas, the indole ring occurs in Jasmine flowers and Orange blossoms. As a ligand, the isatin moiety is potentially ambidentate and can coordinate the metal ions either through its lactam or lactim forms. In a previous study, the ligational behavior of a phenolic quinolyl hydrazone towards copper(II- ions has been studied. As continuation of our interest, the present study is planned to check the ligational behavior of an isatinic quinolyl hydrazone. Results New homo- and heteroleptic copper(II- complexes were obtained from the reaction of an isatinic quinolyl hydrazone (HL with several copper(II- salts viz. Clˉ, Brˉ, NO3ˉ, ClO4-, SO42- and AcO-. The obtained complexes have Oh, Td and D4h- symmetry and fulfill the strong coordinating ability of Clˉ, Brˉ, NO3ˉ and SO42- anions. Depending on the type of the anion, the ligand coordinates the copper(II- ions either through its lactam (NO3ˉ and ClO4- or lactim (the others forms. Conclusion The effect of anion for the same metal ion is obvious from either the geometry of the isolated complexes (Oh, Td and D4h or the various modes of bonding. Also, the obtained complexes fulfill the strong coordinating ability of Clˉ, Brˉ, NO3ˉ and SO42- anions in consistency with the donor ability of the anions. In case of copper(II- acetate, a unique homoleptic complex (5 was obtained in which the AcO- anion acts as a base enough to quantitatively deprotonate the hydrazone. The isatinic hydrazone uses its lactim form in most complexes.

  18. Catechol oxidase activity of a series of new dinuclear copper(II) complexes with 3,5-DTBC and TCC as substrates: syntheses, X-ray crystal structures, spectroscopic characterization of the adducts and kinetic studies.

    Science.gov (United States)

    Banu, Kazi Sabnam; Chattopadhyay, Tanmay; Banerjee, Arpita; Bhattacharya, Santanu; Suresh, Eringathodi; Nethaji, Munirathinam; Zangrando, Ennio; Das, Debasis

    2008-08-18

    A series of dinuclear copper(II) complexes has been synthesized with the aim to investigate their applicability as potential structure and function models for the active site of catechol oxidase enzyme. They have been characterized by routine physicochemical techniques as well as by X-ray single-crystal structure analysis: [Cu 2(H 2L2 (2))(OH)(H 2O)(NO 3)](NO 3) 3.2H 2O ( 1), [Cu(HL1 (4))(H 2O)(NO 3)] 2(NO 3) 2.2H 2O ( 2), [Cu(L1 (1))(H 2O)(NO 3)] 2 ( 3), [Cu 2(L2 (3))(OH)(H 2O) 2](NO 3) 2, ( 4) and [Cu 2(L2 (1))(N 3) 3] ( 5) [L1 = 2-formyl-4-methyl-6R-iminomethyl-phenolato and L2 = 2,6-bis(R-iminomethyl)-4-methyl-phenolato; for L1 (1) and L2 (1), R = N-propylmorpholine; for L2 (2), R = N-ethylpiperazine; for L2 (3), R = N-ethylpyrrolidine, and for L1 (4), R = N-ethylmorpholine]. Dinuclear 1 and 4 possess two "end-off" compartmental ligands with exogenous mu-hydroxido and endogenous mu-phenoxido groups leading to intermetallic distances of 2.9794(15) and 2.9435(9) A, respectively; 2 and 3 are formed by two tridentate compartmental ligands where the copper centers are connected by endogenous phenoxido bridges with Cu-Cu separations of 3.0213(13) and 3.0152(15) A, respectively; 5 is built by an end-off compartmental ligand having exogenous mu-azido and endogenous mu-phenoxido groups with a Cu-Cu distance of 3.133(2) A (mean of two independent molecules). The catecholase activity of all of the complexes has been investigated in acetonitrile and methanol medium by UV-vis spectrophotometric study using 3,5-di- tert-butylcatechol (3,5-DTBC) and tetrachlorocatechol (TCC) as substrates. In acetonitrile medium, the conversion of 3,5-DTBC to 3,5-di- tert-butylbenzoquinone (3,5-DTBQ) catalyzed by 1- 5 is observed to proceed via the formation of two enzyme-substrate adducts, ES1 and ES2, detected spectroscopically for the first time. In methanol medium no such enzyme-substrate adduct has been detected, and the 3,5-DTBC to 3,5-DTBQ conversion is observed to be catalyzed by 1- 5

  19. Phosphate effects on copper(II) and lead(II) sorption to ferrihydrite

    Science.gov (United States)

    Tiberg, Charlotta; Sjöstedt, Carin; Persson, Ingmar; Gustafsson, Jon Petter

    2013-11-01

    Transport of lead(II) and copper(II) ions in soil is affected by the soil phosphorus status. Part of the explanation may be that phosphate increases the adsorption of copper(II) and lead(II) to iron (hydr)oxides in soil, but the details of these interactions are poorly known. Knowledge about such mechanisms is important, for example, in risk assessments of contaminated sites and development of remediation methods. We used a combination of batch experiments, extended X-ray absorption fine structure (EXAFS) spectroscopy and surface complexation modeling with the three-plane CD-MUSIC model to study the effect of phosphate on sorption of copper(II) and lead(II) to ferrihydrite. The aim was to identify the surface complexes formed and to derive constants for the surface complexation reactions. In the batch experiments phosphate greatly enhanced the adsorption of copper(II) and lead(II) to ferrihydrite at pH < 6. The largest effects were seen for lead(II).

  20. Copper (II) complexes with aroylhydrazones

    Indian Academy of Sciences (India)

    Copper(II) complexes with aroylhydrazones ... The coordination chemistry of copper(II) with tridentate aroylhydrazones is briefly discussed in this article. ... EPR spectroscopy and variable temperature magnetic susceptibility measurements have been used to reveal the nature of the coordination geometry and magnetic ...

  1. Formation of a new copper(II) dimer through heterocyclic ligand ring opening reaction: Supramolecular features and magnetic properties

    Science.gov (United States)

    Gonçalves, Bruna Lisboa; Gervini, Vanessa Carratu; Flores, Alex Fabiani Claro; Junior, Jorge Luiz Pimentel; Bortoluzzi, Adailton João; Burrow, Robert Alan; Duarte, Rafael; da Silva, Robson Ricardo; Vicenti, Juliano Rosa de Menezes

    2017-01-01

    Two new compounds were synthesized and characterized in this work: the heterocycle (Z)-1-(4-(hydroxyimino)-3,5-dimethyl-1-(methylcarbamothioyl)-4,5-dihydro-1H-pyrazol-5-yl)-4-methylthiosemicarbazide and a copper(II) thiosemicarbazonato dimeric complex. Green prismatic single crystals of the dimer were obtained by the reaction of the heterocycle with copper(II) chloride dihydrate. Both compounds were essentially characterized by spectroscopic methods and X-ray diffraction crystallography. The crystal structures revealed molecules connected through supramolecular hydrogen bond interactions and copper(II) centers in a slightly distorted square-pyramidal environment. SQUID magnetometry performed for the dimer revealed both ferromagnetic and antiferromagnetic interactions in the studied complex, presenting a critical temperature of 19 K.

  2. Interactions between copper(II) and DOM in the urban stormwater runoff: modeling and characterizations.

    Science.gov (United States)

    Zhao, Chen; Wang, Chong-Chen; Li, Jun-Qi; Wang, Peng; Ou, Jia-Qi; Cui, Jing-Rui

    2018-01-01

    Dissolved organic matter (DOM) can strongly interact with both organic and inorganic contaminants to influence their transportation, transformation, bioavailability, toxicity and even their ultimate fate. Within this work, DOM was extracted from urban stormwater runoff samples collected from a regular sampling site of a typical residential area in Beijing, China. Copper(II) ions were selected as model to investigate the interactions between DOM and typical heavy metals. Both ultraviolet (UV) absorbance and fluorescence titration methods were introduced to determine the complex capacities (CL) and conditional stability constants (log KM) of bonding between DOM and copper (II) ions, which revealed that the values of CL were 85.62 and 87.23 μmol mg-1 and the log KM values were 5.37 and 5.48, respectively. The results suggested the successful complexation between DOM and copper(II) ions. Furthermore, morphology of the DOM binding to copper(II) ions was confirmed by both energy-dispersive X-ray spectroscopy (EDX) and X-ray photoelectron spectroscopy (XPS), which can facilitate to clarify the corresponding mechanism. The Cu 2p3/2 peak at 933.7 eV and the characteristic shake-up peaks of Cu-O were found in the XPS spectra, implying that copper(II) ions might coordinate with hydroxyl (aliphatic or phenolic) or carboxyl groups. With these profitable results, it can be concluded that DOM in urban stormwater runoff has a strong binding affinity with copper(II) ions, which may further lead to potentially significant influence on their migration and transformation.

  3. Synthesis, characterization, crystal structure determination and computational study of a new Cu(II) complex of bis [2-{(E)-[2-chloroethyl)imino]methyl}phenolato)] copper(II) Schiff base complex

    Science.gov (United States)

    Grivani, Gholamhossein; Vakili, Mohammad; Khalaji, Aliakbar Dehno; Bruno, Giuseppe; Rudbari, Hadi Amiri; Taghavi, Maedeh

    2016-07-01

    The copper (II) Schiff base complex of [CuL2] (1), HL = 2-{(E)-[2-chloroethyl) imino]methyl}phenol, has been synthesized and characterized by elemental (CHN) analysis, UV-Vis and FT-IR spectroscopy. The molecular structure of 1 was determined by single crystal X-ray diffraction technique. The conformational analysis and molecular structures of CuL2 were investigated by means of density functional theory (DFT) calculations at B3LYP/6-311G* level. An excellent agreement was observed between theoretical and experimental results. The Schiff base ligand of HL acts as a chelating ligand and coordinates via one nitrogen atom and one oxygen atom to the metal center. The copper (II) center is coordinated by two nitrogen atoms and two oxygen atoms from two Schiff base ligands in an approximately square planar trans-[MN2O2] coordination geometry. Thermogravimetric analysis of CuL2 showed that it was decomposed in five stages. In addition, the CuL2 complex thermally decomposed in air at 660 °C and the XRD pattern of the obtained solid showed the formation of CuO nanoparticles with an average size of 34 nm.

  4. Preparation and characterization of surfactant-modified hydroxyapatite/zeolite composite and its adsorption behavior toward humic acid and copper(II).

    Science.gov (United States)

    Zhan, Yanhui; Lin, Jianwei; Li, Jia

    2013-04-01

    A novel composite material, i.e., surfactant-modified hydroxyapatite/zeolite composite, was used as an adsorbent to remove humic acid (HA) and copper(II) from aqueous solution. Hydroxyapatite/zeolite composite (HZC) and surfactant-modified HZC (SMHZC) were prepared and characterized by X-ray diffraction, Fourier transform infrared spectroscopy, and field emission scanning electron microscope. The adsorption of HA and copper(II) on SMHZC was investigated. For comparison purposes, HA adsorption onto HZC was also investigated. SMHZC exhibited much higher HA adsorption capacity than HZC. The HA adsorption capacity for SMHZC decreased slightly with increasing pH from 3 to 8 but decreased significantly with increasing pH from 8 to 12. The copper(II) adsorption capacity for SMHZC increased with increasing pH from 3 to 6.5. The adsorption kinetic data of HA and copper(II) on SMHZC obeyed a pseudo-second-order kinetic model. The adsorption of HA and copper(II) on SMHZC took place in three different stages: fast external surface adsorption, gradual adsorption controlled by both film and intra-particle diffusions, and final equilibrium stage. The equilibrium adsorption data of HA on SMHZC better fitted to the Langmuir isotherm model than the Freundlich isotherm model. The equilibrium adsorption data of copper(II) on SMHZC could be described by the Langmuir, Freundlich, and Dubinin-Radushkevich isotherm models. The presence of copper(II) in solution enhanced HA adsorption onto SMHZC. The presence of HA in solution enhanced copper(II) adsorption onto SMHZC. The mechanisms for the adsorption of HA on SMHZC at pH 7 may include electrostatic attraction, organic partitioning, hydrogen bonding, and Lewis acid-base interaction. The mechanisms for the adsorption of copper(II) on SMHZC at pH 6 may include surface complexation, ion exchange, and dissolution-precipitation. The obtained results indicate that SMHZC can be used as an effective adsorbent to simultaneously remove HA and

  5. Mixed-ligand binuclear copper (II) complex of 5 ...

    Indian Academy of Sciences (India)

    Absorption spectroscopy exhibits d-d transition at 628 nm, which further supports the square pyramidal geometry around the copper(II) ions. EPR spectrum of the copper(II) complex at room temperature shows a broad signal without any splitting pattern at ∥ = 2.26, ⊥ = 2.03 and the magnetic moment (eff = 1.31 BM) ...

  6. Copper(II)–imida‐salen Complexes Encapsulated into NaY Zeolite for Oxidations Reactions

    DEFF Research Database (Denmark)

    Kuźniarska‐Biernacka, Iwona; Carvalho, M. Alice; Rasmussen, Søren Birk

    2013-01-01

    heterogeneous catalysts were characterized by SEM, XRD, FTIR, EPR and Raman spectroscopy as well as by chemical analysis. The structures of the copper(II) complexes were proposed on the basis of theoretical studies (DFT). The catalytic activities of the encapsulated copper(II) complexes in NaY were compared...

  7. Synthesis and characterization of thermally stable oligomer-metal complexes of copper(II), nickel(II), zinc(II) and cobalt(II) derived from oligo-p-nitrophenylazomethinephenol

    OpenAIRE

    Ufuk S. Vural; Hasan Mart; H. Okkes Demir; Ozlem Sarıöz; Vefa Muradoğlu; M. Cihangir Koç

    2006-01-01

    Thermally stable metal complexes based on oligomers were prepared by the reaction between oligo-p-nitrophenilazomethinephenol (ONPAP) and Cu(II), Ni(II), Zn(II) and Co(II) ions. The properties of oligomer-metal complexes were studied by elemental, FT-IR and magnetic moments analyses. The thermal stabilities of the oligomer-metal complexes were compared by thermogravimetric (TG) and differential thermal (DTA) analyses. According to TG, oligomer-metal complexes were stable against to temperatur...

  8. An efficient, cost effective, sensing behaviour liquid-liquid extraction and spectrophotometric determination of copper(II) incorporated with 4-(4‧-chlorobenzylideneimino)-3-methyl-5-mercapto-1, 2, 4-triazole: Analysis of food samples, leafy vegetables, fertilizers and environmental samples

    Science.gov (United States)

    Barache, Umesh B.; Shaikh, Abdul B.; Lokhande, Tukaram N.; Kamble, Ganesh S.; Anuse, Mansing A.; Gaikwad, Shashikant H.

    2018-01-01

    The aim of the present work is to develop an efficient, simple and selective moreover cost-effective method for the extractive spectrophotometric determination of copper(II) by using the Schiff base 4-(4‧-chlorobenzylideneimino)-3-methyl-5-mercapto-1, 2, 4-triazole [CBIMMT]. This chromogenic reagent forms a yellow coloured complex with copper(II) in acetate buffer at pH 4.2. The copper(II) complex with ligand is instantly extracted into chloroform and shows a maximum absorbance at 414 nm which remains stable for > 48 h. The composition of extracted complex is found to be 1:2 [copper(II): reagent] which was ascertained using Job's method of continuous variation, mole ratio method and slope ratio method. Under optimal conditions, the copper(II) complex in chloroform adheres to Beer's law up to 17.5 μg mL- 1 of copper(II). The optimum concentration range obtained from Ringbom's plot is from 5 μg mL- 1 to 17.5 μg mL- 1. The molar absorptivity, Sandell's sensitivity and enrichment factor of the extracted copper(II) chelate are 0.33813 × 104 L mol- 1 cm- 1, 0.01996 μg cm- 2 and 2.49 respectively. In the extraction of copper(II), several affecting factors including the solution pH, ligand concentration, equilibrium time, effect of foreign ions are optimized. The interfering effects of various cations and anions were also studied and use of masking agents enhances the selectivity of the method. The chromogenic sulphur containing reagent, 4-(4‧-chlorobenzylideneimino)-3-methyl-5-mercapto-1, 2, 4-triazole has been synthesized in a single step with high purity and yield. The synthesized reagent has been successfully applied first time for determination of copper(II). The reagent forms stable chelate with copper(II) in buffer medium instantly and quantitatively extracted in chloroform within a minute. The method is successfully applied for the determination of copper(II) in various synthetic mixtures, complexes, fertilizers, environmental samples such as food samples

  9. An efficient, cost effective, sensing behaviour liquid-liquid extraction and spectrophotometric determination of copper(II) incorporated with 4-(4'-chlorobenzylideneimino)-3-methyl-5-mercapto-1, 2, 4-triazole: Analysis of food samples, leafy vegetables, fertilizers and environmental samples.

    Science.gov (United States)

    Barache, Umesh B; Shaikh, Abdul B; Lokhande, Tukaram N; Kamble, Ganesh S; Anuse, Mansing A; Gaikwad, Shashikant H

    2018-01-15

    The aim of the present work is to develop an efficient, simple and selective moreover cost-effective method for the extractive spectrophotometric determination of copper(II) by using the Schiff base 4-(4'-chlorobenzylideneimino)-3-methyl-5-mercapto-1, 2, 4-triazole [CBIMMT]. This chromogenic reagent forms a yellow coloured complex with copper(II) in acetate buffer at pH4.2. The copper(II) complex with ligand is instantly extracted into chloroform and shows a maximum absorbance at 414nm which remains stable for >48h. The composition of extracted complex is found to be 1:2 [copper(II): reagent] which was ascertained using Job's method of continuous variation, mole ratio method and slope ratio method. Under optimal conditions, the copper(II) complex in chloroform adheres to Beer's law up to 17.5μgmL(-1) of copper(II). The optimum concentration range obtained from Ringbom's plot is from 5μgmL(-1) to 17.5μgmL(-1). The molar absorptivity, Sandell's sensitivity and enrichment factor of the extracted copper(II) chelate are 0.33813×10(4)Lmol(-1)cm(-1), 0.01996μgcm(-2) and 2.49 respectively. In the extraction of copper(II), several affecting factors including the solution pH, ligand concentration, equilibrium time, effect of foreign ions are optimized. The interfering effects of various cations and anions were also studied and use of masking agents enhances the selectivity of the method. The chromogenic sulphur containing reagent, 4-(4'-chlorobenzylideneimino)-3-methyl-5-mercapto-1, 2, 4-triazole has been synthesized in a single step with high purity and yield. The synthesized reagent has been successfully applied first time for determination of copper(II). The reagent forms stable chelate with copper(II) in buffer medium instantly and quantitatively extracted in chloroform within a minute. The method is successfully applied for the determination of copper(II) in various synthetic mixtures, complexes, fertilizers, environmental samples such as food samples, leafy

  10. Synthesis and characterization of thermally stable oligomer-metal complexes of copper(II, nickel(II, zinc(II and cobalt(II derived from oligo-p-nitrophenylazomethinephenol

    Directory of Open Access Journals (Sweden)

    Ufuk S. Vural

    2006-12-01

    Full Text Available Thermally stable metal complexes based on oligomers were prepared by the reaction between oligo-p-nitrophenilazomethinephenol (ONPAP and Cu(II, Ni(II, Zn(II and Co(II ions. The properties of oligomer-metal complexes were studied by elemental, FT-IR and magnetic moments analyses. The thermal stabilities of the oligomer-metal complexes were compared by thermogravimetric (TG and differential thermal (DTA analyses. According to TG, oligomer-metal complexes were stable against to temperature and thermooxidative decomposition. The weight losses of oligomer-metal complexes were found to be 5 and 50 % at 200 and > 850 (Cu(II, 172 and 600 (Ni(II, 252 and > 850 (Zn(II and 174 and 510 (Co(II, oC, respectively. Based on half degradation temperature parameters Cu(II and Zn(II complexes were more resistant than the others.

  11. Spectroscopic studies on chromium(III), manganese(II), cobalt(II), nickel(II) and copper(II) complexes with hexadentate nitrogen-sulfur donor [N(2)S(4)] macrocyclic ligand.

    Science.gov (United States)

    Shukla, Deepak; Gupta, Lokesh Kumar; Chandra, Sulekh

    2008-12-01

    Complexes of transition metals have been synthesized with hexadentate ligand (2,6-bis(((2-mercaptophenyl)thio)methyl)pyridinato)metal(II). These complexes have been synthesized via the two step template reaction by using the benzene dithiol, 2,6-bis(chloro)methyl pyridine and corresponding metal salt as key raw materials. The structures of the complexes have been elucidated on the basis of elemental analysis, molar conductance measurements, magnetic susceptibility measurements, IR, electronic and EPR spectral studies. All of the complexes were found to possess six-coordinated geometry and are of high spin type.

  12. Spectroscopic studies on chromium(III), manganese(II), cobalt(II), nickel(II) and copper(II) complexes with hexadentate nitrogen-sulfur donor [N 2S 4] macrocyclic ligand

    Science.gov (United States)

    Shukla, Deepak; Gupta, Lokesh Kumar; Chandra, Sulekh

    2008-12-01

    Complexes of transition metals have been synthesized with hexadentate ligand (2,6-bis(((2-mercaptophenyl)thio)methyl)pyridinato)metal(II). These complexes have been synthesized via the two step template reaction by using the benzene dithiol, 2,6-bis(chloro)methyl pyridine and corresponding metal salt as key raw materials. The structures of the complexes have been elucidated on the basis of elemental analysis, molar conductance measurements, magnetic susceptibility measurements, IR, electronic and EPR spectral studies. All of the complexes were found to possess six-coordinated geometry and are of high spin type.

  13. Synthesis, physico-chemical studies of manganese(II), cobalt(II), nickel(II), copper(II) and zinc(II) complexes with some p-substituted acetophenone benzoylhydrazones and their antimicrobial activity.

    Science.gov (United States)

    Singh, Vinod P; Singh, Shweta; Katiyar, Anshu

    2009-04-01

    Complexes of the type [M(pabh)(H2O)Cl], [M(pcbh)(H2O)Cl] and [M(Hpabh)(H2O)2 (SO4)] where, M = Mn(II), Co(II), Ni(II), Cu(II) and Zn(II); Hpabh = p-amino acetophenone benzoyl hydrazone and Hpcbh = p-chloro acetophenone benzoyl hydrazone have been synthesized and characterized with the help of elemental analyses, electrical conductance, magnetic susceptibility measurements, electronic, ESR and IR spectra, thermal (TGA & DTA) and X-ray diffraction studies. Co(II), Ni(II) and Cu(II) chloride complexes are square planar, whereas their sulfate complexes have spin-free octahedral geometry. ESR spectra of Cu(II) complexes with Hpabh are axial and suggest d(x(2)-y(2) as the ground state. The ligand is bidentate bonding through > C = N--and deprotonated enolate group in all the chloro complexes, whereas, >C = N and >C = O groups in all the sulfato complexes. Thermal studies (TGA & DTA) on [Cu(Hpabh)(H2O)2(SO4)] indicate a multistep decomposition pattern, which are both exothermic and endothermic in nature. X-ray powder diffraction parameters for [Co(pabh)(H2O)Cl] and [Ni(Hpabh)(H2O)2(SO4)] correspond to tetragonal and orthorhombic crystal lattices, respectively. The ligands as well as their complexes show a significant antifungal and antibacterial activity. The metal complexes are more active than the ligand.

  14. Synthesis, structure information, DNA/BSA binding affinity and in vitro cytotoxic studies of mixed ligand copper(II) complexes containing a phenylalanine derivative and diimine co-ligands.

    Science.gov (United States)

    Annaraj, B; Balakrishnan, C; Neelakantan, M A

    2016-07-01

    Binary [Cu(PAIC)(H2O)2]·H2O (1) and mixed ligand [Cu(PAIC)(L)]·2H2O complexes, where PAIC=phenylalanine imidazole carboxylic acid, L=diimine coligands [2,2'-bipyridine (bpy) (2) and 1,10-phenanthroline (phen) (3)] have been synthesized and fully characterized by analytical and spectral techniques. The X-ray structure of [Cu(PAIC)(phen)]·2H2O (3) shows a N4O coordination with square pyramidal geometry around the copper (II) atom. The spin Hamiltonian parameters calculated for the complexes account for the distorted square planar structure and rules out the possibility of a trigonal bipyramidal structure. Interaction of the complexes (1-3) with calf thymus DNA (CT DNA) was studied by using different techniques (absorption titration, fluorescence quenching and thermal melting) and the studies suggest that these complexes bind to CT DNA through intercalation. The DNA-binding affinity of the complexes has further been explained by DFT computational results. Binding activity of Bovine serum albumin (BSA) reveals that the complexes can strongly quench the intrinsic fluorescence of BSA through a static quenching mechanism. DNA cleavage experiments using plasmid DNA pUC 19 show that the complexes exhibit efficient chemical nuclease activity even in the absence of any external additives. The cytotoxicity of the complexes against human normal cell line (HBL 100) and human breast cancer cell line (MCF-7) shows that metal complexation of the ligands results in a significant enhancement in the cell death of MCF-7. Finally, docking studies on DNA and protein binding interactions were performed. Copyright © 2016 Elsevier B.V. All rights reserved.

  15. A Computational Study of Calcium(II) and Copper(II) Ion Binding to the Hyaluronate Molecule

    Science.gov (United States)

    Pirc, Elizabeta Tratar; Zidar, Jernej; Bukovec, Peter

    2012-01-01

    The hyaluronate molecule is a negatively charged polysaccharide that performs a plethora of physiological functions in many cell tissues depending on its conformation. In the present paper, molecular modeling at three levels of theory and two basis sets was used to gain a deeper insight in the complex molecular structure of calcium(II) and copper(II) hyaluronate. Simulation results were compared with the experimental data (EXAFS or X-ray). It was found that B3LYP does not properly reproduce the experimental data while the HF and M06 methods do. Simulation data confirm that the N-acetyl group of the N-acetylglucosamine residue does not participate in the coordination bonding to the calcium(II) or copper(II) ion, as evident from the experimental data. PMID:23109898

  16. New 8-hydroxyquinoline galactosides. The role of the sugar in the antiproliferative activity of copper(II) ionophores.

    Science.gov (United States)

    Oliveri, Valentina; Viale, Maurizio; Aiello, Cinzia; Vecchio, Graziella

    2015-01-01

    8-Hydroxyquinoline derivatives and their metal complexes have recently awakened interest as promising therapeutic agents in cancer therapy. We have previously synthesized and evaluated glucoconjugated 8-hydroxyquinolines as copper ionophores activated by β-glucosidases. In order to further evaluate the crucial role of the sugar, we designed and synthesized a series of new galactoconjugates of 8-hydroxyquinolines and investigated their biological properties in comparison with the 8-hydroxyquinoline analogs. The effect of copper(II) ions on their biological activities was evaluated. In particular, two compounds possess a pharmacologically relevant antiproliferative activity against specific tumor cells in the presence of copper(II) ions. Furthermore, the antiproliferative activity of the selected galactosides was successfully investigated in the presence of β-galactosidase as a preliminary model of antibody directed enzyme prodrug therapy. Copyright © 2014 Elsevier Inc. All rights reserved.

  17. A novel ferrocenic copper(II) complex Salen-like, derived from 5-chloromethyl-2-hydroxyacetophenone and N-ferrocenmethylaniline: Design, spectral approach and solvent effect towards electrochemical behavior of Fc+/Fc redox couple

    OpenAIRE

    Ouennoughi, Yasmina; Karce, Houssam Eddine; Aggoun, Djouhra; Lanez, Touhami; Ruiz-Rosas, Ramiro; Bouzerafa, Brahim; Ourari, Ali; Morallon, Emilia

    2017-01-01

    This paper reports the synthesis, spectroscopic characterizations and electrochemical behavior of the obtained tetradentate copper (II)-Schiff base complex with its two wings as ferrocenylaniline moieties. This new ferrocenic derivative with two ferrocenylaniline entities surrounding the copper (II)-Salen complex (5) was synthesized by reacting N-ferrocenmethyl-N-phenyl-5-aminomethyl-2-hydroxyacetophenone (3) with one half equivalent of 1,2-diaminoethane in absolute ethanol. As for the interm...

  18. V-shaped ligand 1,3-bis(1-ethylbenzimidazol-2-yl)-2-thiapropane and manganese(II), cobalt(II) and copper(II) complexes: Synthesis, crystal structure, DNA-binding properties and antioxidant activities.

    Science.gov (United States)

    Wu, Huilu; Yang, Zaihui; Wang, Fei; Peng, Hongping; Zhang, Han; Wang, Cuiping; Wang, Kaitong

    2015-07-01

    A V-shaped ligand 1,3-bis(1-ethylbenzimidazol-2-yl)-2-thiapropane (bebt) and its transition metal complexes, [Mn(bebt)(pic)2]·CH3OH (pic=picrate) 1, [Co(bebt)2](pic)22 and [Cu(bebt)2](pic)2·2DMF 3, have been synthesized and characterized. The coordinate forms of complexes 1 and 2 are basically alike, which can be described as six-coordinated distorted octahedron. The geometric structure around Cu(II) atom can be described as distorted tetrahedral in complex 3. The DNA-binding properties of the ligand bebt and complexes have been investigated by electronic absorption, fluorescence, and viscosity measurements. The results suggest that bebt and complexes bind to DNA via an intercalative binding mode and the order of the binding affinity is 1DNA-binding properties are also discussed. Moreover, the complex 3 possess significant antioxidant activity against superoxide and hydroxyl radicals, and the scavenging effects of it are stronger than standard mannitol and vitamin C. Copyright © 2015 Elsevier B.V. All rights reserved.

  19. Effect of copper(II) on natural organic matter removal during drinking water coagulation using aluminum-based coagulants.

