Geometry and Framework Interactions of Zeolite-Encapsulated Copper(II)-Histidine Complexes

NARCIS (Netherlands)

Weckhuysen, B.M.; Grommen, R.; Manikandan, P.; Gao, Y.; Shane, T.; Shane, J.J.; Schoonheydt, R.A.; Goldfarb, D.

2000-01-01

The coordination geometry of zeolite-encapsulated copper(II)-histidine (CuHis) complexes, prepared by ion exchange of the complexes from aqueous solutions into zeolite NaY, was determined by a combination of UV-vis-NIR diffuse reflectance spectroscopy (DRS), X-band EPR, electron-spin-echo envelope

Synthesis, spectral, thermal and antimicrobial studies on cobalt(II), nickel(II), copper(II), zinc(II) and palladium(II) complexes containing thiosemicarbazone ligand

Science.gov (United States)

El-Sawaf, Ayman K.; El-Essawy, Farag; Nassar, Amal A.; El-Samanody, El-Sayed A.

2018-04-01

The coordination characteristic of new N4-morpholinyl isatin-3-thiosemicarbazone (HL) towards Co(II), Ni(II), Cu(II), Zn(II) and Pd(II) has been studies. The structures of the complexes were described by elemental analyses, molar conductivity, magnetic, thermal and spectral (IR, UV-Vis, 1H and 13C NMR and ESR) studies. On the basis of analytical and spectral studies the ligand behaves as monobasic tridentate ONS donor forming two five membered rings towards cobalt, copper and palladium and afforded complexes of the kind [M(L)X], (Mdbnd Co, Cu or Pd; Xdbnd Cl, Br or OAc). Whereas the ligand bound to NiCl2 as neutral tridentate ONS donor and with ZnCl2 as neutral bidentate NS donor. The newly synthesized thiosemicarbazone ligand and some of its complexes were examined for antimicrobial activity against 2 gram negative bacterial strains (Escherichia coli Pseudomonas and aeruginosa), 2 gram positive bacterial strains (Streptococcus pneumoniae and Staphylococcus aureus)} and two Pathogenic fungi (Aspergillus fumigatus and Candida albicans). All metal complexes possess higher antimicrobial activity comparing with the free thiosemicarbazone ligand. The high potent activities of the complexes may arise from the coordination and chelation, which tends to make metal complexes act as more controlling and potent antimicrobial agents, thus hindering the growing of the microorganisms. The antimicrobial results also show that copper bromide complex is better antimicrobial agent as compared to the Schiff base and its metal complexes.

Synthesis and properties of complexes of copper(II), nickel(II), cobalt(II) and uranyl ions with 3-(p-tolylsulphonamido)rhodamine

International Nuclear Information System (INIS)

El-Bindary, A.A.; El-Sonbati, A.Z.

2000-01-01

Metal complexes of copper(II), nickel(II), cobalt(II) and uranyl ions with 3-(p-tolylsulphonamido)rhodamine (HL) have been prepared and characterized by chemical and thermal analyses, molar conductivity , magnetic susceptibility measurements, and infrared, electronic and EPR spectra. The visible and EPR spectra indicated that the Cu(II) complex has a tetragonal geometry. From EPR spectrum of the Cu(II) complex,various parameters were calculated. The crystal field parameters of Ni(II) complex were calculated and were found to agree fairly well with the values reported for known square pyramidal complexes. The infrared spectral studies showed a monobasic bidentate behaviour with the oxygen and nitrogen donor system. Thermal stabilities of the complexes are also reported. (author)

potentiometric studies of the complexes formed by copper (ii)

African Journals Online (AJOL)

MBI

The overall stability constants of copper (II) and zinc (II) ions with some polar ... The average number of coordinated amino acids to the copper (II) and zinc (II) ions .... of chelated rings (Yamuchi and Odani, 1996). ... Synthesis and techniques in.

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.

and copper(II)

Indian Academy of Sciences (India)

Unknown

(II) and copper(II)–zinc(II) complexes. SUBODH KUMAR1, R N PATEL1*, P V KHADIKAR1 and. K B PANDEYA2. 1 Department of Chemistry, APS University, Rewa 486 003, India. 2 CSJM University, Kanpur 208 016, India e-mail: (R N Patel) ...

Hypoxia targeting copper complexes

International Nuclear Information System (INIS)

Dearling, J.L.

1998-11-01

The importance and incidence of tumour hypoxia, its measurement and current treatments available, including pharmacological and radiopharmacological methods of targeting hypoxia, are discussed. A variety of in vitro and in vivo methods for imposing hypoxia have been developed and are reviewed. Copper, its chemistry, biochemistry and radiochemistry, the potential for use of copper radionuclides and its use to date in this field is considered with particular reference to the thiosemicarbazones. Their biological activity, metal chelation, in vitro and in vivo studies of their radiocopper complexes and the potential for their use as hypoxia targeting radiopharmaceuticals is described. The reduction of the copper(II) complex to copper(l), its pivotal importance in their biological behaviour, and the potential for manipulation of this to effect hypoxia selectivity are described. An in vitro method for assessing the hypoxia selectivity of radiopharmaceuticals is reported. The rapid deoxygenation and high viability of a mammalian cell culture in this system is discussed and factors which may affect the cellular uptake of a radiopharmaceutical are described. The design, synthesis and complexation with copper and radiocopper of a range of bis(thiosemicarbazones) is reported. Synthesis of these compounds is simple giving high yields of pure products. The characteristics of the radiocopper complexes ( 64 Cu) including lipophilicity and redox activity are reported (reduction potentials in the range -0.314 - -0.590 V). High cellular uptakes of the radiocopper complexes of the ligands, in hypoxic and normoxic EMT6 and CHO320 cells, were observed. Extremes of selectivity are shown ranging from the hypoxia selective 64 Cu(II)ATSM to normoxic cell selective 64 Cu(II)GTS. The selectivities observed are compared with the physico chemical characteristics of the complexes. A good correlation exists between selectivity of the complex and its Cu(II)/Cu(I) reduction potential, with hypoxia

Changes in magnetic properties from solid state to solution in a trinuclear linear copper(II) complex

NARCIS (Netherlands)

Koval, I.A.; Akhideno, H.; Tanase, S.; Belle, C.; Duboc, C.; Saint-Aman, E.; Gamez, P.; Tooke, D.M.; Spek, A.L.; Pierre, J.-L.; Reedijk, J.

2007-01-01

A linear trinuclear copper(II) complex containing phenoxido- and alkoxido-bridges between the metal centers has been isolated and structurally characterized. The complex cation consists of a linear array of three copper ions, assembled by means of two doubly deprotonated ligands. The octahedral

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.

Synthesis, characterization and thermal studies of nickel (II), copper (II), zinc (II) and cadmium (II) complexes with some mixed ligands

International Nuclear Information System (INIS)

Mitra, Samiran; Kundu, Parimal; Singh, Rajkumar Bhubon

1998-01-01

Dichloro-(DCA) and trichloroacetate(TCA) -cyclic ligand morpholine (Morph)/thiomorpholine (Tmorph)/methylmorpholine (Mmorph)/dimethyl-piperazine (DMP) complexes of nickel (II), copper (II), zinc (II) and cadmium (II) with the compositions [Ni(tmorph) 2 (DCA) 2 ], [Ni(tmorph) 2 (TCA) 2 ].2H 2 O, [Cu(DMP) 2 (TCA) 2 ],[ML 2 X 2 ].nH 2 O where M=Zn II or Cd II , L=Morph, DMP or tmorph and X=DCA or TCA and n=O except in case of [Cd (Morph) 2 (TCA) 2 ] where n=1 have been synthesised. Some intermediate complexes have been isolated by temperature arrest technique (pyrolysis) and characterised. Configurational and conformational changes have been studied by elemental analyses, IR and electronic spectra, magnetic moment data (in the case of Ni(II) and Cu(II) complexes) and thermal analysis. E a * , ΔH, and ΔS for the decomposition reaction of these complexes are evaluated and the stability of the complexes with respect to activation energy has also been compared. The linear correlation has been found between E a * and ΔS for the decomposition of the complexes. (author)

XAFS Study of the Ferro- and Antiferromagnetic Binuclear Copper(II) Complexes of Azomethine Based Tridentate Ligands

International Nuclear Information System (INIS)

Vlasenko, Valery G.; Vasilchenko, Igor S.; Shestakova, Tatiana E.; Uraev, Ali I.; Burlov, Anatolii S.; Garnovskii, Alexander D.; Pirog, Irina V.

2007-01-01

Binuclear copper complexes are known to be models for metalloenzymes containing copper active sites, and some of them are of considerable interest due to their magnetic and charge transfer properties. The reactions of the complex formation of bibasic tridentate heterocyclic imines with copper acetate leads to two types of chelates with mono deprotonated ligands and with totally deprotonated ligands. Cu K-edge EXAFS has been applied to determine the local structure around the metal center in copper(II) azomethine complexes with five tridentate ligands: 1-(salycilideneimino)- or 1-(2-tosylaminobenzilideneimino)-2-amino(oxo, thio)benzimidazoles. It has been found that some of the chelates studied are bridged binuclear copper complexes, and others are mononuclear complexes. The copper-copper interatomic distances in the bridged binuclear copper complexes were found to be 2.85-3.01 A. Variable temperature magnetic susceptibility data indicate the presence of both ferromagnetic and antiferromagnetic interactions within the dimer, the former is dominating at low temperatures and the latter at high temperatures

Comparative study of copper(II)-curcumin complexes as superoxide dismutase mimics and free radical scavengers.

Science.gov (United States)

Barik, Atanu; Mishra, Beena; Kunwar, Amit; Kadam, Ramakant M; Shen, Liang; Dutta, Sabari; Padhye, Subhash; Satpati, Ashis K; Zhang, Hong-Yu; Indira Priyadarsini, K

2007-04-01

Two stoichiometrically different copper(II) complexes of curcumin (stoichiometry, 1:1 and 1:2 for copper:curcumin), were examined for their superoxide dismutase (SOD) activity, free radical-scavenging ability and antioxidant potential. Both the complexes are soluble in lipids and DMSO. The formation constants of the complexes were determined by voltammetry. EPR spectra of the complexes in DMSO at 77K showed that the 1:2 Cu(II)-curcumin complex is square planar and the 1:1 Cu(II)-curcumin complex is distorted orthorhombic. Cu(II)-curcumin complex (1:1) with larger distortion from square planar structure shows higher SOD activity. These complexes inhibit gamma-radiation induced lipid peroxidation in liposomes and react with DPPH acting as free radical scavengers. One-electron oxidation of the two complexes by radiolytically generated azide radicals in Tx-100 micellar solutions produced phenoxyl radicals, indicating that the phenolic moiety of curcumin in the complexes participates in free radical reactions. Depending on the structure, these two complexes possess different SOD activities, free radical neutralizing abilities and antioxidant potentials. In addition, quantum chemical calculations with density functional theory have been performed to support the experimental observations.

EXAFS Studies of Some Copper(II) Mixed-Ligand Complexes

International Nuclear Information System (INIS)

Joshi, S. K.; Katare, R. K.; Shrivastava, B. D.

2007-01-01

X-ray K-absorption spectroscopic studies have been carried out on copper (II) mixed-ligand complexes with glutamic acid and aspartic acid as the primary ligands, where as water, pyridine, imidazole and benz-imidazole have been used as secondary ligands. Chemical shifts obtained from the X-ray absorption data have indicated that the glutamic acid complexes are more ionic as compared to their corresponding aspartic acid complexes having similar secondary ligands. Further, we have estimated the average metal-ligand bond distances from the from structure data. For the different complexes studied under the present investigation, the studies reveal that the bonding parameter α1 decreases with the increase in the percentage covalency of the metal-ligand bond. Thus, the bonding parameter α1 may be used for the estimation of percentage covalency of the metal-ligand bond in other similar complexes

Distinctive EPR signals provide an understanding of the affinity of bis-(3-hydroxy-4-pyridinonato) copper(II) complexes for hydrophobic environments.

Science.gov (United States)

Rangel, Maria; Leite, Andreia; Silva, André M N; Moniz, Tânia; Nunes, Ana; Amorim, M João; Queirós, Carla; Cunha-Silva, Luís; Gameiro, Paula; Burgess, John

2014-07-07

In this work we report the synthesis and characterization of a set of 3-hydroxy-4-pyridinone copper(ii) complexes with variable lipophilicity. EPR spectroscopy was used to characterize the structure of copper(ii) complexes in solution, and as a tool to gain insight into solvent interactions. EPR spectra of solutions of the [CuL2] complexes recorded in different solvents reveal the presence of two copper species whose ratio depends on the nature of the solvent. Investigation of EPR spectra in the pure solvents methanol, dimethylsulfoxide, dichloromethane and their 50% (v/v) mixtures with toluene allowed the characterization of two types of copper signals (gzz = 2.30 and gzz = 2.26) whose spin-Hamiltonian parameters are consistent with solvated and non-solvated square-planar copper(ii) complexes. Regarding the potential biological application of ligands and complexes and to get insight into the partition properties in water-membrane interfaces, EPR spectra were also obtained in water-saturated octanol, an aqueous solution buffered at pH = 7.4 and liposome suspensions, for three compounds representative of different hydro-lipophilic balances. Analysis of the EPR spectra obtained in liposomes allowed establishment of the location of the complexes in the water and lipid phases. In view of the results of this work we put forward the use of EPR spectroscopy to assess the affinity of copper(ii) complexes for a hydrophobic environment and also to obtain indirect information about the lipophilicity of the ligands and similar EPR silent complexes.

Synthesis and properties of a trinuclear copper(II) complex with trithiocyanurate bridge

Czech Academy of Sciences Publication Activity Database

Kopel, P.; Čermáková, Š.; Doležal, Karel; Kalińska, B.; Bieńko, A.; Mroziński, J.

2007-01-01

Roč. 81, č. 3 (2007), s. 327-335 ISSN 0137- 5083 Institutional research plan: CEZ:AV0Z50380511 Keywords : copper(II) * trithiocyanuric acid complexes * magnetic properties Subject RIV: CA - Inorganic Chemistry Impact factor: 0.483, year: 2007 http://ichf.edu.pl/pjch/pj-2007/pj-2007-03a.pdf

High stability and biological activity of the copper(II) complexes of alloferon 1 analogues containing tryptophan.

Science.gov (United States)

Kadej, Agnieszka; Kuczer, Mariola; Czarniewska, Elżbieta; Urbański, Arkadiusz; Rosiński, Grzegorz; Kowalik-Jankowska, Teresa

2016-10-01

Copper(II) complex formation processes between the alloferon 1 (Allo1) (HGVSGHGQHGVHG) analogues where the tryptophan residue is introducing in the place His residue H1W, H6W, H9W and H12W have been studied by potentiometric, UV-visible, CD and EPR spectroscopic, and MS methods. For all analogues of alloferon 1 complex speciation have been obtained for a 1:1 metal-to-ligand molar ratio and 2:1 of H1W because of precipitation at higher (2:1, 3:1 and 4:1) ratios. At physiological pH7.4 and a 1:1 metal-to-ligand molar ratio the tryptophan analogues of alloferon 1 form the CuH -1 L and/or CuH -2 L complexes with the 4N binding mode. The introduction of tryptophan in place of histidine residues changes the distribution diagram of the complexes formed with the change of pH and their stability constants compared to the respective substituted alanine analogues of alloferon 1. The CuH -1 L, CuH -2 L and CuH -3 L complexes of the tryptophan analogues are more stable from 1 to 5 log units in comparison to those of the alanine analogues. This stabilization of the complexes may result from cation(Cu(II))-π and indole/imidazole ring interactions. The induction of apoptosis in vivo, in Tenebrio molitor cells by the ligands and their copper(II) complexes at pH7.4 was studied. The biological results show that copper(II) ions in vivo did not cause any apparent apoptotic features. The most active were the H12W peptide and Cu(II)-H12W complex formed at pH7.4. Copyright © 2016 Elsevier Inc. All rights reserved.