    Science.gov (United States)

    Liu, Guojing; Zhang, Xiangru; Talley, Jeffrey W

    2007-06-01

    Coagulation has been proposed as a best available technology for controlling natural organic matter (NOM) during drinking water treatment. The presence of heavy metals such as copper(II) in source water, which may form copper-NOM complexes and/or interact with a coagulant, may pose a potential challenge on the coagulation of NOM. In this work, the effect of copper(II) on NOM removal by coagulation using alum or PAX-18 (a commercial polymerized aluminum chloride from Kemiron Inc., Bartow, Florida) was examined. The results show that the presence of 1 to 10 mg/L of copper(H) in the simulated waters improved the total organic carbon (TOC) removal by up to 25% for alum coagulation and by up to 22% for PAX-18 coagulation. The increased NOM removal with the presence of copper(II) in the waters can most likely be ascribed to the formation copper-NOM complexes that may be more adsorbable on aluminum precipitates and to the formation of copper(II) co-precipitates that may also adsorb NOM. The presence of 1 to 5 mg/L of copper(I) in the waters containing 3 mg/L NOM as carbon was reduced below the maximum contaminant level goal (1.3 mg/L as copper) using either coagulant. The results suggest that the presence of copper(H) in source water may not adversely affect the NOM removal by coagulation. A good linear correlation was observed between the TOC removal efficiency and the log-total moles of the precipitated metals, which include the metal ion from a coagulant and the divalent metal ion(s) in source water.

  20. 1.1.3. Substitution on Re(IV complexes: a tool for the synthesis of novel mono- and polynuclear compounds

    Directory of Open Access Journals (Sweden)

    Carlos Kremer

    2014-04-01

    Full Text Available Rhenium(IV complexes are relatively scarce if compared with those of other oxidation states as Re(V or Re(VII. It is a 5d3 ion, and usually forms octahedral complexes which are reasonably stable against redox processes and inert to ligand substitution. This is the basis for the preparation of mononuclear species that can act as ligands towards other transition metal ions. For example, complexes containing dicarboxylic ligands, [ReX4(ox]2–and [ReX4(mal]2– (X = Cl, Br; ox = oxalato; mal = malonato, or N-donor ligands, [ReCl5(pyz]– (pyz = pyrazine have been used as building blocks to construct heteropolynuclear complexes. The different synthetic routes, as well as the designed structures, from discrete binuclear complexes to extended chain-like compounds, are reviewed in this contribution.

  1. Synthesis, characterisation and antimicrobial activities of cobalt(II, copper(II and zinc(II mixed-ligand complexes containing 1,10-phenanthroline and 2,2’-bipyridine

    Directory of Open Access Journals (Sweden)

    A. Mohamadou

    2010-06-01

    Full Text Available Three new 1,10-phenanthroline and 2,2’-bipyridine mixed-ligand complexes of [Co(bpy(phen2](NO32.2H2O, [Cu(bpy(phen H2O 2]Cl2.2H2O, and [Zn(bpy2(phen]Cl2.6H2O were synthesized. The complexes were characterized by elemental, IR and visible spectroscopic analyses and the results indicate that both ligands are coordinated to the respective metal ions giving octahedral complexes. Antimicrobial studies showed that there is increased antimicrobial activity of the metal ions on coordination to the ligands. The water soluble complexes showed antimicrobial activities that are higher than those of the metal salts and 2,2’-bipyridine but lower than those of 1,10-phenanthroline. The copper complex [Cu(bpy(phen(H2O 2]Cl2.2H2O shows the highest activity.

  2. Synthesis, characterization, X-ray crystal structures and antibacterial activities of Schiff base ligands derived from allylamine and their vanadium(IV), cobalt(III), nickel(II), copper(II), zinc(II) and palladium(II) complexes

    Science.gov (United States)

    Amiri Rudbari, Hadi; Iravani, Mohammad Reza; Moazam, Vahid; Askari, Banafshe; Khorshidifard, Mahsa; Habibi, Neda; Bruno, Giuseppe

    2016-12-01

    A new Schiff base ligand, HL2, and four new Schiff base complexes, NiL12, PdL12, NiL22 and ZnL22, have been prepared and characterized by elemental analysis (CHN), FT-IR and UV-Vis spectroscopy. 1H and 13C NMR techniques were employed for characterization of the ligand (HL2) and the diamagnetic complexes (PdL12 and ZnL22). The molecular structures of PdL12, NiL22 and ZnL22 complexes were determined by the single crystal X-ray diffraction technique. The crystallographic data reveal that in these complexes the metal centers are four-coordinated by two phenolate oxygen and two imine nitrogen atoms of two Schiff base ligands. The geometry around the metal center in the PdL12 and NiL22 complexes is square-planar and for ZnL22 it is a distorted tetrahedral.In the end, five new (HL2, NiL12, PdL12, NiL22 and ZnL22) and six reported (HL1, VOL12, CoL13, CuL12, ZnL12 and Zn2L14) Schiff base compounds were tested for their in vitro antimicrobial activity against Staphylococcus aureus and Escherichia coli as examples of Gram-positive and Gram-negative bacterial strains, respectively, by disc diffusion method.

  3. Synthesis and crystal structure of the dinuclear copper(II) Schiff base complex μ-hydroxido-μ-chlorido-bis{[bis(trans-2-nitrocinnamaldehyde)ethylenediamine]chloridocopper(II)} dichloromethane sesquisolvate.

    Science.gov (United States)

    Barati, Kazem; Clegg, William; Habibi, Mohammad Hossein; Harrington, Ross W; Lalegani, Arash; Montazerozohori, Morteza

    2016-03-01

    Transition metal complexes of Schiff base ligands have been shown to have particular application in catalysis and magnetism. The chemistry of copper complexes is of interest owing to their importance in biological and industrial processes. The reaction of copper(I) chloride with the bidentate Schiff base N,N'-bis(trans-2-nitrocinnamaldehyde)ethylenediamine {Nca2en, systematic name: (1E,1'E,2E,2'E)-N,N'-(ethane-1,2-diyl)bis[3-(2-nitrophenyl)prop-2-en-1-imine]} in a 1:1 molar ratio in dichloromethane without exclusion of air or moisture resulted in the formation of the title complex μ-chlorido-μ-hydroxido-bis(chlorido{(1E,1'E,2E,2'E)-N,N'-(ethane-1,2-diyl)bis[3-(2-nitrophenyl)prop-2-en-1-imine]-κ(2)N,N'}copper(II)) dichloromethane sesquisolvate, [Cu2Cl3(OH)(C20H18N4O4)2]·1.5CH2Cl2. The dinuclear complex has a folded four-membered ring in an unsymmetrical Cu2OCl3 core in which the approximate trigonal bipyramidal coordination displays different angular distortions in the equatorial planes of the two Cu(II) atoms; the chloride bridge is asymmetric, but the hydroxide bridge is symmetric. The chelate rings of the two Nca2en ligands have different conformations, leading to a more marked bowing of one of the ligands compared with the other. This is the first reported dinuclear complex, and the first five-coordinate complex, of the Nca2en Schiff base ligand. Molecules of the dimer are associated in pairs by ring-stacking interactions supported by C-H...Cl interactions with solvent molecules; a further ring-stacking interaction exists between the two Schiff base ligands of each molecule.

  4. Characterization of the Copper(II) Binding Sites in Human Carbonic Anhydrase II

    Science.gov (United States)

    Nettles, Whitnee L.; Song, He; Farquhar, Erik R.; Fitzkee, Nicholas C.; Emerson, Joseph P.

    2015-01-01

    Human carbonic anhydrase (CA) is a well-studied, robust, mononuclear Zn-containing metalloprotein that serves as an excellent biological ligand system to study the thermodynamics associated with metal ion coordination chemistry in aqueous solution. The apo-form of human carbonic anhydrase II (CA) binds two equivalents of copper(II) with high affinity. The Cu2+ ions bind independently forming two non-coupled type-II copper centers in CA (CuA and CuB). However, the location and coordination mode of the CuA site in solution is unclear, compared to the CuB site that has been well characterized. Using paramagnetic NMR techniques and X-ray absorption spectroscopy we have identified an N-terminal Cu2+ binding location and collected information on the coordination mode of the CuA site in CA, which is consistent with a four to five coordinate N-terminal Cu2+ binding site reminiscent to a number of N-terminal copper(II) binding sites including the copper(II)-ATCUN and copper(II)-beta-amyloid complexes. Additionally, we report a more detailed analysis of the thermodynamics associated with copper(II) binding to CA. Although we are still unable to fully deconvolute Cu2+ binding data to the high-affinity CuA site, we have derived pH- and buffer-independent values for the thermodynamics parameters K and ΔH associated with Cu2+ binding to the CuB site of CA to be 2 × 109 and −17.4 kcal/mol, respectively. PMID:26010488

  5. Toward a novel metal-based chemotherapy against tropical diseases. 6. Synthesis and characterization of new copper(II) and gold(I) clotrimazole and ketoconazole complexes and evaluation of their activity against Trypanosoma cruzi.

    Science.gov (United States)

    Navarro, M; Cisneros-Fajardo, E J; Lehmann, T; Sánchez-Delgado, R A; Atencio, R; Silva, P; Lira, R; Urbina, J A

    2001-12-31

    The complexes [Cu(CTZ)(4)]Cl(2).2H(2)O (1), [Cu(CTZ)Cl(2)](2) (2), [Cu(KTZ)(3)Cl(2)] (3), and [Cu(KTZ)Cl(2)](2).2H(2)O (4) were prepared by reaction of CuCl(2) with CTZ and KTZ (where CTZ = 1-[[(2-chlorophenyl)diphenyl]methyl]-1H-imidazole and KTZ = cis-1-acetyl-4-[4-[[2-(2,4-dichlorophenyl)-2-(1H-imidazol-1-ylmethyl)-1,3-dioxolan-4-yl]methoxy]phenyl]piperazine), respectively, in acetonitrile at different ligand to metal molar ratios. Gold complexes [Au(PPh(3))(CTZ)]PF(6) (5) and [Au(PPh(3))(KTZ)]PF(6).H(2)O (6) were synthesized by reaction of AuClPPh(3), with KPF(6) and CTZ or KTZ in acetonitrile. All the new compounds were characterized by NMR spectroscopy and microanalytical methods, and for the paramagnetic species EPR spectroscopy and DC magnetic susceptibility measurements were also employed. The solid-state structure of 1 has been determined by X-ray crystallography. 1 crystallizes in the triclinic space group P(-)1, with a = 12.773(2) A, b = 15.326(4) A, c = 11.641(2) A, V = 1957.4(7) A(3), Z = 1, and D(calcd) = 1.284 g/cm(3). The structure refinement converged at R1 = 0.0731 and wR2 = 0.1962. Complex 1 displayed a square-planar structure typical for tetrakis(imidazole)copper(II) complexes. The new compounds were tested for in vitro activity against cultures of epimastigotes of Trypanosoma cruzi, the causative agent of Chagas disease. At concentrations equivalent to 10(-6) M of total CTZ or KTZ (in DMSO) all the complexes exhibited significantly higher growth inhibitory activity than their respective parental compounds.

  6. Preparation and thermal decomposition of copper(II, zinc(II and cadmium(II chelates with 8-hydroxyquinoline

    Directory of Open Access Journals (Sweden)

    Crespi Marisa S.

    1999-01-01

    Full Text Available When the compounds are heated in an inert atmosphere it can be verified the consecutive partial sublimation, fusion, partial volatilization and partial thermal decomposition of the anhydrous complexes. When in an oxidating atmosphere the above process is only verified to Cu(II chelates. Anhydrous copper(II complexes present a monoclinic structure in the b form and the volatilized compound in a a form. Zinc(II and cadmium(II hydrated complexes are isomorphous and they present different cell dimensions from those reported previously.

  7. Electron delocalisation in a trinuclear copper(II) complex: high-field EPR characterization and magnetic properties of Na3[Cu3(mal)3(H2O)] x 8H2O.

    Science.gov (United States)

    Gautier-Luneau, Isabelle; Phanon, Delphine; Duboc, Carole; Luneau, Dominique; Pierre, Jean-Louis

    2005-12-07

    The complex Na3[Cu3(mal)3(H2O)] x 8H2O was obtained from evaporation of an aqueous solution containing Cu(OAc)2, malic acid (HO2CCH2CHOHCO2H) and NaOH and was characterised by X-ray diffraction on single crystal, X-band and high-field EPR spectroscopy (HF-EPR) and magnetic susceptibility measurements. The trinuclear complex [Cu3(mal)3(H2O)]3- is trapped in a three-dimensional network with sodium cations. The three copper atoms are connected by alkoxo bridges and form an almost isosceles triangle with Cu...Cu distances of 3.076(1), 3.504(1) and 3.513(1) A. Two of the copper ions are also bridged by an extra aquo ligand. EPR spectroscopy combined with magnetic susceptibility measurements provide a powerful tool to resolve the electronic structure of the complex. The overall magnetic behaviour corresponds to an antiferromagnetically coupled triangular system. The 285 GHz-EPR spectrum (g = 2; 10.18 T) is characteristic of a spin state S = 1/2, with a rhombic anisotropy of [g]. This rhombic pattern allows us to propose that the electronic spin density is delocalised on the three copper ions.

  8. Synthesis and Characterization of Acyclic and Cyclic Azabridged Ligands Incorporating 2,2'-Bipyridine Subunits and Their Complexes With Copper(II, Cobalt(II, and Nickel(II

    Directory of Open Access Journals (Sweden)

    Andrea Pappalardo

    2003-07-01

    Full Text Available The synthesis of a series of N,N'-disubstituted acyclic (AL and cyclic (CL aza-bridged ligands incorporating 2,2-pipryidine subunits is described. 1H-NMR and IR spectral data support the proposed ligand structures. Dynamic 1H-NMR studies on diurea and diamide derivatives point to the presence of slowly interconverting conformers on the 1H-NMR time-scale, owing to N−H···N hydrogen bonding and/or a restricted rotation around the amide bonds. The ligands synthesized form 1:1 complexes with divalent transition metal ions. Upon complexation, bis-ester derivatives AL5 and CL5 undergo a metal-induced hydrolysis of the ester groups to carboxyl functions, which act as additional binding sites for the metal ion, as well as hydrogen-bonding donor-acceptor binding site to produce dimeric complexes.

  9. Four- and five-coordinate copper(II) complexes with N-(4,4-diphenyl-5-oxo-4,5-dihydro-1H-imidazol-2-yl)glycine.

    Science.gov (United States)

    Sieroń, Lesław; Kieć-Kononowicz, Katarzyna; Karolak-Wojciechowska, Janina

    2008-02-01

    The two title mononuclear compounds are four-coordinate bis[N-(5-oxo-4,4-diphenyl-4,5-dihydro-1H-imidazolidin-2-ylidene)glycinato]copper(II) dimethylformamide disolvate, [Cu(C(17)H(14)N(3)O(3))(2)].2C(3)H(7)NO, (I), and five-coordinate aquabis[N-(5-oxo-4,4-diphenyl-4,5-dihydro-1H-imidazolidin-2-ylidene)glycinato]copper(II) dimethylformamide disolvate, [Cu(C(17)H(14)N(3)O(3))(2)(H(2)O)].2C(3)H(7)NO, (II). In (I), the Cu(II) ion lies on an inversion centre with one-half of the complex molecule in the asymmetric unit, while in (II) there are two independent ligand molecules in the asymmetric unit, with the Cu(II) ion and coordinated water molecule located on a general position. In both crystal structures, the complex molecules assemble in ribbons via N-H...O hydrogen-bond networks.

  10. Synthesis and Spectral Investigations of Manganese(II, Cobalt(II, Nickel(II, Copper(II and Zinc(II Complexes of New Polydentate Ligands Containing a 1,8-Naphthyridine Moiety

    Directory of Open Access Journals (Sweden)

    Sunkari Jyothi

    2006-12-01

    Full Text Available 2-(o-Hydroxyphenyl-1,8-naphthyridine (HN, 2-(4-hydroxy-6-methylpyran-2-one-3-yl-1,8-naphthyridine (HMPN and 2-(benzimidazol-2-yl-1,8-naphthyridine(BN react with acetates of Mn(II, Co(II, Ni(II, Cu(II and Zn(II to yield metal ioncomplexes of definite composition. These compounds were characterized by elementalanalyses, molar conductivity, magnetic susceptibility measurements, thermal studies, IR,UV-visible, NMR and mass spectral investigations. The complexes are found to have theformulae [M(HN2(H2O2], [M(HMPN2(H2O2] and [M(BN2(OAc2], respectively.

  11. Synthesis, structure, and magnetism of hexanuclear copper(II) phosphonates.

    Science.gov (United States)

    Chandrasekhar, Vadapalli; Senapati, Tapas; Sañudo, E Carolina

    2008-10-20

    The reaction of Cu(ClO4)2 x 6 H2O with cyclopentylphosphonic acid and 1,10-phenanthroline (phen) in the presence of triethylamine afforded a hexanuclear copper(II) complex [Cu6(C5H9PO3)4(1,10-phen)6(MeOH)4](ClO4)4 (1) in over 80% yield. The hexanuclear assembly is held together by the coordination action of four tridentate dianionic [RPO3](2-) ligands giving rise to two Cu2P2O4 eight-membered rings in the top and the bottom that are connected to each other by a central Cu2O2 four-membered ring. Every copper atom in 1 is bound by a chelating phenanthroline ligand. Each of the two terminal pairs of copper atoms in the hexanuclear assembly contains methanol molecules of coordination. These labile methanol molecules can be replaced by 1,3-bis(4-pyridyl)propane (bpp) to afford [Cu6(C5H9PO3)4(1,10-phen)6(bpp)2](ClO4)4 (2) where the pincer-like bipyridine ligand acts as a stopper to close both ends of the open hexanuclear cage. Instead, treatment of the in situ generated [Cu6(C5H9PO3)4(2,2'-bpy)6(MeOH)4](ClO4)4 with 4,4'-bipyridine results in the formation of a rail-road-like one-dimensional polymer [{Cu6(C5H9PO3)4(2,2'-bpy)6(4,4'-bpy)2}(ClO4)4]n (3). In addition to structural studies, detailed magnetic studies have been carried out on 1-3 which reveal an S = 1 spin ground-state with low lying excited states.

  12. Ab initio calculations concerning the reaction mechanism of the copper(II) catalyzed glycine condensation in aqueous sodium chloride solution

    Science.gov (United States)

    Liedl, Klaus R.; Rode, Bernd M.

    1992-09-01

    Starting from results of detailed experimental work concerning the copper(II) catalyzed glycine condensation, quantum-mechanical studies of species which should be relevant for the reaction mechanism are presented. This reaction is of special interest because it could be important in explaining the formation of the first peptides on prebiotic earth. SCF geometry optimizations of aquo-chloro-glycinato—copper(II) complexes at Hartree—Fock level were performed especially to study the necessity of chlorine for the reaction. In that way a hypothetical reaction mechanism could be confirmed. Structural distortions as expected from the Jahn—Teller effect resulted from optimizations of copper complexes in C1 geometry.

  13. A rapid and sensitive extractive spectrophotometric determination of copper(II) in pharmaceutical and environmental samples using benzildithiosemicarbazone.

    Science.gov (United States)

    Reddy, B K; Kumar, J R; Reddy, K J; Sarma, L S; Reddy, A V

    2003-03-01

    Benzildithiosemicarbazone (BDTSC) is proposed as a sensitive and selective analytical reagent for the extractive spectrophotometric determination of copper(II). BDTSC reacts with copper(II) in the pH range 1.0-7.0 to form a yellowish complex. Beer's law is obeyed in the concentration range 0.5-0.4 microg cm(-3). The yellowish Cu(II)-BDTSC complex in chloroform shows a maximum absorbance at 380 nm, with molar absorptivity and Sandell's sensitivity values of 1.63 x 10(4) dm3 mol(-1) cm(-1) and 0.00389 microg cm(-2), respectively. A repetition of the method is checked by finding the relative standard deviation (RSD) (n = 10), which is 0.6%. The composition of the Cu(II)-BDTSC complex is established as 1:1 by slope analysis, molar ratio and Asmus' methods. An excellent linearity with a correlation coefficient value of 0.98 is obtained for the Cu(II)-BDTSC complex. The instability constant of the complex calculated from Edmond and Birnbaum's method is 7.70 x 10(-4) and that of Asmus' method is 7.66 x 10(-4), at room temperature. The method is successfully employed for the determination copper(II) in pharmaceutical and environmental samples. The reliability of the method is assured by analyzing the standard alloys (BCS 5g, 10g, 19e, 78, 32a, 207 and 179) and by inter-comparison of experimental values, using an atomic absorption spectrometer.

  14. Copper(II) and zinc(II) ion binding properties of a MAP type branched ligand with histidines as surface functionalities.

    Science.gov (United States)

    Kolozsi, András; Vosekalna, Ilze; Martinek, Tamás; Larsen, Erik; Gyurcsik, Béla

    2009-08-07

    A novel branched peptide type ligand consisting of three lysines as branching units and four histidines as functional groups has been designed and prepared by solid phase peptide synthesis. The N-terminal histidines offer eight primary protonation/metal ion binding sites: four amino and four imidazole groups, capable of binding up to two metal ions. We examined the protonation equilibria, and the complex formation processes with copper(II) and zinc(II) ions in c(M):c(L) = 1:1 and 2:1 initial concentration ratio in aqueous solutions. The composition, speciation and the solution structure of the complexes have been determined by combined pH-potentiometric titrations, visible absorption, circular dichroism and NMR spectroscopy. In the case of both metal ions, mono- and dimetallic complexes formed with bis-histamine type coordination as the main species. While above pH 8 the precipitation of a neutral complex was observed for both metal ions, in the copper(II) containing systems it dissolved in alkaline solutions (pH > 11.0). The resulting complex in an equimolar system displays deprotonated amide-nitrogen coordination, with fused five-membered chelate rings around the metal ion in [CuLH(-3)](-). At the same time, only one copper(II) is able to coordinate in the same manner in the [Cu(2)LH(-5)](-) species. The second metal ion is probably surrounded by two amide nitrogens and two others either from amino or imidazole donor groups.

  15. Strong effect of copper(II) coordination on antiproliferative activity of thiosemicarbazone-piperazine and thiosemicarbazone-morpholine hybrids.

    Science.gov (United States)

    Bacher, Felix; Dömötör, Orsolya; Chugunova, Anastasia; Nagy, Nóra V; Filipović, Lana; Radulović, Siniša; Enyedy, Éva A; Arion, Vladimir B

    2015-05-21

    In this study, 2-formylpyridine thiosemicarbazones and three different heterocyclic pharmacophores were combined to prepare thiosemicarbazone–piperazine mPip-FTSC (HL1) and mPip-dm-FTSC (HL2), thiosemicarbazone–morpholine Morph-FTSC (HL3) and Morph-dm-FTSC (HL4), thiosemicarbazone–methylpyrrole-2-carboxylate hybrids mPyrr-FTSC (HL5) and mPyrr-dm-FTSC (HL6) as well as their copper(II) complexes [CuCl(mPipH-FTSC-H)]Cl (1 + H)Cl, [CuCl(mPipH-dm-FTSC-H)]Cl (2 + H)Cl, [CuCl(Morph-FTSC-H)] (3), [CuCl(Morph-dm-FTSC-H)] (4), [CuCl(mPyrr-FTSC-H)(H2O)] (5) and [CuCl(mPyrr-dm-FTSC-H)(H2O)] (6). The substances were characterized by elemental analysis, one- and two-dimensional NMR spectroscopy (HL1–HL6), ESI mass spectrometry, IR and UV–vis spectroscopy and single crystal X-ray diffraction (1–5). All compounds were prepared in an effort to generate potential antitumor agents with an improved therapeutic index. In addition, the effect of structural alterations with organic hybrids on aqueous solubility and copper(II) coordination ability was investigated. Complexation of ligands HL2 and HL4 with copper(II) was studied in aqueous solution by pH-potentiometry, UV–vis spectrophotometry and EPR spectroscopy. Proton dissociation processes of HL2 and HL4 were also characterized in detail and microscopic constants for the Z/E isomers were determined. While the hybrids HL5, HL6 and their copper(II) complexes 5 and 6 proved to be insoluble in aqueous solution, precluding antiproliferative activity studies, the thiosemicarbazone–piperazine and thiosemicarbazone–morpholine hybrids HL1–HL4, as well as copper(II) complexes 1–4 were soluble in water enabling cytotoxicity assays. Interestingly, the metal-free hybrids showed very low or even a lack of cytotoxicity (IC50 values > 300 μM) in two human cancer cell lines HeLa (cervical carcinoma) and A549 (alveolar basal adenocarcinoma), whereas their copper(II) complexes were cytotoxic showing IC50 values from 25.5 to 65.1

  16. COPPER(II) COMPLEXES OF o -VANILLIN ACETYLHYDRAZONE ...

    African Journals Online (AJOL)

    The PDF file you selected should load here if your Web browser has a PDF reader plug-in installed (for example, a recent version of Adobe Acrobat Reader). If you would like more information about how to print, save, and work with PDFs, Highwire Press provides a helpful Frequently Asked Questions about PDFs.

  17. Synthesis and structure of copper(II) complexes: Potential cyanide ...

    Indian Academy of Sciences (India)

    erty to oxidize primary alcohol to aldehyde since they are potential N,O donor .... a )2Cu] and [(L 2 b )2Cu] are given in table 1. 2.5 Procedure for the catalytic oxidation of benzyl alcohol. A mixture of benzyl alcohol (0.5mmol), catalyst. [(L 2 a )2Cu] (4mol%) or [(L ... millimeters against the test organisms. The minimal inhibitory ...

  18. Mixed-ligand binuclear copper(II) complex of 5 ...

    Indian Academy of Sciences (India)

    Biochem. 68 79. 40. Gabbay E J, Scofield R E and Baxter C S 1973 J. Am. Chem. Soc. 95 7850. 41. Ramakrishnan S, Shakthipriya D, Suresh E, Periasamy. V S, Akbarsha M A and Palaniandavar M 2011 Inorg. Chem. 50 6458. 42. Anbu S, Kandaswamy M, Kamalraj S, Muthumarry J and Varghese B 2011 Dalton Trans.

  19. Catalytic wet oxidation of thiocyanate with homogeneous copper(II) sulphate catalyst

    Energy Technology Data Exchange (ETDEWEB)

    Collado, Sergio; Laca, Adriana [Department of Chemical Engineering and Environmental Technology, University of Oviedo, c/ Julian Claveria s/n, E-33071, Oviedo (Spain); Diaz, Mario, E-mail: mariodiaz@uniovi.es [Department of Chemical Engineering and Environmental Technology, University of Oviedo, c/ Julian Claveria s/n, E-33071, Oviedo (Spain)

    2010-05-15

    The wet oxidation of thiocyanate has been investigated in a semi-batch reactor at temperatures between 423 and 473 K and pressures between 6.1 x 10{sup 3} and 1.0 x 10{sup 4} kPa in the presence of copper(II) sulphate as catalyst. The effects of copper concentration, initial thiocyanate concentration, pressure and temperature on the reaction rate were analyzed and the main products of reaction were identified. A kinetic model for the Cu-catalyzed reaction is here proposed, including temperature, oxygen concentration, and the reduction of Cu{sup 2+} to Cu{sup +} that gives an accurate prediction of the oxidation process under the assayed conditions. A mechanistic model based on the formation of a transition complex between a copper cation and two thiocyanate anions has been proposed for the catalytic wet oxidation.

  20. Catalytic wet oxidation of thiocyanate with homogeneous copper(II) sulphate catalyst.

    Science.gov (United States)

    Collado, Sergio; Laca, Adriana; Díaz, Mario

    2010-05-15

    The wet oxidation of thiocyanate has been investigated in a semi-batch reactor at temperatures between 423 and 473 K and pressures between 6.1 x 10(3) and 1.0 x 10(4)kPa in the presence of copper(II) sulphate as catalyst. The effects of copper concentration, initial thiocyanate concentration, pressure and temperature on the reaction rate were analyzed and the main products of reaction were identified. A kinetic model for the Cu-catalyzed reaction is here proposed, including temperature, oxygen concentration, and the reduction of Cu(2+) to Cu(+) that gives an accurate prediction of the oxidation process under the assayed conditions. A mechanistic model based on the formation of a transition complex between a copper cation and two thiocyanate anions has been proposed for the catalytic wet oxidation. Copyright (c) 2009 Elsevier B.V. All rights reserved.

  1. Copper(II) assembling with bis(2-pyridylcarbonyl)amidate and N,N'-2,2-phenylenebis(oxamate).

    Science.gov (United States)

    Simões, Tatiana R G; Mambrini, Raquel V; Reis, Daniella O; Marinho, Maria V; Ribeiro, Marcos A; Pinheiro, Carlos B; Ferrando-Soria, Jesús; Déniz, Mariadel; Ruiz-Pérez, Catalina; Cangussu, Danielle; Stumpf, Humberto O; Lloret, Francesc; Julve, Miguel

    2013-04-28

    We herein present the synthesis and X-ray structures of five copper(II) complexes of formulae [Cu(bpca)(CF3SO3)(H2O)]·H2O (1), [Cu(bpca)(Phpr)(H2O)]·3/2H2O (2), {[Cu(bpca)]2[Cu(opba)(H2O)]}·H2O (3), {[Cu(bpca)]2(H2opba)}2·6H2O (4) and [Cu(bpca)(EtH2opba)]n (5), where bpca = bis(2-pyridylcarbonyl)amidate, Phpr = 3-phenylpropionate, CF3SO3(−) = triflate (anion of the trifluoromethanesulphonic acid), H4opba = N,N′-1,2-phenylenebis(oxamic acid), and EtH3opba = monoethyl ester derivative of the H4opba. 1 and 2 are mononuclear copper(II) complexes where the copper atom is five-coordinate in distorted square pyramidal surroundings with a tridentate bpca and a water molecule (1)/carboxylate oxygen (2) building the basal plane and a triflate oxygen (1)/water molecule (2) filling the apical position. 3 is a neutral tricopper(II) complex where the [Cu(opba)(H2O)]2− unit acts as a bis-bidentate ligand toward two peripheral [Cu(bpca)]+ fragments. The three crystallographically independent copper(II) ions in 3 are five-coordinate with two nitrogen and two oxygen atoms (inner copper atom)/three bpca-nitrogen and an oxamate oxygen (outer copper atom) building the basal plane plus a water molecule (inner copper)/an oxamate oxygen (outer copper) in the apical position (inner copper atom) of somewhat distorted square pyramidal surroundings. 4 is a centrosymmetric tetracopper(II) compound where four [Cu(bpca)]+ fragments are assembled by two H2opba2− groups adopting an unusual bidentate/bis-monodentate bridging mode. The two crystallographically independent copper(II) ions in 4 are also five-coordinate having the three bpca-nitrogens in basal positions, the other two sites of the distorted square pyramid being filled by two oxygens of either a bidentate oxamate (at one copper centre) or two bis-monodentate oxamates (at the other copper atom). 5 is a zigzag chain of [Cu(bpca)(H2O)]+ units which are connected through the EtH2opba− ligand adopting a bidentate

  2. Investigation of the interaction of copper(II) oxide and electron beam irradiation crosslinkable polyethylene

    Science.gov (United States)

    Bee, Soo-Tueen; Sin, Lee Tin; Ratnam, C. T.; Haraveen, K. J. S.; Tee, Tiam-Ting; Rahmat, A. R.

    2015-10-01

    In this study, the effects of electron beam irradiation on the properties of copper(II) oxide when added to low-density polyethylene (LDPE) blends were investigated. It was found that the addition of low loading level of copper(II) oxide (⩽2 phr) to LDPE results in significantly poorer gel content and hot set results. However, the incorporation of higher loading level of copper(II) oxide (⩾3 phr) could slightly increase the degree of crosslinking in all irradiated LDPE composites. This is due to the fact that higher amounts of copper(II) oxide could slightly induce the formation of free radicals in LDPE matrix. Besides, increasing irradiation doses was also found to gradually increase the gel content of LDPE composites by generating higher amounts of free radicals. As a consequence, these higher amounts of free radicals released in the LDPE matrix could significantly increase the degree of crosslinking. The addition of copper(II) oxide could reduce the tensile strength and fracture strain (elongation at break) of LDPE composites because of poorer interfacial adhesion effect between copper(II) oxide particles and LDPE matrix. Meanwhile, increasing irradiation doses on all copper(II) oxide added LDPE composites could marginally increase the tensile strength. In addition, increasing irradiation dose could enhance the thermal stability of LDPE composites by increasing the decomposition temperature. The oxidation induction time (OIT) analysis showed that, because of the crosslinking network in the copper(II) oxide added LDPE composites, oxidation reaction is much delayed.

  3. Copper(II) enhances membrane-bound α-synuclein helix formation.

    Science.gov (United States)

    Lucas, Heather R; Lee, Jennifer C

    2011-03-01

    Interactions of copper and membranes with α-synuclein have been implicated in pathogenic mechanisms of Parkinson's disease, yet work examining both concurrently is scarce. We have examined the effect of copper(ii) on protein/vesicle binding and found that both the copper(ii) affinity and α-helical content are enhanced for the membrane-bound protein.

  4. Copper(II) enhances membrane-bound α-synuclein helix formation

    OpenAIRE

    Lucas, Heather R.; Lee, Jennifer C.

    2011-01-01

    Interactions of copper and membranes with α-synuclein have been implicated in pathogenic mechanisms of Parkinson’s disease, yet work examining both concurrently is scarce. We have examined the effect of copper(II) on protein/vesicle binding and found that both the copper(II) affinity and α-helical content are enhanced for the membrane-bound protein.

  5. Synthesis and Characterization of the Ligand Based on Benzimidazole and Its Copper Complex: DNA Binding and Antioxidant Activity

    OpenAIRE

    Wu, Huilu; Kou, Fan; Jia, Fei; Liu, Bin; Yuan, Jingkun; Bai, Ying

    2011-01-01

    A new copper(II) complex with formulae of [Cu(buobb)2](pic)2, where buobb stands for the ligand of 1,3-bis(1- butylbenzimidazol-2-yl)-2-oxopropane and pic represents 2,4,6-trinitrophenol, has been synthesized and characterized by elemental analyses, molar conductivity, IR, UV-Vis spectra measurements, and cyclic voltammetry. The crystal structure of the copper(II) complex has been determined by X-ray single-crystal diffraction. The coordination environment around each copper(II) atom can be d...

  6. Synergistic extraction and spectrophotometric determination of copper(II) using 1-(2',4'-dinitro aminophenyl)-4,4,6-trimethyl-1,4-dihydropyrimidine-2-thiol: analysis of alloys, pharmaceuticals and biological samples.

    Science.gov (United States)

    Kamble, Ganesh S; Kolekar, Sanjay S; Anuse, Mansing A

    2011-05-01

    A simple and selective spectrophotometric method was developed for the determination of copper(II) with 1-(2',4'-dinitro aminophenyl)-4,4,6-trimethyl-1,4-dihydropyrimidine-2-thiol [2',4'-dinitro APTPT] as a chromogenic reagent. The procedure was based on the synergistic extraction of copper(II) with 2',4'-dinitro APTPT in the presence of 0.5 mol L(-1) pyridine to give green colored ternary complex of a molar ratio 1:2:2 (M:L:Py) in the pH range 8.7-10.5. It exhibits a maximum absorption of colored complex at 445 nm and 645 nm in chloroform against the reagent blank. Beer's law was followed in the concentration range 10-80 μg mL(-1) of copper(II) and optimum range of 20-70 μg mL(-1) the metal as evaluated from Ringbom's plot. The molar absorptivity and Sandell's sensitivity of copper(II)-2',4'-dinitro APTPT-pyridine complex in chloroform are 0.87×10(3) L mol(-1)c m(-1) and 0.072 μg cm(-2), respectively. The interfering effects of various cations and anions were also studied, and use of suitable masking agents enhances the selectivity of the method. The proposed method is rapid, reproducible and successfully applied for the determination of copper(II) in binary and synthetic mixtures, alloys, pharmaceutical formulations, environmental and fertilizer samples. Comparison of the results with those obtained using an atomic absorption spectrophotometer also tested the validity of the method. Copyright © 2011 Elsevier B.V. All rights reserved.

  7. SUPPORTING INFORMATION Photocytotoxic ternary copper(II ...

    Indian Academy of Sciences (India)

    aditya

    The energy optimized structure of complex 2 along with the FMOs[color codes: C black, N green, O blue, Cu red, and H white]. . Figure S8. The spectral traces showing the decrease of emission intensity of ct-DNA bound ethidium bromide on increasing complex 2concentration in 5 mMTris-HCl buffer medium. . Figure S9.

  8. Catalytic aspects of a copper (II) complex: biological oxidase to ...

    Indian Academy of Sciences (India)

    This copper complex displays excellent catalytic efficiency, kcat /KM (h⁻¹) = 6.17 × 10⁵ towards the oxidative coupling of 2-aminophenol (2-AP) to aminophenoxazin-3-one. Further, upon stoichiometric addition of copper(II) complex to 3,5-DTBC in presence of molecular oxygen in ethanol medium, the copper complex ...

  9. [Bactericidal properties of copper (II) complexes with 1-alkylimidazole].

    Science.gov (United States)

    Radzymińska-Lenarcik, E; Mirska, I; Pernak, J

    1998-01-01

    The copper(II) complexes with 1-alkylimidazole were prepared. Bactericidal properties of the obtained complexes against Staphylococcus aureus, Micrococcus luteus and Pseudomonas aeruginosa were studied. Particularly high activity against microbial strains was shown by complex [Cu(1-C4H9Im)4(CIO4)2].

  10. New Bioactive Heteroleptic Copper(II) Carboxylates: Structure, Enzymatic and DNA-Binding Studies.

    Science.gov (United States)

    Mushtaq, Afifa; Ali, Saqib; Tahir, Muhammad; Ismail, Hammad; Mirza, Bushra; Saadiq, Muhammad; Haleem, Muhammad; Iqbal, Muhammad

    2017-06-01

    Two new binuclear O-bridged copper(II) carboxylates with chemical formulas [Cu2(3-ClC6H4CH2COO)4(phen)2] (1) and [Cu2(3-ClC6H4CH2COO)4(bipy)2] (2) where phen = 1,10-phenanthroline and bipy = 2,2'-bipyridine have been synthesized and characterized by FT-IR, UV-Visible spectroscopy, CHN analysis and single crystal XRD. The results revealed distorted square pyramidal geometry around each copper atom of 1 and 2. The DNA interaction studies showed strong binding with Kb = 5.07 × 103 and 4.62 × 103 M-1 for 1 and 2, respectively. Both complexes showed strong enzyme inhibition, i.e., 70% and 90% for α-glucosidase with IC50 = 34.6 and 30.1 μM for 1 and 2, respectively, where acarbose was employed as control. However, both the complexes were found inactive against α-amylase. Using galantamine hydrobromide as control, 1 showed moderate inhibition activity (47%) with IC50 = 179.4 μM for acetylcholine esterase whereas 2 showed strong inhibition activity (76%) with IC50 = 95.8 μM for butyrylcholine esterase. The data reflects active anti-diabetic and anti-Alzheimer's nature of the synthesized complexes.

  11. Copper(II) enhances membrane-bound α-synuclein helix formation

    Science.gov (United States)

    Lucas, Heather R.

    2011-01-01

    Interactions of copper and membranes with α-synuclein have been implicated in pathogenic mechanisms of Parkinson’s disease, yet work examining both concurrently is scarce. We have examined the effect of copper(II) on protein/vesicle binding and found that both the copper(II) affinity and α-helical content are enhanced for the membrane-bound protein. PMID:21290070

  12. Synthesis and enantiopreferential DNA-binding profile of late 3d transition metal R- and S-enantiomeric complexes derived from N,N-bis-(1-benzyl-2-ethoxyethane): Validation of R-enantiomer of copper(II) complex as a human topoisomerase II inhibitor.

    Science.gov (United States)

    Arjmand, Farukh; Sharma, Girish Chandra; Muddassir, Mohd; Tabassum, Sartaj

    2011-08-01

    To evaluate the biological preference of chiral drug candidates for molecular target DNA, new potential metal-based chemotherapeutic agents 1-3 (a and b) of late 3d transition metals Ni(II), Cu(II), and Zn(II), respectively, derived from (R)- and (S)-2-amino-2-phenylethanol with CH(2) CH(2)  linker were synthesized and thoroughly characterized. Interaction studies of 1-3 (a and b) with calf thymus DNA in Tris buffer were studied by electronic absorption titrations, luminescence titrations, cyclic voltammetry, and circular dichroism. The results reveal that the extent of DNA binding of R-enantiomer of copper 1a was highest in comparison to rest of the complexes via electrostatic interaction mode. The nuclease activity of 1(a and b) with supercoiled pBR322 DNA was further examined by gel electrophoresis, which reveals that complex 1a exhibits a remarkable DNA cleavage activity (concentration dependent) with pBR322DNA, and the cleavage activity of both enantiomers of complex 1 was significantly enhanced in the presence of activators. The activating efficiency follows the order Asc > H(2) O(2) > MPA for 1a, and reverse order was observed for 1b, because of the differences in enantioselectivity and conformation. Further, it was observed that cleavage reaction involves singlet oxygen species and superoxide radicals via oxidative cleavage mechanism. In addition, complex 1a exhibits significant inhibitory effects on the topoisomerase II (topo II) activity at a very low concentration ∼24 μM, which suggest that complex 1a is indeed catalytic inhibitor or (poison) of human topo II. Copyright © 2011 Wiley-Liss, Inc.

  13. Versatility of azide in serendipitous assembly of copper(II) magnetic polyclusters.

    Science.gov (United States)

    Mukherjee, Sandip; Mukherjee, Partha Sarathi

    2013-11-19

    Engineering at the molecular level is one of the most exciting new developments for the generation of functional materials. However, the concept of designing polynuclear extended structures from bottom up is still not mature. Although progress has been made with secondary building units (SBUs) in metal organic frameworks (MOFs), the control seems to be just an illusion when it comes to bridging ligands such as the azide ion. When we say that the azido ligand is versatile in its bridging capabilities, what we mean is that it would be difficult to predict or control its bridging properties. However, this kind of serendipity is not always bad news. For example, scientists have shown that the azido ligand can mediate magnetic exchanges between paramagnetic metals in a predictable fashion (usually depending upon the bonding geometries). Therefore, it is a well-respected ligand in polynuclear assemblies. Serendipitous assemblies offer new magnetic structures that we may not otherwise even think about synthesizing. The azido ligand forms a variety of complexes with copper(II) using different blocking amines or pyridine based ligands. Its structural nature changes upon changing the substitution on amine, as well as the amount of blocking ligand. In principle, if we take any of these complexes and provide more coordination sites to the bridging azido ligands by removing a fraction of the blocking ligands, we can get new complexes with intricate structural networks and therefore different magnetic properties with the same components as used for the parent complex. In this Account, we mainly discuss the development of a number of new topological and magnetic exchange systems synthesized using this concept. Not all of these new complexes can be grouped according to their basic building structures or even by the ratio of the metal to blocking ligand. Therefore, we divided the discussion by the nuclearity of the basic building structures. Some of the complexes with the same

  14. Carboxylate-bridged Cu(II) coordination polymeric complex ...

    Indian Academy of Sciences (India)

    SABITHAKALA THATITURI

    Keywords. Copper(II)polymeric complex; ferromagnetism; electrochemical studies; crystal structure. ... The electron transfer mechanism of copper(II) complex ... EPR spec- trum was obtained using BRUKER Xenon EMX-ER073 spectrometer. X-ray powder diffractograms were recorded on a SMART Bruker D8 advance X-ray ...

  15. Studies of copper(II) sulphide ion-selective electrodes.

    Science.gov (United States)

    Johansson, G; Edström, K

    1972-12-01

    Changes in liquid junction potentials in copper(II) solutions were measured when different reference electrodes were used. The slope and intercept of a calibration curve for a copper-selective electrode will depend on the selection of reference electrode. The condition of the electrode surface of an Orion copper-selective electrode was studied microscopically and the influence of redox potential on stability of the electrode against corrosion is discussed. Oxidizing solutions will produce pits at dislocations in the material and there will be a mixed electrode potential. The slope, stability, and speed of response are much lower when the surface contains pits. Diamond-polishing was shown to improve the electrode significantly.

  16. Bis[(E-4-bromo-2-(methoxyiminomethylphenolato-κ2N,O1]copper(II

    Directory of Open Access Journals (Sweden)

    Shang-Sheng Gong

    2009-12-01

    Full Text Available In the title centrosymmetric mononuclear copper(II complex, [Cu(C8H7BrNO22], the CuII atom, lying on an inversion centre, is four-coordinated in a trans-CuN2O2 square-planar geometry by two phenolate O atoms and two oxime N atoms from two symmetry-related N,O-bidentate oxime-type ligands. Intermolecular C—H...O hydrogen bonds link neighbouring molecules into a one-dimensional supramolecular structure with an R22(14 ring motif. This structure is further stabilized by π–π stacking interactions between adjacent benzene rings [centroid–centroid distance = 3.862 (1 Å].

  17. Coordination of different ligands to copper(II) and cobalt(III) metal centers enhances Zika virus and dengue virus loads in both arthropod cells and human keratinocytes.

    Science.gov (United States)

    Dutta, Shovan; Celestine, Michael J; Khanal, Supreet; Huddleston, Alexis; Simms, Colin; Arca, Jessa Faye; Mitra, Amlan; Heller, Loree; Kraj, Piotr J; Ledizet, Michel; Anderson, John F; Neelakanta, Girish; Holder, Alvin A; Sultana, Hameeda

    2018-01-01

    Trace elements such as copper and cobalt have been associated with virus-host interactions. However, studies to show the effect of conjugation of copper(II) or cobalt(III) metal centers to thiosemicarbazone ligand(s) derived from either food additives or mosquito repellent such as 2-acetylethiazole or citral, respectively, on Zika virus (ZIKV) or dengue virus (serotype 2; DENV2) infections have not been explored. In this study, we show that four compounds comprising of thiosemicarbazone ligand derived from 2-acetylethiazole viz., (E)-N-ethyl-2-[1-(thiazol-2-yl)ethylidene]hydrazinecarbothioamide (acetylethTSC) (compound 1), a copper(II) complex with acetylethTSC as a ligand (compound 2), a thiosemicarbazone ligand-derived from citral (compound 3) and a cobalt(III) complex with a citral-thiosemicarbazone ligand (compound 4) increased DENV2 and ZIKV replication in both mosquito C6/36 cells and human keratinocytes (HaCaT cells). Treatment of both cell lines with compounds 2 or 4 showed increased dengue viral titers at all three tested doses. Enhanced dengue viral plaque formation was also noted at the tested dose of 100μM, suggesting higher production of infectious viral particles. Treatment with the compounds 2 or 4 enhanced ZIKV and DENV2 RNA levels in HeLa cell line and primary cultures of mouse bone marrow derived dendritic cells. Also, pre- or post treatments with conjugated compounds 2 or 4 showed higher loads of ZIKV or DENV2 envelope (E) protein in HaCaT cells. No changes in loads of E-protein were found in ZIKV-infected C6/36 cells, when compounds were treated after infection. In addition, we tested bis(1,10-phenanthroline)copper(II) chloride ([Cu(phen)2]Cl2, (compound 5) and tris(1,10-phenanthroline)cobalt(III) chloride ([Co(phen)3]Cl3, (compound 6) that also showed enhanced DENV2 loads. Also, we found that copper(II) chloride dehydrate (CuCl2·2H2O) or cobalt(II) chloride hexahydrate (CoCl2·6H2O) alone had no effects as "free" cations. Taken together

  18. Synthesis of new oxamide-based ligand and its coordination behavior towards copper(II) ion: spectral and electrochemical studies.

    Science.gov (United States)

    Krishnapriya, K R; Saravanakumar, D; Arunkumar, P; Kandaswamy, M

    2008-04-01

    A new ligand N,N'-bis{3-(2-formyl-4-methyl-phenol)-6-iminopropyl}oxamide (L) and its mono- and binuclear copper(II) complexes have been synthesized and characterized. The ligand shows absorption maxima at 249 and 360 with a weak transition at 455 nm. The ligand was found to be fluorescent and shows an emission maximum at 516 nm on excitation at 360 nm. The electronic spectra of the mono- and binuclear Cu(II) complexes exhibited a d-d transition in the region 520-560 nm characteristic of square planar geometry around Cu(II) ion. The ESR spectrum of the mononuclear complex showed four lines with nuclear hyperfine splitting. The binuclear complex showed a broad ESR spectrum with g=2.10 due to antiferromagnetic interaction between the two Cu(II) ions. The room-temperature magnetic moment values (micro(eff)) for the mono- and binuclear Cu(II) complexes are found to be 1.70 micro(B) and 1.45 micro(B), respectively. The electrochemical studies of the mononuclear Cu(II) complex showed a single irreversible one-electron wave at -0.70 V (E(pc)) and the binuclear Cu(II) complex showed two irreversible one-electron reduction waves at -0.75 V (E(pc)(1)) and -1.27 V (E(pc)(2)) in the cathodic region.

  19. Extractive spectrophotometric determination of copper(II in water and alloy samples with 3-methoxy-4-hydroxy benzaldehyde-4-bromophenyl hydrazone (3,4-MHBBPH

    Directory of Open Access Journals (Sweden)

    D. REKHA

    2007-03-01

    Full Text Available A facile, sensitive and selective extractive spectrophotometricmethod was developed for the determination of copper(II in various water and alloy samples using a newly synthesized reagent, 3-methoxy-4-hydroxy benzaldehyde 4-bromophenyl hydrazone (3,4-MHBBPH. Copper(II forms a orange colored complex with (3,4-MHBBPH in acetate buffermedium (pH 4 which increases the sensitivity and the complexwas extracted into chloroform. Under optimum conditions, the maximum absorption of the chloroform extract was measured at 462 nm. The Beer law was obeyed in the range of 0.20 to 4.0 mg ml-1 of copper. The molar absorptivity and the Sandell's sensitivity of the complex were 2.0520 ´ 104 mol-1 cm-1 and 0.2540 mg cm-2, respectively. The detection limit was found to be 0.0270 mg mL-1. Adetailed study of various interfering ions made the method more sensitive. The method was successfully applied for the determination of Cu(II in water and alloy samples. The performance of the present method was evaluated in terms of Student 't' test and Variance ratio 'f ' test, which indicate the significance of the present method over reported methods.

  20. Rapid, synergistic extractive spectrophotometric determination of copper(II) by using sensitive chromogenic reagent N″,N″'-bis[(E)-(4-fluorophenyl) methylidene]thiocarbonohydrazide.

    Science.gov (United States)

    Nalawade, Rekha A; Nalawade, Avinash M; Kamble, Ganesh S; Anuse, Mansing A

    2015-07-05

    A rapid and simple spectrophotometric method was developed for the determination of copper(II) by using newly synthesized chromogenic reagent, N″,N″'-bis[(E)-(4-fluorophenyl)methylidene]thiocarbonohydrazide [bis(4-fluoroPM)TCH]. The reagent is highly sensitive and it forms yellow colored ternary complex with copper(II) in presence pyridine having composition 1:1:2 (M:L:Py) in the acidic pH range. Absorption of colored complex in amyl acetate is measured with reagent as a blank at λmax 375 nm. The synergistic effect is observed due to pyridine forming adduct with reagent in the organic phase. Beer's law was obeyed in the concentration range from 2.0 to 14 μg mL(-1) for copper(II)-[bis(4-fluoroPM)TCH]-Py complex. Molar absorptivity and Sandell's sensitivity values for Cu(II)-bis(4-fluoroPM)TCH]-Py complex are 0.42545×10(5) and 0.0014 μg/cm(2), respectively. The selectivity of the developed method was checked in the presence of various foreign ions. The developed method showed relative standard deviation (R.S.D.) of 0.13% for n=10. The composition of Cu(II)-[bis(4-fluoroPM)TCH]-Py complex was determined by known methods such as Job's method of continuous variation, mole ratio method and slope ratio method. It is found that the ternary complex is stable for more than 24h. Various factors influencing on the degree of complexation, such as, effect of pH, reagent concentration, synergent concentration, solvent etc. were studied. The accuracy and reliability of method was verified by AAS. This method is found to be simple, rapid and reproducible. Copyright © 2015. Published by Elsevier B.V.

  1. Phase stabilization in cinnarizine complexes using X-ray profile ...

    Indian Academy of Sciences (India)

    Abstract. Characterization of cobalt(II), cadmium(II), copper(II) and tin(II) cinnarizine complexes have been carried out using conductivity, electronic spectra, infrared, nmr, thermogravimetric and X- ray analyses to establish the nature of phase stabilization in these materials. Also, the intrinsic strain components present in ...

  2. Phase stabilization in cinnarizine complexes using X-ray profile ...

    Indian Academy of Sciences (India)

    Characterization of cobalt(II), cadmium(II), copper(II) and tin(II) cinnarizine complexes have been carried out using conductivity, electronic spectra, infrared, nmr, thermogravimetric and Xray analyses to establish the nature of phase stabilization in these materials. Also, the intrinsic strain components present in these ...

  3. Studies on transition metal complexes of herbicidal compounds. II ...

    African Journals Online (AJOL)

    2(2-Hydroxyethyl)hydrazino-4-ethylamino-6-isopropylamino-s-triazine (HEATZ), a derivative of 2-chloro-4-ethylamino-6-isopropylamino-s-triazine, atrazine (ATZ) – a well known herbicide has been studied for complex formation with cobalt(II), nickel(II), and copper(II). Analytical, conductance, thermal, and spectral studies ...

  4. Carboxylate-bridged Cu (II) coordination polymeric complex ...

    Indian Academy of Sciences (India)

    Carboxylate-bridged Cu(II) coordination polymeric complex: synthesis, crystal structure, magnetic properties, DNA binding and electrochemical studies ... Abstract. A novel water-soluble carboxylate-bridged copper(II) coordination polymer,Cu-BIG was formed by the reaction of Cu(ClO₄)₂ ·6H₂O and tridentate ...

  5. Unprecedented hetero-geometric discrete copper (II) complexes ...

    Indian Academy of Sciences (India)

    Unprecedented hetero-geometric discrete copper(II) complexes: Crystal structure and bio-mimicking of Catecholase activity. ABHRANIL DE DHANANJAY DEY HARE RAM YADAV MILAN MAJI VINAYAK RANE R M KADAM ANGSHUMAN ROY CHOUDHURY BHASKAR BISWAS. Regular Article Volume 128 Issue 11 ...

  6. Copper complexes as biomimetic models of catechol oxidase : mechanistic studies

    NARCIS (Netherlands)

    Koval, Iryna A.

    2006-01-01

    The research described in this thesis deals with the synthesis of copper(II) complexes with phenol-based or macrocyclic ligands, which can be regarded as model compounds of the active site of catechol oxidase, and with the mechanism of the catalytic oxidation of catechol mediated by these compounds.

  7. Acid-base characterization, coordination properties towards copper(II) ions and DNA interaction studies of ribavirin, an antiviral drug.

    Science.gov (United States)

    Nagaj, Justyna; Starosta, Radosław; Jeżowska-Bojczuk, Małgorzata

    2015-01-01

    We have studied processes of copper(II) ion binding by ribavirin, an antiviral agent used in treating hepatitis C, which is accompanied usually by an increased copper level in the serum and liver tissue. Protonation equilibria and Cu(II) binding were investigated using the UV-visible, EPR and NMR spectroscopic techniques as well as the DFT (density functional theory) calculations. The spectroscopic data suggest that the first complex is formed in the water solution at pH as low as 0.5. In this compound Cu(II) ion is bound to one of the nitrogen atoms from the triazole ring. Above pH6.0, the metal ion is surrounded by two nitrogen and two oxygen atoms from two ligand molecules. The DFT calculations allowed to determine the exact structure of this complex. We found that in the lowest energy isomer two molecules of the ligand coordinate via O and N4 atoms in trans positions. The hypothetical oxidative properties of the investigated system were also examined. It proved not to generate plasmid DNA scission products. However, the calf thymus (CT)-DNA binding studies showed that it reacts with ribavirin and its cupric complex. Moreover, the interaction with the complex is much more efficient. Copyright © 2014 Elsevier Inc. All rights reserved.

  8. Rational design of a novel azoimine appended maleonitrile-based Salen chemosensor for rapid naked-eye detection of copper(II) ion in aqueous media.

    Science.gov (United States)

    Rezaeian, Khatereh; Khanmohammadi, Hamid; Arab, Vajihe

    2015-12-05

    Achieving specific selectivity and high sensitivity for the colorimetric recognition of copper(II) ions in aqueous media over a complex background of potentially competing metal ions is inherently challenging in sensor development. Thus, a novel azo-azomethine receptor (L) based on the combination of 2-amino-3-(5-bromo-2-hydroxybenzylamino)maleonitrile and azo-coupled salicylaldehyde scaffold has been designed and synthesized for the naked-eye and rapid detection of Cu(2+) ion at trace level in a wide pH range. Accordingly, the devised chemosensor distinguished Cu(2+) from other metal ions by distinct color change from light yellow to light brown without any expensive equipment. The binding stoichiometry between Cu(2+) and L has been investigated using Job's plot and MALDI-TOF mass analysis. Remarkably, the current sensor can detect Cu(2+) ions even at 1.07 μM level, which is lower than the World Health Organization (WHO) permissible level (30 μM) in drinking water. Furthermore, sensor L was successfully utilized in the preparation of test strips for the detection of copper(II) ions from aqueous environment. Copyright © 2015 Elsevier B.V. All rights reserved.

  9. RECOVERY OF COPPER(II) AND CHROMIUM(III) FROM NITRATE ...

    African Journals Online (AJOL)

    Guerdouh A and Barkat D

    2016-05-01

    May 1, 2016 ... ABSTRACT. The solvent extraction of copper(II) and chromium(III) from nitrate medium with salicylideneaniline (HL) is studied as a function of various parameters: pH, concentration of salicylideneaniline, contact time and the nature of anoin (nitrate and sulfate) in aqueous phase. Chromium(III) is not ...

  10. Removal of copper(II) ion from aqueous solution by high-porosity ...

    African Journals Online (AJOL)

    The removal of copper(II) ion from aqueous solution by the granular activated carbon, obtained from hazelnut shells (ACHS) (Corylus avellana L. var. lunga istriana), was investigated. The ACHS was prepared from ground dried hazelnut shells by specific method carbonisation and water steam activation at 950oC for 2 h.

  11. Copper (II) Schiff base complexes and their mixed thin layers with ...

    Indian Academy of Sciences (India)

    Copper(II) Schiff base complexes and their mixed thin layers with ZnO nanoparticles. MAGDALENA ... Keywords. Thin layer; ZnO nanoparticles; copper complexes; AFM; SEM; fluorescence. ... Zinc oxide was synthesized using a simple homogeneous precipitation method with zinc acetate as a starting material. Thin layers ...

  12. STUDIES ON SOME VO(IV), Ni(II) AND Cu(II) COMPLEXES OF NON ...

    African Journals Online (AJOL)

    a

    planar complexes are diamagnetic [23]. The Ni(II) complexes reported in this work, are diamagnetic and consequently, four coordinate, square planar in geometry [19-20, 23], ruling out the presence of paramagnetic, tetrahedral forms. The room temperature magnetic moments of the copper(II) compounds are expected to be.

  13. Complexity

    Indian Academy of Sciences (India)

    Rahul Pandit

    2008-10-31

    Oct 31, 2008 ... ”The more complex a thing is, the more you can talk about it.” - attributed to Giorgio Parisi. ▻ ”C'est magnifique, mais ce n'est pas de la science.” (It is magnificent, but not all of it is science.) - attributed ... Earliest examples: theoretical computer science, algorithmic complexity, etc. ▻ Rapid progress after the ...