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

Stability constants of glutarate complexes of copper(II), zinc(II), cobalt(II) and uranyl(II) by paper electrophoresis

International Nuclear Information System (INIS)

Singh, R.K.P.; Yadava, J.R.; Yadava, K.L.

1981-01-01

Stability constants of Copper(II), Zinc(II), Cobalt(II) and Uranyl(II) glutarates have been determined by paper electrophoresis. Glutaric acid (0.005 mol dmsup(-3)) was added to the background electrolyte : 0.1 mol dmsup(-3) HClO 4 . The proportions of (CH 2 ) 3 COOH COO - and (CH 2 ) 3 C 2 O 4 2- were varied by changing the pH of the electrolyte. These anions yielded the complexes Cu(CH 2 ) 3 C 2 O 4 , [Zn(CH 2 ) 3 COOH COO] + [Co(CH 2 ) 3 COOH COO] + and UO 2 (CH 2 ) 3 C 2 O 4 whose stability constants are found to be 10sup(3.9), 10sup(2.9), 10sup(2.7) and 10sup(13.5) respectively. (author)

A peroxynitrite complex of copper: formation from a copper-nitrosyl complex, transformation to nitrite and exogenous phenol oxidative coupling or nitration.

Science.gov (United States)

Park, Ga Young; Deepalatha, Subramanian; Puiu, Simona C; Lee, Dong-Heon; Mondal, Biplab; Narducci Sarjeant, Amy A; del Rio, Diego; Pau, Monita Y M; Solomon, Edward I; Karlin, Kenneth D

2009-11-01

Reaction of nitrogen monoxide with a copper(I) complex possessing a tridentate alkylamine ligand gives a Cu(I)-(*NO) adduct, which when exposed to dioxygen generates a peroxynitrite (O=NOO(-))-Cu(II) species. This undergoes thermal transformation to produce a copper(II) nitrito (NO(2) (-)) complex and 0.5 mol equiv O(2). In the presence of a substituted phenol, the peroxynitrite complex effects oxidative coupling, whereas addition of chloride ion to dissociate the peroxynitrite moiety instead leads to phenol ortho nitration. Discussions include the structures (including electronic description) of the copper-nitrosyl and copper-peroxynitrite complexes and the formation of the latter, based on density functional theory calculations and accompanying spectroscopic data.

Copper(II) Thiosemicarbazone Complexes and Their Proligands upon UVA Irradiation: An EPR and Spectrophotometric Steady-State Study.

Science.gov (United States)

Hricovíni, Michal; Mazúr, Milan; Sîrbu, Angela; Palamarciuc, Oleg; Arion, Vladimir B; Brezová, Vlasta

2018-03-21

X- and Q-band electron paramagnetic resonance (EPR) spectroscopy was used to characterize polycrystalline Cu(II) complexes that contained sodium 5-sulfonate salicylaldehyde thiosemicarbazones possessing a hydrogen, methyl, ethyl, or phenyl substituent at the terminal nitrogen. The ability of thiosemicarbazone proligands to generate superoxide radical anions and hydroxyl radicals upon their exposure to UVA irradiation in aerated aqueous solutions was evidenced by the EPR spin trapping technique. The UVA irradiation of proligands in neutral or alkaline solutions and dimethylsulfoxide (DMSO) caused a significant decrease in the absorption bands of aldimine and phenolic chromophores. Mixing of proligand solutions with the equimolar amount of copper(II) ions resulted in the formation of 1:1 Cu(II)-to-ligand complex, with the EPR and UV-Vis spectra fully compatible with those obtained for the dissolved Cu(II) thiosemicarbazone complexes. The formation of the complexes fully inhibited the photoinduced generation of reactive oxygen species, and only subtle changes were found in the electronic absorption spectra of the complexes in aqueous and DMSO solutions upon UVA steady-state irradiation. The dark redox activity of copper(II) complexes and proligand/Cu(II) aqueous solutions towards hydrogen peroxide which resulted in the generation of hydroxyl radicals, was confirmed by spin trapping experiments.

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.

EPR studies on binuclear copper(II) complexes with N,N',N'',N'''-tetrakis(2-pyridylmethyl)-1,4,8,11-tetraaza-cyclotetradecane in solutions

International Nuclear Information System (INIS)

Jezierska, J.; Ozarowski, A.; Vuckovic, G.

1997-01-01

Binuclear copper(II) complexes of macrocyclic ligand TMPC (tetraazamacrocycle with four pendant 2-pirydylmethyl groups attached to the ring nitrogen atoms) with various anions forming bridge between copper ions, or coordinating to copper(II) ions at the apex, were prepared and their frozen solutions in DMF and NMF were investigated by EPR. The spectroscopic results have been interpreted in terms of molecular structure of investigated complexes

Synthesis and characterization of nickel(II), cobalt(II), copper(II), manganese(II), zinc(II), zirconium(IV), dioxouranium(VI) and dioxomolybdenum(VI) complexes of a new Schiff base derived from salicylaldehyde and 5-methylpyrazole-3-carbohydrazide

International Nuclear Information System (INIS)

Syamal, A.; Maurya, M.R.

1986-01-01

Synthesis of a new Schiff base derived from salicylaldehyde and 5-methylpyrazole-3-carbohydrazide, and its coordination compounds with nickel(II), cobalt(II), copper(II), manganese(II), zinc(II), zirconium(IV), dioxouranium(VI) and dioxomolybdenum(VI) are described. The ligand and the complexes have been characterized on the basis of analytical, conductance, molecular weight, i.r., electronic and n.m.r. spectra and magnetic susceptibility measurements. The stoichiometries of the complexes are represented as NiL . 3H 2 O, CoL . 2H 2 O, CuL, MnL . 2H 2 O, ZnL . H 2 O, Zr(OH) 2 (LH) 2 , Zr(OH) 2 L . 2MeOH, UO 2 L . MeOH and MoO 2 L . MeOH (where LH 2 =Schiff base). The copper(II) complex shows a subnormal magnetic moment due to antiferromagnetic exchange interaction while the nickel(II), cobalt(II) and manganese(II) complexes show normal magnetic moments at room temperature. The i.r. and n.m.r. spectral studies show that the Schiff base behaves as a dibasic and tridentate ligand coordinating through the deprotonated phenolic oxygen, enolic oxygen and azomethine nitrogen. (orig.)

(II) COMPLEX COMPOUND

African Journals Online (AJOL)

user

electrochemical sensors, as well as in various chromatographic ... were carried out using Jenway pH meter Model 3320 and a conductivity ... Figure 1: the proposed molecular structure of the copper (II) Schiff base complex. M = Cu (II) or Mn (II).

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.

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.

Antimicrobial and mutagenic activity of some carbono- and thiocarbonohydrazone ligands and their copper(II), iron(II) and zinc(II) complexes.

Science.gov (United States)

Bacchi, A; Carcelli, M; Pelagatti, P; Pelizzi, C; Pelizzi, G; Zani, F

1999-06-15

Several mono- and bis- carbono- and thiocarbonohydrazone ligands have been synthesised and characterised; the X-ray diffraction analysis of bis(phenyl 2-pyridyl ketone) thiocarbonohydrazone is reported. The coordinating properties of the ligands have been studied towards Cu(II), Fe(II), and Zn(II) salts. The ligands and the metal complexes were tested in vitro against Gram positive and Gram negative bacteria, yeasts and moulds. In general, the bisthiocarbonohydrazones possess the best antimicrobial properties and Gram positive bacteria are the most sensitive microorganisms. Bis(ethyl 2-pyridyl ketone) thiocarbonohydrazone, bis(butyl 2-pyridyl ketone)thiocarbonohydrazone and Cu(H2nft)Cl2 (H2nft, bis(5-nitrofuraldehyde)thiocarbonohydrazone) reveal a strong activity with minimum inhibitory concentrations of 0.7 microgram ml-1 against Bacillus subtilis and of 3 micrograms ml-1 against Staphylococcus aureus. Cu(II) complexes are more effective than Fe(II) and Zn(II) ones. All bisthiocarbono- and carbonohydrazones are devoid of mutagenic properties, with the exception of the compounds derived from 5-nitrofuraldehyde. On the contrary a weak mutagenicity, that disappears in the copper complexes, is exhibited by monosubstituted thiocarbonohydrazones.

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

Indian Academy of Sciences (India)

Copper; X-ray structure; radical activity; catechol oxidase activity. 1. Introduction ... dylamine and thiocyanate ions but none of these groups .... Independent reflections. 7978 ... was added to it to achieve the ultimate concentration of .... as exchange couples so as to form a single species with ... cantly on central Cu(II) ion.

Synthesis, crystal structure and excellent photoluminescence properties of copper (II and cobalt (II complexes with Bis(1[(4-butylphenylimino]methyl naphthalen-2-ol Schiff base

Directory of Open Access Journals (Sweden)

V.B. Nagaveni

2018-03-01

Full Text Available Copper (II and Cobalt (II metal complexes (4a- and 4b-complexes using Schiff base ligand 1-[(4-butylphenylimino]methyl naphthalen-2-ol (3 have been synthesized. The single crystals of Copper (II and Cobalt (II complex phosphors were grown and characterized by Fourier-Transform Infrared (FT-IR, single crystal X-ray diffraction (XRD, SEM (Scanning Electron Microscope and EDS (Energy Dispersive X-ray spectroscopy. Photoluminescence study of the phosphors revealed the presence of excitation peaks at 333 nm and 360 nm for 4a-complex (λemi = 495 nm and excitation peaks at 300 nm and 360 nm for 4b-complex (λemi = 496 nm. The calculated CCT values of the complexes pointed out that these materials can be used to obtain cold white light from the light emitting devices. Diffuse reflectance spectra (DRS showed the measured band gap energies of 1.78 eV and 1.44 eV for Cu (II and Co (II complexes, respectively. It is concluded that the 4a- and 4b-complexes become white and blue green light emitting diodes respectively and will be useful in the development of strong electroluminescent materials. Keywords: 1[(4-butylphenylimino]methylnaphthalen-2-ol, Schiff base, Cu (II and Co (IIcomplex, Photoluminescence, Single crystal XRD, OLED

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.

Steric Effects on the Binding of Phosphate and Polyphosphate Anions by Zinc(II) and Copper(II) Dinuclear Complexes of m-Xylyl-bis-cyclen.

Science.gov (United States)

Esteves, Catarina V; Esteban-Gómez, David; Platas-Iglesias, Carlos; Tripier, Raphaël; Delgado, Rita

2018-05-11

The triethylbenzene-bis-cyclen (cyclen = 1,4,7,10-tetraazacyclododecane) compound (tbmce) was designed with an imposed structural rigidity at the m-xylyl spacer to be compared to a less restrained and known parent compound (bmce). The framework of both compounds differs only in the substituents of the m-xylyl spacer. The study was centered in the differences observed in the acid-base reactions of both compounds, their copper(II) and zinc(II) complexation behaviors, as well as in the uptake of phosphate and polyphosphate anions (HPPi 3- , ATP 4- , ADP 3- , AMP 2- , PhPO 4 2- , and HPO 4 2- ). On the one hand, the acid-base reactions showed lower values for the third and fourth protonation constants of tbmce than for bmce, suggesting that the ethyl groups of the spacer in tbmce force the two cyclen units to more conformational restricted positions. On the other hand, the stability constant values for copper(II) and zinc(II) complexes revealed that bmce is a better chelator than tbmce pointing out to additional conformational restraints imposed by the triethylbenzene spacer. The binding studies of phosphates by the dinuclear copper(II) and zinc(II) complexes showed much smaller effective association constants for the dicopper complexes. Single-crystal X-ray and computational (density functional theory) studies suggest that anion binding promotes the formation of tetranuclear entities in which anions are bridging the metal centers. Our studies also revealed the dinuclear zinc(II) complex of bmce as a promising receptor for phosphate anions, with the largest effective association constant of 5.94 log units being observed for the formation of [Zn 2 bmce(HPPi)] + . Accordingly, a colorimetric study via an indicator displacement assay to detect phosphates in aqueous solution found that the [Zn 2 bmce] 4+ complex acts as the best receptor for pyrophosphate displaying a detection limit of 2.5 nM by changes visible to naked eye.

Standard molar enthalpies of formation of copper(II) β-diketonates and monothio-β-diketonates

International Nuclear Information System (INIS)

Ribeiro da Silva, Manuel A.V.; Santos, Luis M.N.B.F.

2006-01-01

The standard (p o =0.1MPa) molar enthalpies of formation of the crystalline complexes of dibenzoylmethane (Hdbm), thenoyltrifluoroacetone (Httfa), monothiodibenzoylmethane (HdbmS), and monothiothenoyltrifluoroacetone (HttfaS) of copper(II) were determined, at T=298.15K, by high precision solution-reaction calorimetry. The standard molar enthalpies of sublimation of the copper(II) β-diketonate complexes were measured by high-temperature Calvet microcalorimetry. From the standard molar enthalpies of formation of the complexes in the gaseous state, the mean molar dissociation enthalpies copper(II)-ligand, m >(Cu-L), were derived. Δ f H m o (cr)Δ cr g H m o kJ.mol -1 kJ.mol -1 Bis(dibenzoylmethanate)copper(II), Cu(dbm) 2 -364.0+/-3.9230.7+/-8.2Bis(thenoyltrifluoroacetonate)copper(II), Cu(ttfa) 2 -1824.3+/-8.3167.9+/-7.4Bis(monothiodibenzoylmethanate)copper(II), Cu(dbmS) 2 35.6+/-7.7[241+/-15]Bis(monothiothenoyltrifluoroacetonate) copper(II), Cu(ttfaS) 2 -1405.7+/-8.3[177+/-15

Interpretation of the Electron Paramagnetic Resonance Spectra of Copper(II)-Tyrosine Complex

Science.gov (United States)

Xu, Xiao-Hui; Kuang, Min-Quan

2017-12-01

The electron paramagnetic resonance (EPR) spectra of [Cu(l-tyrosine)2]n (CuA) were interpreted based on the fourth-order perturbation treatments where the contributions due to the local distortion, ligand orbit and spin-orbit coupling were included. The calculated band transitions d_{x^2} - y^2 to dxy (≈16412 cm-1) and d_{z^2} (≈14845 cm-1) agree well with the band analysis results (d_{x^2} - y^2 \\to d_{xy} ≈16410 and d_{x^2} - y^2 \\to d_{z^2} ≈14850 cm-1). The unresolved separations d_{x^2} - y^2 \\to d_{xz} and d_{x^2} - y^2 \\to d_{yz} in the absorption spectra were evaluated as 26283 and 26262 cm-1, respectively. For CuA, copper chromophores in 1,3-diaminorpropane isophtalate copper(II) complex (CuB) and N-methyl-1,2-diaminoetaane-bis copper(II) polymer (CuC), the transition d_{x^2} - y^2 \\to d_{xy} (=E1≈10Dq) suffered an increase with a decrease in R̅L which was evaluated as the mean value of the copper-ligand bond lengths. The correlations between the tetragonal elongation ratio ρ (=(Rz-R̅L)/R̅L) (or the ratio G=(gz-ge)/((gx+gy)/2-ge)) and the g isotropy gav (=(gx+gy+gz)/3) (or the covalency factor N) for CuA, CuB and CuC were acquired and all the results were discussed.

Synthesis, Characterization and DNA Cleavage of Copper(II ...

African Journals Online (AJOL)

Purpose: To study deoxyribonucleic acid (DNA) shearing capability of copper(II) complex of dithiothreitol (DTT) and to fevaluate its potential application in cancer therapy. Methods: A parrot green complex was synthesized by grinding copper acetate monohydrate and DTT in 1:2 molar ratio in a mortar until no fumes of acetic ...

Antimicrobial mechanism of copper (II 1,10-phenanthroline and 2,2′-bipyridyl complex on bacterial and fungal pathogens

Directory of Open Access Journals (Sweden)

S. Chandraleka

2014-12-01

Full Text Available Copper based metallo drugs were prepared and their antibacterial, antifungal, molecular mechanism of [Cu(SAlaPhen]·H2O and [Cu(SAlabpy]·H2O complexes were investigated. The [Cu(SAlaPhen]·H2O and [Cu(SAlabpy]·H2O were derived from the Schiff base alanine salicylaldehyde. [Cu(SAlaPhen]·H2O showed noteworthy antibacterial and antifungal activity than the [Cu(SAlabpy]·H2O and ligand alanine, salicylaldehyde. The [Cu(SAlaPhen]·H2O complex showed significant antibacterial activity against Salmonella typhi, Staphylococcus aureus, Salmonella paratyphi and the antifungal activity against Candida albicans and Cryptococcus neoformans in well diffusion assay. The mode of action of copper (II complex was analyzed by DNA cleavage activity and in silico molecular docking. The present findings provide important insight into the molecular mechanism of copper (II complexes in susceptible bacterial and fungal pathogens. These results collectively support the use of [Cu(SAlaPhen]·H2O complex as a suitable drug to treat bacterial and fungal infections.

Halogen-bonded network of trinuclear copper(II 4-iodopyrazolate complexes formed by mutual breakdown of chloroform and nanojars

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Stuart A. Surmann

2016-11-01

Full Text Available Crystals of bis(tetrabutylammonium di-μ3-chlorido-tris(μ2-4-iodopyrazolato-κ2N:N′tris[chloridocuprate(II] 1,4-dioxane hemisolvate, (C16H36N2[Cu3(C3H2IN23Cl5]·0.5C4H8O or (Bu4N2[CuII3(μ3-Cl2(μ-4-I-pz3Cl3]·0.5C4H8O, were obtained by evaporating a solution of (Bu4N2[{CuII(μ-OH(μ-4-I-pz}nCO3] (n = 27–31 nanojars in chloroform/1,4-dioxane. The decomposition of chloroform in the presence of oxygen and moisture provides HCl, which leads to the breakdown of nanojars to the title trinuclear copper(II pyrazolate complex, and possibly CuII ions and free 4-iodopyrazole. CuII ions, in turn, act as catalyst for the accelerated decomposition of chloroform, ultimately leading to the complete breakdown of nanojars. The crystal structure presented here provides the first structural description of a trinuclear copper(II pyrazolate complex with iodine-substituted pyrazoles. In contrast to related trinuclear complexes based on differently substituted 4-R-pyrazoles (R = H, Cl, Br, Me, the [Cu3(μ-4-I-pz3Cl3] core in the title complex is nearly planar. This difference is likely a result of the presence of the iodine substituent, which provides a unique, novel feature in copper pyrazolate chemistry. Thus, the iodine atoms form halogen bonds with the terminal chlorido ligands of the surrounding complexes [mean length of I...Cl contacts = 3.48 (1 Å], leading to an extended two-dimensional, halogen-bonded network along (-110. The cavities within this framework are filled by centrosymmetric 1,4-dioxane solvent molecules, which create further bridges via C—H...Cl hydrogen bonds with terminal chlorido ligands of the trinuclear complex not involved in halogen bonding.

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.

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

The oxidation of phenol, cychohexanol and hydroquinone has been screened in the presence of copper(II) complexes with the Schiff‐base salen ligand, 1,5‐bis[(E)‐5‐chloro‐2‐hydroxybenzylideneamino]‐1H‐imidazole‐4‐carbonitrile, and encapsulated into NaY zeolite by using two different methods. The new...

Standard molar enthalpies of formation of copper(II) {beta}-diketonates and monothio-{beta}-diketonates

Energy Technology Data Exchange (ETDEWEB)

Ribeiro da Silva, Manuel A.V. [Centro de Investigacao em Quimica, Departamento de Quimica, Faculdade de Ciencias, Universidade do Porto, Rua do Campo Alegre, 687, P-4169-007 Porto (Portugal)]. E-mail: risilva@fc.up.pt; Santos, Luis M.N.B.F. [Centro de Investigacao em Quimica, Departamento de Quimica, Faculdade de Ciencias, Universidade do Porto, Rua do Campo Alegre, 687, P-4169-007 Porto (Portugal)

2006-07-15

The standard (p{sup o}=0.1MPa) molar enthalpies of formation of the crystalline complexes of dibenzoylmethane (Hdbm), thenoyltrifluoroacetone (Httfa), monothiodibenzoylmethane (HdbmS), and monothiothenoyltrifluoroacetone (HttfaS) of copper(II) were determined, at T=298.15K, by high precision solution-reaction calorimetry. The standard molar enthalpies of sublimation of the copper(II) {beta}-diketonate complexes were measured by high-temperature Calvet microcalorimetry. From the standard molar enthalpies of formation of the complexes in the gaseous state, the mean molar dissociation enthalpies copper(II)-ligand, (Cu-L), were derived. {delta}{sub f}H{sub m}{sup o} (cr){delta}{sub cr}{sup g}H{sub m}{sup o} kJ.mol{sup -1}kJ.mol{sup -1}Bis(dibenzoylmethanate)copper(II), Cu(dbm){sub 2}-364.0+/-3.9230.7+/-8.2Bis(thenoyltrifluoroacetonate)copper(II), Cu(ttfa){sub 2}-1824.3+/-8.3167.9+/-7.4Bis(monothiodibenzoylmethanate)copper(II), Cu(dbmS){sub 2}35.6+/-7.7[241+/-15]Bis(monothiothenoyltrifluoroacetonate) copper(II), Cu(ttfaS){sub 2}-1405.7+/-8.3[177+/-15].

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.

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.

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

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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.

Ni (II) and Cu(II) complexes of

African Journals Online (AJOL)

ADOWIE PERE

ABSTRACT: The objective of this study is to investigate the antimicrobial activity of novel. Schiff base metal complexes. The resistance of micro-organisms to classical antimicrobial compounds poses a challenge to effective management and treatment of some diseases. In line with this, copper (II), nickel (II) and cobalt (II) ...

Copper (II) and zinc (II) complexes with flavanone derivatives: Identification of potential cholinesterase inhibitors by on-flow assays.

Science.gov (United States)

Sarria, André Lucio Franceschini; Vilela, Adriana Ferreira Lopes; Frugeri, Bárbara Mammana; Fernandes, João Batista; Carlos, Rose Maria; da Silva, Maria Fátima das Graças Fernandes; Cass, Quezia Bezerra; Cardoso, Carmen Lúcia

2016-11-01

Metal chelates strongly influence the nature and magnitude of pharmacological activities in flavonoids. In recent years, studies have shown that a promising class of flavanone-metal ion complexes can act as selective cholinesterase inhibitors (ChEIs), which has led our group to synthesize a new series of flavanone derivatives (hesperidin, hesperetin, naringin, and naringenin) complexed to either copper (II) or zinc (II) and to evaluate their potential use as selective ChEIs. Most of the synthesized complexes exhibited greater inhibitory activity against acetylcholinesterase (AChE) than against butyrylcholinesterase (BChE). Nine of these complexes constituted potent, reversible, and selective ChEIs with inhibitory potency (IC 50 ) and inhibitory constant (K i ) ranging from 0.02 to 4.5μM. Copper complexes with flavanone-bipyridine derivatives afforded the best inhibitory activity against AChE and BChE. The complex Cu(naringin)(2,2'-bipyridine) (11) gave IC 50 and K i values of 0.012±0.002 and 0.07±0.01μM for huAChE, respectively, which were lower than the inhibitory values obtained for standard galanthamine (IC 50 =206±30.0 and K i =126±18.0μM). Evaluation of the inhibitory activity of this complex against butyrylcholinesterase from human serum (huBChE) gave IC 50 and K i values of 8.0±1.4 and 2.0±0.1μM, respectively. A Liquid Chromatography-Immobilized Capillary Enzyme Reactor by UV detection (LC-ICER-UV) assay allowed us to determine the IC 50 and K i values and the type of mechanism for the best inhibitors. Copyright © 2016 Elsevier Inc. All rights reserved.

Copper complexes as chemical nucleases

Indian Academy of Sciences (India)

Unknown

anticancer drug famotidine has been shown as a better catalyst than CuCl2 for sulfite ... Effect of addition of bis-chelate copper(II) complexes (dpq, •; phen, ; ..... Reproduction, Development & Genetics for their help in the DNA cleavage studies ...

Antibacterial activity of nicotine and its copper complex

International Nuclear Information System (INIS)

Zaidi, M.I.; Gul, A.

2005-01-01

Nicotine and its metal complex; Cu(II)-nicotine was isolated from leaves of Nicotiana tabacum using metal ions following the method of Munir et al., 1994. Their antibacterial activity against ten different species of gram positive and gram negative bacteria were studied. For comparative study, pure sample of nicotine and metal salts used for complexation; Copper(II) chloride were also subjected to antibacterial tests with the same species of bacteria under similar conditions. Results indicated that nicotine had no effect on all the bacteria tested except Escherichia coli, Pseudomonas aeroginosa and Enterococcus faecalis, which showed 14 mm zone of inhibition at 200 mu g l00 mul/sup -1/ Copper(II) chloride was found to be effective against seven species and ineffective against three species of selected bacteria. On the other hand, Cu(II)-nicotine complex was ineffective against five species of bacteria at lower level while at higher level, only one species of bacteria showed resistance against this complex. The complex was compared with three standard antibiotics. Thus, this complex can be used against a variety of microorganisms at higher level. (author)

Template Synthesis, Crystal Structure, and Magnetic Properties of a Dinuclear Copper(II) Complex with Cooperative Hydrogen Bonding

International Nuclear Information System (INIS)

Kang, Shin Geol; Nam, Kwang Hee; Min, Kil Sik; Lee, Uk

2011-01-01

The dinuclear complex with cooperative hydrogen bonds can be prepared by the metal-directed reaction of Eq. This work shows that the coordinated hydroxyl group trans to the secondary amino group is deprotonated more readily than that trans to the tertiary amino group and acts as the hydrogen-bond accepter. The lattice water molecules in act as bridges between the two mononuclear units through hydrogen bonds. The complex is quite stable as the dimeric form even in various polar solvents. The complex exhibits a weak antiferromagnetic interaction between the metal ions in spite of relatively long Cu···Cu distance. This strongly supports the suggestion that the antiferromagnetic behavior is closely related to the cooperative hydrogen bonds. The design and synthesis of polynuclear transition metal complexes have received much attention because of their potential applications in various fields, such as catalysis, supramolecular chemistry, and materials chemistry. Until now, various types of dinuclear copper(II) complexes have been prepared and investigated. Some dinuclear copper(II) complexes resulting from cooperative hydrogen bonding, such as containing two N_2O_2 donor sets, are also reported

Bis[2-(cyclopentyliminomethyl-5-methoxyphenolato]copper(II

Directory of Open Access Journals (Sweden)

Xiao-Hui Ji

2010-08-01

Full Text Available The title compound, [Cu(C13H16NO22], is a mononuclear copper(II complex derived from the Schiff base ligand 2-(cyclopentyliminomethyl-5-methoxyphenol and copper acetate. The CuII atom is four-coordinated by the phenolate O atoms and imine N atoms from two Schiff base ligands, in a highly distorted square-planar geometry. The O- and N-donor atoms are mutually trans and the dihedral angle between the two benzene rings is 55.8 (3°.

Synthesis, molecular docking and DNA binding studies of phthalimide-based copper(II) complex: In vitro antibacterial, hemolytic and antioxidant assessment

Science.gov (United States)

Arif, Rizwan; Nayab, Pattan Sirajuddin; Ansari, Istikhar A.; Shahid, M.; Irfan, Mohammad; Alam, Shadab; Abid, Mohammad; Rahisuddin

2018-05-01

In the present research work, we prepared N-substituted phthalimide, 2-(-(2-(2-(2-(1,3-dioxoisoindoline-2-yl-ethylamino)ethylamino)ethyl)isoindoline-1,3-dione (DEEI) and its copper(II) complex. The ligand (DEEI) and its Cu(II) complex were structurally identified using absorption, FTIR, NMR, electron spin resonance, X-ray diffraction spectral studies, thermogravimetric and elemental analyses. The electronic spectrum and magnetic moment value proposed that Cu(II) complex has square planar geometry. The DNA interaction ability of the ligand (DEEI) and Cu(II) complex was studied by means of absorption and fluorescence spectrophotometer, viscosity measurements, cyclic voltammetery, and circular dichroism methods. The extent of DNA binding (Kb) with Calf thymus (Ct-DNA) follows the order of Cu(II) complex (1.11 × 106 M-1) > DEEI (1.0 × 105 M-1), indicating that Cu(II) complex interact with Ct-DNA through groove binding mode and more sturdily than ligand (DEEI). Interestingly, in silico predictions were corroborated with in vitro DNA binding studies. The antibacterial evaluation of these compounds was screened against a panel of bacterial strains Pseudomonas aeruginosa (MTCC 2453), Salmonella enterica (MTCC 3224), Streptococcus pneumoniae (MTCC 655), Enterococcus faecalis (MTCC 439), Klebsiella pneumonia and Escherichia coli (ATCC 25922). The results showed that the copper(II) complex has significant antibacterial potential (IC50 = 0.0019 μg/mL) against Salmonella enteric comparable with ligand (DEEI) and standard drug ciprofloxacin. Growth curve study of Cu(II) complex against only three bacterial strains S. enterica, E. faecalis and S. pneumoniae showed its bactericidal nature. Cu(II) complex showed less than 2% hemolysis on human RBCs indicating its non toxic nature. The results of antioxidant assay demonstrated that scavenging activity of Cu(II) complex is higher as compared to ligand and ascorbic acid as standard.

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.

Luminescent zinc(ii) and copper(i) complexes for high-performance solution-processed monochromic and white organic light-emitting devices.

Science.gov (United States)

Cheng, Gang; So, Gary Kwok-Ming; To, Wai-Pong; Chen, Yong; Kwok, Chi-Chung; Ma, Chensheng; Guan, Xiangguo; Chang, Xiaoyong; Kwok, Wai-Ming; Che, Chi-Ming

2015-08-01

The synthesis and spectroscopic properties of luminescent tetranuclear zinc(ii) complexes of substituted 7-azaindoles and a series of luminescent copper(i) complexes containing 7,8-bis(diphenylphosphino)-7,8-dicarba- nido -undecaborate ligand are described. These complexes are stable towards air and moisture. Thin film samples of the luminescent copper(i) complexes in 2,6-dicarbazolo-1,5-pyridine and zinc(ii) complexes in poly(methyl methacrylate) showed emission quantum yields of up to 0.60 (for Cu-3 ) and 0.96 (for Zn-1 ), respectively. Their photophysical properties were examined by ultrafast time-resolved emission spectroscopy, temperature dependent emission lifetime measurements and density functional theory calculations. Monochromic blue and orange solution-processed OLEDs with these Zn(ii) and Cu(i) complexes as light-emitting dopants have been fabricated, respectively. Maximum external quantum efficiency (EQE) of 5.55% and Commission Internationale de l'Eclairage (CIE) coordinates of (0.16, 0.19) were accomplished with the optimized Zn-1 -OLED while these values were, respectively 15.64% and (0.48, 0.51) for the optimized Cu-3 -OLED. Solution-processed white OLEDs having maximum EQE of 6.88%, CIE coordinates of (0.42, 0.44), and colour rendering index of 81 were fabricated by using these luminescent Zn(ii) and Cu(i) complexes as blue and orange light-emitting dopant materials, respectively.

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.