  14. Biosorption of copper(II) and lead(II) onto potassium hydroxide treated pine cone powder.

    Science.gov (United States)

    Ofomaja, A E; Naidoo, E B; Modise, S J

    2010-08-01

    Pine cone powder surface was treated with potassium hydroxide and applied for copper(II) and lead(II) removal from solution. Isotherm experiments and desorption tests were conducted and kinetic analysis was performed with increasing temperatures. As solution pH increased, the biosorption capacity and the change in hydrogen ion concentration in solution increased. The change in hydrogen ion concentration for lead(II) biosorption was slightly higher than for copper(II) biosorption. The results revealed that ion-exchange is the main mechanism for biosorption for both metal ions. The pseudo-first order kinetic model was unable to describe the biosorption process throughout the effective biosorption period while the modified pseudo-first order kinetics gave a better fit but could not predict the experimentally observed equilibrium capacities. The pseudo-second order kinetics gave a better fit to the experimental data over the temperature range from 291 to 347 K and the equilibrium capacity increased from 15.73 to 19.22 mg g(-1) for copper(II) and from 23.74 to 26.27 for lead(II). Activation energy was higher for lead(II) (22.40 kJ mol(-1)) than for copper(II) (20.36 kJ mol(-1)). The free energy of activation was higher for lead(II) than for copper(II) and the values of DeltaH* and DeltaS* indicate that the contribution of reorientation to the activation stage is higher for lead(II) than copper(II). This implies that lead(II) biosorption is more spontaneous than copper(II) biosorption. Equilibrium studies showed that the Langmuir isotherm gave a better fit for the equilibrium data indicating monolayer coverage of the biosorbent surface. There was only a small interaction between metal ions when simultaneously biosorbed and cation competition was higher for the Cu-Pb system than for the Pb-Cu system. Desorption studies and the Dubinin-Radushkevich isotherm and energy parameter, E, also support the ion-exchange mechanism. Copyright 2010 Elsevier Ltd. All rights reserved.

  15. Selective determination of trace copper(II) by cathodic adsorptive stripping voltammetry with a naphthol-derivative Schiff's base.

    Science.gov (United States)

    Shamsipur, Mojtaba; Saeidi, Mahboubeh; Sharghi, Hashem; Naeimi, Hossein

    2003-01-01

    A selective and sensitive stripping voltammetric method for the determination of trace amounts of copper(II) with a recently synthesized naphthol-derivative Schiff's base (2,2'-[1,2-ethanediylbis(nitriloethylidyne)]bis(1-naphthalene)) is presented. The method is based on adsorptive accumulation of the resulting copper-Schiff's base complex on a hanging mercury drop electrode, followed by the stripping voltammetric measurement at the reduction current of adsorbed complex at -0.15 V (vs. Ag/AgCl). The optimal conditions for the stripping analysis of copper include pH 5.5 to 6.5, 8 microM Schiff's base and an accumulation potential of -0.05 V (vs. Ag/AgCI). The peak current is linearly proportional to the copper concentration over a range 2.3-50.8 ng ml(-1) with a limit of detection of 1.9 ng ml(-1). The accumulation time and RSD are 90 s and (3.2-3.5)%, respectively. The method was applied to the determination of copper in some analytical grade salts, tap water, human serum and sheep's liver.

  16. Magneto-structural versatility of copper(II)-3-phenylpropionate coordination polymers with N-donor coligands.

    Science.gov (United States)

    de Campos, Nathália R; Ribeiro, Marcos A; Oliveira, Willian X C; Reis, Daniella O; Stumpf, Humberto O; Doriguetto, Antônio C; Machado, Flávia C; Pinheiro, Carlos B; Lloret, Francesc; Julve, Miguel; Cano, Joan; Marinho, Maria V

    2016-01-07

    A novel series of copper(II) coordination polymers [Cu2(O2CC8H9)4(pyz)]n (1), [Cu2(O2CC8H9)4(dps)]n (2), {[Cu(O2CC8H9)2(dps)(H2O)]·H2O}n (3), {[NaCu(O2CC8H9)2(bpm)(NO3)]·H2O}n (4), and [Cu4(O2CC8H9)6(OH)2(bpp)2]n (5) [O2CC8H9− = 3-phenylpropionate anion, pyz = pyrazine, dps = di(4-pyridyl)sulfide, bpm = 2,2′-bipyrimidine, and bpp = 1,3-bis(4-pyridyl)propane] have been synthesized and magneto-structurally investigated. Compounds 1 and 2 belong to a large group of copper(II) carboxylates where bis-monodentate pyz (1) and dps (2) ligands connect the paddle-wheel [CuII2(μ-O2CC8H9)4] units leading to alternating copper(II) chains. The structure of 3 consists of uniform chains of trans-[CuII(O2CC8H9)2] units linked by the bis-monodentate dps ligand. Compound 4 consists of heterobimetallic chains where [NaI2CuII2(μ-O2CC8H9)4(NO3)2] units are doubly bridged by bis-bidentate bpm ligands. Compound 5 is also a chain compound whose structure is made up by tetranuclear [CuII4(μ3-OH)2(μ-O2CC8H9)4(O2CC8H9)2] units which are doubly bridged by bis-monodentate bpp ligands. The magnetic properties were investigated in the temperature range 1.8–300 K. Strong antiferromagnetic interactions across the quadruple syn–syn carboxylate are observed in 1 and 2 [J = −378 (1) and −348 cm−1 (2)] whereas a weak ferromagnetic coupling through the double out-of-plane oxo(carboxylate) bridge occurs in 4 [J = +2.66 cm−1], the spin Hamiltonian being defined as H = −JS1·S2 with S1 = S2 = SCu = 1/2. A quasi Curie law is observed for 3 (θ = −0.36 cm−1), the bis-monodentate dps ligand being a very poor mediator of magnetic interactions. The analysis of the magnetic properties of 5 is quite complex because of the presence of two crystallographically independent tetracopper(II) units with single-μ-hydroxo, di-μ-hydroxo, μ3-hydroxo and single-μ-hydroxo plus double syn,syn carboxylate bridges in each one. The nature and values of the magnetic couplings for 5 obtained by

  17. Oxidative double dehalogenation of tetrachlorocatechol by a bio-inspired Cu II complex: formation of chloranilic acid

    NARCIS (Netherlands)

    Bruijnincx, P.C.A.|info:eu-repo/dai/nl/33799529X; Viciano-Chumillas, M.; Lutz, M.|info:eu-repo/dai/nl/304828971; Spek, A.L.|info:eu-repo/dai/nl/156517566; Reedijk, J.; van Koten, G.|info:eu-repo/dai/nl/073839191; Klein Gebbink, R.J.M.|info:eu-repo/dai/nl/166032646

    2008-01-01

    Copper(II) complexes of the potentially tripodal N,N,O ligand 3,3-bis(1-methylimidazol-2-yl)propionate (L1) and its conjugate acid HL1 have been synthesised and structurally and spectroscopically characterised. The reaction of equimolar amounts of ligand and CuII resulted in the complexes

  18. Highly selective oxalate-membrane electrode based on 2,2'-[1,4-butandiyle bis(nitrilo propylidine)]bis-1-naphtholato copper(II).

    Science.gov (United States)

    Ardakani, M Mazloum; Jalayer, M; Naeimi, H; Heidarnezhad, A; Zare, H R

    2006-01-15

    A new oxalate-selective electrode based on the complex 2,2'-[1,4-butandiyle bis(nitrilo propylidine)]bis-1-naphtholato copper(II) (CuL) as the membrane carrier was developed. The electrode exhibited a good Nernstian slope of -29.2+/-0.6 mV/decade (mean value+/-standard deviation, n=5) and a linear range of 5.0 x 10(-8) to 1.0 x 10(-1)M for oxalate. The limit of detection was 5.0 x 10(-8)M. This electrode represents a fast response time (i.e. 10-15s) and could be used for more than 3 months. The selectivity coefficients were determined by the fixed interference method (FIM) and could be used in the pH range of 2.0-7.0. It was employed as an indicator electrode for the determination of oxalate in water samples.

  19. Low-temperature atomic layer deposition of copper(II) oxide thin films

    Energy Technology Data Exchange (ETDEWEB)

    Iivonen, Tomi, E-mail: tomi.iivonen@helsinki.fi; Hämäläinen, Jani; Mattinen, Miika; Popov, Georgi; Leskelä, Markku [Laboratory of Inorganic Chemistry, Department of Chemistry, University of Helsinki, P.O. Box 55, FI-00014 Helsinki (Finland); Marchand, Benoît; Mizohata, Kenichiro [Division of Materials Physics, Department of Physics, University of Helsinki, P.O. Box 43, FI-00014 Helsinki (Finland); Kim, Jiyeon; Fischer, Roland A. [Chair of Inorganic Chemistry II, Ruhr-University Bochum, Universitätsstrasse 150, 44780 Bochum (Germany)

    2016-01-15

    Copper(II) oxide thin films were grown by atomic layer deposition (ALD) using bis-(dimethylamino-2-propoxide)copper [Cu(dmap){sub 2}] and ozone in a temperature window of 80–140 °C. A thorough characterization of the films was performed using x-ray diffraction, x-ray reflectivity, UV‐Vis spectrophotometry, atomic force microscopy, field emission scanning electron microscopy, x-ray photoelectron spectroscopy, and time-of-flight elastic recoil detection analysis techniques. The process was found to produce polycrystalline copper(II) oxide films with a growth rate of 0.2–0.3 Å per cycle. Impurity content in the films was relatively small for a low temperature ALD process.

  20. Copper(II tetrafluoroborate as mild and versatile catalyst for the

    Directory of Open Access Journals (Sweden)

    Jihillu. S. Yadav

    2008-12-01

    Full Text Available A variety of -acetamido ketones and ketoesters are readily prepared in high yields under extremelymild conditions via a three component coupling of aromatic aldehydes, enolizable ketones or -ketoesters andnitriles in the presence of 10 mol% of copper(II tetrafluoroborate and a stoichiometric amount of acetylchloride. A solution of 10 mol% of Cu(BF42 in acetonitrile provides a convenient reaction medium to carry out athree component reaction under mild conditions

  1. A soft copper(II) porous coordination polymer with unprecedented aqua bridge and selective adsorption properties.

    Science.gov (United States)

    Quartapelle Procopio, Elsa; Fukushima, Tomohiro; Barea, Elisa; Navarro, Jorge A R; Horike, Satoshi; Kitagawa, Susumu

    2012-10-08

    Herein, the synthesis, crystal structure, and full characterization of a new soft porous coordination polymer (PCP) of ([Cu(2)(dmcapz)(2)(OH(2))]DMF(1.5))(n) (1) formulation, which is easily obtained in the reaction of CuX(2) (X = Cl, NO(3)) salts with 3,5-dimethyl-4-carboxypyrazole (H(2)dmcapz) is present. Compound 1 shows a copper(II) dinuclear secondary building unit (SBU), which is supported by two pyrazolate bridges and an unprecedented H(2)O bridge. The dinuclear SBUs are further bridged by the carboxylate ligands to build a diamondoid porous network. The structural transformations taking place in 1 framework upon guest removal/uptake has been studied in detail. Indeed, the removal of the bridging water molecules gives rise to a metastable evacuated phase (1 b) that transforms into an extremely stable porous material (1 c) after freezing at liquid-nitrogen temperature. The soaking of 1 c into water allows the complete and instantaneous recover of the water-exchanged material (1 a'). Remarkably, 1 b and 1 c materials possess structural bistability, which results in the switchable adsorptive functions. Therefore, the gas-adsorption properties of both materials have been studied by means of single-component gas adsorption isotherms as well as by variable-temperature pulse-gas chromatography. Both materials present permanent porosity and selective gas-adsorption properties towards a variety of gases and vapors of environmental and industrial interest. Moreover, the flexible nature of the coordination network and the presence of highly active convergent open metal sites confer on these materials intriguing gas-adsorption properties with guest-triggered framework-breathing phenomena being observed. The plasticity of Cu(II) metal center and its ability to form stable complexes with different coordination numbers is at the origin of the structural transformations and the selective-adsorption properties of the studied materials. Copyright © 2012 WILEY

  2. Copper (II) nickel (II), cobalt (II) and oxovanadium (IV) complexes of ...

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Chemical Sciences; Volume 112; Issue 3. Copper(II) nickel(II), cobalt(II) and oxovanadium(IV) complexes of substituted ∙ - ... Author Affiliations. S Sevagapandian1 K Nehru1 P R Athappan1. Department of Inorganic Chemistry, Madurai Kamaraj University, Madurai 625 021, India ...

  3. Copper (II) complex as a precursor for formation of cyano-bridged ...

    Indian Academy of Sciences (India)

    Copper(II) complex as a precursor for formation of cyano-bridged pentanuclear FeIII-CuII bimetallic assembly: Synthesis, characterization, crystal structure and ... ATCC 27853 strains were studied and compared with standard drugs, which showed moderate antibacterial activity compared with Penicillin and Gentamicin.

  4. Synthesis, characterization, anti-microbial, DNA binding and cleavage studies of Schiff base metal complexes

    Directory of Open Access Journals (Sweden)

    Poomalai Jayaseelan

    2016-09-01

    Full Text Available A novel Schiff base ligand has been prepared by the condensation between butanedione monoxime with 3,3′-diaminobenzidine. The ligand and metal complexes have been characterized by elemental analysis, UV, IR, 1H NMR, conductivity measurements, EPR and magnetic studies. The molar conductance studies of Cu(II, Ni(II, Co(II and Mn(II complexes showed non-electrolyte in nature. The ligand acts as dibasic with two N4-tetradentate sites and can coordinate with two metal ions to form binuclear complexes. The spectroscopic data of metal complexes indicated that the metal ions are complexed with azomethine nitrogen and oxyimino nitrogen atoms. The binuclear metal complexes exhibit octahedral arrangements. DNA binding properties of copper(II metal complex have been investigated by electronic absorption spectroscopy. Results suggest that the copper(II complex bind to DNA via an intercalation binding mode. The nucleolytic cleavage activities of the ligand and their complexes were assayed on CT-DNA using gel electrophoresis in the presence and absence of H2O2. The ligand showed increased nuclease activity when administered as copper complex and copper(II complex behave as efficient chemical nucleases with hydrogen peroxide activation. The anti-microbial activities and thermal studies have also been studied. In anti-microbial activity all complexes showed good anti-microbial activity higher than ligand against gram positive, gram negative bacteria and fungi.

  5. Influence of pH on the speciation of copper(II) in reactions with the green tea polyphenols, epigallocatechin gallate and gallic acid

    Science.gov (United States)

    Pirker, Katharina F.; Baratto, Maria Camilla; Basosi, Riccardo; Goodman, Bernard A.

    2012-01-01

    Changes in speciation of copper(II) in reactions with epigallocatechin gallate (EGCG) and gallic acid (GA) as a function of pH have been investigated by multifrequency (X- and S-band) EPR spectroscopy in the fluid and frozen states. The EPR spectra show the formation of three distinct mononuclear species with each of the polyphenols, and these are interpreted in terms of one mono- and two bis-complexes. However, di- or polymeric complexes dominate the Cu(II) speciation in the pH range 4–8, and it is only at alkaline pH values that these mononuclear complexes make appreciable contributions to the metal speciation. Each mononuclear complex displays linewidth anisotropy in fluid solution as a consequence of incomplete averaging of the spin Hamiltonian parameters through molecular motion. Rotational correlation times for the individual complexes have been estimated by analysing the lineshape anisotropy of the fluid solution spectra using parameters determined by simulation of the rigid limit spectra. These show that the molecular masses increase with increasing pH, indicating either coordination of increasing numbers of polyphenol molecules as ligands to the copper or the increasing involvement of polyphenol dimers as ligands in the copper coordination sphere. PMID:22542590

  6. Selective flotation-spectrophotometric determination of trace copper(II) in natural waters, human blood and drug samples using phenanthraquinone monophenylthiosemicarbazone.

    Science.gov (United States)

    Khalifa, M E; Akl, M A; Ghazy, S E

    2001-06-01

    Copper(II) forms 1:1 and 1:2 intense red complexes with phenanthraquinone monophenylthiosemicarbazone (PPT) at pH 3-3.5 and > or =6.5, respectively. These complexes exhibit maximal absorbance at 545 and 517 nm, the molar absorptivity being 2.3 x 10(4) and 4.8 x 10(4) l mol(-1) cm(-1), respectively. However, the 1:1 complex was quantitatively floated with oleic acid (HOL) surfactant in the pH range 4.5-5.5, providing a highly selective and sensitive procedure for the spectrophotometric determination of CuII. The molar absorptivity of the floated Cu-PPT complex was 1.5 x 10(5) l mol)(-1) cm(-1). Beer's law was obeyed over the range 3-400 ppb at 545 nm. The analytical parameters affecting the flotation process and hence the determination of copper traces were reported. Also, the structure of the isolated solid complex and the mechanism of flotation were suggested. Moreover, the procedure was successfully applied to the analysis of CuII in natural waters, serum blood and some drug samples.

  7. Correlation between DNA interactions and cytotoxic activity of four new ternary compounds of copper(II) with N-donor heterocyclic ligands.

    Science.gov (United States)

    Silva, Priscila P; Guerra, Wendell; Dos Santos, Geandson Coelho; Fernandes, Nelson G; Silveira, Josiane N; da Costa Ferreira, Ana M; Bortolotto, Tiago; Terenzi, Hernán; Bortoluzzi, Adailton João; Neves, Ademir; Pereira-Maia, Elene C

    2014-03-01

    Four new ternary complexes of copper(II) were synthesized and characterized: [Cu(hyd)(bpy)(acn)(ClO4)](ClO4)] (1), [Cu(hyd)(phen)(acn)(ClO4)](ClO4)] (2), [Cu(Shyd)(bpy)(acn)(ClO4)](ClO4)] (3) and [Cu(Shyd)(phen)(acn)(ClO4)](ClO4)] (4), in which acn=acetonitrile; hyd=2-furoic acid hydrazide, bpy=2,2-bipyridine; phen=1,10-phenanthroline and Shyd=2-thiophenecarboxylic acid hydrazide. The cytotoxic activity of the complexes in a chronic myelogenous leukemia cell line was investigated. All complexes are able to enter cells and inhibit cellular growth in a concentration-dependent manner, with an activity higher than that of the corresponding free ligands. The substitution of Shyd for hyd increases the activity, while the substitution of bpy for phen renders the complex less active. Therefore, the most potent complex is 4 with an IC50 value of 1.5±0.2μM. The intracellular copper concentration needed to inhibit 50% of cell growth is approximately 7×10(-15)mol/cell. It is worth notifying that a correlation between cytotoxic activity, DNA binding affinity and DNA cleavage was found: 1<3<2<4. © 2013.

  8. Efficient electron-induced removal of oxalate ions and formation of copper nanoparticles from copper(II oxalate precursor layers

    Directory of Open Access Journals (Sweden)

    Kai Rückriem

    2016-06-01

    Full Text Available Copper(II oxalate grown on carboxy-terminated self-assembled monolayers (SAM using a step-by-step approach was used as precursor for the electron-induced synthesis of surface-supported copper nanoparticles. The precursor material was deposited by dipping the surfaces alternately in ethanolic solutions of copper(II acetate and oxalic acid with intermediate thorough rinsing steps. The deposition of copper(II oxalate and the efficient electron-induced removal of the oxalate ions was monitored by reflection absorption infrared spectroscopy (RAIRS. Helium ion microscopy (HIM reveals the formation of spherical nanoparticles with well-defined size and X-ray photoelectron spectroscopy (XPS confirms their metallic nature. Continued irradiation after depletion of oxalate does not lead to further particle growth giving evidence that nanoparticle formation is primarily controlled by the available amount of precursor.

  9. Copper(II) binding to the human Doppel protein may mark its functional diversity from the prion protein.

    Science.gov (United States)

    Cereghetti, Grazia M; Negro, Alessandro; Vinck, Evi; Massimino, Maria L; Sorgato, Maria C; Van Doorslaer, Sabine

    2004-08-27

    Doppel (Dpl) is the first described homologue of the prion protein, the main constituent of the agent responsible for prion diseases. The cellular prion protein (PrP(C)) is predominantly present in the central nervous system. Although its role is not yet completely clarified, PrP(C) seems to be involved in Cu(2+) recycling from synaptic clefts and in preventing neuronal oxidative damage. Conversely, Dpl is expressed in heart and testis and has been shown to regulate male fertility by intervening in gametogenesis and sperm-egg interactions. Therefore, despite a high sequence homology and a similar three-dimensional fold, the functions of PrP(C) and Dpl appear unrelated. Here we show by electron paramagnetic resonance and fluorescence spectroscopy that the in vitro binding of copper(II) to human recombinant Dpl occurs with a different pattern from that observed for recombinant PrP. At physiological pH values, two copper(II)-binding sites with different affinities were found in Dpl. At lower pH values, two additional copper(II)-binding sites can be identified as follows: one complex is present only at pH 4, and the other is observed in the pH range 5-6. As derived from the electron paramagnetic resonance characteristics, all Dpl-copper(II) complexes have a different coordination sphere from those present in PrP. Furthermore, in contrast to the effect shown previously for PrP(C), addition of Cu(2+) to Dpl-expressing cells does not cause Dpl internalization. These results suggest that binding of the ion to PrP(C) and Dpl may contribute to the different functional roles ascribed to these highly homologous proteins.

  10. Synthesis, structure, and magnetic properties of regular alternating μ-bpm/di-μ-X copper(II) chains (bpm = 2,2'-bipyrimidine; X = OH, F).

    Science.gov (United States)

    Marino, Nadia; Armentano, Donatella; De Munno, Giovanni; Cano, Joan; Lloret, Francesc; Julve, Miguel

    2012-04-02

    The preparation and X-ray crystal structure of four 2,2'-bipyrimidine (bpm)-containing copper(II) complexes of formula {[Cu(2)(μ-bpm)(H(2)O)(4)(μ-OH)(2)][Mn(H(2)O)(6)](SO(4))(2)}(n) (1), {[Cu(2)(μ-bpm)(H(2)O)(4)(μ-OH)(2)]SiF(6)}(n) (2), {Cu(2)(μ-bpm)(H(2)O)(2)(μ-F)(2)F(2)}(n) (3), and [Cu(bpm)(H(2)O)(2)F(NO(3))][Cu(bpm)(H(2)O)(3)F]NO(3)·2H(2)O (4) are reported. The structures of 1-3 consist of chains of copper(II) ions with regular alternation of bis-bidentate bpm and di-μ-hydroxo (1 and 2) or di-μ-fluoro (3) groups, the electroneutrality being achieved by either hexaaqua manganese(II) cations plus uncoordinated sulfate anions (1), uncoordinated hexafluorosilicate anions (2), or terminally bound fluoride ligands (3). Each copper(II) ion in 1-4 is six-coordinated in elongated octahedral surroundings. 1 and 2 show identical, linear chain motifs with two bpm-nitrogen atoms and two hydroxo groups building the equatorial plane at each copper(II) ion and the axial position being filled by water molecules. In the case of 3, the axial sites at the copper atom are occupied by a bpm-nitrogen atom and a bis-monodentate fluoride anion, producing a "step-like" chain motif. The values of the angle at the hydroxo and fluoro bridges are 94.11(6) (1), 94.75(4) (2), and 101.43(4)° (3). In each case, the copper-copper separation through the bis-bidentate bpm [5.428(1) (1), 5.449(1) (2), and 5.9250(4) Å (3)] is considerably longer than that through the di-μ-hydroxo [2.8320(4) (1) and 2.824(1) Å (2)] or di-μ-fluoro [3.3027(4) Å (3)] bridges. Compound 4 is a mononuclear species whose structure is made up of neutral [Cu(bpm)(H(2)O)(2)F(NO(3))] units, [Cu(bpm)(H(2)O)(3)F](+) cations, uncoordinated nitrate anions, and crystallization water molecules, giving rise to a pseudo-helical, one-dimensional (1D) supramolecular motif. The magnetic properties of 1-3 have been investigated in the temperature range 1.9-300 K. Relatively large, alternating antiferro- [J = -149 (1) and

  11. Study of the interaction mechanism in the biosorption of copper(II) ions onto posidonia oceanica and peat

    Energy Technology Data Exchange (ETDEWEB)

    Izquierdo, Marta; Marzal, Paula; Gabaldon, Carmen [Departamento de Ingenieria Quimica, Escuela Tecnica Superior de Ingenieria, Universitat de Valencia, Valencia (Spain); Silvetti, Margherita; Castaldi, Paola [Dipartimento di Scienze Ambientali e Agrarie e Biotecnologie Agro-Alimentari, Sez. Chimica Agraria ed Ambientale, University of Sassari, Sassari (Italy)

    2012-04-15

    A systematic approach was used to characterize the biosorption of copper(II) onto two biosorbents, Posidonia oceanica and peat, focusing on the interaction mechanisms, the copper(II) sorption-desorption process and the thermal behavior of the biosorbents. Sorption isotherms at pH 4-6 were obtained and the experimental data were fitted to the Langmuir model with a maximum uptake (q{sub max}) at pH 6 of 85.78 and 49.69 mg g{sup -1}, for P. oceanica and peat, respectively. A sequential desorption (SD) with water, Ca(NO{sub 3}){sub 2}, and EDTA was applied to copper-saturated biosorbents. Around 65-70% copper(II) were desorbed with EDTA, indicating that this heavy metal was strongly bound. The reversibility of copper(II) sorption was obtained by desorption with HCl and SD. Fourier transform IR spectroscopy (FTIR) analysis detected the presence of peaks associated with OH groups in aromatic and aliphatic structures, CH, CH{sub 2}, and CH{sub 3} in aliphatic structures, COO{sup -} and COOH groups and unsaturated aromatic structures on the surface of both biosorbents, as well as peaks corresponding to Si-O groups on the surface of peat. The results of SEM-EDX and FTIR analysis of copper-saturated samples demonstrated that ion exchange was one of the mechanisms involved in copper(II) retention. Thermal analysis of biosorbent samples showed that copper(II) sorption-desorption processes affected the thermal stability of the biosorbents. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  12. Synthesis, characterization and investigation of electrochemical and spectroelectrochemical properties of non-peripherally tetra-5-methyl-1,3,4-thiadiazole substituted copper(II) iron(II) and oxo-titanium (IV) phthalocyanines

    Science.gov (United States)

    Demirbaş, Ümit; Akyüz, Duygu; Akçay, Hakkı Türker; Barut, Burak; Koca, Atıf; Kantekin, Halit

    2017-09-01

    In this study novel substituted phthalonitrile (3) and non-peripherally tetra 5-Methyl-1,3,4-thiadiazole substituted copper(II) (4), iron(II) (5) and oxo-titanium (IV) (6) phthalocyanines were synthesized. These novel compounds were fully characterized by FT-IR, 1H NMR, UV-vis and MALDI-TOF mass spectroscopic techniques. Voltammetric and in situ spectroelectrochemical measurements were performed for metallo-phthalocyanines (4-6). TiIVOPc and FeIIPc showed metal-based and ligand-based electron transfer reactions while CuIIPc shows only ligand-based electron transfer reaction. Voltammetric measurements indicated that the complexes have reversible, diffusion controlled and one-electron redox reactions. The assignments of the redox processes and color of the electrogenerated species of the complexes were determined with in-situ spectroelectrochemical and electrocolorimetric measurements. These measurements showed that the complexes can be used as the electrochromic materials for various display technologies.

  13. Developing Anticancer Copper(II) Pro-drugs Based on the Nature of Cancer Cells and the Human Serum Albumin Carrier IIA Subdomain.

    Science.gov (United States)

    Gou, Yi; Qi, Jinxu; Ajayi, Joshua-Paul; Zhang, Yao; Zhou, Zuping; Wu, Xiaoyang; Yang, Feng; Liang, Hong

    2015-10-05

    To synergistically enhance the selectivity and efficiency of anticancer copper drugs, we proposed and built a model to develop anticancer copper pro-drugs based on the nature of human serum albumin (HSA) IIA subdomain and cancer cells. Three copper(II) compounds of a 2-hydroxy-1-naphthaldehyde benzoyl hydrazone Schiff-base ligand in the presence pyridine, imidazole, or indazole ligands were synthesized (C1-C3). The structures of three HSA complexes revealed that the Cu compounds bind to the hydrophobic cavity in the HSA IIA subdomain. Among them, the pyridine and imidazole ligands of C1 and C2 are replaced by Lys199, and His242 directly coordinates with Cu(II). The indazole and Br ligands of C3 are replaced by Lys199 and His242, respectively. Compared with the Cu(II) compounds alone, the HSA complexes enhance cytotoxicity in MCF-7 cells approximately 3-5-fold, but do not raise cytotoxicity levels in normal cells in vitro through selectively accumulating in cancer cells to some extent. We find that the HSA complex has a stronger capacity for cell cycle arrest in the G2/M phase of MCF-7 by targeting cyclin-dependent kinase 1 (CDK1) and down-regulating the expression of CDK1 and cyclin B1. Moreover, the HSA complex promotes MCF-7 cell apoptosis possibly through the intrinsic reactive oxygen species (ROS) mediated mitochondrial pathway, accompanied by the regulation of Bcl-2 family proteins.

  14. Mechanochemical synthesis in copper(II) halide/pyridine systems: single crystal X-ray diffraction and IR spectroscopic studies.