Adsorption of lead(II) and copper(II) on activated carbon by complexation with surface functional groups

International Nuclear Information System (INIS)

Pesavento, Maria; Profumo, Antonella; Alberti, Giancarla; Conti, Fabio

2003-01-01

The adsorption of lead(II) and copper(II) on an activated carbon (Filtrasorb 300, Chemviron) was characterized assuming that it takes place by formation of complexes with functional groups, present in the activated carbon. Their concentration and conditional adsorption coefficients were determined for each metal by titration of the carbon in suspension in aqueous phase, at constant acidity, with the metal itself. For each titration point, the concentration of the metal in the solution phase after equilibration was determined, and the data were processed by the Ruzic linearization method, to obtain the concentration of the active sites involved in the sorption, and the conditional constant. The effect of the pH was also examined, in the range 4-6, obtaining that the adsorption increases at increasing pH. The protonation and adsorption constants were determined from the conditional adsorption coefficients obtained at the different acidities. The concentration of the active sites is 0.023 and 0.042 mmol g -1 , and the protonation constants are 1.0x10 6 and 4.6x10 4 M -1 for Pb(II) and Cu(II). The corresponding adsorption constants are respectively 1.4x10 5 and 6.3x10 3 M -1 . All the parameters are affected by a large uncertainty, probably due to the heterogeneity of the active groups in the activated carbon. Even if so, these parameters make it possible a good prediction of the adsorption in a wide range of conditions. Other sorption mechanism can be set up at different conditions, in particular at different pH, as it has been demonstrated in the case of copper(II)

Adsorption of lead(II) and copper(II) on activated carbon by complexation with surface functional groups

Energy Technology Data Exchange (ETDEWEB)

Pesavento, Maria; Profumo, Antonella; Alberti, Giancarla; Conti, Fabio

2003-03-17

The adsorption of lead(II) and copper(II) on an activated carbon (Filtrasorb 300, Chemviron) was characterized assuming that it takes place by formation of complexes with functional groups, present in the activated carbon. Their concentration and conditional adsorption coefficients were determined for each metal by titration of the carbon in suspension in aqueous phase, at constant acidity, with the metal itself. For each titration point, the concentration of the metal in the solution phase after equilibration was determined, and the data were processed by the Ruzic linearization method, to obtain the concentration of the active sites involved in the sorption, and the conditional constant. The effect of the pH was also examined, in the range 4-6, obtaining that the adsorption increases at increasing pH. The protonation and adsorption constants were determined from the conditional adsorption coefficients obtained at the different acidities. The concentration of the active sites is 0.023 and 0.042 mmol g{sup -1}, and the protonation constants are 1.0x10{sup 6} and 4.6x10{sup 4} M{sup -1} for Pb(II) and Cu(II). The corresponding adsorption constants are respectively 1.4x10{sup 5} and 6.3x10{sup 3} M{sup -1}. All the parameters are affected by a large uncertainty, probably due to the heterogeneity of the active groups in the activated carbon. Even if so, these parameters make it possible a good prediction of the adsorption in a wide range of conditions. Other sorption mechanism can be set up at different conditions, in particular at different pH, as it has been demonstrated in the case of copper(II)

potentiometric studies of the complexes formed by copper (ii) and zinc

African Journals Online (AJOL)

MBI

, P. M. B. 3011, Kano, Nigeria e-mail: jnaaliya@yahoo.com. ABSTRACT. The overall stability constants of copper (II) and zinc (II) ions with some polar uncharged amino acids including proline, threonine and asparagines were determined by ...

Synthesis, X-ray crystal structures, and phosphate ester cleavage properties of bis(2-pyridylmethyl)amine copper(II) complexes with guanidinium pendant groups.

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Belousoff, Matthew J; Tjioe, Linda; Graham, Bim; Spiccia, Leone

2008-10-06

Three new derivatives of bis(2-pyridylmethyl)amine (DPA) featuring ethylguanidinium (L (1)), propylguanidinium (L (2)), or butylguanidinium (L (3)) pendant groups have been prepared by the reaction of N, N- bis(2-pyridylmethyl)alkane-alpha,omega-diamines with 1 H-pyrazole-1-carboxamidine hydrochloride. The corresponding mononuclear copper(II) complexes were prepared by reacting the ligands with copper(II) nitrate and were isolated as [Cu(LH (+))(OH 2)](ClO 4) 3. xNaClO 4. yH 2O ( C1: L = L (1), x = 2, y = 3; C2: L = L (2), x = 2, y = 4; C3: L = L (3), x = 1, y = 0) following cation exchange purification. Recrystallization yielded crystals of composition [Cu(LH (+))(X)](ClO 4) 3.X ( C1': L = L (1), X = MeOH; C2': L = L (2), X = H 2O; C3': L = L (3), X = H 2O), which were suitable for X-ray crystallography. The crystal structures of C1', C2', and C3' indicate that the DPA moieties of the ligands coordinate to the copper(II) centers in a meridional fashion, with a water or methanol molecule occupying the fourth basal position. Weakly bound perchlorate anions located in the axial positions complete the distorted octahedral coordination spheres. The noncoordinating, monoprotonated guanidinium groups project away from the Cu(II)-DPA units and are involved in extensive charge-assisted hydrogen-bonding interactions with cocrystallized water/methanol molecules and perchlorate anions within the crystal lattices. The copper(II) complexes were tested for their ability to promote the cleavage of two model phosphodiesters, bis( p-nitrophenyl)phosphate (BNPP) and uridine-3'- p-nitrophenylphosphate (UpNP), as well as supercoiled plasmid DNA (pBR 322). While the presence of the guanidine pendants was found to be detrimental to BNPP cleavage efficiency, the functionalized complexes were found to cleave plasmid DNA and, in some cases, the model ribose phosphate diester, UpNP, at a faster rate than the parent copper(II) complex of DPA.

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

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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.

Synthesis, characterization, and antimicrobial activity of silver(I) and copper(II) complexes of phosphate derivatives of pyridine and benzimidazole.

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Kalinowska-Lis, Urszula; Szewczyk, Eligia M; Chęcińska, Lilianna; Wojciechowski, Jakub M; Wolf, Wojciech M; Ochocki, Justyn

2014-01-01

Two silver(I) complexes--[Ag(4-pmOpe)]NO₃}(n) and [Ag(2-bimOpe)₂]NO₃--and three copper(II) complexes--[Cu₄Cl₆O(2-bimOpe)₄], [CuCl₂(4-pmOpe)₂], and [CuCl₂(2-bis(pm)Ope]--were synthesized by reaction of silver(I) nitrate or copper(II) chloride with phosphate derivatives of pyridine and benzimidazole, namely diethyl (pyridin-4-ylmethyl)phosphate (4-pmOpe), 1H-benzimidazol-2-ylmethyl diethyl phosphate (2-bimOpe), and ethyl bis(pyridin-2-ylmethyl)phosphate (2-bis(pm)Ope). These compounds were characterized by ¹H, ¹³C, and ³¹P NMR as well as IR spectroscopy, elemental analysis, and ESIMS spectrometry. Additionally, molecular and crystal structures of {[Ag(4-pmOpe)]NO₃}n and [Cu₄Cl₆O(2-bimOpe)₄] were determined by single-crystal X-ray diffraction analysis. The antimicrobial profiles of synthesized complexes and free ligands against test organisms from the ATCC and clinical sources were determined. Silver(I) complexes showed good antimicrobial activities against Candida albicans strains (MIC values of ∼19 μM). [Ag(2-bimOpe)₂]NO₃ was particularly active against Pseudomonas aeruginosa and methicillin-resistant Staphylococcus epidermidis, with MIC values of ∼5 and ∼10 μM, respectively. Neither copper(II) complexes nor the free ligands inhibited the growth of test organisms at concentrations below 500 μg mL⁻¹. Copyright © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Fluorescence-based detection of nitric oxide in aqueous and methanol media using a copper(II) complex.

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Mondal, Biplab; Kumar, Pankaj; Ghosh, Pokhraj; Kalita, Apurba

2011-03-14

The quenched fluorescent intensity of a copper(II) complex, 1, of a fluorescent ligand, in degassed methanol or aqueous (buffered at pH 7.2) solution, was found to reappear on exposure to nitric oxide. Thus, it can function as a fluorescence based nitric oxide sensor. It has been found that the present complex can be used to sense nanomolar quantities of nitric oxide in both methanol and pH 7.2 buffered-water medium.

Drastic Effect of the Peptide Sequence on the Copper-Binding Properties of Tripeptides and the Electrochemical Behaviour of Their Copper(II) Complexes.

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Mena, Silvia; Mirats, Andrea; Caballero, Ana B; Guirado, Gonzalo; Barrios, Leoní A; Teat, Simon J; Rodriguez-Santiago, Luis; Sodupe, Mariona; Gamez, Patrick

2018-04-06

The binding and electrochemical properties of the complexes Cu II -HAH, Cu II -HWH, Cu II -Ac-HWH, Cu II -HHW, and Cu II -WHH have been studied by using NMR and UV/Vis spectroscopies, CV, and density functional calculations. The results obtained highlight the importance of the peptidic sequence on the coordination properties and, consequently, on the redox properties of their Cu II complexes. For Cu II -HAH and Cu II -HWH, no cathodic processes are observed up to -1.2 V; that is, the complexes exhibit very high stability towards copper reduction. This behaviour is associated with the formation of very stable square-planar (5,5,6)-membered chelate rings (ATCUN motif), which enclose two deprotonated amides. In contrast, for non-ATCUN Cu II -Ac-HWH, Cu II -HHW complexes, simulations seem to indicate that only one deprotonated amide is enclosed in the coordination sphere. In these cases, the main electrochemical feature is a reductive irreversible one electron-transfer process from Cu II to Cu I , accompanied with structural changes of the metal coordination sphere and reprotonation of the amide. Finally, for Cu II -WHH, two major species have been detected: one at low pH (10) with an ATCUN motif, both species coexisting at intermediate pH. The present study shows that the use of CV, using glassy carbon as a working electrode, is an ideal and rapid tool for the determination of the redox properties of Cu II metallopeptides. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

A novel aggregation induced emission active cyclometalated Ir(III) complex as a luminescent probe for detection of copper(II) ion in aqueous solution

Energy Technology Data Exchange (ETDEWEB)

Shen, Wei; Yan, Liqiang; Tian, Wenwen; Cui, Xia; Qi, Zhengjian, E-mail: qizhengjian@seu.edu.cn; Sun, Yueming, E-mail: sun@seu.edu.cn

2016-09-15

We report the synthesis and characterization of a novel aggregation induced emission (AIE) active cyclometalated Ir(III) complex, namely [Ir(dfppy){sub 2}(phen-DPA)]PF{sub 6}, where dfppy and phen-DPA represent 2-(2,4-difluorophenyl)pyridine and 2-(bis(pyridin-2-ylmethyl)amino)-N-(1,10-phenanthrolin-5-yl)acetamide, respectively. The complex showed remarkable selectivity for copper(II) in aqueous solution over other competitive ions. Furthermore, this sensor showed a rapid and reversible response to copper(II) in aqueous solution with a detection limit of 65 nM.

Synthesis, physico-chemical characterization and biological activity of copper(ii and nickel(ii complexes with l-benzoyl-2-methylbenzimidazole derivatives

Directory of Open Access Journals (Sweden)

Podunavac-Kuzmanović Sanja O.

2002-01-01

Full Text Available Chlorides of copper(II and nickel(ll react with 1-benzoyl-2-methylbenzimidazole or 1-(4-chlorobenzoyl-2-methylbenzimidazole to give complexes of the type [M(LnCln(H20∙Cln (M = Cu or Ni; L = (1-benzoyl-2-methylbenzimidazole or 1-(4-chlorobenzoyl-2-methylbenzimidazole; n=O, 1 or 2. The complexes were synthesized and characterized by elemental analysis, molar conductivity magnetic susceptibility measurements and IR spectra. These studies suggest that all the complexes possess an octahedral stereochemistry. The antibacterial activity of (1-benzoyl-2-methylbenzimidazole or 1-(4-chlorobenzoyl-2-methylbenzimidazole and their complexes was evaluated against Escherichia coli and Bacillus sp.

Synthesis, spectroscopic characterization, crystallographic studies and antibacterial assays of new copper(II) complexes with sulfathiazole and nimesulide

Science.gov (United States)

Nunes, Julia Helena Bormio; de Paiva, Raphael Enoque Ferraz; Cuin, Alexandre; da Costa Ferreira, Ana Maria; Lustri, Wilton Rogério; Corbi, Pedro Paulo

2016-05-01

New ternary copper(II) complexes of sulfathiazole (SFT, C9H8N3O2S2) or nimesulide (NMS, C13H11N2O5S) and 2,2‧-bipyridine (bipy) were synthesized, and characterized by chemical and spectroscopic techniques. Elemental analyses indicated a 2:1:1 sulfonamide/copper/bipy composition for both complexes. Mass spectrometric measurements permitted identifying the molecular ions [Cu(SFT)2(bipy)+H]+ and [Cu(NMS)2(bipy)+H]+ at m/z 728 and 835, respectively, confirming the proposed compositions. Crystal structure of the [Cu(SFT)2(bipy)] complex was solved by powder X-ray diffraction analysis (PXRD), attesting that the Cu(II) ion is hexacoordinated in a distorted octahedral geometry. Each SFT molecule coordinates to the metal ion by the nitrogen atoms of the SO2-N group and of the heterocyclic ring. The coordination sphere is completed by a bipyridine. Electronic paramagnetic resonance (EPR) studies were carried out for the [Cu(NMS)2(bipy)] complex, indicating a tetragonal environment around the metal ion. It was suggested that NMS coordinates to Cu(II) by the nitrogen and oxygen atoms of the SO2-N group, which was confirmed by infrared spectroscopic studies. Biological studies showed the antibacterial activity of both Cu-SFT and Cu-NMS complexes, with the minimum inhibitory concentration (MIC) values ranging from 0.10 to 0.84 mmol L-1 against Gram-negative bacteria for [Cu(SFT)2(bipy)], and from 1.50 to 3.00 mmol L-1 against Gram-positive and -negative bacteria for [Cu(NMS)2(bipy)].

The ligational behavior of an isatinic quinolyl hydrazone towards copper(II- ions

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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.

Structural and magnetic characterization of a tetranuclear copper(II) cubane stabilized by intramolecular metal cation-π interactions.

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Papadakis, Raffaello; Rivière, Eric; Giorgi, Michel; Jamet, Hélène; Rousselot-Pailley, Pierre; Réglier, Marius; Simaan, A Jalila; Tron, Thierry

2013-05-20

A novel tetranuclear copper(II) complex (1) was synthesized from the self-assembly of copper(II) perchlorate and the ligand N-benzyl-1-(2-pyridyl)methaneimine (L(1)). Single-crystal X-ray diffraction studies revealed that complex 1 consists of a Cu4(OH)4 cubane core, where the four copper(II) centers are linked by μ3-hydroxo bridges. Each copper(II) ion is in a distorted square-pyramidal geometry. X-ray analysis also evidenced an unusual metal cation-π interaction between the copper ions and phenyl substituents of the ligand. Calculations based on the density functional theory method were used to quantify the strength of this metal-π interaction, which appears as an important stabilizing parameter of the cubane core, possibly acting as a driving parameter in the self-aggregation process. In contrast, using the ligand N-phenethyl-1-(2-pyridyl)methaneimine (L(2)), which only differs from L(1) by one methylene group, the same synthetic procedure led to a binuclear bis(μ-hydroxo)copper(II) complex (2) displaying intermolecular π-π interactions or, by a slight variation of the experimental conditions, to a mononuclear complex (3). These complexes were studied by X-ray diffraction techniques. The magnetic properties of complexes 1 and 2 are reported and discussed.

Effect of Grafted Hydroquinone on the Acid-Base Properties of Poly(acrylic acid in the Presence of Copper (II

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Nabila Bensacia

2015-01-01

Full Text Available Potentiometric titration of poly(acrylic acid and hydroquinone-functionalized poly(acrylic acid was conducted in the presence of copper (II. The effects of hydroquinone functionalizing and copper (II complexing on the potentiometric titration of poly(acrylic acid were studied in an ionic environment and in its absence. Henderson-Hasselbalch equation was applied to assess its validity for this titration. Coordination number and the stability constants of the copper- (II-complexed polymers were determined, and results showed the formation of mostly monodentate and bidentate copper- (II-polymer complexes.

Synthesis, Characterization and DNA Cleavage of Copper(II ...

African Journals Online (AJOL)

Keywords: DNA shearing, Copper(II) complex, Dithiothreitol, Attenuated total reflectance-Fourier transform .... confirm the fragmentation of DNA by the newly .... sperm. Biochem Biophys Acta 1986; 884: 124-134. 7. Cornell NW, Crivaro KE.

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, (1)H 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 μ(B) per Cu(II)) and 6 (2.79 μ(B) per Cu(II)) 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. Copyright © 2012 Elsevier B.V. All rights reserved.

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

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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).

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

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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.

Liquid-crystalline dendrimer Cu(II) complexes and Cu(0) nanoclusters based on the Cu(II) complexes: An electron paramagnetic resonance investigation

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Domracheva, N. E.; Mirea, A.; Schwoerer, M.; Torre-Lorente, L.; Lattermann, G.

2007-07-01

New nanostructured materials, namely, the liquid-crystalline copper(II) complexes that contain poly(propylene imine) dendrimer ligands of the first (ligand 1) and second (ligand 2) generations and which have a columnar mesophase and different copper contents (x = Cu/L), are investigated by EPR spectroscopy. The influence of water molecules and nitrate counterions on the magnetic properties of complex 2 (x = 7.3) is studied. It is demonstrated that water molecules can extract some of the copper ions from dendrimer complexes and form hexaaqua copper complexes with free ions. The dimer spectra of fully hydrated complex 2 (x = 7.3) are observed at temperatures T dendrimer copper(II) complex. The temperature-induced valence tautomerism attended by electron transport is revealed for the first time in blue dendrimer complexes 1 (x = 1.9) with a dimer structure. The activation energy for electron transport is estimated to be 0.35 meV. The coordination of the copper ion site (NO4) and the structural arrangement of green complexes 1 (x = 1.9) in the columnar mesophase are determined. Complexes of this type form linear chains in which nitrate counterions serve as bridges between copper centers. It is revealed that green complexes 1 (x = 1.9) dissolved in isotropic inert solvents can be oriented in the magnetic field (B 0 = 8000 G). The degree of orientation of these complexes is rather high (S z = 0.76) and close to that of systems with a complete ordering (S z = 1) in the magnetic field. Copper(0) nanoclusters prepared by reduction of complex 2 (x = 7.3) in two reducing agents (NaBH4, N2H4 · H2O) are examined. A model is proposed for a possible location of Cu(0) nanoclusters in a dendrimer matrix.

Synthesis, thermogravimetric, spectroscopic and theoretical characterization of copper(II) complex with 4-chloro-2-nitrobenzenosulfonamide

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Camí, G.; Chacón Villalba, E.; Di Santi, Y.; Colinas, P.; Estiu, G.; Soria, D. B.

2011-05-01

4-Chloro-2-nitrobenzenesulfonamide (ClNbsa) was purified and characterized. A new copper(II) complex, [Cu(ClNbsa) 2(NH 3) 2], has been prepared using the sulfonamide as ligand. The thermal behavior of both, the ligand and the Cu(II) complex, was investigated by thermogravimetric analyses (TG) and differential thermal analysis (DT), and the electronic characteristics analyzed by UV-VIS, FTIR, Raman and 1H NMR spectroscopies. The experimental IR, Raman and UV-VIS spectra have been assigned on the basis of DFT calculations at the B3LYP level of theory using the standard (6-31 + G ∗∗) basis set. The geometries have been fully optimized in vacuum and in modeled dimethylsulfoxide (DMSO) solvent, using for the latter a continuum solvation model that reproduced the experimental conditions of the UV-VIS spectroscopy. The theoretical results converged to stable conformations for the free sulfonamide and for the complex, suggesting for the latter a distorted square planar geometry in both environments.

Synthesis, characterization, spectroscopic and theoretical studies of new zinc(II), copper(II) and nickel(II) complexes based on imine ligand containing 2-aminothiophenol moiety

Science.gov (United States)

Shafaatian, Bita; Mousavi, S. Sedighe; Afshari, Sadegh

2016-11-01

New dimer complexes of zinc(II), copper(II) and nickel(II) were synthesized using the Schiff base ligand which was formed by the condensation of 2-aminothiophenol and 2-hydroxy-5-methyl benzaldehyde. This tridentate Schiff base ligand was coordinated to the metal ions through the NSO donor atoms. In order to prevent the oxidation of the thiole group during the formation of Schiff base and its complexes, all of the reactions were carried out under an inert atmosphere of argon. The X-ray structure of the Schiff base ligand showed that in the crystalline form the SH groups were oxidized to produce a disulfide Schiff base as a new double Schiff base ligand. The molar conductivity values of the complexes in dichloromethane implied the presence of non-electrolyte species. The fluorescence properties of the Schiff base ligand and its complexes were also studied in dichloromethane. The products were characterized by FT-IR, 1H NMR, UV/Vis spectroscopies, elemental analysis, and conductometry. The crystal structure of the double Schiff base was determined by single crystal X-ray diffraction. Furthermore, the density functional theory (DFT) calculations were performed at the B3LYP/6-31G(d,p) level of theory for the determination of the optimized structures of Schiff base complexes.

Isolation of a new two-dimensional honeycomb carbonato-bridged copper(II) complex exhibiting long-range ferromagnetic ordering.

Science.gov (United States)

Majumder, Arpi; Choudhury, Chirantan Roy; Mitra, Samiran; Rosair, Georgina M; El Fallah, M Salah; Ribas, Joan

2005-04-28

Atmospheric CO2 fixation by an aqueous solution containing Cu(ClO4)2.6H2O and 4-aminopyridine (4-apy) yields a novel example of a two-dimensional mu3-CO3 bridged copper(II) complex {[Cu(4-apy)2]3(mu3-CO3)2(ClO4)2.(1/2)CH3OH}n that has been characterized by IR, UV and X-ray crystallography; preliminary magnetic measurements show that complex exhibits long-range ordered ferromagnetic coupling.

Copper(II) and molybdenum(VI) complexes of a tridentate ONN donor isothiosemicarbazone: synthesis, characterization, X-ray, TGA and DFT

Czech Academy of Sciences Publication Activity Database

Fasihizad, A.; Akbari, A.; Ahmadi, M.; Dušek, Michal; Henriques, Margarida Isabel Sousa; Pojarová, Michaela

2016-01-01

Roč. 115, Sep (2016), s. 297-305 ISSN 0277-5387 R&D Projects: GA ČR(CZ) GA14-03276S; GA MŠk LO1603 EU Projects: European Commission(XE) CZ.2.16/3.1.00/24510 Institutional support: RVO:68378271 Keywords : isothiosemicarbazone * Copper(II) complex * molybdenum(VI) complex * crystal structure * DFT Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.926, year: 2016

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

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.

Synthesis, characterization and behavior to gamma radiation of copper (II) complex and l-asparagine

International Nuclear Information System (INIS)

Rodrigues, E.R.

1982-01-01

Synthesis and caracterization of coordination compound formed by interation between l-asparagina (HL) and copper (II) ion are discussed. Elemental analysis, Visible and Ultraviolet electronic Spectroscopy, Infrared Vibrational Spectroscopy, Proton Nuclear Magnetic Resonance and melting and/or decomposition point are made; it is also possible to: a) Synthesize the complex with high degree of purity; b)determine the #betta# sub(max) for absorption in the Visible and Ultraviolet, as well as the molar absorption coefficient; c) determine the probable structure of the complex; d) calculate the kinetic parameters and the break factor by means of radiolysis in ammoniacal aqueous solution of sample submitted by a 60 Co source of #betta#-radiation (Gamma Cell); e) separate the complex from the ionic fractions formed by radiolysis, by means of cromatography in their layers; f) determine the porcentage of Cu in this complex by neutron activation; g) justify the complex resistence in solid phase, to gamma radiation. (A.R.H.) [pt

Copper(II) complexes of alloferon 1 with point mutations (H1A) and (H9A) stability structure and biological activity.

Science.gov (United States)

Matusiak, Agnieszka; Kuczer, Mariola; Czarniewska, Elżbieta; Rosiński, Grzegorz; Kowalik-Jankowska, Teresa

2014-09-01

Mono- and polynuclear copper(II) complexes of the alloferon 1 with point mutations (H1A) A(1)GVSGH(6)GQH(9)GVH(12)G (Allo1A) and (H9A) H(1)GVSGH(6)GQA(9)GVH(12)G (Allo9A) have been studied by potentiometric, UV-visible, CD, EPR spectroscopic and mass spectrometry (MS) methods. To obtain a complete complex speciation different metal-to-ligand molar ratios ranging from 1:1 to 4:1 for Allo1A and to 3:1 for Allo9A were studied. The presence of the His residue in first position of the peptide chain changes the coordination abilities of the Allo9A peptide in comparison to that of the Allo1A. Imidazole-N3 atom of N-terminal His residue of the Allo9A peptide forms stable 6-membered chelate with the terminal amino group. Furthermore, the presence of two additional histidine residues in the Allo9A peptide (H(6),H(12)) leads to the formation of the CuL complex with 4N {NH2,NIm-H(1),NIm-H(6),NIm-H(12)} binding site in wide pH range (5-8). For the Cu(II)-Allo1A system, the results demonstrated that at physiological pH7.4 the predominant complex the CuH-1L consists of the 3N {NH2,N(-),CO,NIm} coordination mode. The inductions of phenoloxidase activity and apoptosis in vivo in Tenebrio molitor cells by the ligands and their copper(II) complexes at pH7.4 were studied. The Allo1A, Allo1K peptides and their copper(II) complexes displayed the lowest hemocytotoxic activity while the most active was the Cu(II)-Allo9A complex formed at pH7.4. The results may suggest that the N-terminal-His(1) and His(6) residues may be more important for their proapoptotic properties in insects than those at positions 9 and 12 in the peptide chain. Copyright © 2014 Elsevier Inc. All rights reserved.

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.

Nickel(II) and copper(II) complexes of N,N-dialkyl-N‧-3-chlorobenzoylthiourea: Synthesis, characterization, crystal structures, Hirshfeld surfaces and antimicrobial activity

Science.gov (United States)

Binzet, Gun; Gumus, Ilkay; Dogen, Aylin; Flörke, Ulrich; Kulcu, Nevzat; Arslan, Hakan

2018-06-01

We synthesized four new N,N-dialkyl-N‧-3-chlorobenzoylthiourea ligands (Alkyl: Dimethyl, diethyl, di-n-propyl and di-n-butyl) and their metal complexes with copper and nickel atoms. The structure of all synthesized compounds was fully characterized by physicochemical, spectroscopic and single crystal X-ray diffraction analysis techniques. The physical, spectral and analytical data of the newly synthesized metal complexes have shown the formation of 1:2 (metal:ligand) ratio. The benzoylthiourea ligands coordinate with metal atoms through oxygen and sulphur atoms. The metal atoms are in slightly distorted square-planar coordination geometry in Ni(II) or Cu(II) complex. Two oxygen and two sulphur atoms are mutually cis to each other in Ni(II) or Cu(II) complex. The intermolecular contacts in the compounds, which are HL1 and HL3, were examined by Hirshfeld surfaces and fingerprint plots using the data obtained from X-ray single crystal diffraction measurement. Besides these, their antimicrobial activities against Gram-positive bacteria (Bacillus subtilis, Staphylococcus aureus, Streptococcus pyogenes and Enterococcus faecalis) and Gram-negative bacteria (Escherichia coli and Pseudomonas aeruginosa) and anti-yeast activity (Candida glabrata, Candida parapsilosis and Candida albicans) were investigated. This exhibited some promising results towards testing organism. Among all the compounds, Ni(L1)2 complex showed high activity against Bacillus subtilis with MIC values at 7.81 μg/mL.

copper(II)

Indian Academy of Sciences (India)

Unknown

bis(2,2,6,6-tetramethyl-3,5-heptadionato)copper(II) ... Abstract. Equilibrium concentrations of various condensed and gaseous phases have been thermodyna- ... phere, over a wide range of substrate temperatures and total reactor pressures.

Ternary copper(II) complex: NCI60 screening, toxicity studies, and evaluation of efficacy in xenograft models of nasopharyngeal carcinoma

Science.gov (United States)

Chu, Tai-Lin; Abdul Aziz, Norazlin; Mohd Kornain, Noor-Kaslina; Samiulla, D. S.; Lo, Kwok-Wai; Ng, Chew-Hee

2018-01-01

Copper(II) ternary complex, [Cu(phen)(C-dmg)(H2O)]NO3 was evaluated against a panel of cell lines, tested for in vivo efficacy in nasopharyngeal carcinoma xenograft models as well as for toxicity in NOD scid gamma mice. The Cu(II) complex displayed broad spectrum cytotoxicity against multiple cancer types, including lung, colon, central nervous system, melanoma, ovarian, and prostate cancer cell lines in the NCI-60 panel. The Cu(II) complex did not cause significant induction of cytochrome P450 (CYP) 3A and 1A enzymes but moderately inhibited CYP isoforms 1A2, 2C9, 2C19, 2D6, 2B6, 2C8 and 3A4. The complex significantly inhibited tumor growth in nasopharyngeal carcinoma xenograft bearing mice models at doses which were well tolerated without causing significant or permanent toxic side effects. However, higher doses which resulted in better inhibition of tumor growth also resulted in toxicity. PMID:29329342

Complexes of cobalt(II), nickel(II), copper(II), zinc(II), cadmium(II) and dioxouranium(II) with thiophene-2-aldehydethiosemicarbazone

International Nuclear Information System (INIS)

Singh, Balwan; Misra, Harihar

1986-01-01

Metal complexes of thiosemicarbazides have been known for their pharmacological applications. Significant antitubercular, fungicidal and antiviral activities have been reported for thiosemicarbazides and their derivatives. The present study describes the systhesis and characterisation of complexes of Co II , Cu II , Zn II ,Cd II and UO II with thiosemicarbazone obtained by condensing thiophene-2-aldehyde with thiosemicarbazide. 17 refs., 2 tables. (author)

Structure-antiproliferative activity studies on l-proline- and homoproline-4-N-pyrrolidine-3-thiosemicarbazone hybrids and their nickel(ii), palladium(ii) and copper(ii) complexes.