    Science.gov (United States)

    Bowmaker, Graham A; Di Nicola, Corrado; Pettinari, Claudio; Skelton, Brian W; Somers, Neil; White, Allan H

    2011-05-14

    Whereas complexes of divalent metal halides (X = Cl, Br, I) with/from pyridine commonly crystallise as trans-[M(py)(4)X(2)]·2py, M on a site of 222 symmetry in space group Ccca, true for CuCl(2) and CuBr(2) in particular, the copper(II) iodide adduct is of the form [Cu(py)(4)I]I·2py, Cu on a site of mm2 symmetry in space group Cmcm, and five-coordinate (square-pyramidal), the same cationic species also being found in 2[Cu(py)(4)I](I(3))·[(py)(2)Cu(μ-I)(2)Cu(py)(2)] (structurally defined). Bromide or N-thiocyanate may be substituted for the unbound iodide ion in the solvated salt, resulting in complexes which crystallize in space group Ccca, but with both anions and the metal atom disordered. In [Cu(py)(4)(I(3))(2)], a pair of long Cu···I contacts approach a square-planar Cu(py)(4) array. Assignments of the ν(CuN) and ν(CuX) (X = Br, I, SCN) bands in the far-IR spectra are made, the latter with the aid of analogous assignments for [Cu(py)(2)X(2)] (X = Cl, Br), which show a dependence of ν(CuX) on the Cu-X bond length that is very similar to that determined previously for copper(i) halide complexes. The structure of the adventitious complex [(trans-)(H(2)O)(py)(4)CuClCu(py)(4)](I(3))(3)·H(2)O is also recorded, with six- and five-coordinate copper atoms; rational synthesis provides [{Cu(py)(4)}(2)(μ-Cl)](I(3))(3)·H(2)O with one water molecule less. In [{Cu(py)(4)Cl}((∞|∞))](I(3))·3py, square pyramidal [Cu(py)(4)Cl](+) cations, assisted by Cl···Cu interactions, stack to give rise to infinite polymeric strings. Several of these compounds were prepared mechanochemically, illustrating the applicability of this method to syntheses involving redox reactions as well as to complex syntheses involving up to five components. The totality of results demonstrates that the [Cu(II)(py)(4)] entity can be stabilized in an unexpectedly diverse range of mononuclear and multinuclear complexes through the presence of lattice pyridine molecules, the bulky triiodide

  15. STUDY OF COPPER(II) COMPLEXES CONTAINING AMINO ACIDS OF INTEREST FOR BRAIN CHEMISTRY

    OpenAIRE

    LUCIANA DORNELAS PINTO

    2010-01-01

    Foram sintetizados 16 complexos de cobre(II) coordenados com seis aminoácidos presentes na placa b-amilóide, que está associada à Doença de Alzheimer - ácido aspártico, ácido glutâmico, metionina, glicina, serina e arginina, outros dois aminoácidos também encontrados no cérebro - cisteína e homocisteína, além da L-carnitina e acetil-L-carnitina que vêm sendo utilizados como suplemento alimentar em pacientes com doenças neurodegenerativas. Nosso objetivo foi verificar a afinidade do cobre(II) ...

  16. Iron(III) and copper(II) complexes of trans-bis(ferrocenyl)porphyrin ...

    Indian Academy of Sciences (India)

    F and Guldi D M In Handbook of Poprhyrin Science;. Kadish K K, Smith K M and Guilard R 2010 Eds.; World. Scientific: Singapore, 1 133; (b) Suijkerbuijk B M J M and Gebbink R J M K 2008 Angew. Chem. Int. Ed. 47. 7396. 4. Bucher C, Devillers C H, Moutet J C, Royal G, Saint-. Aman E 2009 Coord. Chem. Rev. 253 21 ...

  17. Styrene Oxidation by Copper(II Complexes Salen-Type Encapsulated into Nay Zeolite

    Directory of Open Access Journals (Sweden)

    Kuźniarska-Biernacka I.

    2013-12-01

    Full Text Available Osadzenie kompleksu miedzi(II z zasadą Schitta typu salen na zeolicie typu NaY zostało prze powadzone za pomocą dwóch metod „flexible ligand" i „in situ”. Katalityczne właściwości otrzymanego kompleksu oraz jego heterogenizowanych analogów badano w reakcji utleniania styrenu w obecności TBHP. Jako rozpuszczalnik stosowano acetonitryl. Testowane katalizatory wykazują średnią aktywność katalityczną z tendencją wytwarzania aldehy du benzoesowego. Oba heterogenizowane katalizatory mogą być wykorzystywane ponownie bez utraty aktywności katalitycznych.

  18. A ruthenium(II) complex as turn-on Cu(II) luminescent sensor based on oxidative cyclization mechanism and its application in vivo

    Science.gov (United States)

    Zhang, Yunfei; Liu, Zonglun; Yang, Kui; Zhang, Yi; Xu, Yongqian; Li, Hongjuan; Wang, Chaoxia; Lu, Aiping; Sun, Shiguo

    2015-02-01

    Copper ions play a vital role in a variety of fundamental physiological processes not only in human beings and plants, but also for extensive insects and microorganisms. In this paper, a novel water-soluble ruthenium(II) complex as a turn-on copper(II) ions luminescent sensor based on o-(phenylazo)aniline was designed and synthesized. The azo group would undergo a specific oxidative cyclization reaction with copper(II) ions and turn into high luminescent benzotriazole, triggering significant luminescent increasements which were linear to the concentrations of copper(II) ions. The sensor distinguished by its high sensitivity (over 80-fold luminescent switch-on response), good selectivity (the changes of the emission intensity in the presence of other metal ions or amino acids were negligible) and low detection limit (4.42 nM) in water. Moreover, the copper(II) luminescent sensor exhibited good photostability under light irradiation. Furthermore, the applicability of the proposed sensor in biological samples assay was also studied and imaged copper(II) ions in living pea aphids successfully.

  19. trans-Bis(perchlorato-κOtetrakis(1H-pyrazole-κN2copper(II

    Directory of Open Access Journals (Sweden)

    Viktor Zapol'skii

    2008-10-01

    Full Text Available The title compound, [Cu(ClO42(C3H4N24], was obtained unexpectedly by the reaction of copper(II perchlorate hexahydrate with equimolar amounts of 1-chloro-1-nitro-2,2,2-tripyrazolylethane in methanol solution. The crystal structure comprises octahedrally coordinated Cu2+ ions, located on an inversion centre, with four pyrazole ligands in the equatorial plane. The average Cu—N distance is 2.000 (1 Å. Two perchlorate ions are coordinated to copper in trans positions [Cu—O = 2.4163 (11 Å].

  20. Copper(II) Binding to ?-Synuclein, the Parkinson?s Protein

    OpenAIRE

    Lee, Jennifer C.; Gray, Harry B.; Winkler, Jay R.

    2008-01-01

    Variations in tryptophan fluorescence intensities confirm that copper(II) interacts with α-synuclein, a protein implicated in Parkinson’s disease. Trp4 fluorescence decay kinetics measured for the F4W protein show that Cu(II) binds tightly (K_d ∼ 100 nM) near the N-terminus at pH 7. Work on a F4W/H50S mutant indicates that a histidine imidazole is not a ligand in this high-affinity site.

  1. A [2 x 2] nickel(ii) grid and a copper(ii) square result from differing binding modes of a pyrazine-based diamide ligand.

    Science.gov (United States)

    Klingele, Julia; Boas, John F; Pilbrow, John R; Moubaraki, Boujemaa; Murray, Keith S; Berry, Kevin J; Hunter, Keith A; Jameson, Geoffrey B; Boyd, Peter D W; Brooker, Sally

    2007-02-14

    The potentially bis-terdentate diamide ligand N,N'-bis[2-(2-pyridyl)ethyl]pyrazine-2,3-dicarboxamide (H(2)L(Et)) was structurally characterised. Potentiometric titrations revealed rather low pK(a) values for the deprotonation of the first amide group of H(2)L(Et) (14.2) and N,N'-bis(2-pyridylmethyl)pyrazine-2,3-dicarboxamide (H(2)L(Me), 13.1). Two tetranuclear copper(ii) square complexes of H(2)L(Et) with a paddle-wheel appearance, in which each ligand strand acts as a linear N(3)-NO hybrid terdentate-bidentate chelate, have been isolated and structurally characterised. Complex [Cu(II)(4)(H(2)L(Et))(2)(HL(Et))(2)](BF(4))(6).3MeCN.0.5H(2)O (.3MeCN.0.5H(2)O), with two nondeprotonated zwitterionic ligand strands and two monodeprotonated ligand strands, is formed in the 1 : 1 reaction of H(2)L(Et) and Cu(BF(4))(2).4H(2)O. It has a polymeric chain structure of tetranuclear subunits connected by N-H[dot dot dot]N hydrogen bonds. The same reaction carried out with one equivalent of base gives the related compound [Cu(II)(4)(HL(Et))(4)](BF(4))(4) (), with all four ligand strands monodeprotonated. It consists of isolated tetranuclear units. In both .3MeCN.0.5 H(2)O and the copper(ii) ions are in five-coordinate N(4)O environments but the degree of trigonality (tau) differs [.3MeCN.0.5H(2)O 0.14 complex, [Ni(II)(4)(HL(Et))(4)](BF(4)).10H(2)O (.10H(2)O), is formed. The structure determination showed that the nickel(ii) ions have N(6) distorted octahedral coordination spheres and all four ligand strands are monodeprotonated and act as N(3)-N(3) bis-terdentate chelates. Magnetic susceptibility data show that the complexes .4H(2)O, and .10H(2)O exhibit very weak antiferromagnetic spin coupling. The energies and multiplicities of the spin states of .4H(2)O and were determined from the temperature dependence of the magnetic susceptibility and indicate that a singlet state is lowest and the quintet state highest. This is consistent with the X-band EPR spectra of polycrystalline

  2. Sonochemical Synthesis and Characterization of the Copper(II) Nanocomplex: DNA- and BSA-Binding, Cell Imaging, and Cytotoxicity Against the Human Carcinoma Cell Lines.

    Science.gov (United States)

    Anjomshoa, Marzieh; Torkzadeh-Mahani, Masoud; Dashtrazmi, Ebrahim; Adeli-Sardou, Mahboubeh

    2016-03-01

    The focus of the present work is the preparation of new metal-based nanodrug to overcome limitations of chemotherapy such as poor water solubility of most common chemotherapeutic drugs. The copper(II) complex of 1,2,4-triazine derivatives, [Cu(dppt)2(H2O)2](2+) (dppt is 5,6-diphenyl- 3- (2-pyridyl)-1,2,4-triazine), has been synthesized at nano-size by sonochemical method and characterized by FTIR, zetasizer, and scanning electron microscopy (SEM). The interaction of the complex and nanocomplex with fish sperm DNA (FS-DNA) and BSA have been investigated under physiological conditions by a series of experimental methods. The results have indicated that the complex binds to FS-DNA by two biding modes, viz., electrostatic and intercalates into the base pairs of DNA. The competitive study with ethidium bromide (EB) shows that the complex and nanocomplex competes for the DNA-binding sites with EB. Protein binding studies show that the complex and nanocomplex could bind with BSA. The results of synchronous fluorescence of BSA show that additions of the complex affect the microenvironment of both tyrosine and tryptophan residues during the binding process. The in vitro cytotoxicity of the complex (solution in DMSO) and nanocomplex (colloid in H2O) against the human carcinoma cell lines (MCF-7 and A-549) was evaluated by MTT assay. The results of in vitro cytotoxicity indicate that the complex and nanocomplex have excellent cytotoxicity activity against MCF-7 and A-549. Results of the microscopic analyses of the cancer cells confirm the results of the cytotoxicity.

  3. Effect of Phosphorylation and Copper(II or Iron(II Ions Enrichment on Some Physicochemical Properties of Spelt Starch

    Directory of Open Access Journals (Sweden)

    Jacek Rożnowski

    Full Text Available ABSTRACT: This paper provides an assessment of the effect of saturation of spelt starch and monostarch phosphate with copper or iron ions on selected physicochemical properties of the resulting modified starches. Native and modified spelt starch samples were analyzed for selected mineral element content using Atomic Absorption Spectroscopy (AAS. Thermodynamic properties were measured using DSC, and pasting properties by RVA. Flow curves of 5% pastes were plotted and described using the Herschel-Bulkley model. The structure recovery ratio was measured. AAS analysis established the presence of iron(II and copper(II ions in the samples of modified starches and that potassium and magnesium ions had leached from them. In comparison to unfortified samples, enriching native starch with copper(II ions decreases value of all temperatures of phase transformation about 1.3-2.7 °C, but in case of monostarch phosphates bigger changes (2.8-3.7 °C were observed. Fortified native spelt starch with copper(II ions caused increasing the final viscosity of paste from 362 to 429 mPa·s. However, presence iron(II ions in samples caused reduced its final viscosity by 170 (spelt starch and 103 mPa·s (monostarch phosphate. Furthermore, enriching monostarch phosphate contributed to reduce degree of structure recovery of pastes from 70.9% to 66.6% in case of copper(II ions and to 59.9% in case of iron(II ions.

  4. Flotation of traces of silver and copper(II) ions with a methyl cellosolve solution of dithizone.

    Science.gov (United States)

    Hiraide, M; Mizuike, A

    1975-06-01

    Microgram quantities of silver and copper(II) ions in aqueous solutions are collected on dithizone precipitates, which are then floated with the aid of small nitrogen bubbles. This separation technique has been successfully applied to the atomic-absorption spectrophotometric determination of down to a tenth ppm of silver and copper in high-purity lead and zinc metals.

  5. Performance Evaluation of Monolith Based Immobilized Acetylcholinesterase Flow-Through Reactor for Copper(II Determination with Spectrophotometric Detection

    Directory of Open Access Journals (Sweden)

    Parawee Rattanakit

    2014-01-01

    Full Text Available A monolith based immobilized acetylcholinesterase (AChE flow-through reactor has been developed for the determination of copper(II using flow injection spectrophotometric system. The bioreactor was prepared inside a microcapillary column by in situ polymerization of butyl methacrylate, ethylene dimethacrylate, and 2,2-dimethoxy-1,2-diphynyletane-1-one in the presence of 1-decanol, followed by vinyl azlactone functionalization and AChE immobilization. The behavior of AChE before and after being immobilized on the monolith was evaluated by kinetic parameters from Lineweaver and Burk equation. The detection was based on measuring inhibition effect on the enzymatic activity of AChE by copper(II using Ellman’s reaction with spectrophotometric detection at 410 nm. The linear range of the calibration graph was obtained over the range of 0.02–3.00 mg L−1. The detection limit, defined as 10% inhibition (I10, was found to be 0.04 mg L−1. The repeatability was 3.35 % (n=5 for 1.00 mg L−1 of copper(II. The proposed method was applied to the determination of copper(II in natural water samples with sampling rate of 4 h−1.

  6. Synthesis, Characterization and DNA Cleavage of Copper(II ...

    African Journals Online (AJOL)

    characterization and DNA interactions of copper (II) and nickel (II) complexes with unsymmetrical Schiff base ligands. Indian J Chem 2013; 52A: 845-853. 23. Neves A, Bortoluzzi AJ, Jovito R, Peralta RA, Souza BD,. Szpoganicz B, Joussef AC, Terenzi H, Severino PC,. Fischer FL, Schenk G, Riley MJ, Smith SJ, Gahan LR.

  7. Copper(II) activated transformation of azomethine to imidate

    Indian Academy of Sciences (India)

    Administrator

    Tridentate Schiff bases are excellent ligands in forming dinuclear complexes of metal ions which prefer square-planar geometry. Deprotonated monobasic arylhydrazones of 2- pyridine-carboxaldehyde can coordinate a metal ion via the pyridine-N, the imine-N and the amide-O atoms. We are interested in amide-O bridged ...

  8. The unusual coordination abilities of the peptides with betaXaaHisGlyHis sequence. The influence of structural modification of the peptide chain on the copper(II) binding.

    Science.gov (United States)

    Brasuń, Justyna; Czapor, Hanna; Matera-Witkiewicz, Agnieszka; Kotynia, Aleksandra; Sochacka, Aleksandra; Cebrat, Marek

    2010-07-28

    The coordination abilities of tetrapeptides containing beta-amino acids towards Cu(II) ions are presented. The studied tetrapeptides were: Ac-betaAlaHisGlyHis, betaAlaHisGlyHis, Ac-betaAspHisGlyHis, betaAspHisGlyHis, Ac-betaAspHisGly-dHis and betaAspHisGly-dHis. Thorough potentiometric titrations were carried out to establish the stoichiometry of the resulting metal-ligand complexes and the role of free -alphaCOO(-) side chain group in metal binding. The copper(II) coordination mode of the complexes was investigated by performing detailed spectroscopic analyses (UV-Vis, EPR, CD) in strict correlation with potentiometric measurements.

  9. Highly efficient visual detection of trace copper(II) and protein by the quantum photoelectric effect.

    Science.gov (United States)

    Wang, Peng; Lei, Jianping; Su, Mengqi; Liu, Yueting; Hao, Qing; Ju, Huangxian

    2013-09-17

    This work presented a photocurrent response mechanism of quantum dots (QDs) under illumination with the concept of a quantum photoelectric effect. Upon irradiation, the photoelectron could directly escape from QDs. By using nitro blue tetrazolium (NBT) to capture the photoelectron, a new visual system was proposed due to the formation of an insoluble reduction product, purple formazan, which could be used to visualize the quantum photoelectric effect. The interaction of copper(II) with QDs could form trapping sites to interfere with the quantum confinement and thus blocked the escape of photoelectron, leading to a "signal off" visual method for sensitive copper(II) detection. Meanwhile, by using QDs as a signal tag to label antibody, a "signal on" visual method was also proposed for immunoassay of corresponding protein. With meso-2,3-dimercaptosuccinic-capped CdTe QDs and carcino-embryonic antigen as models, the proposed visual detection methods showed high sensitivity, low detection limit, and wide detectable concentration ranges. The visualization of quantum photoelectric effect could be simply extended for the detection of other targets. This work opens a new visual detection way and provides a highly efficient tool for bioanalysis.

  10. IR and ESR studies on novel Cu(II) theophyllinato complexes containing mono- or bidentate ligands

    Science.gov (United States)

    Forizs, Edit; David, L.; Cozar, O.; Chiş, V.; Damian, G.; Csibi, Jolán

    1999-05-01

    Three mixed-ligand copper(II) complexes containing theophylline and mono- or bidentate N-donor ligands (2,2'-bipyridine, 4-fluoraniline and 1,10-phenanthroline) were synthesized and characterized by elemental analysis, IR and ESR spectra. According to IR and ESR data the Cu(II) complexes exhibit a distorted tetrahedral coordination of copper by two nitrogen atoms of the monodentate or bidentate ligands and the two monodentate theophyllinate anion bonded through N(7) atom.

  11. Anion exchange coupled with the reduction and dimerisation of a copper(ii) nitrate complex of tripyridyl dithioether via a single-crystal-to-single-crystal transformationElectronic supplementary information (ESI) available: PXRD patterns, ESI-MS spectrum, SEM images, AFM images, UV spectra, crystal structures and TGA data. CCDC 1511571-1511577. For ESI and crystallographic data in CIF or other electronic format see DOI: 10.1039/c6sc05341f

    National Research Council Canada - National Science Library

    Lee, Hyeong-Hwan; Park, In-Hyeok; Kim, Seulgi; Lee, Eunji; Ju, Huiyeong; Jung, Jong Hwa; Ikeda, Mari; Habata, Yoichi; Lee, Shim Sung

    2017-01-01

    ... ). To avoid the formation of undesired mixed products, a copper( ii ) nitrate complex-mediated approach involving anion exchange and cation reduction was employed to generate a monomeric complex, [Cu II ( L )NO 3 ]NO 3 ·toluene ( 2...

  12. Inhibition of the catecholase activity of biomimetic dinuclear copper complexes by kojic acid.

    Science.gov (United States)

    Battaini, G; Monzani, E; Casella, L; Santagostini, L; Pagliarin, R

    2000-04-01

    The inhibition of the catechol oxidase activity exhibited by three dinuclear copper(II) complexes, derived from different diaminotetrabenzimidazole ligands, by kojic acid [5-hydroxy-2-(hydroxymethyl)-gamma-pyrone] has been studied. The catalytic mechanism of the catecholase reaction proceeds in two steps and for both of these inhibition by kojic acid is of competitive type. The inhibitor binds strongly to the dicopper(II) complex in the first step and to the dicopper-dioxygen adduct in the second step, preventing in both cases the binding of the catechol substrate. Binding studies of kojic acid to the dinuclear copper(II) complexes and a series of mononuclear analogs, carried out spectrophotometrically and by NMR, enable us to propose that the inhibitor acts as a bridging ligand between the metal centers in the dicopper(II) catalysts.

  13. Solvent-controlled synthesis of tetranuclear cage-like copper(II) silsesquioxanes. Remarkable features of the cage structures and their high catalytic activity in oxidation with peroxides.

    Science.gov (United States)

    Dronova, Marina S; Bilyachenko, Alexey N; Yalymov, Alexey I; Kozlov, Yuriy N; Shul'pina, Lidia S; Korlyukov, Alexander A; Arkhipov, Dmitry E; Levitsky, Mikhail M; Shubina, Elena S; Shul'pin, Georgiy B

    2014-01-14

    Two principally different in their molecular architecture isomeric tetranuclear copper(ii) silsesquioxanes, "Globule"-like compound [(PhSiO1.5)12(CuO)4(NaO0.5)4] (1) and "Sandwich"-like derivative [(PhSiO1.5)6(CuO)4(NaO0.5)4(PhSiO1.5)6] (2), were synthesized by the partial cleavage of polymeric copper(ii) silsesquioxane [(PhSiO1.5)2(CuO)]n by tetraphenylcyclotetrasiloxanolate. The route leading to the formation of either 1 or 2 entirely depends on the nature and composition of the solvent used for this reaction. Thus, the process in an ethanol-1-butanol solution gives compound 1. When a 1,4-dioxane-methanol mixture was used, compound 2 was prepared. The structures and unusual crystal packing of the cages were confirmed by the X-ray studies. It has been found that the reaction of benzene with H2O2 in acetonitrile solution at 50 °C catalyzed by 1 requires addition of trifluoroacetic acid (TFA) in low concentration and gives phenol with a turnover number (TON) of 250 after 3 h. The initial reaction rate W0 linearly depends on the concentration of catalyst 2. The oxidation of 1-phenylethanol to acetophenone with hydrogen peroxide catalyzed by complex 1 in the presence of TFA is not efficient. In contrast, 1 exhibited excellent activity in the oxidation with tert-butyl hydroperoxide (TBHP) in the absence of any acid (the yield of acetophenone was close to the quantitative, TON attained 475 after 2 h). A kinetic study of this reaction led to the conclusion that the process occurs with the participation of radicals tert-BuO˙ produced in the Cu-promoted decomposition of TBHP. The mode of dependence of W0 on the initial concentration of TBHP indicates the formation of an intermediate adduct between the catalyst 1 and TBHP (characterized by the equilibrium constant K1≈ 2 M(-1) for the conditions of conducted experiments) followed by subsequent decomposition of the adduct (k2≈ 0.2 s(-1)) to generate an intermediate species tert-BuO˙ which induces the alcohol oxidation.

  14. Supramolecular spectroscopic and thermal studies of azodye complexes

    Science.gov (United States)

    El-Sonbati, A. Z.; Diab, M. A.; El-Bindary, A. A.; Morgan, Sh. M.

    2014-06-01

    A series of heterocyclic ligand of copper(II) complexes have been synthesized by the reaction of copper(II) acetate with 5-(4‧-derivatives phenylazo)-2-thioxothiazolidin-4-one (HLn) yields 1:1 and 1:2 (M:L) complexes depending on the reaction conditions. The elemental analysis, spectral (IR and ESR), conductance, magnetic measurements, and thermogravimetric analysis (TGA) are used to characterize the isolated complexes. It is found that the change of substituent affects the thermal properties of azodye rhodanine derivatives and their Cu(II) complexes. The molecular and electronic structures of the investigated compounds (HLn) were also studied using quantum chemical calculations. According to intramolecular hydrogen bond leads to increasing of the complexes stability. The data revealed that the coordination geometry around Cu(II) in all complexes (1-4) exhibit a trans square planar by NO monobasic bidentate and the two monobasic bidentate in octahedral complexes (5-7). Electronic, magnetic data and ESR spectra proposed the square planar structure for all complexes (1-4) under investigation. The value of covalency factor ( and orbital reduction factor K accounts for the covalent nature of the complexes. The activation thermodynamic parameters, such as activation energy (Ea), enthalpy (ΔH*), entropy (ΔS*), and Gibbs free energy change of the decomposition (ΔG*) are calculated using Coats-Redfern and Horowitz-Metzger methods.

  15. Synthesis, characterization and investigation of electrochemical and spectroelectrochemical properties of peripherally tetra 4-phenylthiazole-2-thiol substituted metal-free, zinc(II), copper(II) and cobalt(II) phthalocyanines

    Science.gov (United States)

    Demirbaş, Ümit; Akçay, Hakkı Türker; Koca, Atıf; Kantekin, Halit

    2017-08-01

    In this study novel peripherally tetra 4-phenylthiazole-2-thiol substituted metal-free phthalocyanine (4) and its zinc(II) (5), copper(II) (6) and cobalt(II) (7) derivatives were synthesized and characterized by a combination of various spectroscopic techniques such as FT-IR, 1H-NMR, UV-vis and MALDI-TOF mass. Electrochemical characterizations of metallo-phthalocyanine complexes were conducted by voltammetric and in situ spectroelectrochemical measurements. CoIIPc went [CoIIPc-2]/[CoIPc-2]1-, [CoIPc-2]1-/[CoIPc-3]2-, [CoIPc-3]2-/[CoIPc-4]3- and [CoIIPc-2]/[CoIIPc-2]1+ reduction and oxidation processes respectively. Differently ZnIIPc only showed four ligand-based reductions and two ligand based oxidation processes.

  16. Kinetic and equilibrium studies for the adsorption process of cadmium(II) and copper(II) onto Pseudomonas aeruginosa using square wave anodic stripping voltammetry method.

    Science.gov (United States)

    Kong, Bo; Tang, Biyu; Liu, Xiaoying; Zeng, Xiandong; Duan, Haiyan; Luo, Shenglian; Wei, Wanzhi

    2009-08-15

    A novel method for the simultaneous determination of cadmium(II) and copper(II) during the adsorption process onto Pseudomonas aeruginosa was developed. The concentration of the free metal ions was successfully detected by square wave anodic stripping voltammetry (SWASV) on the mercaptoethane sulfonate (MES) modified gold electrode, while the P. aeruginosa was efficiently avoided approaching to the electrode surface by the MES monolayer. And the anodic stripping peaks of Cd(2+) and Cu(2+) appear at -0.13 and 0.34V respectively, at the concentration range of 5-50 microM, the peak currents of SWASV present linear relationships with the concentrations of cadmium and copper respectively. As the determination of Cd(2+) and Cu(2+) was in real time and without pretreatment, the kinetic characteristics of the adsorption process were studied and all the corresponding regression parameters were obtained by fitting the electrochemical experimental data to the pseudo-second-order kinetic model. Moreover, Langmuir and Freundlich models well described the biosorption isotherms. And there were some differences in the amount of metal ion adsorbed at equilibrium (q(e)) and other kinetics parameters when the two ions coexisted were compared with the unaccompanied condition, which were also discussed in this paper. The proposed electrode system provides excellent platform for the simultaneous determination of trace metals in complex biosorption process.

  17. Synthesis, spectroscopic characterization, electrochemical behaviour and thermal decomposition studies of some transition metal complexes with an azo derivative

    Science.gov (United States)

    Sujamol, M. S.; Athira, C. J.; Sindhu, Y.; Mohanan, K.

    2010-01-01

    Complexes of manganese(II), cobalt(II), nickel(II), copper(II) and zinc(II) with a novel heterocyclic azo derivative, formed by coupling diazotized 2-amino-3-carbethoxy-4,5-dimethylthiophene with acetylacetone were synthesized and characterized on the basis of elemental analyses, molar conductance, magnetic susceptibility measurements, UV-vis, IR, 1H NMR and EPR spectral data. Spectral studies revealed that the ligand existed in an internally hydrogen bonded azo-enol form rather than the keto-hydrazone form and coordinated to the metal ion in a tridentate fashion. Analytical data revealed that all the complexes exhibited 1:1 metal-ligand ratio. On the basis of electronic spectral data and magnetic susceptibility measurements, suitable geometry was proposed for each complex. The nickel(II) complex has undergone facile transesterification reaction when refluxed in methanol for a long period. The ligand and the copper(II) complex were subjected to X-ray diffraction study. The electrochemical behaviour of copper(II) complex was investigated by cyclic voltammetry. The thermal behaviour of the same complex was also examined by thermogravimetry.

  18. Structural and biological aspects of copper (II) complexes with 2-methyl-3-amino-(3H)-quinazolin-4-one.

    Science.gov (United States)

    Ramadan, A M

    1997-02-15

    A series of new copper (II) complexes with 2-methyl-3-amino(3H)-quinazolin-4-one (MAQ) and various anions (Cl-, Br-, ClO(-)4, NO(-)3, SCN-, and SO(2-)4 was prepared. Their structures and properties were characterized by elemental analysis, IR, UV-Vis and ESR spectroscopy, molar conductivity, and magnetic moment measurements. The square-planar complex was only obtained in the presence of perchlorate anion, whereas the five coordinate species, which have a square-pyramidal structure, were obtained for chloro and bromo complexes. In the case of hexa coordinate complexes, in which nitrate, sulphate, or thiocyanate is attached to a copper(II) ion in a 1:2 (metal:ligand) ratio, a distorted octahedral geometry around copper(II) is proposed. The antimicrobial activity of the free ligand and its copper(II) complexes clearly illustrates that the compounds have both an antibacterial and antifungal potency against the organisms tested. In most cases, the complexes were found to be more active than the free ligand, but in some cases, an equal activity was displayed. To further elucidate the biological activity of the complexes, their activities towards active oxygen species, such as H2O2 and O(-)2, were investigated. A probable mechanism for the cytotoxic reaction with the different organisms is proposed.

  19. Modeling data of copper(II) sorption onto the composite sorbent based on cation exchanger and tin(IV) hydroxide

    Science.gov (United States)

    Ikanina, Elena V.; Kalyaeva, Mariya I.; Markov, Vyacheslav F.