Science.gov (United States)

Dobrova, Aliona; Platzer, Sonja; Bacher, Felix; Milunovic, Miljan N M; Dobrov, Anatolie; Spengler, Gabriella; Enyedy, Éva A; Novitchi, Ghenadie; Arion, Vladimir B

2016-09-14

Two water-soluble thiosemicarbazone-proline (H2L(1)) and thiosemicarbazone-homoproline hybrids (H2L(2)) were synthesised. By reaction of H2L(1) with NiCl2·6H2O, PdCl2 and CuCl2·2H2O in ethanol, the series of square-planar complexes [Ni(H2L(1))Cl]Cl·1.3H2O (1·1.3H2O), [Pd(H2L(1))Cl]Cl·H2O (2·H2O) and [Cu(H2L(1))Cl]Cl·0.7H2O (3·0.7H2O) was prepared, and starting from H2L(2) and CuCl2·2H2O in methanol, the complex [Cu(H2L(2))Cl2]·H2O (4·H2O) was obtained. The compounds have been characterised by elemental analysis, spectroscopic methods (IR, UV-vis and NMR spectroscopy), ESI mass spectrometry and single crystal X-ray crystallography (H2L(1), 1, 2 and 4). As a solid, 1 is diamagnetic, while it is paramagnetic in methanolic solution. The effective magnetic moment of 3.26 B.M. at room temperature indicates the change in coordination geometry from square-planar to octahedral upon dissolution. The in vitro anticancer potency of ligand precursors H2L(1) and H2L(2) and metal complexes 1-4 was studied in three human cancer cell lines (A549, CH1 and SW480) and in noncancerous murine embryonal fibroblasts (NIH/3T3), and the mechanism of cell death was also assayed by flow cytometry. Clear-cut structure-activity relationships have been established. The metal ions exert marked effects in a divergent manner: copper(ii) increases, whereas nickel(ii) and palladium(ii) decrease the cytotoxicity of the hybrids. The antiproliferative activity of H2L(1) and metal complexes 1-3 decreases in all three tumour cell lines in the following rank order: 3 > H2L(1) > 1 > 2. The role of square-planar geometry in the underlying mechanism of cytotoxicity of the metal complexes studied seems to be negligible, while structural modifications at the terminal amino group of thiosemicarbazide and proline moieties are significant for enhancing the antiproliferative activity of both hybrids and copper(ii) complexes.

Kinetics and equilibria for the formation of a new DNA metal-intercalator: the cyclic polyamine Neotrien/copper(II) complex.

Science.gov (United States)

Biver, Tarita; Secco, Fernando; Tinè, Maria Rosaria; Venturini, Marcella

2004-01-01

A study has been performed of the kinetics and equilibria involved in complex formation between the macrocyclic polyamine 2,5,8,11-tetraaza[12]-[12](2,9)[1,10]-phenanthrolinophane (Neotrien) and Cu(II) in acidic aqueous solution and ionic strength 0.5 M (NaCl), by means of the stopped-flow method and UV spectrophotometry. Spectrophotometric titrations and kinetic experiments revealed that the binding of Cu(II) to Neotrien gives rise to several 1:1 complexes differing in their degree of protonation. Under the experimental hydrogen ion concentration range investigated, complexation occurs by two parallel paths: (a) M2+ + (H4L)4+ (MH4L)6+ and (b) M2+ + (H3L)3+ (MH3L)5+. The rate constants values found for complex formation, by paths (a) and (b), are much lower than the values expected from water exchange at copper(II) and other amine/Cu(II) complexation kinetic constants. Kinetic experiments at different NaCl concentrations indicated that this finding was not due to chloride ion competition in complex formation with Neotrien, but it was related to a ring rigidity effect. As the phenanthroline moiety could, in principle, interact with nucleic acids by intercalation or external binding, some preliminary measurements concerned with the possible interactions occurring between the Cu(II)/Neotrien complex and calf thymus DNA (CT-DNA) have also been carried out. The absorption spectra of the Cu(II)/Neotrien complex change upon addition of CT-DNA at pH 7.0, revealing the occurrence of complex-nucleic acid interactions. Moreover, fluorescence titrations, carried out by adding the Cu(II)/Neotrien complex to CT-DNA, previously saturated with ethidium bromide (EB), show that the Cu(II)/Neotrien complex is able to displace EB from DNA, suggesting the complex is able to intercalate into the polynucleotide and then to cleave the phosphodiester bond of DNA.

In vitro antioxidant activity, enzyme kinetics, biostability and cellular SOD mimicking ability of 1:1 curcumin-copper (II) complex

International Nuclear Information System (INIS)

Kunwar, A.; Mishra, B.; Barik, A.; Priyadarsini, K.I.; Narang, H.; Krishna, M.

2008-01-01

In vitro antioxidant activity of 1:1 curcumin copper (II) complex was evaluated by following the inhibition of γ-radiation induced lipid peroxidation and protein oxidation in model systems. The SOD enzyme kinetic parameters K m and V max values and the turn over number of the complex were determined. The complex is stable in bio-fluids and prevents oxidation of lipid and protein solution in presence of H 2 O 2 and showed reduction in MnSOD level in spleen cells without having any effect on cell viability. (author)

In vitro antioxidant activity, enzyme kinetics, biostability and cellular SOD mimicking ability of 1:1 curcumin-copper (II) complex

Energy Technology Data Exchange (ETDEWEB)

Kunwar, A; Mishra, B; Barik, A; Priyadarsini, K I [Radiation and Photochemistry Div., Bhabha Atomic Research Centre, Mumbai (India); Narang, H; Krishna, M [Radiation Biology and Health Sciences Div., Bhabha Atomic Research Centre, Mumbai (India)

2008-01-15

In vitro antioxidant activity of 1:1 curcumin copper (II) complex was evaluated by following the inhibition of {gamma}-radiation induced lipid peroxidation and protein oxidation in model systems. The SOD enzyme kinetic parameters K{sub m} and V{sub max} values and the turn over number of the complex were determined. The complex is stable in bio-fluids and prevents oxidation of lipid and protein solution in presence of H{sub 2}O{sub 2} and showed reduction in MnSOD level in spleen cells without having any effect on cell viability. (author)

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 (C L ) and conditional stability constants (log K M ) of bonding between DOM and copper (II) ions, which revealed that the values of C L were 85.62 and 87.23 μmol mg -1 and the log K M 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 2p 3/2 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.

Synthesis and Crystal Structure of a 4,4'-bipyridine Linked Dinuclear Copper(II) Complex Derived from 2-{[2-(2-hydroxyethylamino)ethylimino]methyl}-6-methylphenol.

Science.gov (United States)

Zhang, Xiu-Zhen; Gu, Yitong; Li, Yuntong; Liu, Andong; Liu, Fuyao; You, Zhonglu; Zhu, Hai-Liang

2016-12-01

A novel 4,4'-bipyridine linked dinuclear copper(II) complex, [Cu2L2(bipy)](NO3)2·bipy (L = 2-[2-(2-hydroxyethylamino) ethylimino]methyl-6-methylphenol; bipy = 4,4'-bipyridine), was prepared and characterized by elemental analyses, IR spectroscopy, and single-crystal X-ray diffraction. The Cu···Cu distance is 11.129(2) Å. The CuII atom is coordinated by one phenolate O, one imine N, and one amine N atoms of a Schiff base ligand, and one N atom of the bridging 4,4'-bipyridine ligand, forming a square planar geometry. In the crystal structure of the complex, the dinuclear copper complex cations are linked by 4,4'-bipyridine molecules through intermolecular O-H···N hydrogen bonds, to form 1D chains running in the [2 0 -1] direction.

Electrochemical Water Oxidation and Stereoselective Oxygen Atom Transfer Mediated by a Copper Complex.

Science.gov (United States)

Kafentzi, Maria-Chrysanthi; Papadakis, Raffaello; Gennarini, Federica; Kochem, Amélie; Iranzo, Olga; Le Mest, Yves; Le Poul, Nicolas; Tron, Thierry; Faure, Bruno; Simaan, A Jalila; Réglier, Marius

2018-04-06

Water oxidation by copper-based complexes to form dioxygen has attracted attention in recent years, with the aim of developing efficient and cheap catalysts for chemical energy storage. In addition, high-valent metal-oxo species produced by the oxidation of metal complexes in the presence of water can be used to achieve substrate oxygenation with the use of H 2 O as an oxygen source. To date, this strategy has not been reported for copper complexes. Herein, a copper(II) complex, [(RPY2)Cu(OTf) 2 ] (RPY2=N-substituted bis[2-pyridyl(ethylamine)] ligands; R=indane; OTf=triflate), is used. This complex, which contains an oxidizable substrate moiety (indane), is used as a tool to monitor an intramolecular oxygen atom transfer reaction. Electrochemical properties were investigated and, upon electrolysis at 1.30 V versus a normal hydrogen electrode (NHE), both dioxygen production and oxygenation of the indane moiety were observed. The ligand was oxidized in a highly diastereoselective manner, which indicated that the observed reactivity was mediated by metal-centered reactive species. The pH dependence of the reactivity was monitored and correlated with speciation deduced from different techniques, ranging from potentiometric titrations to spectroscopic studies and DFT calculations. Water oxidation for dioxygen production occurs at neutral pH and is probably mediated by the oxidation of a mononuclear copper(II) precursor. It is achieved with a rather low overpotential (280 mV at pH 7), although with limited efficiency. On the other hand, oxygenation is maximum at pH 8-8.5 and is probably mediated by the electrochemical oxidation of an antiferromagnetically coupled dinuclear bis(μ-hydroxo) copper(II) precursor. This constitutes the first example of copper-centered oxidative water activation for a selective oxygenation reaction. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Biologically active new Fe(II, Co(II, Ni(II, Cu(II, Zn(II and Cd(II complexes of N-(2-thienylmethylenemethanamine

Directory of Open Access Journals (Sweden)

C. SPÎNU

2008-04-01

Full Text Available Iron(II, cobalt(II, nickel (II, copper (II, zinc(II and cadmium(II complexes of the type ML2Cl2, where M is a metal and L is the Schiff base N-(2-thienylmethylenemethanamine (TNAM formed by the condensation of 2-thiophenecarboxaldehyde and methylamine, were prepared and characterized by elemental analysis as well as magnetic and spectroscopic measurements. The elemental analyses suggest the stoichiometry to be 1:2 (metal:ligand. Magnetic susceptibility data coupled with electronic, ESR and Mössbauer spectra suggest a distorted octahedral structure for the Fe(II, Co(II and Ni(II complexes, a square-planar geometry for the Cu(II compound and a tetrahedral geometry for the Zn(II and Cd(II complexes. The infrared and NMR spectra of the complexes agree with co-ordination to the central metal atom through nitrogen and sulphur atoms. Conductance measurements suggest the non-electrolytic nature of the complexes, except for the Cu(II, Zn(II and Cd(II complexes, which are 1:2 electrolytes. The Schiff base and its metal chelates were screened for their biological activity against Escherichia coli, Staphylococcus aureus and Pseudomonas aeruginosa and the metal chelates were found to possess better antibacterial activity than that of the uncomplexed Schiff base.

Copper(II) cyanido-bridged bimetallic nitroprusside-based complexes: Syntheses, X-ray structures, magnetic properties, 57Fe Moessbauer spectroscopy and thermal studies

International Nuclear Information System (INIS)

Travnicek, Zdenek; Herchel, Radovan; Mikulik, Jiri; Zboril, Radek

2010-01-01

Three heterobimetallic cyanido-bridged copper(II) nitroprusside-based complexes of the compositions [Cu(tet)Fe(CN) 5 NO].H 2 O (1), where tet=N,N'-bis(3-aminopropyl)ethylenediamine, [Cu(hto)Fe(CN) 5 NO].2H 2 O (2), where hto=1,3,6,9,11,14-hexaazatricyclo[12.2.1.1 6,9 ]octadecane and [Cu(nme) 2 Fe(CN) 5 NO].H 2 O (3), where nme=N-methylethylenediamine, were synthesized and characterized by elemental analyses, 57 Fe Moessbauer and FTIR spectroscopies, thermal analysis, magnetic measurements and single-crystal X-ray analysis. The products of thermal degradation processes of 2 and 3 were studied by XRD, 57 Fe Moessbauer spectroscopy, SEM and EDS, and they were identified as mixtures of CuFe 2 O 4 and CuO. - Three heterobimetallic cyano-bridged copper(II) nitroprusside-based complexes of the general compositions of [Cu(L)Fe(CN) 5 NO].xH 2 O, where L=N,N'-bis(3-aminopropyl)ethylenediamine (complex 1), 1,3,6,9,11,14-hexaazatricyclo[12.2.1.1 6,9 ]-octadecane (complex 2) and N-methylethylenediamine (complex 3), were synthesized, and fully structurally and magnetically characterized. SEM, EDS, XRD and 57 Fe Moessbauer experiments were used for characterization of thermal decomposition products of complexes 2 and 3.

Photocleavage of DNA by copper(II) complexes

Indian Academy of Sciences (India)

Department of Inorganic and Physical Chemistry, Indian Institute of Science, Bangalore 560 012 e-mail: ... induced DNA cleavage activity is summarized in this article. ... per(II) complexes play important roles in DNA cleavage reactions.

The thermal decomposition of copper(II) oxalate revisited

International Nuclear Information System (INIS)

Lamprecht, Emmanuel; Watkins, Gareth M.; Brown, Michael E.

2006-01-01

DSC, TG and TG-FT-IR, and XRPD have been used to examine the effects of supposedly inert atmospheres of argon and nitrogen on the mechanism of the thermal decomposition of copper(II) oxalate. The DSC curves in pure argon at 10 deg. C min -1 show a broad endotherm with onset at about 280 deg. C and maximum at about 295 deg. C. In mixtures of argon and nitrogen, as the proportion of argon gas is decreased, the endothermic character of the decomposition decreases until, when nitrogen is the main component, the decomposition exhibits a complex broad exothermic character. XRPD studies showed that, regardless of the proportions of nitrogen and argon, the DSC residues consisted of mainly copper metal with small amounts of copper(I) oxide (cuprite) and, under some conditions, traces of copper(II) oxide (tenorite). Various explanations for this behaviour are discussed and a possible answer lies in the disproportionation of CO 2 (g) to form small quantities of O 2 (g) or monatomic oxygen. The possibility exists that the exothermicity in nitrogen could be explained by reaction of the nitrogen with atomic oxygen to form N 2 O(g), but this product could not be detected using TG-FT-IR

The thermal decomposition of copper(II) oxalate revisited

Energy Technology Data Exchange (ETDEWEB)

Lamprecht, Emmanuel [Chemistry Department, Rhodes University, Grahamstown 6140 (South Africa); Watkins, Gareth M. [Chemistry Department, Rhodes University, Grahamstown 6140 (South Africa); Brown, Michael E. [Chemistry Department, Rhodes University, Grahamstown 6140 (South Africa)]. E-mail: m.brown@ru.ac.za

2006-07-01

DSC, TG and TG-FT-IR, and XRPD have been used to examine the effects of supposedly inert atmospheres of argon and nitrogen on the mechanism of the thermal decomposition of copper(II) oxalate. The DSC curves in pure argon at 10 deg. C min{sup -1} show a broad endotherm with onset at about 280 deg. C and maximum at about 295 deg. C. In mixtures of argon and nitrogen, as the proportion of argon gas is decreased, the endothermic character of the decomposition decreases until, when nitrogen is the main component, the decomposition exhibits a complex broad exothermic character. XRPD studies showed that, regardless of the proportions of nitrogen and argon, the DSC residues consisted of mainly copper metal with small amounts of copper(I) oxide (cuprite) and, under some conditions, traces of copper(II) oxide (tenorite). Various explanations for this behaviour are discussed and a possible answer lies in the disproportionation of CO{sub 2}(g) to form small quantities of O{sub 2}(g) or monatomic oxygen. The possibility exists that the exothermicity in nitrogen could be explained by reaction of the nitrogen with atomic oxygen to form N{sub 2}O(g), but this product could not be detected using TG-FT-IR.