    2017-09-01

    The methodology of stepwise synthesis of the composite sorbent based on cation exchanger and tin(IV) hydroxide was demonstrated. The results of copper(II) sorption onto the composite sorbent are presented. Langmuir, Freundlich and Temkin adsorption isotherms were used in mathematical modeling of the sorption data. The Langmuir model most accurately describes the sorption process. The constants of the Langmuir model and the specific surface area of the composite sorbent were defined. Granules of the composite sorbent were studied by scanning electron microscopy (SEM) and energy-dispersive X-ray microanalysis (EDXMA). The distribution coefficients of copper(II) in the composite sorbent and the sorption degree from CuSO4 aqueous solutions of various concentrations were computed.

  20. RECOVERY OF COPPER(II AND CHROMIUM(III FROM NITRATE MEDIUM WITH SALICYLIDENEANILINE DISSOLVED IN 1-OCTANOL

    Directory of Open Access Journals (Sweden)

    A. Guerdouh

    2016-05-01

    Full Text Available The solvent extraction of copper(II and chromium(III from nitrate medium with salicylideneaniline (HL is studied as a function of various parameters: pH, concentration of salicylideneaniline, contact time and the nature of anoin (nitrate and sulfate in aqueous phase. Chromium(III is not extracted by salicylideneaniline  diluted in 1-octanol. Copper(II is only extracted by salicylideneaniline and it was found that the highest extractability achieved to 95% at pH 4.9, The stoichiometry of the extracted species was determined by using the method of slope analysis. Elemental analysis, UV–vis and IR-spectra were used to confirm the structure. It is found that the copper (II is extracted as CuL2.2H2O Their equilibrium constant, distribution coefficient, percentage extraction (%E and free energy are also calculated.

  1. Comparitive study on structural, magnetic and spectroscopic properties of four new copper(II) coordination polymers with 4‧-substituted terpyridine ligands

    Science.gov (United States)

    Toledo, Dominique; Vega, Andrés; Pizarro, Nancy; Baggio, Ricardo; Peña, Octavio; Roisnel, Thierry; Pivan, Jean-Yves; Moreno, Yanko

    2017-09-01

    The synthesis and characterization of four copper(II) complexes with different terpyridyl ligands have been carried out, their crystal and molecular structures determined and their magnetic and luminescent properties analyzed. The ligands used in the coordination reactions were 4‧-(3-methyl-2-thienyl)-4,2‧:6‧,4''-terpyridine (4-stpy), -4‧-(4-quinolinyl)-4,2‧:6‧,4''-terpyridine (4-qtpy), 4‧-(4-quinolinyl)-3,2‧:6‧,3''-terpyridine (3-qtpy, unreported so far) and 4‧-(4-cyanophenyl)-4,2‧:6‧,4''-terpyridine (4-cntpy); the reaction of these ligands with Cu(II)-hexafluoroacetylacetone (Cu(hfacac)2) gives rise to coordination polymers Cu(4-stpy)(hfacac)2 (I), Cu(4-qtpy)(hfacac)2 (II), Cu(3-qtpy)(hfacac)2 (III) and Cu(4-cntpy)(hfacac)2 (IV). The different location of the nitrogen atom of the outer ring is responsible for the different coordination modes. The emission spectra of dichloromethane solutions are consistent with dissociation of the complexes; the emission maxima simulate those of the free ligands. The emission of I, III and IV in the solid state is essentially quenched upon complexation with Cu(II), whereas for compound II an emission at 420 nm is observed. The interaction between copper centers has been related with the coplanarity of terpyridine rings. Complexes I-III exhibit a paramagnetic behavior, while compound IV, with the smallest torsion angle between pyridine moieties, shows an antiferromagnetic behavior described by a dimeric model, with J=-4.38 cm-1, g =2.06 and ρ=0.07.

  2. Spectrophotometric Determination of Metoprolol Tartrate in Pharmaceutical Dosage Forms on Complex Formation with Cu(II

    Directory of Open Access Journals (Sweden)

    Mustafa Cesme

    2011-06-01

    Full Text Available A new, simple, sensitive and accurate spectrophotometric method has been developed for the assay of metoprolol tartrate (MPT, which is based on the complexation of drug with copper(II [Cu(II] at pH 6.0, using Britton-Robinson buffer solution, to produce a blue adduct. The latter has a maximum absorbance at 675 nm and obeys Beer’s law within the concentration range 8.5-70 mg/mL. Regression analysis of the calibration data showed a good correlation coefficient (r = 0.998 with a limit of detection of 5.56 mg/mL. The proposed procedure has been successfully applied to the determination of this drug in its tablets. In addition, the spectral data and stability constant for the binuclear copper(II complex of MPT (Cu2MPT2Cl2 have been reported.

  3. CFD simulation of copper(II) extraction with TFA in non-dispersive hollow fiber membrane contactors.

    Science.gov (United States)

    Muhammad, Amir; Younas, Mohammad; Rezakazemi, Mashallah

    2018-01-27

    This study presents computational fluid dynamics (CFD) simulation of dispersion-free liquid-liquid extraction of copper(II) with trifluoroacetylacetone (TFA) in hollow fiber membrane contactor (HFMC). Mass and momentum balance Navier-Stokes equations were coupled to address the transport of copper(II) solute across membrane contactor. Model equations were simulated using COMSOL Multiphysics™. The simulation was run to study the detailed concentration distribution of copper(II) and to investigate the effects of various parameters like membrane characteristics, partition coefficient, and flow configuration on extraction efficiency. Once-through extraction was found to be increased from 10 to 100% when partition coefficient was raised from 1 to 10. Similarly, the extraction efficiency was almost doubled when porosity to tortuosity ratio of membrane was increased from 0.05 to 0.81. Furthermore, the study revealed that CFD can be used as an effective optimization tool for the development of economical membrane-based dispersion-free extraction processes.

  4. Touching the upper limit for ferromagnetic interactions in hetero-bridged dinuclear [Cu2(II)] complexes using a novel N5-dinucleating ligand bearing an endogenous monoatomic amido(R-NH(-))-bridging group.

    Science.gov (United States)

    Colacio, Enrique; Perea-Buceta, Jesús E; Mota, Antonio J; Brechin, Euan K; Prescimone, Alessandro; Hänninen, Mikko; Seppälä, Petri; Sillanpää, Reijo

    2012-01-21

    A novel N(5)-dinucleating ligand 4-amino-3,5-bis(bipyridine-2-yl)-1,2,4-triazole allows the preparation for the first time, and under mild conditions, of single and mixed amido(R-NH(-))-bridged copper(II) complexes, the latter exhibiting very strong ferromagnetic coupling. This journal is © The Royal Society of Chemistry 2012

  5. Cyclometalated heteronuclear Pt/Ag and Pt/Tl complexes: a structural and photophysical study.

    Science.gov (United States)

    Jamali, Sirous; Ghazfar, Reza; Lalinde, Elena; Jamshidi, Zahra; Samouei, Hamidreza; Shahsavari, Hamid R; Moreno, M Teresa; Escudero-Adán, Eduardo; Benet-Buchholz, Jordi; Milic, Dalibor

    2014-01-21

    To investigate the factors influencing the luminescent properties of polymetallic cycloplatinated complexes a detailed study of the photophysical and structural properties of the heteronuclear complexes [Pt2Me2(bhq)2(μ-dppy)2Ag2(μ-acetone)](BF4)2, 2, [PtMe(bhq)(dppy)Tl]PF6, 3, and [Pt2Me2(bhq)2(dppy)2Tl]PF6, 4, [bhq = benzo[h]quinoline, dppy = 2-(diphenylphosphino)pyridine] was conducted. Complexes 3 and 4 synthesized by the reaction of [PtMe(bhq)(dppy)], 1, with TlPF6 (1 or 1/2 equiv.) and stabilized by unsupported Pt-Tl bonds as revealed by multinuclear NMR spectroscopy and confirmed by X-ray crystallography for 3. DFT calculations for the previously reported butterfly Pt2Ag2 cluster 2 reveal that in the optimized geometry the bridging acetone molecule is removed and the metal core displays a planar-shaped geometry in which according to a QTAIM calculation and natural bond orbital (NBO) analysis the Ag···Ag metallophilic interaction is strengthened. In contrast to the precursor 1, which is only emissive in glassy solutions ((3)MLCT 485 nm), all 2-4 heteropolynuclear complexes display intense emissions in the solid state and in glassy solutions. Time-dependent density functional theory (TD-DFT) is used to elucidate the origin of the electronic transitions in the heteronuclear complexes 2 and 3. The low energy absorption and intense orange emission for cluster 2 (solid 77 K and glass) are attributed to metal-metal to ligand charge transfer (MM'LCT) with a minor L'LCT contribution. For 3 and 4 two different bands are developed: the high energy band (602-630 nm) observed for 4 at 77 K (solid, glass) and in diluted glasses for 3 is ascribed to emission from discrete Pt2Tl units of mixed (3)L'LCT/(3)LM'CT origin. However, the low energy band (670-690 nm) observed at room temperature (solid) for both complexes and also in concentrated glasses for 3 is assigned to (3)ππ excited states arising from intermolecular interactions.

  6. Enantioselective Henry reaction catalyzed by "ship in a bottle" complexes.

    Science.gov (United States)

    Bania, Kusum K; Karunakar, Galla V; Goutham, Kommuru; Deka, Ramesh C

    2013-07-15

    Two chiral Schiff-base complexes of copper(II) have been successfully encapsulated inside the cavity of zeolite-NaY via a "ship in a bottle" synthesis method. The presence of the two complexes inside the cages of zeolite-Y has been confirmed based on various spectrochemical and physicochemical techniques, viz. FTIR, UV-vis/DRS, ESR, XPS, CV, EDX, SEM, and TGA. Zeolite-encapsulated chiral copper(II) Schiff-base complexes are found to give a high-enantioselective (84% ee, R conformation) nitro-aldol product at -20 °C. The encapsulated copper complexes are found to show higher catalytic efficiency than their homogeneous counterparts under identical conditions. Density functional theory (DFT) calculation has been implemented to understand the effect of the zeolite matrix on structural, electronic, and reactivity properties of the synthesized complexes. Theoretical calculation predicts that upon encapsulation into the zeolite matrix the Cu center becomes more susceptible to nucleophilic attack, favoring a nitro-aldol reaction. A plausible mechanism is suggested based on the experimental and theoretical results. The structures of reaction intermediates and transition state(s) involved in the catalytic cycle are derived using DFT.

  7. Fabrication and characterization of copper(II)-chitosan complexes as antibiotic-free antibacterial biomaterial.

    Science.gov (United States)

    Gritsch, Lukas; Lovell, Christopher; Goldmann, Wolfgang H; Boccaccini, Aldo R

    2018-01-01

    We produced and characterized copper(II)-chitosan complexes fabricated via in-situ precipitation as antibiotic-free antibacterial biomaterials. Copper was bound to chitosan from a dilute acetic acid solution of chitosan and copper(II) chloride exploiting the ability of the polysaccharide to chelate metal ions. The influence of copper(II) ions on the morphology, structure and hydrophobicity of the complexes was evaluated using scanning electron microscopy, energy-dispersive X-ray spectroscopy, attenuated total reflectance Fourier transform infrared spectroscopy and static contact-angle measurements. To assess the biological response to the materials, cell viability and antibacterial assays were performed using mouse embryonic fibroblasts and both Gram-positive and -negative bacteria. Combined analysis of cell and bacterial studies identified a threshold concentration at which the material shows outstanding antibacterial properties without significantly affecting fibroblast viability. This key outcome sets copper(II)- chitosan as a promising biomaterial and encourages further investigation on similar systems toward the development of new antibiotic-free antibacterial technologies. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  8. Solid Phase Extraction of Trace Copper(II Using Modified Nano Polyacrylonitrile Fiber

    Directory of Open Access Journals (Sweden)

    A. Moghimi

    2012-07-01

    Full Text Available A simple method has been developed for the preconcentration of copper(II based on the adsorption of its Modified nano polyacrylonitrile fiber. Modified nano polyacrylonitrile fiber (PANF was prepared by adding of acrylic fibers to mSethanolamine (MMA with different concentration solutions. The stability of a chemically Modified nano polyacrylonitrile fiber especially in concentrated hydrochloric acid which was then used as a recycling and pre-concentration reagent for further uses of modified nano polyacrylonitrile fiber. The application of this Modified nano polyacrylonitrile fiber for sorption of a series of metal ions was performed by using different controlling factors such as the pH of metal ion solution and the equilibration shaking time by the static technique. Cu (II was found to exhibit the highest affinity towards extraction by these Modified nano polyacrylonitrile fiber phases. The pronounced selectivity was also confirmed from the determined distribution coefficient (Kd of all the metal ions, showing the highest value reported for Cu (II to occur by Modified nano polyacrylonitrile fiber. The potential applications ofModified nano polyacrylonitrile fiber for selective extraction of Cu(II to occur from aqueous solution were successfully accomplished as well as pre- concentration of low concentration of Cu(II (60 pg ml-1 from natural tap water with a pre-concentration factor of 100 for Cu(II off-line analysis by flame atomic absorption analysis.

  9. Biosorption Performance of Encapsulated Candida krusei for the removal of Copper(II).

    Science.gov (United States)

    Luk, Chi Him Jim; Yip, Joanne; Yuen, Chun Wah Marcus; Pang, Siu Kwong; Lam, Kim Hung; Kan, Chi Wai

    2017-05-19

    The use of microorganisms in biosorption is one of the most promising ways to remove trace amounts of heavy metal ions. Nevertheless, the enhancement of the successful removal of heavy metal ions by using different combinations of biosorbents is not generally guaranteed which leaves room to explore the application of the technique. In this study, the performance of free and immobilized forms of a yeast strain, Candida krusei (C. krusei), and calcium alginate (CaAlg) are evaluated for their ability to remove copper(II). Infrared spectroscopy, studies on the effects of pH and temperature, and kinetics and isotherm modelling are carried out to evaluate the biosorption. The infrared spectroscopy shows that the primary biosorption sites on the biosorbents are carboxylate groups. In addition, a higher pH and higher temperatures promote biosorption while a decline in biosorption ability is observed for C. krusei at 50 °C. The kinetics study shows that C. krusei, CaAlg and immobilized C. krusei (MCaAlg) conform with good correlation to pseudo-second order kinetics. MCaAlg and CaAlg fit well to the Langmuir isotherm while C. krusei fits well to the Temkin isotherm. From the experimental data, encapsulating C. krusei showed improved biosoprtion and address clogging in practical applications.

  10. Indirect spectrophotometric determination of thiocyanate by extraction as bisthiocyanatobisquinolinemercury(II) complex and its ligand substitution reaction with dithizone.

    Science.gov (United States)

    Einaga, H; Ishii, H; Iwasaki, I

    1973-10-01

    Thiocyanate forms with mercury(II) in the presence of quinoline a mixed-ligand mercury(II) complex, bisthiocyanatobisquinolinemercury(II), and is extracted into chloroform. This mixed-ligand complex is treated with dithizone and forms the bisdithizonatomercury(II) complex. Maximum and constant absorbance of the dithizone complex is obtained when thiocyanate is extracted at pH 5.1-6.5, and Beer's law is obeyed at 498 nm, where the difference in absorbance between the dithizone complex and dithizone is largest. Chloride, bromide, iodide, cyanide and large amounts of ammonium and copper(II) ions interfere.

  11. Newer mixed ligand Schiff base complexes from aquo-N-(2‧-hydroxy acetophenone) glycinatocopper(II) as synthon: DFT, antimicrobial activity and molecular docking study

    Science.gov (United States)

    Pramanik, Harun A. R.; Das, Dharitri; Paul, Pradip C.; Mondal, Paritosh; Bhattacharjee, Chira R.

    2014-02-01

    Synthesis of a series of newer mixed ligand copper(II) complexes of aminoacid Schiff base of the type [CuL(X)] (L = N-(2‧-hydroxy acetophenone) glycinate, X = imidazole (im) 2, benzimidazole (benz) 3, pyridine (py) 4, hydrazine (hz) 5,8-hydroxyquinoline (8-hq) 6, pyrrolidine (pyrr) 7, piperidine (pip) 8, and nicotinamide (nic) 9) have been accomplished from the interaction of an aquated Schiff base complex, [CuL(H2O)]·H2O, 1 with some selected neutral nitrogen-donor ligands. The copper(II) Schiff base complex, [CuL(H2O)]·H2O, L = N-(2‧-hydroxy acetophenone) glycinate was synthesized from the reaction of glycine and 2‧ hydroxy acetophenone and copper(II) acetate. The compounds were characterised by elemental analysis, spectral, magnetic and thermal studies. The density functional theory calculations were performed using LANL2DZ and 6-311 G(d, p) basis sets with B3LYP correlation functional to ascertain the stable electronic structure, HOMO-LUMO energy gap, chemical hardness and dipole moment of the mixed ligand complexes. A distorted square planar geometry has been conjectured for the complexes. Antibacterial activities of the ligand and its metal complexes have been tested against selected gram-positive and gram-negative strains and correlated with computational docking scores.

  12. Antibacterial, antifungal and in vitro antileukaemia activity of metal complexes with thiosemicarbazones

    Science.gov (United States)

    Pahontu, Elena; Julea, Felicia; Rosu, Tudor; Purcarea, Victor; Chumakov, Yurie; Petrenco, Petru; Gulea, Aurelian

    2015-01-01

    1-phenyl-3-methyl-4-benzoyl-5-pyrazolone 4-ethyl-thiosemicarbazone (HL) and its copper(II), vanadium(V) and nickel(II) complexes: [Cu(L)(Cl)]·C2H5OH·(1), [Cu(L)2]·H2O (2), [Cu(L)(Br)]·H2O·CH3OH (3), [Cu(L)(NO3)]·2C2H5OH (4), [VO2(L)]·2H2O (5), [Ni(L)2]·H2O (6), were synthesized and characterized. The ligand has been characterized by elemental analyses, IR, 1H NMR and 13C NMR spectroscopy. The tridentate nature of the ligand is evident from the IR spectra. The copper(II), vanadium(V) and nickel(II) complexes have been characterized by different physico-chemical techniques such as molar conductivity, magnetic susceptibility measurements and electronic, infrared and electron paramagnetic resonance spectral studies. The structures of the ligand and its copper(II) (2, 4), and vanadium(V) (5) complexes have been determined by single-crystal X-ray diffraction. The composition of the coordination polyhedron of the central atom in 2, 4 and 5 is different. The tetrahedral coordination geometry of Cu was found in complex 2 while in complex 4, it is square planar, in complex 5 the coordination polyhedron of the central ion is distorted square pyramid. The in vitro antibacterial activity of the complexes against Escherichia coli, Salmonella abony, Staphylococcus aureus, Bacillus cereus and the antifungal activity against Candida albicans strains was higher for the metal complexes than for free ligand. The effect of the free ligand and its metal complexes on the proliferation of HL-60 cells was tested. PMID:25708540

  13. Green and selective synthesis of N-substituted amides using water soluble porphyrazinato copper(II) catalyst

    Energy Technology Data Exchange (ETDEWEB)

    Ghodsinia, Sara S.E.; Akhlaghinia, Batool; Eshghi, Hossein, E-mail: akhlaghinia@um.ac.ir [Ferdowsi University of Mashhad (Iran, Islamic Republic of). Faculty of Sciences. Department of Chemistry; Safaei, Elham [Institute for Advanced Studies in Basic Sciences (IASBS), Zanjan (Iran, Islamic Republic of). Department of Chemistry

    2013-06-15

    N, N',N{sup ,} N{sup '}-Tetramethyl tetra-2,3-pyridinoporphyrazinato copper(II) methyl sulfate ([Cu(2,3-tmtppa)](MeSO{sub 4}){sub 4}) efficiently catalyzed the direct conversion of nitriles to N-substituted amides. The one pot selective synthesis of the N-substituted amides from nitriles and primary amines was performed in refluxing H{sub 2}O. The catalyst was recovered and reused at least four times, maintaining its efficiency. (author)

  14. Scalable room-temperature conversion of copper(II) hydroxide into HKUST-1 (Cu3 (btc)2).

    Science.gov (United States)

    Majano, Gerardo; Pérez-Ramírez, Javier

    2013-02-20

    Copper(II) hydroxide is converted directly to HKUST-1 (Cu(3) (btc)(2) ) after only 5 min at room-temperature in aqueous ethanolic solution without the need of additional solvents. Scale up to the kilogram scale does not influence porous properties yielding pure-phase product with a remarkable total surface area exceeding 1700 m(2) g(-1) featuring aggregates of nanometer-sized crystals (<600 nm) and extremely high space-time yields. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Synthesis, thermogravimetric study and crystal structure of an N-rich copper(II) compound with tren ligands and nitrate counter-anions

    Energy Technology Data Exchange (ETDEWEB)

    Pérez-Toro, Inmaculada; Domínguez-Martín, Alicia [Department of Inorganic Chemistry, Faculty of Pharmacy, University of Granada, 18071 Granada (Spain); Choquesillo-Lazarte, Duane [Laboratorio de Estudios Cristalográficos, IACT, CSIC-Universidad de Granada, Av. de las Palmeras 4, E-18100 Armilla, Granada (Spain); Vílchez-Rodríguez, Esther [Department of Inorganic Chemistry, Faculty of Pharmacy, University of Granada, 18071 Granada (Spain); Department of Inorganic Chemistry, Faculty of Pharmacy, University of Santiago de Compostela, 15782 Santiago de Compostela (Spain); Castiñeiras, Alfonso [Department of Inorganic Chemistry, Faculty of Pharmacy, University of Santiago de Compostela, 15782 Santiago de Compostela (Spain); Niclós-Gutiérrez, Juan, E-mail: jniclos@ugr.es [Department of Inorganic Chemistry, Faculty of Pharmacy, University of Granada, 18071 Granada (Spain)

    2014-10-10

    The N-rich salt [{Cu(tren)}{sub 3}(μ{sub 3}-tren)]{sub 2}(NO{sub 3}){sub 12}·3H{sub 2}O has been studied by XRD and by coupled TG and FT-IR spectroscopy of the evolved gases. After water loss, thermal decomposition of the nitrate ions and some tren ligands in the salt are overlapped. - Highlights: • A novel N-rich copper(II)-tren complex has been crystallized as a 3-hydrated nitrate salt. • Tren acts both as tripodal tetradentate and as μ{sub 3}-tren bridging ligand. • Copper(II) centers exhibit distorted trigonal bipyramidal coordination. • Coupled thermogravimetry and FT-IR spectra of evolved gases have been used. • Decomposition of nitrate anions and tren ligands occurs in an overlapped step. - Abstract: The compound [{Cu(tren)}{sub 3}(μ3-tren)]{sub 2}(NO{sub 3}){sub 12}·3H{sub 2}O has been synthesized, crystallized and characterized by single crystal X-ray diffraction, thermogravimetry (TG) coupled to FT-IR spectroscopy of the evolved gases, TG–differential scanning calorimetry (DSC) and electronic (diffuse reflectance) and FT-IR spectroscopies. The sample loses the crystallization water between room temperature and 200 °C. The decomposition of the salt begins with an overlapped decomposition of nitrate anions and some tren ligands where CO{sub 2}, H{sub 2}O, CO, NH{sub 3}, N{sub 2}O, NO and NO{sub 2} are evolved (205–235 °C). Then decomposition of additional tren ligands takes place (235–725 °C). Finally a non-pure CuO residue is obtained at 725 °C.

  16. Crystal structure of di-μ-chlorido-bis[chloridobis(1,2-dimethyl-5-nitro-1H-imidazole-κN3copper(II] acetonitrile disolvate

    Directory of Open Access Journals (Sweden)

    Patrick J. Quinlivan

    2016-11-01

    Full Text Available 1,2-Dimethyl-5-nitroimidazole (dimetridazole, dimet is a compound that belongs to a class of nitroimidazole drugs that are effective at inhibiting the activity of certain parasites and bacteria. However, there are few reports that describe structures of compounds that feature metals complexed by dimet. Therefore, we report here that dimet reacts with CuCl2·H2O to yield a chloride-bridged copper(II dimer, [Cu2Cl4(C5H7N3O24] or [Cu(μ-ClCl(dimet2]2. In this molecule, the CuII ions are coordinated in an approximately trigonal–bipyramidal manner, and the molecule lies across an inversion center. The dihedral angle between the imidazole rings in the asymmetric unit is 4.28 (7°. Compared to metronidazole, dimetridazole lacks the hydroxyethyl group, and thus cannot form intermolecular O...H hydrogen-bonding interactions. Instead, [Cu(μ-ClCl(dimet2]2 exhibits weak intermolecular interactions between the hydrogen atoms of C—H groups and (i oxygen in the nitro groups, and (ii the terminal and bridging chloride ligands. The unit cell contains four disordered acetonitrile molecules. These were modeled as providing a diffuse contribution to the overall scattering by SQUEEZE [Spek (2015. Acta Cryst. C71, 9–18], which identified two voids, each with a volume of 163 Å3 and a count of 46 electrons, indicative of a total of four acetonitrile molecules. These acetonitrile molecules are included in the chemical formula to give the expected calculated density and F(000.

  17. Synthesis and crystal structure of an iron(II) dimeric complex

    OpenAIRE

    Roy, Partha; Dhara, Koushik; Chakraborty, Jishnunil; Nethaji, Munirathinam; Banerjee, Pradyot

    2007-01-01

    An iron(II) complex, $[Fe_2(salen)_2]$ has been prepared by the reaction of $[Fe^{III}(salen)Cl]$ with copper(II) malonate dihydrate [salen = N,N'-ethylenebis(salicylideneiminato) dianion] in N,N-dimethylformamide-water mixture. The complex has been characterized by FT-IR spectroscopy, UV-vis spectra, thermogravimetric analysis, cyclic voltammetry and X-ray crystallography. The iron(II) complex 1 crystallizes in the monoclinic, space group C2/c, a = 26.664(5) \\AA, b = 6.9943(11) \\AA, c = 14.7...

  18. Synthesis and Structure of a New Copper(II) Coordination Polymer Alternately Bridged by Oxamido and Carboxylate Groups: Evaluation of DNA/BSA Binding and Cytotoxic Activities.

    Science.gov (United States)

    Jin, Xiao-Ting; Zheng, Kang; Li, Yan-Tuan; Wu, Zhi-Yong; Yan, Cui-Wei

    2015-08-01

    A new one-dimensional (1D) copper(II) coordination polymer {[Cu2 (dmaepox)(dabt)](NO3) · 0.5 H2 O}n , where H3 dmaepox and dabt denote N-benzoato-N'-(3-methylaminopropyl)oxamide and 2,2'-diamino-4,4'-bithiazole, respectively, was synthesized and characterized by single-crystal X-ray diffraction and other methods. The crystal structure analysis revealed that the two copper(II) ions are bridged alternately by cis-oxamido and carboxylato groups to form a 1-D coordination polymer with the corresponding Cu · · · Cu separations of 5.1946(19) and 5.038(2) Å. There is a three-dimensional supramolecular structure constructed by hydrogen bonding and π-π stacking interactions in the crystal. The reactivity towards herring sperm DNA (HS-DNA) and bovine serum albumin (BSA) indicated that the copper(II) polymer can interact with the DNA in the mode of intercalation, and bind to BSA responsible for quenching of tryptophan fluorescence by the static quenching mechanism. The in vitro cytotoxicity suggested that the copper(II) polymer exhibits cytotoxic effects against the selected tumor cell lines. © 2015 Wiley Periodicals, Inc.

  19. Characterisation of spin-waves in copper(II) deuteroformate tetradeuterate: A square ¤S¤=1/2 Heisenberg antiferromagnet

    DEFF Research Database (Denmark)

    Clarke, S.J.; Harrison, A.; Mason, T.E.

    1999-01-01

    Copper(II) formate tetrahydrate (CFTH) is a model square S = 1/2 Heisenberg antiferromagnet with T-N = 16.54 +/- 0.05 K. The dispersion of spin-waves in the magnetic layers of a fully deuterated sample of this material has been mapped at 4.3 K by inelastic neutron scattering from the zone centre ...

  20. Synthesis, characterization, and X-ray crystal structures of cyclam derivatives. 5. Copper(II) binding studies of a pyridine-strapped 5,12-dioxocyclam-based macrobicycle.

    Science.gov (United States)

    Meyer, Michel; Frémond, Laurent; Espinosa, Enrique; Guilard, Roger; Ou, Zhongping; Kadish, Karl M

    2004-09-06

    The copper(II) binding properties of the macrobicyclic diamide 1,9,12,18,22-pentaazatricyclo[7.6.6.1(3,7)]docosa-3,5,7(22)-triene-13,19-dione (L1) have been fully investigated by spectroscopic (IR, UV-vis, EPR, MALDI-TOF MS), X-ray diffraction, potentiometric, electrochemical, and spectroelectrochemical methods. This constrained receptor possesses a hemispherical cavity created by cross-bridging the 1 and 8 positions of trans-dioxocyclam (1,4,8,11-tetraazacyclotetradecane-5,12-dione, L2) with a 2,6-pyridyl strap. Treatment of L1 with a copper salt in methanol produces a red complex of [Cu(L1H(-1))]+ formula in which the copper atom is embedded in a 13-membered ring and coordinated by both amines as well as the pyridine and one deprotonated amide nitrogen atoms. Infrared spectroscopy provides evidence for protonation of the carbonyl oxygen atom belonging to the copper-bound amide of [Cu(L1H(-1))]+ under strongly acidic conditions. The resulting conversion of the amidate into an iminol group highlights the inert character of the corresponding complexes, which do not dissociate at low pH values. In contrast, both secondary amides of L1 deprotonate in the presence of a weak base, thus affording a blue pentacoordinated [Cu(L1H(-2))] compound where the copper atom sits in the center of the 14-membered dioxocyclam fragment. In aqueous solution, both complexes undergo a pH-driven (pK(a) = 8.73(2)) molecular reorganization, which is reminiscent of a glider motion. The copper(II) cation switches rapidly and reversibly from a four-coordinate flattened tetrahedral arrangement of the donor atoms in the red species to a five-coordinate environment in the blue species, which is intermediate between a square pyramid and a trigonal bipyramid. Conversion of the red to the blue form was also demonstrated to occur upon reduction of [Cu(L1H(-1))]+ by cyclic voltammetry (E(pc) = -0.64 V/SCE in CH(3)CN).