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

Energy Technology Data Exchange (ETDEWEB)

Haleel, A.; Mahendiran, D. [Post-Graduate and Research Department of Chemistry, The New College (Autonomous), Chennai 600 014 (India); Veena, V.; Sakthivel, N. [Department of Biotechnology, Pondicherry University, Pondicherry 605 014 (India); Rahiman, A. Kalilur, E-mail: akrahmanjkr@gmail.com [Post-Graduate and Research Department of Chemistry, The New College (Autonomous), Chennai 600 014 (India)

2016-11-01

A series of heteroleptic mononuclear copper(II) complexes of the type [Cu(L{sup 1–3})(diimine)]ClO{sub 4} (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{sup 1}), ethyl 5-methyl-7-(4-diethylamino-2-hydroxyphenyl)-4,7-dihydrotetrazolo[1,5-a] pyrimidine-6-carboxylate (HL{sup 2}) or ethyl 5-methyl-7-(2-hydroxy-4-nitrophenyl)-4,7-dihydrotetrazolo[1,5-a] pyrimidine-6-carboxylate (HL{sup 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

Application of Box-Behnken design in the optimization of catalytic behavior of a new mixed chelate of copper (II) complex in chemiluminescence reaction of luminol

International Nuclear Information System (INIS)

Khajvand, Tahereh; Chaichi, Mohammad Javad; Nazari, OmLeila; Golchoubian, Hamid

2011-01-01

In this work, we observed an enhancement of chemiluminescence (CL) emission of luminol when a new mixed chelate of copper complex (N-(2-(2-aminoethylamino)ethyl)-1H-pyrrole-2-carboxamide-Cu(II)) was mixed with a solution containing luminol in methanol/water. The Box-Behnken design matrix and response surface methodology (RSM) have been applied to design the experiments to evaluate the interactive effects of the three most important operating variables-luminol (10 -4 -10 -2 M), fluorescein (10 -5 -10 -3 M) and hydrogen peroxide (1-3 M) concentrations on the CL emission of luminol. The total 15 experiments were conducted in the present study towards the construction of a quadratic model. Independent variables luminol and hydrogen peroxide have significant value P F less than 0.0500 indicate that model terms are significant for the CL emission of luminol. The regression equation coefficients were calculated and the data fitted to a second-order polynomial equation for CL emission of luminol. The new introduced inorganic catalyst of luminol CL reaction can be effect more than that of the common ones such as potassium hexacyanoferrate (III) and copper (II) acetate. - Research highlights: → In this study we introduce a new mixed chelate of copper complex as a catalyst of luminol chemiluminescence (CL) reaction. → The copper complex (N-(2-(2-aminoethylamino)ethyl)-1H-pyrrole-2-carboxamide-Cu(II)) catalyst luminol reaction more than that of copper acetate and potassium hexacyanoferrate (III). → The Box-Behnken design matrix and response surface methodology are used for prediction of CL intensity of luminol. → There are good correlation between experimental and expected CL intensity that predicted by the theoretical model. → Fluorescein used as a fluorescer in the luminol CL reaction in presence of the new catalyst.

Tetranuclear copper(II) complexes bridged by alpha-D-glucose-1-phosphate and incorporation of sugar acids through the Cu4 core structural changes.

Science.gov (United States)

Kato, Merii; Sah, Ajay Kumar; Tanase, Tomoaki; Mikuriya, Masahiro

2006-08-21

Tetranuclear copper(II) complexes containing alpha-D-glucose-1-phosphate (alpha-D-Glc-1P), [Cu4(mu-OH){mu-(alpha-D-Glc-1P)}2(bpy)4(H2O)2]X3 [X = NO3 (1a), Cl (1b), Br (1c)], and [Cu4(mu-OH){mu-(alpha-D-Glc-1P)}2(phen)4(H2O)2](NO3)3 (2) were prepared by reacting the copper(II) salt with Na2[alpha-D-Glc-1P] in the presence of diimine ancillary ligands, and the structure of 2 was characterized by X-ray crystallography to comprise four {Cu(phen)}2+ fragments connected by the two sugar phosphate dianions in 1,3-O,O' and 1,1-O mu4-bridging fashion as well as a mu-hydroxo anion. The crystal structure of 2 involves two chemically independent complex cations in which the C2 enantiomeric structure for the trapezoidal tetracopper(II) framework is switched according to the orientation of the alpha-D-glucopyranosyl moieties. Temperature-dependent magnetic susceptibility data of 1a indicated that antiferromagnetic spin coupling is operative between the two metal ions joined by the hydroxo bridge (J = -52 cm(-1)) while antiferromagnetic interaction through the Cu-O-Cu sugar phosphate bridges is weak (J = -13 cm(-1)). Complex 1a readily reacted with carboxylic acids to afford the tetranuclear copper(II) complexes, [Cu4{mu-(alpha-D-Glc-1P)}2(mu-CA)2(bpy)4](NO3)2 [CA = CH3COO (3), o-C6H4(COO)(COOH) (4)]. Reactions with m-phenylenediacetic acid [m-C6H4(CH2COOH)2] also gave the discrete tetracopper(II) cationic complex [Cu4{mu-(alpha-D-Glc-1P)}2(mu-m-C6H4(CH2COO)(CH2COOH))2(bpy)4](NO3)2 (5a) as well as the cluster polymer formulated as {[Cu4{mu-(alpha-D-Glc-1P)}2(mu-m-C6H4(CH2COO)2)(bpy)4](NO3)2}n (5b). The tetracopper structure of 1a is converted into a symmetrical rectangular core in complexes 3, 4, and 5b, where the hydroxo bridge is dissociated and, instead, two carboxylate anions bridge another pair of Cu(II) ions in a 1,1-O monodentate fashion. The similar reactions were applied to incorporate sugar acids onto the tetranuclear copper(II) centers. Reactions of 1a with delta

Copper (II) complexes of bidentate ligands exhibit potent anti-cancer activity regardless of platinum sensitivity status.

Science.gov (United States)

Wehbe, Mohamed; Lo, Cody; Leung, Ada W Y; Dragowska, Wieslawa H; Ryan, Gemma M; Bally, Marcel B

2017-12-01

Insensitivity to platinum, either through inherent or acquired resistance, is a major clinical problem in the treatment of many solid tumors. Here, we explored the therapeutic potential of diethyldithiocarbamate (DDC), pyrithione (Pyr), plumbagin (Plum), 8-hydroxyquinoline (8-HQ), clioquinol (CQ) copper complexes in a panel of cancer cell lines that differ in their sensitivity to platins (cisplatin/carboplatin) using a high-content imaging system. Our data suggest that the copper complexes were effective against both platinum sensitive (IC 50  ~ 1 μM platinum) and insensitive (IC 50  > 5 μM platinum) cell lines. Furthermore, copper complexes of DDC, Pyr and 8-HQ had greater therapeutic activity compared to the copper-free ligands in all cell lines; whereas the copper-dependent activities of Plum and CQ were cell-line specific. Four of the copper complexes (Cu(DDC) 2 , Cu(Pyr) 2 , Cu(Plum) 2 and Cu(8-HQ) 2 ) showed IC 50 values less than that of cisplatin in all tested cell lines. The complex copper DDC (Cu(DDC) 2 ) was selected for in vivo evaluation due to its low nano-molar range activity in vitro and the availability of an injectable liposomal formulation. Liposomal (Cu(DDC) 2 ) was tested in a fast-growing platinum-resistant A2780-CP ovarian xenograft model and was found to achieve a statistically significant reduction (50%; p < 0.05) in tumour size. This work supports the potential use of copper-based therapeutics to treat cancers that are insensitive to platinum drugs.

Kinetics of the metal exchange in Bis(salicylaldiminato)-copper(II)-complexes. Pt. 3. Influence of the electron density at the donor nitrogen

Energy Technology Data Exchange (ETDEWEB)

Winkler, H; Wannowius, K J; Elias, H [Technische Hochschule Darmstadt (Germany, F.R.). Fachbereich Anorganische Chemie und Kernchemie

1977-01-01

The kinetics of isotopic copper exchange between various (bis-(N-phenyl-salicylaldiminato))copper(II)complexes (= CuL/sub 2/) and mono(pyridine)copper(II)acetate (= CuAc/sub 2/py) was studied in dichloromethane as solvent in the temperature range -20 to +20/sup 0/C. The exchange follows the experimental rate law (5), which is simplified in certain cases due to k''((CuAc/sub 2/py)/sub 2/)/sup 1///sup 2/ < 1. The variation of substituents X on the salicylaldehyde ring and of substituents Y on the N-phenyl ring leads via Hammett plots to the conclusion that substituent effects become apparent as rate increasing or rate decreasing only in those cases, in which they cause an increase or decrease in electron density at the donor oxygen. Substituents Y in 2-position, and especially in 2.6-position, reduce the rate of exchange with increasing van der Waals radius of Y. The mechanistic implications of the results are discussed. (orig.) 891 HK.

Theoretical description of copper Cu(I)/Cu(II) complexes in mixed ammine-aqua environment. DFT and ab initio quantum chemical study

International Nuclear Information System (INIS)

Pavelka, Matej; Burda, Jaroslav V.

2005-01-01

This work is devoted to investigate the interactions of the Cu(I)/Cu(II) cation with variable ammonia-water ligand field by the quantum chemical approach. For that purpose, the optimization of the [Cu(NH 3 ) m (H 2 O) n ] 2+/+ complexes (where n varies from 0 to 4 or 6 and m + n = 4 or 6) has been performed at the DFT/6-31+G(d) level of theory in conjunction with the B3PW91 hybrid functional. Based on the results of the single-point B3LYP/6-311++G(2df,2pd) calculations, the stabilization energies were determined. The two-coordinated copper(I) complexes appeared to be the most stable compounds with the remaining water or ammonia molecules in the second solvation shell. In the case of the Cu(II) systems, four-coordinated complexes were found to be the most stable. In order to examine and explain bonding characteristics, Morokuma interaction energy decomposition (for selected Cu + complexes) and Natural Population Analysis for all systems were performed. It was found that the most stable structures correlate with the highest donation effects. Therefore, more polarizable ammonia molecules exhibit higher donation than water and thus make stronger bonds to copper. This can be demonstrated by the fact that the NH 3 molecule always tries to occupy the first solvation shell in mixed ammine-aqua complexes

Interaction of a copper (II) complex containing an artificial sweetener (aspartame) with calf thymus DNA.

Science.gov (United States)

Shahabadi, Nahid; Khodaei, Mohammad Mehdi; Kashanian, Soheila; Kheirdoosh, Fahimeh

2014-01-01

A copper (II) complex containing aspartame (APM) as ligand, Cu(APM)2Cl2⋅2H2O, was synthesized and characterized. In vitro binding interaction of this complex with native calf thymus DNA (CT-DNA) was studied at physiological pH. The interaction was studied using different methods: spectrophotometric, spectrofluorometric, competition experiment, circular dichroism (CD) and viscosimetric techniques. Hyperchromicity was observed in UV absorption band of Cu(APM)2Cl2⋅2H2O. A strong fluorescence quenching reaction of DNA to Cu(APM)2Cl2⋅2H2O was observed and the binding constants (Kf) and corresponding numbers of binding sites (n) were calculated at different temperatures. Thermodynamic parameters, enthalpy change (ΔH) and entropy change (ΔS) were calculated to be+89.3 kJ mol(-1) and+379.3 J mol(-1) K(-1) according to Van't Hoff equation which indicated that reaction is predominantly entropically driven. Experimental results from spectroscopic methods were comparable and further supported by viscosity measurements. We suggest that Cu(APM)2Cl2⋅2H2O interacts with calf thymus DNA via a groove interaction mode with an intrinsic binding constant of 8×10+4 M(-1). Binding of this copper complex to DNA was found to be stronger compared to aspartame which was studied recently. Copyright © 2013 Elsevier B.V. All rights reserved.

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.

21 CFR 73.1125 - Potassium sodium copper chloropyhllin (chlorophyllin-copper complex).

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 1 2010-04-01 2010-04-01 false Potassium sodium copper chloropyhllin (chlorophyllin-copper complex). 73.1125 Section 73.1125 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT....1125 Potassium sodium copper chloropyhllin (chlorophyllin-copper complex). (a) Identity. (1) The color...

21 CFR 73.2125 - Potassium sodium copper chlorophyllin (chlorophyllin-copper complex).

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 1 2010-04-01 2010-04-01 false Potassium sodium copper chlorophyllin (chlorophyllin-copper complex). 73.2125 Section 73.2125 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT... § 73.2125 Potassium sodium copper chlorophyllin (chlorophyllin-copper complex). (a) Identity and...

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.

Synthesis, structures and Helicobacter pylori urease inhibitory activity of copper(II) complexes with tridentate aroylhydrazone ligands.

Science.gov (United States)

Pan, Lin; Wang, Cunfang; Yan, Kai; Zhao, Kedong; Sheng, Guihua; Zhu, Hailiang; Zhao, Xinlu; Qu, Dan; Niu, Fang; You, Zhonglu

2016-06-01

A series of new copper(II) complexes were prepared. They are [CuL(1)(NCS)] (1), [CuClL(1)]·CH3OH (2), [CuClL(2)]·CH3OH (3), [CuL(3)(NCS)]·CH3OH (4), [CuL(4)(NCS)]·0.4H2O (5), and [CuL(5)(bipy)] (6), where L(1), L(2), L(3) and L(4) are the deprotonated form of N'-(2-hydroxybenzylidene)-3-methylbenzohydrazide, 4-bromo-N'-(2-hydroxy-5-methoxybenzylidene)benzohydrazide, N'-(2-hydroxy-5-methoxybenzylidene)-3-methylbenzohydrazide and 2-chloro-N'-(2-hydroxy-5-methoxybenzylidene)benzohydrazide, respectively, L(5) is the dianionic form of N'-(2-hydroxybenzylidene)-3-methylbenzohydrazide, and bipy is 2,2'-bipyridine. The complexes were characterized by infrared and UV-Vis spectra and single crystal X-ray diffraction. The Cu atoms in complexes 1, 2, 3, 4 and 5 are coordinated by the NOO donor set of the aroylhydrazone ligands, and one Cl or thiocyanate N atom, forming square planar coordination. The Cu atom in complex 6 is in a square pyramidal coordination, with the NOO donor set of L(1), and one N atom of bipy defining the basal plane, and with the other N atom of bipy occupying the apical position. Complexes 1, 2, 3, 4 and 5 show effective urease inhibitory activities, with IC50 values of 5.14, 0.20, 4.06, 5.52 and 0.26μM, respectively. Complex 6 has very weak activity against urease, with IC50 value over 100μM. Molecular docking study of the complexes with the Helicobacter pylori urease was performed. The relationship between structures and urease inhibitory activities indicated that copper complexes with square planar coordination are better models for urease inhibition. Copyright © 2016 Elsevier Inc. All rights reserved.

Copper(II) oxide solubility behavior in aqueous sodium phosphate solutions at elevated temperatures

International Nuclear Information System (INIS)

Ziemniak, S.E.; Jones, M.E.; Combs, K.E.S.

1990-02-01

A platinum-lined, flowing autoclave facility is used to investigate the solubility behavior of copper(II) oxide (CuO) in aqueous sodium phosphate solutions at temperatures between 292 and 535 K. Copper solubilities are observed to increase continuously with temperature and phosphate concentration. The measured solubility is examined via a Cu(II) ion hydrolysis/complexing model and thermodynamic functions for the hydrolysis/complexing reactions are obtained from a least- squares analysis of the data. Altogether, thermochemical properties are established for five anionic complexes: Cu(OH) 3 - , Cu(OH) 4 = , Cu(OH) 2 (HPO 4 ) = , Cu(OH) 3 (H 2 PO 4 ) = , and Cu(OH) 2 (PO 4 ) ≡ . Precise thermochemical parameters are also derived for the Cu(OH) + hydroxocomplex based on CuO solubility behavior previously observed in pure water (*) at elevated temperatures. The relative ease of Cu(II) ion hydrolysis is such that Cu(OH) 3 - species become the preferred hydroxocomplex for pH ≥ 9.4. 20 refs., 8 figs., 6 tabs

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

Indian Academy of Sciences (India)

Thin layer; ZnO nanoparticles; copper complexes; AFM; SEM; fluorescence. 1. Introduction ... ZnO nanopowders29,30 and ZnO nanoparticles doped by different metal ...... Roy S, Choubey S, Bhar K, Khan S, Mitra P and Ghosh. B K 2013 J. Mol ...