  1. Interaction of the human prion PrP(106-126) sequence with copper(II), manganese(II), and zinc(II): NMR and EPR studies.

    Science.gov (United States)

    Gaggelli, Elena; Bernardi, Francesca; Molteni, Elena; Pogni, Rebecca; Valensin, Daniela; Valensin, Gianni; Remelli, Maurizio; Luczkowski, Marek; Kozlowski, Henryk

    2005-01-26

    The synthetic peptide encompassing residues 106-126 (PrP106-126, KTNMKHMAGAAAAGAVVGGLG) of the human prion protein was considered for its binding properties toward copper(II), manganese(II) and zinc(II) at pH 5.7. 1H and 13C 1D spectra, 1H spin-lattice relaxation rates, and 1H-15N and 1H-13C HSQC 2D experiments were obtained in the absence and in the presence of metal ions. While Zn(II) was found to yield negligible effects upon any NMR parameter, metal-peptide association was demonstrated by the paramagnetic effects of Cu(II) and Mn(II) upon 1D and 2D spectra. Delineation of structures of metal complexes was sought by interpreting the paramagnetic effect on 1H spin-lattice relaxation rates. Exchange of peptide molecules from the metal coordination sphere was shown to provide sizable contribution to the observed relaxation rates. Such contribution was calculated in the case of Cu(II); whereas the faster paramagnetic rates of peptide molecules bound to Mn(II) were determining spin-lattice relaxation rates almost exclusively dominated by exchange. Proton-metal distances were therefore evaluated in the case of the Cu(II) complex only and used as restraints in molecular dynamics calculations where from the structure of the complex was obtained. The peptide was shown to bind copper through the imidazole nitrogen and the ionized amide nitrogen of His-111 and the amino-terminal group with the terminal carboxyl stabilizing the coordination sphere through ionic interactions. The data were interpreted as to demonstrate that the hydrophobic C-terminal region was not affecting the copper-binding properties of the peptide and that this hydrophobic tail is left free to interact with other target molecules. As for the complex with Mn(II), qualitative information was obtained on carbonyl oxygens of Gly-124 and Leu-125, beyond the terminal Gly-126 carboxyl, being at close distance from the metal ion, that also interacts, most likely, through a hydrogen bond of metal-bound water

  2. In vitro Solubility of Copper(II) Sulfate and Dicopper Chloride Trihydroxide for Pigs.

    Science.gov (United States)

    Park, C S; Kim, B G

    2016-11-01

    This study was conducted to determine the solubility of copper (Cu) in two sources of copper(II) sulfate (CuSO4) including monohydrate and pentahydrate and three sources of dicopper chloride trihydroxide (dCCTH) including α-form (dCCTH-α), β-form (dCCTH-β), and a mixture of α- and β-form (dCCTH-αβ) at different pH and a 3-step in vitro digestion assay for pigs. In Exp. 1, Cu sources were incubated in water-based buffers at pH 2.0, 3.0, 4.8, and 6.8 for 4 h using a shaking incubator at 39°C. The CuSO4 sources were completely dissolved within 15 min except at pH 6.8. The solubility of Cu in dCCTH-α was greater (pCopper in dCCTH sources were non-soluble at pH 6.8. In Exp. 2, the solubility of Cu was determined during the 3-step in vitro digestion assay for pigs. All sources of Cu were completely dissolved in step 1 which simulated digestion in the stomach. In Exp. 3, the solubility of Cu in experimental diets including a control diet and diets containing 250 mg/kg of additional Cu from five Cu sources was determined during the in vitro digestion assay. The solubility of Cu in diets containing additional Cu sources were greater (p<0.05) than the control diet in step 1. In conclusion, the solubility of Cu was influenced by pH of digesta but was not different among sources based on the in vitro digestion assay.

  3. Syntheses, crystal structures and magnetic properties of three copper(II) coordination polymers with the flexible ligand 1,2-bis(1,2,4-triazol-1-yl)ethane or 1,2-bis(imidazol-1-yl)ethane

    Science.gov (United States)

    Ding, Jiangang; Ge, Haiyan; Zhang, Yumei; Li, Baolong; Zhang, Yong

    2006-01-01

    In order to investigate the influence of the flexibility of the ligand molecules and the coordination counter anions on the architecture of coordination polymers, three new copper(II) coordination polymers [Cu(bte) 2(dca) 2] n (1), [Cu(bte)(NCS) 2] n (2) and [Cu(bim)(NCS) 2] n (3) were synthesized using the flexible five-membered heterocyclic ligands 1,2-bis(1,2,4-triazol-1-yl)ethane (bte), 1,2-bis(imidazol-1-yl)ethane (bim) and the anion ligands dicyanamide (dca) and thiocyanate. They are characterized by elemental analysis, IR, thermogravimetric analysis and X-ray diffraction analysis. The X-ray diffraction analysis shows that complexes 1, 2 and 3 form the one-dimensional double-stranded chain, linear chain and zigzag chain structures, respectively. The magnetic properties for complexes 1, 2 and 3 have also been studied.

  4. Removal of Copper(II and Zinc(II Ions From Aqueous Solution by Chemical Treatment of Coal Fly Ash

    Directory of Open Access Journals (Sweden)

    Eleonora Sočo

    2015-12-01

    Full Text Available The aim of this study was to investigate the chemical modifications of coal fly ash (CFA treated with HNO3 or ammonium acetate (AcNH4 or NaOH or sodium diethyldithiocarbamate (NaDDTC as an adsorbent for the removal of copper(II and zinc(II ions from aqueous solution. The morphology of fly ash grains before and after modification was examined via X-ray diffraction (XRD and images of scanning electron microscope (SEM. Adsorption of copper(II and zinc(II ions was conducted under batch process at different duration, concentrations and temperature of the suspension. Equilibrium experiments shows that the selectivity of CFA-NaOH nanoparticles towards Cu(II ions is greater than that of Zn(II ions, which is related to their hydrated ionic radius and first hydrolysis equilibrium constant. The adsorption isotherms were described by Langmuir and Freundlich models. Kinetic data revealed that the adsorption fits well by the pseudo-second-order rate model with high regression coefficients. Thermodynamic parameters suggested that the immobilization Cu(II and Zn(II ions onto CFA-NaOH is a spontaneous process. Results demonstrated that the treating coal fly ash with alkaline solution was a promising way to enhance Cu(II and Zn(II ions adsorption.

  5. Preconcentration of copper(II) and mercury(II) using dithizone and carbon powder followed by neutron activation analysis

    Energy Technology Data Exchange (ETDEWEB)

    Akaiwa, H.; Kawamoto, H.; Ogura, K.; Koizumi, T. (Gunma Univ., Kiryu (Japan). Faculty of Technology)

    1981-10-01

    A combined method of dithizone-extraction and carbon powder column adsorption was applied to concentrate trace amounts of copper(II) and mercury(II) in natural water samples before neutron activation analysis. The sample solution was adjusted to pH 1.0 with nitric acid, an aliquot of which was taken in a 500 cm/sup 3/ separating funnel and then 5.0 cm/sup 3/ of 0.01% dithizone-benzene and 25 cm/sup 3/ of n-hexane were added. The mixture was shaken for 10 min and stood for 30 min. After the aqueous phase was discarded, another aliquot of the sample solution was added. The above procedure was repeated until the treatment of the sample solution (1.00 dm/sup 3/) was completed. The organic phase was then flowed through the column (6 mm diameter x 50 mmh) containing carbon powder, and the resulting column was dried. The monitor containing 10 ..mu..g of mercury or copper was also prepared according to the above procedure. The samples and monitors were irradiated together in a pneumatic tube of JRR-3. After cooling, copper and mercury were determined by ..gamma..-spectrometry using /sup 64/Cu, /sup 197/Hg, respectively. The recovery of trace metal ions obtained by this method was more than 99%, and the present method was found to be applicable to the preconcentration of copper(II) and mercury(II) in natural water samples.

  6. Enhancement by Copper(II) of the voltammetric signal of vitamin B2 applied to its determination in breakfast cereals.

    Science.gov (United States)

    Kadara, Rashid O; Fogg, Arnold G; Haggett, Barry G D; Birch, Brian J

    2009-02-11

    Addition of copper(II) to breakfast cereal samples was shown to significantly enhance the analytical signal obtained by electrochemical reduction of vitamin B(2) using linear sweep voltammetry on disposable carbon electrodes. The enhancement was observed only when dissolved oxygen was present. In model solutions the analytical signal was linear in the concentration range 6-150 ng/mL with a calculated limit of detection of 5 ng/mL (S/N = 3). This compared favorably with earlier work using a similar measurement approach--but in the absence of copper--in which the limit of detection was calculated to be 900 ng/mL. The effects of potential interferents commonly found in cereals were examined. In addition to signal attenuation by both sugar and starch (already reported), folic acid was found to increase (+6%) and iron to decrease (-11%) the analytical signal when present in the maximum concentration ratios, with respect to vitamin B(2), that are normally found in breakfast cereals. Nevertheless, the simplicity of the approach was potentially attractive for near-line quality control applications in manufacturing. The utility of the measurement approach was demonstrated by the addition of excess copper(II) sulfate to determine vitamin B(2) in aqueous extracts of breakfast cereals. The results agreed well with those provided by the cereal manufacturer who used an established HPLC method.

  7. Two uranyl complexes with pyromellitic acid. A heterometallic complex with U=O-Cu{sup II} interaction

    Energy Technology Data Exchange (ETDEWEB)

    Liang, Lingling; Cai, Yige; Li, Xiang; Zhang, Ronglan; Zhao, Jianshe [College of Chemistry and Materials, Shaanxi Key Laboratory of Physico-Inorganic Chemistry, Northwest University, Xi' an (China); Liu, Chiyang [Department of Geology, Northwest University, Xi' an (China); Weng, Ng Seik [Department of Chemistry, University of Malaya, Kuala Lumpur (Malaysia)

    2015-08-15

    Two uranyl complexes based on pyromellitic acid were hydrothermally synthesized, and their X-ray single-crystal diffraction structures were determined. Complex [UO{sub 2}(Hbtec)]{sup -}(Himd){sup +}.H{sub 2}O (1) (H{sub 4}btec = pyromellitic acid, imd = imidazole), is an ionic complex, which shows a typical (4, 4) topological structure in the space. A heterometallic complex, UO{sub 2}Cu(btec)(phen) (2) (phen = 1,10-phenanthroline) results from the reaction of uranyl nitrate and copper(II) bromide with pyromellitic acid. The structure of complex 2 revealed that the chains of UO{sub 7} and CuO{sub 3}N{sub 2} units were connected to each other through the carboxyl groups and U=O-Cu interactions to create a two-dimensional framework. (Copyright copyright 2015 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  8. Crystal structure of nonadentate tricompartmental ligand derived from pyridine-2,6-dicarboxylic acid: Spectroscopic, electrochemical and thermal investigations of its transition metal(II) complexes

    Science.gov (United States)

    Vadavi, Ramesh S.; Shenoy, Rashmi V.; Badiger, Dayananda S.; Gudasi, Kalagouda B.; Devi, L. Gomathi; Nethaji, Munirathinam

    2011-07-01

    The coordinating behavior of a new dihydrazone ligand, 2,6-bis[(3-methoxysalicylidene)hydrazinocarbonyl]pyridine towards manganese(II), cobalt(II), nickel(II), copper(II), zinc(II) and cadmium(II) has been described. The metal complexes were characterized by magnetic moments, conductivity measurements, spectral (IR, NMR, UV-Vis, FAB-Mass and EPR) and thermal studies. The ligand crystallizes in triclinic system, space group P-1, with α = 98.491(10)°, β = 110.820(10)° and γ = 92.228(10)°. The cell dimensions are a = 10.196(7) Å, b = 10.814(7) Å, c = 10.017(7) Å, Z = 2 and V = 1117.4(12). IR spectral studies reveal the nonadentate behavior of the ligand. All the complexes are neutral in nature and possess six-coordinate geometry around each metal center. The X-band EPR spectra of copper(II) complex at both room temperature and liquid nitrogen temperature showed unresolved broad signals with giso = 2.106. Cyclic voltametric studies of copper(II) complex at different scan rates reveal that all the reaction occurring are irreversible.

  9. Hydrothermal syntheses and crystal structures of two 4,4'-biphenyldicarboxylate copper(II) complexes with 1,10-phenanthroline

    Science.gov (United States)

    Zhang, Shu-Yan; Yu, Ming-Xin; Zhu, Long-Guan

    2004-08-01

    Two structurally diverse compounds, [Cu(Hbpdc) 2(phen)] ( 1) and [Cu(bpdc)(phen)(H 2O)] n ( 2) (H 2bpdc=4,4'-biphenyldicarboxylic acid, phen=1,10-phenanthroline), were synthesized under hydrothermal conditions. Copper atom in 1 is four-coordinated to one bidentate phen ligand and two monodentate partly deprotonated 4,4'-biphenyldicarboxylates. As expected, the structure of 1 is a monomeric species and affords an extended two-dimensional hydrogen bonding architecture. Each copper atom in 2 is five-coordinated to one phen, one water molecule, and two bis-monodentate fully deprotonated 4,4'-biphenyldicarboxylates. Therefore, the structure of 2 is a one-dimensional chain.

  10. Solubility of Copper(II Sulfate and Dicopper Chloride Trihydroxide for Pigs

    Directory of Open Access Journals (Sweden)

    C. S. Park

    2016-11-01

    Full Text Available This study was conducted to determine the solubility of copper (Cu in two sources of copper(II sulfate (CuSO4 including monohydrate and pentahydrate and three sources of dicopper chloride trihydroxide (dCCTH including α-form (dCCTH-α, β-form (dCCTH-β, and a mixture of α- and β-form (dCCTH-αβ at different pH and a 3-step in vitro digestion assay for pigs. In Exp. 1, Cu sources were incubated in water-based buffers at pH 2.0, 3.0, 4.8, and 6.8 for 4 h using a shaking incubator at 39°C. The CuSO4 sources were completely dissolved within 15 min except at pH 6.8. The solubility of Cu in dCCTH-α was greater (p<0.05 than dCCTH-β but was not different from dCCTH-αβ during 3-h incubation at pH 2.0 and during 2-h incubation at pH 3.0. At pH 4.8, there were no significant differences in solubility of Cu in dCCTH sources. Copper in dCCTH sources were non-soluble at pH 6.8. In Exp. 2, the solubility of Cu was determined during the 3-step in vitro digestion assay for pigs. All sources of Cu were completely dissolved in step 1 which simulated digestion in the stomach. In Exp. 3, the solubility of Cu in experimental diets including a control diet and diets containing 250 mg/kg of additional Cu from five Cu sources was determined during the in vitro digestion assay. The solubility of Cu in diets containing additional Cu sources were greater (p<0.05 than the control diet in step 1. In conclusion, the solubility of Cu was influenced by pH of digesta but was not different among sources based on the in vitro digestion assay.

  11. Metal complexes of N'-(2-hydroxy-5-phenyldiazenyl benzylideneisonicotinohydrazide: Synthesis, spectroscopic characterization and antimicrobial activity

    Directory of Open Access Journals (Sweden)

    El-Tabl Abdou S.

    2013-01-01

    Full Text Available A new series of Cu(II, Ni(II, Co(II, Mn(II, Zn(II, Cd(II, Hg(II , VO(II, UO2(II , Fe(III and Ru(III complexes of N'-(2-hydroxy-5- phenyldiazenylbenzylideneisonicotinohydrazide(H2L have been synthesized and characterized by elemental,1H-NMR, IR, UV-Vis., ESR, magnetic, thermogravimetric analyses(TG and conductivity measurements. The spectral data show that, the ligand behaves as a neutral bidentate, (2, (4, (5, (6 and (14, monobasic bidentate, (3, (7, (8, (9 and (10, monobasic tridentate (11 and (16 or dibasic tridentate (12, (13 and (15 bonded to metal ions via the carbonyl oxygen atom in ketonic or enolic form, azomethine nitrogen atom and/or deprotonated phenolic hydroxyl oxygen. The ESR spectrum of solid vanadyl(II, complex (2 shows axially anisotropic spectrum with eight lines in the low field region and g?>g||, A||>>A?relationship, which is characteristics of distorted octahedral structure with dxy ground state. However, copper(II complexes (4, (5 and (6 and manganese(II complex (10 show an isotropic type while the copper(II complexes (3 and (7show an axial symmetry type with g||>g?>ge indicating a covalent bond character. The antibacterial and antifungal activities of the ligand and its metal complexes show mild activity compared with standard drugs (Tetracycline for bacteria and amphotricene B for fungi.

  12. Kinetics of the oxidative hydroxylation of tetraphosphorus in the presence of copper(II chloride modified by humic (fulvo- acid

    Directory of Open Access Journals (Sweden)

    Zhaksyntay Kairbekov

    2012-12-01

    Full Text Available It was established that in mild conditions (50-70 oC, РО2= 1 atm white phosphorus effectively is oxidized by oxygen in water-toluene solutions of copper(II chloride modified by humic (fulvo- acid to give mainly phosphoric acid. Humic (fulvo- acid was extracted from brown coal of domestic deposit Kiyakty. For determination of optimum parameters of fulvo-acid extraction the laboratory experiments were carried out using the method of experiment planning. The kinetics, intermediate and final products, optimum conditions of new catalytic reaction of P4 oxidation by oxygen in water medium were defined by kinetics, volumometry, redox-potentiometry, 31Р{1Н} NMR spectroscopy and  titration. 

  13. Synthesis, spectroscopic investigation and antimicrobial activities of some transition metal complexes of a [(2-hydroxyacetophenone-3-isatin]-bishydrazone

    Directory of Open Access Journals (Sweden)

    S.S. Swathy

    2016-11-01

    Full Text Available A bishydrazone was obtained by the condensation of isatin monohydrazone with 2-hydroxyacetophenone, which formed a series of complexes with manganese(II, cobalt(II, nickel(II, copper(II and zinc(II. The ligand and the metal complexes were characterized on the basis of elemental analysis, molar conductance, magnetic moment, IR, UV–Visible, mass, 1H NMR, EPR, and thermal analysis. Spectral studies revealed that the ligand acted as monobasic tridentate, coordinating to the metal ion through the deprotonated phenolate oxygen, azomethine nitrogen and carbonyl oxygen atom of the isatin moiety. The low molar conductance values indicate that all complexes are non-electrolytes. Based on the spectral results and magnetic susceptibility measurements, suitable geometry was proposed for each complex. The EPR spectral data indicated that metal–ligand bond had considerable covalent character. The ligand and its nickel(II complex were subjected to XRD studies. Thermal decomposition study of nickel(II complex was also carried out. In vitro biological screening effects of the compounds were tested against the bacteria and the fungal species by the agar disc diffusion method. A comparative study of the MIC values of the ligand and its complexes indicated that the copper(II complex exhibited higher antimicrobial activity than the free ligand. The corrosion inhibitory activity of the ligand and its nickel(II complex used in acid (H2SO4 media was also examined by weight loss measurements.

  14. Effects of [pi]-[pi] interactions on molecular structure and resonance Raman spectra of crystalline copper(II) octaethylporphyrin

    Energy Technology Data Exchange (ETDEWEB)

    Sparks, L.D.; Shelnutt, J.A. (Sandia National Labs., Albuquerque, NM (United States) Univ. of New Mexico, Albuquerque (United States)); Scheidt, W.R. (Univ. of Notre Dame, IN (United States))

    1992-05-27

    Single-crystal resonance Raman measurements were performed on two crystalline phases of copper(II) octaethylporphyrin (CuOEP): triclinic A and triclinic B forms. These are compared to previously acquired resonance Raman data on the triclinic A and triclinic B phases of nickel(II) octaethylporphyrin (NiOEP). The difference in crystal packing between the triclinic A and B structures allows for more extensive [pi]-[pi] interactions in the B form than in the A form. Differences in the single-crystal Raman spectra of the triclinic A and B forms of both Cu- and NiOEP are attributed to these [pi]-[pi] interactions. Specifically, the Raman core-size marker lines, [nu][sub 3], [nu][sub 2], and [nu][sub 10], and the oxidation-state marker line, [nu][sub 4], are affected by the different packing interactions in the two crystals, and the same Raman shifting patterns between the triclinic A and B phases are observed for both Cu- and NiOEP. The metal centers exert a slight influence over the packing-induced frequency shifts in the Raman modes. Spectral results on the CuOEP crystals are also compared to solution Raman data on [pi]-[pi] aggregated and monomeric copper(II) uroporphyrin (CuUroP). Similar to the A and B forms of NiOEP, the CuOEP triclinic A and B crystalline phases mimic the monomer and salt-induced aggregate of CuUroP in solution, as evidenced by similar magnitude upshifts in the Raman modes upon aggregation. A comparison of the structure calculated using molecular mechanics and the structure obtained from X-ray diffraction gives some insight into the effect that [pi]-[pi] interactions have on the structure of CuOEP in the triclinic B crystal.

  15. Copper(II)-catalysed oxidative coupling reaction of 3-hydroxyacetanilide with 3-methyl-2-benzothiazolinone hydrazone for the spectrophotometric determination of traces of copper(II).

    Science.gov (United States)

    Kumar, M S Hemantha; Nagaraja, P; Yathirajan, H S

    2003-01-01

    A spectrophotometric method is developed for the determination of traces of copper(II), based on the catalytic oxidative coupling reaction of 3-hydroxyacetanilide with 3-methyl-2-benzothiazolinone hydrazone in the presence of ammonia and hydrochloric acid. Beer's law is obeyed in the copper(II) concentration range of 0.008-0.16 microg mL(-1), and the molar absorptivity at 530 nm is 2.5x10(5) L mol(-1) cm(-1). The Sandell's sensitivity of the product is 0.000254 microg cm(-2). The optimum reaction conditions and other important analytical parameters have been investigated. The proposed method is applied to the analysis of water and soil samples and the results are compared with the literature method.

  16. A copper(II paddle-wheel structure of tranexamic acid: dichloro-tetrakis[μ-4-(ammoniomethylcyclohexane-1-carboxylato-O,O′]dicopper(II dichloride hexahydrate

    Directory of Open Access Journals (Sweden)

    Muhammad Altaf

    2017-10-01

    Full Text Available Tranexamic acid [systematic name: trans-4-(aminomethylcyclohexane-1-carboxylic acid], is an antifibrinolytic amino acid that exists as a zwitterion [trans-4-(ammoniomethylcyclohexane-1-carboxylate] in the solid state. Its reaction with copper chloride leads to the formation of a compound with a copper(II paddle-wheel structure that crystallizes as a hexahydrate, [Cu2Cl2(C8H15NO24]2+·2Cl−·6H2O. The asymmetric unit is composed of a copper(II cation, two zwitterionic tranexamic acid units, a coordinating Cl− anion and a free Cl− anion, together with three water molecules of crystallization. The whole structure is generated by inversion symmetry, with the Cu...Cu axle of the paddle-wheel dication being located about a center of symmetry. The cyclohexane rings of the zwitterionic tranexamic acid units have chair conformations. The carboxylate groups that bridge the two copper(II cations are inclined to one another by 88.4 (8°. The copper(II cation is ligated by four carboxylate O atoms in the equatorial plane and by a Cl− ion in the axial position. Hence, it has a fivefold O4Cl coordination sphere with a perfect square-pyramidal geometry and a τ5 index of zero. In the crystal, the paddle-wheel dications are linked by a series of N—H...Cl hydrogen bonds, involving the coordinating and free Cl− ions, forming a three-dimensional network. This network is strengthened by a series of N—H...Owater, Owater—H...Cl and Owater—H...O hydrogen bonds.

  17. Spectral, NLO, Fluorescence, and Biological Activity of Knoevenagel Condensate of β-Diketone Ligands and Their Metal(II Complexes

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    S. Sumathi

    2011-01-01

    Full Text Available Transition metal complexes of various acetylacetone-based ligands of the type ML (where M=  Cu(II, Ni(II, Co(II; L=  3-(aryl-pentane-2,4-dione have been synthesized. The structural features have been derived from their elemental analysis, magnetic susceptibility, molar conductance, IR, UV-Vis, H1NMR, mass and ESR spectral studies. Conductivity measurements reveal that all the complexes are nonelectrolytic in nature. Spectroscopic and other analytical data of the complexes suggest square planar geometry for copper(II, cobalt(II, and nickel(II complexes of 3-(3-phenylallylidenepentane-2,4-dione and octahedral geometry for other metal(II complexes. The redox behaviors of the copper(II complexes have been studied by cyclic voltammetry. The free ligands and their metal complexes have been screened for their in vitro biological activities against bacteria and fungus. The metal(II complexes are found to possess increased activities compared to those of the free ligands. All synthesized compounds may serve as potential photoactive materials as indicated from their characteristic fluorescence properties. The second harmonic generation (SHG efficiency of the ligands was found to have considerable effect compared to that of urea and KDP.

  18. Synthesis, characterization and fungicidal activity of binary and ternary metal(II) complexes derived from 4,4‧-((4-nitro-1,2-phenylene) bis(azanylylidene))bis(3-(hydroxyimino)pentan-2-one)

    Science.gov (United States)

    El-Tabl, Abdou S.; Shakdofa, Mohamad M. E.; Whaba, Mohamad A.

    2015-02-01

    Ternary copper(II) and binary copper(II), nickel(II) and cobalt(II) complexes derived from 4,4‧-((4-nitro-1,2-phenylene)bis(azanylylidene))bis(3-(hydroxyimino)pentan-2-one) (H2L) were synthesized and characterized by elemental and thermal analyses, IR, UV-Vis. and 1H NMR spectroscopy, conductivity and magnetic moments measurements. The analytical and spectral data showed that, the ligand acts as dibasic tetradentate or dibasic hexadentate bonding to the metal ion via the two-imine nitrogen, two nitrogen and/or oximato oxygen atoms of deprotonated oxime groups forming five and/or six rings including the metal ions. The complexes adopt either tetragonal distorted octahedral or square planar geometry around metal ions. The ESR spectra of the solid copper(II) complexes are characteristic to d9 configuration and having an axial symmetry type of a d(x2-y2) ground state. The g values confirmed the geometry is elongated tetragonal octahedral geometry with considerably ionic or covalent environment. The antifungal biological activity of the prepared compounds was studied using well diffusion method. The obtained results showed that, the ligand is biologically inactive while its metal complexes were more potent fungicides than the ligand and standard antifungal drug (Amphotericin B).

  19. Synthesis, characterization and fungicidal activity of binary and ternary metal(II) complexes derived from 4,4'-((4-nitro-1,2-phenylene) bis(azanylylidene))bis(3-(hydroxyimino)pentan-2-one).

    Science.gov (United States)

    El-Tabl, Abdou S; Shakdofa, Mohamad M E; Whaba, Mohamad A

    2015-02-05

    Ternary copper(II) and binary copper(II), nickel(II) and cobalt(II) complexes derived from 4,4'-((4-nitro-1,2-phenylene)bis(azanylylidene))bis(3-(hydroxyimino)pentan-2-one) (H2L) were synthesized and characterized by elemental and thermal analyses, IR, UV-Vis. and (1)H NMR spectroscopy, conductivity and magnetic moments measurements. The analytical and spectral data showed that, the ligand acts as dibasic tetradentate or dibasic hexadentate bonding to the metal ion via the two-imine nitrogen, two nitrogen and/or oximato oxygen atoms of deprotonated oxime groups forming five and/or six rings including the metal ions. The complexes adopt either tetragonal distorted octahedral or square planar geometry around metal ions. The ESR spectra of the solid copper(II) complexes are characteristic to d(9) configuration and having an axial symmetry type of a d(x2-y2) ground state. The g values confirmed the geometry is elongated tetragonal octahedral geometry with considerably ionic or covalent environment. The antifungal biological activity of the prepared compounds was studied using well diffusion method. The obtained results showed that, the ligand is biologically inactive while its metal complexes were more potent fungicides than the ligand and standard antifungal drug (Amphotericin B). Copyright © 2014. Published by Elsevier B.V.

  20. Copper(II Extraction from Nitric Acid Solution with 1-Phenyl-3-methyl-4-benzoyl-5-pyrazolone as a Cation Carrier by Liquid Membrane Emulsion

    Directory of Open Access Journals (Sweden)

    Baharuddin Hamzah

    2010-01-01

    Full Text Available Copper(II extraction from nitric acid solution with 1-phenyl-3-methyl-4-benzoil-5-pyrazolone (HPMBP as a cation carrier by liquid membrane emulsion (LME was investigated. The HPMBP initially was synthesized and the synthesis yield is a yellow crystal with melting point of 87-89 °C. The synthesis efficiency is 72.04% and generally the spectra of IR, 1H NMR and 13C NMR agree with HPMBP structure. The optimum condition for copper(II extraction were found as follows: concentration of mixed surfactant (span 80+span 20 was 3%, volume ratio of membrane and internal phase was 1, concentration of HPMBP was 0.020 M, concentration of HCl was 1 M, volume ratio of emulsion and external phase was 0.143. By using these optimum conditions, 30 mL of LME can extract 1000 ppm of copper(II within 210 mL of nitric acid solution with extraction percentage of 97.97%.

  1. Functionalization of a nanostructured hydroxyapatite with copper(II) compounds as pesticide: in situ TEM and ESEM observations of treated Vitis vinifera L. leaves.

    Science.gov (United States)

    Battiston, Enrico; Salvatici, Maria C; Lavacchi, Alessandro; Gatti, Antonietta; Di Marco, Stefano; Mugnai, Laura

    2018-02-19

    The present study evaluates a biocompatible material for plant protection to reduce the amount of active substance applied. We used a synthetic hydroxyapatite (HA) that has been studied extensively due its bioactivity and biocompatibility. Aggregation between HA nanoparticles and four copper(II) compounds applied in Vitis vinifera L. leaves as pesticide was studied. Formulations were characterised by XRD, DLS, electron microscopy and applied in planta to verify the particle aggregation and efficiency in controlling the pathogen, Plasmopara viticola. XRD showed a different interaction between HA and the copper(II) compounds, DLS showed a granular distribution ranging out of the nanometer range and in all formulations, TEM and ESEM microscopy showed large aggregates which were partially nanostructured and were recognised as stable in their micrometric dimension. Such particles did not show phytotoxic effects after their application in planta. A formulation based on HA and the soluble copper(II) compound showed promising results in the control of the fungal pathogen, confirming the potential role of HA an as innovative delivery system of Cu(II) ions. The present work indicates the possibility to improve the biological activity of a bioactive substance by modifying its structure through an achievable formulation with a biocompatible material. This article is protected by copyright. All rights reserved.

  2. Synthesis, complexation, and coordination oligomerization of 1,8-pyrazine-capped 5,12-dioxocyclams.

    Science.gov (United States)

    Hegedus, Louis S; Sundermann, Michael J; Dorhout, Peter K

    2003-07-14

    (Methyl)(methoxy)-5,12-dioxocyclam 1 was alkylated on the secondary amines (capped) with 2,6-bis(bromomethyl)pyrazine. The resulting macrocycle was complexed to copper(II) to produce a five-coordinate complex 5a which was fully characterized by a range of spectroscopic methods (IR, UV-vis, ESR) as well as by X-ray crystallography. The structure of this complex is similar to the previously reported pyridine complex, with the five-coordinate copper having distorted square pyramidal geometry and a Cu-Pz bond length of 2.125 A. Attempts to prepare this same complex under microwave irradiation instead produced a trinuclear complex 6a having an octahedral copper(II) center complexed to two pyrazine-cyclam copper units through the amide carbonyl oxygen and the methoxyl group oxygen of the cyclam unit. The X-ray crystal structure of the trinuclear complex showed extensive distortion in the cyclam rings. The remote nitrogen of pyrazine-cyclam complex 5a was capable of coordinating an additional metal. Treatment with RuCl(2)(DMSO)(4) or Rh(2)(OAc)(4), respectively, produced trimetallic Cu-Ru-Cu complex 7 or tetrametallic Cu-Rh-Rh-Cu complex 8. The latter was fully characterized, including an X-ray crystal structure, and had two pyrazine-cyclam complexes bridged by a Rh(2)(OAc)(4) unit through the remote pyrazine nitrogens. There was little distortion in the pyrazine-cyclam copper units as compared to complex 5a: the four metals were collinear, and the two cyclam units were eclipsed. All of the copper complexes were subjected to cyclic voltametry measurements, and no reversible redox changes were observed. Magnetic measurements of 6a and 8 showed the copper atoms to be weakly antiferromagnetically coupled.

  3. Copper(II) carboxylate dimers prepared from ligands designed to form a robust π···π stacking synthon: supramolecular structures and molecular properties.

    Science.gov (United States)

    Reger, Daniel L; Debreczeni, Agota; Smith, Mark D; Jezierska, Julia; Ozarowski, Andrew

    2012-01-16

    The reactions of bifunctional carboxylate ligands (1,8-naphthalimido)propanoate, (L(C2)(-)), (1,8-naphthalimido)ethanoate, (L(C1)(-)), and (1,8-naphthalimido)benzoate, (L(C4)(-)) with Cu(2)(O(2)CCH(3))(4)(H(2)O)(2) in methanol or ethanol at room temperature lead to the formation of novel dimeric [Cu(2)(L(C2))(4)(MeOH)(2)] (1), [Cu(2)(L(C1))(4)(MeOH)(2)]·2(CH(2)Cl(2)) (2), [Cu(2)(L(C4))(4)(EtOH)(2)]·2(CH(2)Cl(2)) (3) complexes. When the reaction of L(C1)(-) with Cu(2)(O(2)CCH(3))(4)(H(2)O)(2) was carried out at -20 °C in the presence of pyridine, [Cu(2)(L(C1))(4)(py)(4)]·2(CH(2)Cl(2)) (4) was produced. At the core of complexes 1-3 lies the square Cu(2)(O(2)CR)(4) "paddlewheel" secondary building unit, where the two copper centers have a nearly square pyramidal geometry with methanol or ethanol occupying the axial coordination sites. Complex 4 contains a different type of dimeric core generated by two κ(1)-bridging carboxylate ligands. Additionally, two terminal carboxylates and four trans situated pyridine molecules complete the coordination environment of the five-coordinate copper(II) centers. In all four compounds, robust π···π stacking interactions of the naphthalimide rings organize the dimeric units into two-dimensional sheets. These two-dimensional networks are organized into a three-dimensional architecture by two different noncovalent interactions: strong π···π stacking of the naphthalimide rings (also the pyridine rings for 4) in 1, 3, and 4, and intermolecular hydrogen bonding of the coordinated methanol or ethanol molecules in 1-3. Magnetic measurements show that the copper ions in the paddlewheel complexes 1-3 are strongly antiferromagnetically coupled with -J values ranging from 255 to 325 cm(-1), whereas the copper ions in 4 are only weakly antiferromagnetically coupled. Typical values of the zero-field splitting parameter D were found from EPR studies of 1-3and the related known complexes [Cu(2)(L(C2))(4)(py)(2)]·2(CH(2)Cl(2))·(CH(3

  4. Synthesis and spectral studies of copper complexes using a N-octylated bis benzimidazole diamide ligand

    Science.gov (United States)

    Mohapatra, Subash Chandra; Mathur, Pavan

    2011-02-01

    Monomeric Cu(II) and Cu(I) complexes bound to a tetradentate bis-benzimidazole diamide ligand N,N'-bis(N-octyl benzimidazolyl-2yl)(methyl)pentane diamide (O-GBGA) have been isolated and characterized. X-Band EPR spectra of the copper(II) complexes in CH 2Cl 2 were recorded in a frozen solution as solvent at liquid nitrogen temperature. Solution spectra typically indicate a d ground state ( g|| > g⊥ > 2.0023) and show less than four nuclear hyperfine lines with broadening of g⊥ line in some cases, thus indicating distorted tetragonal geometry. One of the copper(II) complexes shows a five line N-SHF structure (16 ± 1 G) implying the binding of imine nitrogen of the benzimidazole to copper ion. α2 ranges from 0.57-0.97 indicating considerable amount of covalent character in Cu-L bond. Anodic shifts in E1/2 values indicate the retention of anion in the coordination sphere of Cu(II), E1/2 values becoming anodic in the order C 6H 5COO - complexes was found to be lower than that of the ligand O-GBGA ( Φ = 0.029) and the relative fluorescence data reveals that fluorescence of such compounds could distinguish between small and large anions.

  5. Study on a pyrazine-modulated tetrapyridyltriamide and its complexes: Synthesis, structure and properties

    Science.gov (United States)

    Wang, Wen-Zhen; Ismayilov, Rayyat Huseyn; Lee, Gene-Hsiang; Wen, Yuh-Sheng; Peng, Shie-Ming

    2010-06-01

    A pyrazine-modulated oligo-α-pyridylamine ligand H 3pzpz and its mononuclear copper(II) and cobalt(II) complexes have been synthesized and structurally characterized. The protonated ligand cation 1 exhibits an anti-anti-anti-anti-syn-anti conformation. H 3pzpz can be a quadridentate ligand and coordinates to metal atoms with all- anti mode in both copper and cobalt mononuclear complexes. The copper(II) ion in 2 is five-coordinated in tetragonal pyramid geometry with one of the perchlorate anions being weakly coordinated in the apex position. The cobalt(II) ion in 3 and 4 is six-coordinated in octahedron geometry. Extensive hydrogen bonds are formed, and construct the complexes 1 and 2 into 2D networks and 3 and 4 into 3D networks. X-band EPR spectra of 2 showed well-resolved hyperfine structures resulting from the two paramagnetic isotopes 63Cu and 65Cu, yielding g = 2.16 and A0 = 67 × 10 -4 cm -1. Complexes 3 and 4 showed spin-orbital coupling and zero-field splitting that is reflected in the magnetic properties.

  6. Role of Metalation in the Topoisomerase IIα Inhibition and Antiproliferation Activity of a Series of α-Heterocyclic-N4-Substituted Thiosemicarbazones and Their Cu(II) Complexes

    Science.gov (United States)

    Zeglis, Brian M.; Divilov, Vadim; Lewis, Jason S.

    2014-01-01

    The topoisomerase-IIα inhibition and antiproliferative activity of α-heterocyclic thiosemicarbazones and their corresponding copper(II) complexes have been investigated. The CuII(thiosemicarbazonato)Cl complexes were shown to catalytically inhibit topoisomerase-IIα at concentrations (0.3–7.2 μM) over an order of magnitude lower than their corresponding thiosemicarbazone ligands alone. The copper complexes were also shown to inhibit the proliferation of breast cancer cells expressing high levels of topoisomerase-IIα (SK-BR-3) at lower concentrations than cells expressing lower levels of the enzyme (MCF-7). PMID:21391686

  7. Synthesis and spectral studies on metal complexes of s-triazine based ligand and non linear optical properties

    Science.gov (United States)

    Shanmugakala, R.; Tharmaraj, P.; Sheela, C. D.

    2014-11-01

    A series of transition metal complexes of type [ML] and [ML2]Cl2 (where M = Cu(II), Ni(II), Co(II) have synthesized from 2-phenylamino-4,6-dichloro-s-triazine and 3,5-dimethyl pyrazole; their characteristics have been investigated by means of elemental analyses, magnetic susceptibility, molar conductance, IR, UV-Vis, Mass, NMR and ESR spectra. The electrochemical behavior of copper(II) complexes we have studied, by using cyclic voltammetry. The ESR spectra of copper(II) complexes are recorded at 300 K and 77 K and their salient features are appropriately reported. Spectral datas, we found, show that the ligand acts as a neutral tridentate, and coordinates through the triazine ring nitrogen and pyrazolyl ring nitrogen atoms to the metal ion. Evident from our findings, the metal(II) complexes of [ML] type exhibit square pyramidal geometry, and that of [ML2]Cl2 exhibit octahedral geometry. The in vitro antimicrobial activities of the ligand and its complexes are evaluated against Bacillus subtilis, Micrococcus luteus, Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus mutans, Escherichia coli, Enterobacter aerogenes, Klebsiella pneumoniae, Proteus vulgaris, Cryptococcus neoformans, Pseudomonas aeruginosa, Salmonella typhi, Serratia marcescens, Shigella flexneri, Vibrio cholera, Vibris parahaemolyticus, Aspergillus niger, Candida albicans and Penicillium oxalicum by well-diffusion method. The second harmonic generation efficiency of the ligand and its complexes are determined and compared with urea and KDP.

  8. Reactivity of copper-α-synuclein peptide complexes relevant to Parkinson's disease.

    Science.gov (United States)

    Dell'Acqua, Simone; Pirota, Valentina; Anzani, Cecilia; Rocco, Michela M; Nicolis, Stefania; Valensin, Daniela; Monzani, Enrico; Casella, Luigi

    2015-07-01

    Parkinson's disease (PD) is a neurodegenerative disorder characterized by the presence of abnormal α-synuclein (αSyn) deposits in the brain. Alterations in metal homeostasis and metal-induced oxidative stress may play a crucial role in the aggregation of αSyn and, consequently, in the pathogenesis of PD. We have therefore investigated the capability of copper-αSyn6 and copper-αSyn15 peptide complexes, with the 1-6 and 1-15 terminal fragments of the protein, to promote redox reactions that can be harmful to other cellular components. The pseudo-tyrosinase activity of copper-αSyn complexes against catecholic (di-tert-butylcatechol (DTBCH2), 4-methylcatechol (4-MC)) and phenolic (phenol) substrates is lower compared to that of free copper(II). In particular, the rates (kcat) of DTBCH2 catalytic oxidation are 0.030 s(-1) and 0.009 s(-1) for the reaction promoted by free copper(II) and [Cu(2+)-αSyn15], respectively. On the other hand, HPLC/ESI-MS analysis of solutions of αSyn15 incubated with copper(II) and 4-MC showed that αSyn is competitively oxidized with remarkable formation of sulfoxide at Met1 and Met5 residues. Moreover, the sulfoxidation of methionine residues, which is related to the aggregation of αSyn, also occurs on peptides not directly bound to copper, indicating that external αSyn can also be oxidized by copper. Therefore, this study strengthens the hypothesis that copper plays an important role in oxidative damage of αSyn which is proposed to be strongly related to the etiology of PD.

  9. Construction of dinuclear complexes using multidentate ligands

    Energy Technology Data Exchange (ETDEWEB)

    Sampson, C.L

    2000-04-01

    This work details the synthesis of novel copper(I), copper(II), nickel(II) and zinc(II) dinuclear complexes. Attempts have been made to control the co-ordination architectures of the metal centres by using bis-bidentate and tridentate chelating N,S- and N-donor ligands to generate dinuclear systems. The ligands were both symmetrically and asymmetrically disubstituted pyridazine-based and pyridine-based ligands consisting of a mixture of N-only and mixed N,S-donors. The study using the pyridazine-based ligands continues previous research in our group using 3,6-bis disubstituted pyridazine-based ligands to form complexes with copper(l) and copper(II). The pyridazine-based ligands have been seen to be bis-bidentate upon co-ordination of copper. The pyridazine-based ligands could be envisaged to generate dinuclear complexes by directly bridging between two metal ions. This study involved the formation of copper(l), nickel(II) and zinc(II) complexes with these ligands. The structural properties of two particular complexes have been explored using X-ray crystallography and spectroscopic techniques. Pyridine-based ligands have also been used previously in our group as tridentate chelating ligands. They have been seen to form dinuclear complexes with copper(I) and copper(II) when reacted with an additional bridging ligand e.g. 4,4'-bipyridine. This provides an alternative method for generating dinuclear complexes. Chapter 1 presents an introduction to the area of supramolecular chemistry from which we can learn the principles of polymer formation and them 'in reverse' to generate discrete dinuclear systems. Chapter 2 details the synthesis of the pyridazine and pyridine-based ligands including a detailed nmr study of the ligands. Since the ligands were synthesised using cyclic thioamides as terminal groups it has been found that thiol-thione tautomerisation occurred during synthesis giving rise to two possible ligand conformations. The nmr study has been used

  10. Synthesis, Characterization and Thermal Analysis of New Cu(II Complexes with Hydrazide Ligands

    Directory of Open Access Journals (Sweden)

    Saber Rajaei

    2010-01-01

    Full Text Available A number of new complexes have been synthesized by reaction of novel ligands acetic acid(4-methyl-benzylidenehydrazide (L1 and acetic acid(naphthalen-1-ylmethylenehydrazide (L2 with copper(II nitrate. These new compounds were characterized by elemental analysis, TG, DTA, IR spectroscopy, UV spectral techniques. The changes observed between the FT-IR and UV-Vis spectra of the ligands and of the complexes allowed us to establish the coordination mode of the metal in complexes. The results suggest that the Schiff bases L1 and L2 coordinate as univalent anions with their bidentate N,O donors derived from the carbonyl and azomethine nitrogen. Also the probing of thermal analysis complexes can detect which complex has excellent thermal stability.

  11. Determination of stability constants of aminoglycoside antibiotics with their metal complexes

    Science.gov (United States)

    Tiwow, Vanny M. A.

    2014-03-01

    One group of aminoglycoside antibiotics contains aminosugars. The aminosugar neomycin B with its derivate product neamine (2-Deoxy-4-0-(2,6-diamino-2,6-dideoxy-α-D-glucopyranosyl)-D-Streptamine) was identified as a free ligands and metal complexes. In particular, the stability constants of metal complexes by potentiometric titration techniques were investigated. Our previous study had determined the acid dissociation constants of these aminosugars with few metal complexes in fair depth. In this work, the complexation of two pyridine-containing amino alcohols and an amino sugar (neamine) have been measured potentiometrically. For instance, the stability constant of copper(II) complexation were determine and the model system generated an excellent fit. Stability constants with several metals have been determined and will be reported.

  12. Copper(II) complexes with unsymmetrical pentadentate ed3a-type diamino-tricarboxylate ligands. Crystal structures, configurational analysis and DFT study of complexes

    NARCIS (Netherlands)

    Matovic, Zoran D.; Meetsma, Auke; Miletic, Vesna D.; van Koningsbruggen, Petra J.; Matović, Zoran D.; Miletić, Vesna D.; D. Matović, Z.; D. Miletić, V.

    2007-01-01

    The O-O-N-N-O-type pentadentate ligands H(3)ed3a, H(3)pd3a and H(3)pd3p (H(3)ed3a stands ethylenediamine-N,N,N'-triacetic acid; H3pd3a stands 1,3-propanediamine-N,N,N'-triacetic acid and H3pd3p stands 1,3-propanediamine-N,N,N'-tri-3-propionic acid) and the corresponding novel octahedral or

  13. Effect of coordinated ligands on antiproliferative activity and DNA cleavage property of three mononuclear Cu(II)-terpyridine complexes.

    Science.gov (United States)

    Manikandamathavan, Verasuntharam M; Rajapandian, Varatharaj; Freddy, Allen J; Weyhermüller, Thomas; Subramanian, Venkatesan; Nair, Balachandran Unni

    2012-11-01

    Three mononuclear copper(II) complexes, [Cu(tpy)Cl(2)] 1, [Cu(tpy)(NO(3))(2)(H(2)O)] 2 and [Cu(Ptpy)Cl(2)]·H(2)O·HCl 3 have been synthesised and characterized by various spectroscopic techniques and single crystal X-ray diffraction. Complexes 1 and 3 have five coordinate geometry in solid state, whereas complex 2 has six coordinate geometry. Mass spectral and EPR evidence suggest that in solution all the three complexes exist predominantly as a four coordinate species. Molecular modelling and DNA cleavage studies indicate that complexes 1 and 2 are DNA minor groove binders, whereas 3 is an intercalator. All the three complexes show nuclease activity in the presence of hydrogen peroxide. The three complexes have been found to be cytotoxic towards A549 lung adenocarcinoma cells. Copyright © 2012 Elsevier Masson SAS. All rights reserved.

  14. The metal complexes of amino acids and their N-substituted derivatives—VI. The physical properties, i.r. spectra and normal coordinate analysis of bivalent metal complexes with DL-threonine

    Science.gov (United States)

    Inomata, Yoshie; Takeuchi, Toshio; Moriwaki, Takao

    Complexes of five bivalent metals with DL-threonine have been prepared and characterized by means of i.r. absorption, powder diffuse reflection, and electronic spectra, X-ray diffraction and magnetic susceptibility. The complexes appear to be of three distinct types. The first type includes ML 2· nH 2O (M = Ni, Cu, Zn; L = DL-threoninato anion), in which the ligand chelates metal ions through the nitrogen atom and the oxygen atom of the carboxylato group. Three species of copper(II) complexes have been prepared. They seem to be two trans forms and one cis form. MnCl 2(HL) 4·H 2O is a second type in which the metal is coordinated through the oxygen atom of the carboxyl group and chloride ions, but is not coordinated through the nitrogen atom. 2CdCl 2·HL·HCl·2H 2O is a third type, in which the metal is coordinated through only chloride ions. In order to assign the observed frequencies of i.r. absorption spectra in detail, a normal coordinate analysis has been accomplished for the complexes of the first type as a 33-body problem. Copper(II) and zinc(II) complexes with L-threonine have been prepared for comparison.

  15. Solid phase extraction of copper(II) ions using C18-silica disks modified by oxime ligands

    Energy Technology Data Exchange (ETDEWEB)

    Dindar, M. Hami; Fathi, S.A.M. [Phase Equilibria Research Laboratory, Department of Chemistry, Faculty of Science, Zanjan University, P.O. Box 45195-313, Zanjan (Iran, Islamic Republic of); Yaftian, M.R., E-mail: yaftian@znu.ac.ir [Phase Equilibria Research Laboratory, Department of Chemistry, Faculty of Science, Zanjan University, P.O. Box 45195-313, Zanjan (Iran, Islamic Republic of); Noushiranzadeh, N. [Phase Equilibria Research Laboratory, Department of Chemistry, Faculty of Science, Zanjan University, P.O. Box 45195-313, Zanjan (Iran, Islamic Republic of)

    2010-07-15

    5-Tert-butyl-2-hydroxy-benzaldehyde oxime (L{sub 1}) and 3,5- di-tert-butyl-2-hydroxy-benzaldehyde oxime (L{sub 2}) are synthesized and characterized by conventional spectroscopic methods. These ligands are used as modifier of octadecyl silica membrane disks for separation and pre-concentration of trace amounts of copper(II) ions, followed by sulfuric or nitric acid elution and flame atomic absorption spectrometric (FAAS) determination. The effect of parameters influencing the extraction efficiency i.e. pH of sample solutions, amount of the oxime, type and volume of eluent, sample solution and eluent flow rates were evaluated. Under optimum experimental conditions, the maximum capacity of the membrane disks modified by 6 mg of L{sub 1} or 4 mg of L{sub 2} was found to be 284.7 ({+-}2.8) {mu}g of copper and 382.5 ({+-}3.1) {mu}g of copper, respectively. The detection limits of the presented methods are 0.29 ng ml{sup -1} for L{sub 1} and 0.25 ng ml{sup -1} for L{sub 2}. The enrichment factors are greater than 400 for both cases. These methods were successfully applied to the extraction, recovery and detection of copper in different water samples.

  16. Ammonia, phosphate, phenol, and copper(II) removal from aqueous solution by subsurface and surface flow constructed wetland.

    Science.gov (United States)

    Mojiri, Amin; Ahmad, Zakiah; Tajuddin, Ramlah Mohd; Arshad, Mohd Fadzil; Gholami, Ali

    2017-07-01

    Water pollution is a global problem. During current study, ammonia, phosphate, phenol, and copper(II) were removed from aqueous solution by subsurface and surface flow constructed wetland. In current investigation, distilled water was polluted with four contaminants including ammonia, phosphate, copper (Cu), and phenol. Response surface methodology and central composite design were applied to optimize pollutant removal during treatment by subsurface flow constructed wetland (SSFCW). Contact time (12 to 80 h) and initial pollutant concentration (20 to 85 mg/L) were selected as independent factors; some upper and lower ranges were also monitored for accuracy. In SSFCW, water hyacinth transplanted in two substrate layers, namely zeolite and cockle shell. SSFCW removed 87.7, 81.4, 74.7, and 54.9% of ammonia, phosphate, Cu, and phenol, respectively, at optimum contact time (64.5 h) and initial pollutant concentration (69.2 mg/L). Aqueous solution was moved to a surface flow constructed wetland (SFCW) after treating via SSFCW at optimum conditions. In SFCW, Typha was transplanted to a fixed powdered substrate layer, including bentonite, zeolite, and cockle shell. SFCW could develop performance of this combined system and could improve elimination efficacy of the four contaminants to 99.99%. So this combined CW showed a good performance in removing pollutants. Graphical abstract Wetlands arrangement for treating aqueous solution in current study.

  17. Synthesis, spectral characterization and study of thermal behavior kinetics by thermogravimetric analysis of metal complexes derived from salicylaldehyde and alkylamine

    Science.gov (United States)

    Bouzerafa, Brahim; Aggoun, Djouhra; Ouennoughi, Yasmina; Ourari, Ali; Ruiz-Rosas, Ramiro; Morallon, Emilia; Mubarak, Mohammad S.

    2017-08-01

    Cobalt(III)- and copper(II)-Schiff base complexes have been prepared by reaction of the bidentate Schiff base ligand (HL: 2-(4-methoxyphenyl)-1-iminosalicylidenethane) with cobalt(II) and copper(II) chlorides. Structures of the synthesized complexes have been characterized by various physicochemical techniques, such as IR and UV-Vis spectroscopy, mass spectrometry, thermogravimetric analysis (TG/DTG), and by elemental analysis. Additionally, the redox behavior of the cobalt(III) and copper(II) complexes has been examined by cyclic voltammetry at a glassy carbon electrode in DMF solutions. Thermogravimetric analysis has been employed to evaluate the thermal stability of the prepared complexes CoIII(L)3·1/2H2O, CuII(L)2, in addition to the previously synthesized HL and NiII(L)2. Furthermore, activation energies of the thermal decomposition were calculated using Kissinger, Ozawa and Coats-Redfern methods. The calculated activation energies were also useful to evaluate kinetic and thermodynamic parameters of the ligand and the corresponding metal complexes including ΔS, ΔH and ΔG. Calculated activation energies follow the order: Ea(NiII(L)2) > Ea(CuII(L)2) > Ea(CoIII(L)3·1/2H2O).

  18. Mixed-ligand complexes of copper (II with ditiolfenols and heterocyclic diamines

    Directory of Open Access Journals (Sweden)

    K. A. Kuliev

    2017-01-01

    Full Text Available By the methods spectrophotometric methods was investigated complex formation of copper with 2,6-ditiolphenol and its derivatives (2,6-ditiol-4-methylphenol, 2,6-ditiol-4-ethylphenol and 2,6-ditiol-4-tert-buthylphenol in the presence of heterocyclic diamines. As heterocyclic diamines phenantroline (Fen, batophenantroline and dipyridile were used. It was established, that mixedligand complex were formed in weak acidic medium (pHop=6,0-8,5. Maximum of light absorption observed at (=522–550 nm. Molar coefficient of light absorption was ( = (3.08–4.92?104. The stoichiometry of complexes had been discovered using shift the equilibrium and relative yield methods. During the extraction of copper(II complexes with ditiol-phenols with the presence of heterocyclic diamines there was discovered that there is no chlorophorm molecules in the composition of the extracted complexes. IR spectra shows that hydroxyl group is involved to the formation of a bond with the metal and that phenantroline is included in the composition of the copper complex. In the organic phase mixed-ligand complexes have the monomeric form and can’t polymerize; that fact can be proved by calculations. By dint of spectrophotometric, IR-spectroscopic, thermogravimetric experiments and some published data we were able to determine the structural formula of complexes. Also had been determined main spectrophotometric characteristics of copper(II mixed-ligand complexes: pH of the beginning of the deposition, optimal pH, detection limit and sensivity. For separation and finding copper, we studied the effect of interfering foreign ions: alkali, alkaline earth and rare earth elements, as well as acid anions selected masking reagents. On the base of the results was offered photometric method for determination of copper in steel different trade-marks and in food. This method characterized by good reproduction (relatively standard deviation no more 0.05 and low limit of discovery.

  19. Multi-functional Copper(II) Drug Candidates as Potential Anti-Cancer Agents

    OpenAIRE

    Mc Givern, Tadhg James Patrick

    2016-01-01

    The development of metal complexes as therapeutic agents remains a focal point of modern medicinal inorganic chemistry. While platinum drugs are well established therapeutic agents, recent progress has shown that some copper complexes possess enhanced cytotoxic activity and in vivo cytotoxic tolerance owing to their DNA binding and DNA scission capabilities. In parallel, the design, synthesis and evaluation of enzyme inhibitors rationally chosen for their potential in suppressing tumour cell ...

  20. High-nuclearity Pt-Tl-Fe complexes: structural, electrochemistry, and spectroelectrochemistry studies.

    Science.gov (United States)

    Díez, Alvaro; Fernández, Julio; Lalinde, Elena; Moreno, M Teresa; Sánchez, Sergio

    2010-12-20

    A series of heteropolynuclear Pt-Tl-Fe complexes have been synthesized and structurally characterized. The final structures strongly depend on the geometry of the precursor and the Pt/Tl ratio used. Thus, the anionic heteroleptic cis-configured [cis-Pt(C(6)F(5))(2)(C≡CFc)(2)](2-) and [Pt(bzq)(C≡CFc)(2)](-) (Fc = ferrocenyl) complexes react with Tl(+) to form discrete octanuclear (PPh(3)Me)(2)[{trans,cis,cis-PtTl(C(6)F(5))(2)(C≡CFc)(2)}(2)] (1), [PtTl(bzq)(C≡CFc)(2)](2) (5; bzq = benzoquinolate), and decanuclear [trans,cis,cis-PtTl(2)(C(6)F(5))(2)(C≡CFc)(2)](2) (3) derivatives, stabilized by both Pt(II)···Tl(I) and Tl(I)···η(2)(alkynyl) bonds. By contrast, Q(2)[trans-Pt(C(6)F(5))(2)(C≡CFc)(2)] (Q = NBu(4)) reacts with Tl(+) to give the one-dimensional (1-D) anionic [(NBu(4)){trans,trans,trans-PtTl(C(6)F(5))(2)(C≡CFc)(2)}](n) (2) and neutral [trans,trans,trans-PtTl(2)(C(6)F(5))(2)(C≡CFc)(2)](n) (4) polymeric chains based on [PtFc(2)](2-) platinate fragments and Tl(+) (2) or [Tl···Tl](2+) (4) units, respectively, connected by Pt(II)···Tl(I) and secondary weak κ-η(1) (2) or η(2) (4) alkynyl···Tl(I) bonding. The formation of 1-4 is reversible, and thus treatment of neutral 3 and 4 with PPh(3)MeBr causes the precipitation of TlBr, returning toward the formation of the anionic 1 and 2' (Q = PPh(3)Me). Two slightly different pseudopolymorphs were found for 2', depending on the crystallization solvent. Finally, the reaction of the homoleptic [Pt(C≡CFc)(4)](2-) with 2 equiv of Tl(+) affords the tetradecanuclear sandwich type complex [Pt(2)Tl(4)(C≡CFc)(8)] (6). Electrochemical, spectroelectrochemical, and theoretical studies have been carried out to elucidate the effect produced by the interaction of the Tl(+) with the Pt-C≡CFc fragments. The cyclic voltammetry (CV) and differential pulse voltammetry (DPV) of 1-5 reveal that, in general, neutralization of the anionic fragments increases the stability of the fully oxidized species and