In vitro and in vivo anti-inflammatory active copper(II-lawsone complexes.

Directory of Open Access Journals (Sweden)

Ján Vančo

Full Text Available We report in vitro and in vivo anti-inflammatory activities of a series of copper(II-lawsone complexes of the general composition [Cu(Law2(LNx(H2O(2-x]·yH2O; where HLaw = 2-hydroxy-1,4-naphthoquinone, x = 1 when LN = pyridine (1 and 2-aminopyridine (3 and x = 2 when LN = imidazole (2, 3-aminopyridine (4, 4-aminopyridine (5, 3-hydroxypyridine (6, and 3,5-dimethylpyrazole (7. The compounds were thoroughly characterized by physical techniques, including single crystal X-ray analysis of complex 2. Some of the complexes showed the ability to suppress significantly the activation of nuclear factor κB (NF-κB both by lipopolysaccharide (LPS and TNF-alpha (complexes 3-7 at 100 nM level in the similar manner as the reference drug prednisone (at 1 μM level. On the other hand, all the complexes 1-7 decreased significantly the levels of the secreted TNF-alpha after the LPS activation of THP-1 cells, thus showing the anti-inflammatory potential via both NF-κB moderation and by other mechanisms, such as influence on TNF-alpha transcription and/or translation and/or secretion. In addition, a strong intracellular pro-oxidative effect of all the complexes has been found at 100 nM dose in vitro. The ability to suppress the inflammatory response, caused by the subcutaneous application of λ-carrageenan, has been determined by in vivo testing in hind-paw edema model on rats. The most active complexes 1-3 (applied in a dose corresponding to 40 μmol Cu/kg, diminished the formation of edema simalarly as the reference drug indomethacine (applied in 10 mg/kg dose. The overall effect of the complexes, dominantly 1-3, shows similarity to anti-inflammatory drug benoxaprofen, known to induce intracellular pro-oxidative effects.

Selective and Efficient Solvent Extraction of Copper(II Ions from Chloride Solutions by Oxime Extractants

Directory of Open Access Journals (Sweden)

Zahra Kaboli Tanha

2016-06-01

Full Text Available Oxime extractants 3-tert-butyl-2-hydroxy-5-methyl benzaldehyde oxime (HL1 and 3-tert-butyl-2-hydroxy-5-methoxy benzaldehyde oxime (HL2 were synthesized and characterized by conventional spectroscopic methods. Suitable lipophilic nature of the prepared extractants allowed examining the ability of these molecules for extraction-separation of copper from its mixture with normally associated metal ions by performing competitive extraction experiments of Cu(II, Co(II, Ni(II, Zn(II, Cd(II and Pb(II ions from chloride solutions. Both ligands transfer selectively the copper ions into dichloromethane by a cation exchange mechanism. Conventional log-log analysis and isotherm curves showed that Cu(II ions are extracted as the complexes with 1:2 metal to ligand ratio by both extractants. Verification of the effect of the organic diluent used in the extraction of copper ions by HL1 and HL2 demonstrated that the extraction efficiency varies as: dichloromethane ~ dichloroethane > toluene > xylene > ethylacetate. Time dependency investigation of the extraction processes revealed that the kinetics of the extraction of copper by HL2 is more rapid than that of HL1. The application of the ligands for extraction-separation of copper ions from leach solutions of cobalt and nickel-cadmium filter-cakes of a zinc production plants was evaluated.

Antibacterial, antimalarial and leishmanicidal activities of Cu (II) and nickel (II) complexes of diclofenac sodium

International Nuclear Information System (INIS)

Rehman, F.U.; Khan, M.F.; Khan, G.M.; Khan, H.; Khan, I.U.

2010-01-01

Metal complexes are famous for a wide array of chemotherapeutic effects. The current study was designed to synthesize and evaluate unexplored chemotherapeutic effects of Cu (II) and Nickel (II) complexes of the non-steroidal anti-inflammatory drug diclofenac. Nickel complex exhibited significant leishmanicidal activity against Lieshmania major, while the copper complex was found to possess low activity against the same pathogen. Both of the complexes revealed low antibacterial activities and were interestingly failed to produce any considerable antimalarial activity against Plasmodium falciparum 3D7. Selective leishmanicidal activities of Nickel (II) complex of diclofenac needs further improvement to be developed as potential new metal-based leishmanicidal agent.(author)

Antibacterial, antimalarial and leishmanicidal activities of Cu (II) and nickel (II) complexes of diclofenac sodium

Energy Technology Data Exchange (ETDEWEB)

Rehman, F U; Khan, M F; Khan, G M; Khan, H [Gomal University, D.I. Khan (Pakistan). Dept. of Faculty of Pharmacy; Khan, I U [University of Peshawar (Pakistan). Dept. of Faculty of Pharmacy

2010-08-15

Metal complexes are famous for a wide array of chemotherapeutic effects. The current study was designed to synthesize and evaluate unexplored chemotherapeutic effects of Cu (II) and Nickel (II) complexes of the non-steroidal anti-inflammatory drug diclofenac. Nickel complex exhibited significant leishmanicidal activity against Lieshmania major, while the copper complex was found to possess low activity against the same pathogen. Both of the complexes revealed low antibacterial activities and were interestingly failed to produce any considerable antimalarial activity against Plasmodium falciparum 3D7. Selective leishmanicidal activities of Nickel (II) complex of diclofenac needs further improvement to be developed as potential new metal-based leishmanicidal agent.(author)

Supramolecular architecture of metal-organic frameworks involving dinuclear copper paddle-wheel complexes.

Science.gov (United States)

Gomathi, Sundaramoorthy; Muthiah, Packianathan Thomas

2013-12-15

The two centrosymmetric dinuclear copper paddle-wheel complexes tetrakis(μ-4-hydroxybenzoato-κ(2)O:O')bis[aquacopper(II)] dimethylformamide disolvate dihydrate, [Cu2(C7H5O3)4(H2O)2]·2C3H7NO·2H2O, (I), and tetrakis(μ-4-methoxybenzoato-κ(2)O:O')bis[(dimethylformamide-κO)copper(II)], [Cu2(C8H7O3)4(C3H7NO)2], (II), crystallize with half of the dinuclear paddle-wheel cage unit in the asymmetric unit and, in addition, complex (I) has one dimethylformamide (DMF) and one water solvent molecule in the asymmetric unit. In both (I) and (II), two Cu(II) ions are bridged by four syn,syn-η(1):η(1):μ carboxylate groups, showing a paddle-wheel cage-type structure with a square-pyramidal coordination geometry. The equatorial positions of (I) and (II) are occupied by the carboxylate groups of 4-hydroxy- and 4-methoxybenzoate ligands, and the axial positions are occupied by aqua and DMF ligands, respectively. The three-dimensional supramolecular metal-organic framework of (I) consists of three different R2(2)(20) and an R4(4)(36) ring motif formed via O-H···O and OW-HW···O hydrogen bonds. Complex (II) simply packs as molecular species.

X-ray diffraction and X-ray K absorption near edge studies of copper (II) complexes with amino acids

Science.gov (United States)

Sharma, P. K.; Mishra, Ashutosh; Malviya, Varsha; Kame, Rashmi; Malviya, P. K.

2017-05-01

Synthesis of copper (II) complexes [CuL1L2X].nH2O, where n=1, 2,3 (X=Cl,Br,NO3) (L1is 2,2’-bipyridine and L2 is L-tyrosine) by the chemical root method. The XRD data for the samples have been recorded. EXAFS spectra have also been recorded at the K-edge of Cu using the dispersive beam line BL-8 at 2.5 Gev Indus-2 Synchrotron radiation source at RRCAT, Indore, India. XRD and EXAFS data have been analysed using the computer software. X-ray diffraction studies of all complexes indicate their crystalline nature. Lattice parameter, bond length, particle size have been determined from XRD data.

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.

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.

Electroforming copper targets for RTNS-II

International Nuclear Information System (INIS)

Kelley, W.K.; Dini, J.W.; Logan, C.M.

1981-01-01

Copper targets used in RTNS II, which is the world's most intense 14-MeV neutron source, contain water cooling channels for temperature control. There are two methods for fabricating these targets: (1) diffusion bonding a copper panel containing photoetched channels to another copper panel, and (2) an electroforming technique which involves filling the photoetched channels with wax, plating thick copper to seal over the channels and then removing the wax. Development of this latter process and results obtained with it are described

Mesoporous silica nanoparticles supported copper(II) and nickel(II) Schiff base complexes: Synthesis, characterization, antibacterial activity and enzyme immobilization

Science.gov (United States)

Tahmasbi, Leila; Sedaghat, Tahereh; Motamedi, Hossein; Kooti, Mohammad

2018-02-01

Mesoporous silica nanoparticles (MSNs) were prepared by sol-gel method and functionalized with 3-aminopropyltriethoxysilane. Schiff base grafted mesoporous silica nanoparticle was synthesized by the condensation of 2-hydroxy-3-methoxybenzaldehyde and amine-functionalized MSNs. The latter material was then treated with Cu(II) and Ni(II) salts separately to obtain copper and nickel complexes anchored mesoporous composites. The newly prepared hybrid organic-inorganic nanocomposites have been characterized by several techniques such as FT-IR, LA-XRD, FE-SEM, TEM, EDS, BET and TGA. The results showed all samples have MCM-41 type ordered mesoporous structure and functionalization occurs mainly inside the mesopore channel. The presence of all elements in synthesized nanocomposites and the coordination of Schiff base via imine nitrogen and phenolate oxygen were confirmed. MSNs and all functionalized MSNs have uniform spherical nanoparticles with a mean diameter less than 100 nm. The as-synthesized mesoporous nanocomposites were investigated for antibacterial activity against Gram-positive (B. subtilis and S. aureus) and Gram-negative (E. coli and P. aeruginosa) bacteria, as carrier for gentamicin and also for immobilization of DNase, coagulase and amylase enzymes. MSN-SB-Ni indicated bacteriocidal effect against S.aureus and all compounds were found to be good carrier for gentamicin. Results of enzyme immobilization for DNase and coagulase and α-amylase revealed that supported metal complexes efficiently immobilized enzymes.

FEATURES OF INITIATION OF STYRENE POLYMERIZATION BY CUMENE HYDROPEROXIDE IN PRESENCE OF ACETULACETONATE OF COPPER(II

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A. V. Grekova

2016-04-01

Full Text Available Kinetics of sectional styrene polymerization initiated by cumene hydroperoxide, acetylacetonate of copper(II and by the system of cumene hydroperoxide — acetylacetonate of copper(II in a temperature range 333-363 K is studied. Kinetic parameters of polymerization process are determined. It is shown, that system of cumene hydroperoxide — acetylacetonate of copper(II is in 5-6 times more effective on the initiating ability comparatively to application of its individual components. From findings ensues that decline of energy of activating of initiation from 110 kdzh/mol’ to 87 kdzh/mol’ for cumene hydroperoxide at the use of the studied system is caused with participating of monomer in preliminary complexation facilitating formation of free radicals.

Spectroscopic characterization of schiff base-copper complexes immobilized in smectite clays

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Patrícia M. Dias

2010-01-01

Full Text Available Herein, the immobilization of some Schiff base-copper(II complexes in smectite clays is described as a strategy for the heterogenization of homogeneous catalysts. The obtained materials were characterized by spectroscopic techniques, mostly UV/Vis, EPR, XANES and luminescence spectroscopy. SWy-2 and synthetic Laponite clays were used for the immobilization of two different complexes that have previously shown catalytic activity in the dismutation of superoxide radicals, and disproportionation of hydrogen peroxide. The obtained results indicated the occurrence of an intriguing intramolecular redox process involving copper and the imine ligand at the surface of the clays. These studies are supported by computational calculations.

Protective role of quercetin against copper(II)-induced oxidative stress: A spectroscopic, theoretical and DNA damage study.

Science.gov (United States)

Jomova, Klaudia; Lawson, Michael; Drostinova, Lenka; Lauro, Peter; Poprac, Patrik; Brezova, Vlasta; Michalik, Martin; Lukes, Vladimir; Valko, Marian

2017-12-01

The radical scavenging and metal chelating properties of flavonoids indicate that they may play a protective role in diseases with perturbed metal homeostasis such as Alzheimer's disease. In this work we investigated the effect of the coordination of quercetin to copper(II) in view of the formation of ROS in Cu-catalyzed Fenton reaction. ABTS and DPPH assays confirmed that the copper(II)-quercetin complex exhibits a stronger radical scavenging activity than does quercetin alone. EPR spin trapping experiments have shown that chelation of quercetin to copper significantly suppressed the formation of hydroxyl radicals in the Cu(II)-Fenton reaction. DNA damage experiments revealed a protective effect for quercetin, but only at higher stoichiometric ratios of quercetin relative to copper. DNA protective effect of quercetin against ROS attack was described by two mechanisms. The first mechanism lies in suppressed formation of ROS due to the decreased catalytic action of copper in the Fenton reaction, as a consequence of its chelation and direct scavenging of ROS by free quercetin. Since the Cu-quercetin complex intercalates into DNA, the second mechanism was attributed to a suppressed intercalating ability of the Cu-quercetin complex due to the mildly intercalating free quercetin into DNA, thus creating a protective wall against stronger intercalators. Copyright © 2017 Elsevier Ltd. All rights reserved.

Biosorption characteristics of copper (II), chromium (III), nickel (II), and lead (II) from aqueous solutions by Chara sp. and Cladophora sp.

Science.gov (United States)

Elmaci, Ayşe; Yonar, Taner; Ozengin, Nihan

2007-09-01

The aim of this research was to expose individual removals of copper, chromium, nickel, and lead from aqueous solutions via biosorption using nonliving algae species, Chara sp. and Cladophora sp. Optimum pH values for biosorption of copper (II), chromium (III), nickel (II), and lead (II) from aqueous solutions were determined to be 6, 7, 7, and 3 for Cladophora sp. and 5, 3, 5, and 4 for Chara sp. respectively. Maximum adsorption capacities of Chara sp. [10.54 for chromium (III) and 61.72 for lead (II)] and Cladophora sp. [6.59 for chromium (III) and 16.75 and 23.25 for lead (II)] for chromium (III) and lead (II) are similar. On the other hand, copper (II) and nickel (II) biosorption capacity of Cladophora sp. [14.28 for copper (II) and 16.75 for nickel (II)] is greater than Chara sp. [6.506 for copper (II) and 11.76 for nickel (II)]. Significantly high correlation coefficients indicated for the Langmuir adsorption isotherm models can be used to describe the equilibrium behavior of copper, chromium, nickel, and lead adsorption onto Cladophora sp. and Chara sp.

Nonlinear optical and G-Quadruplex DNA stabilization properties of novel mixed ligand copper(II) complexes and coordination polymers: Synthesis, structural characterization and computational studies

Science.gov (United States)

Rajasekhar, Bathula; Bodavarapu, Navya; Sridevi, M.; Thamizhselvi, G.; RizhaNazar, K.; Padmanaban, R.; Swu, Toka

2018-03-01

The present study reports the synthesis and evaluation of nonlinear optical property and G-Quadruplex DNA Stabilization of five novel copper(II) mixed ligand complexes. They were synthesized from copper(II) salt, 2,5- and 2,3- pyridinedicarboxylic acid, diethylenetriamine and amide based ligand (AL). The crystal structure of these complexes were determined through X-ray diffraction and supported by ESI-MAS, NMR, UV-Vis and FT-IR spectroscopic methods. Their nonlinear optical property was studied using Gaussian09 computer program. For structural optimization and nonlinear optical property, density functional theory (DFT) based B3LYP method was used with LANL2DZ basis set for metal ion and 6-31G∗ for C,H,N,O and Cl atoms. The present work reveals that pre-polarized Complex-2 showed higher β value (29.59 × 10-30e.s.u) as compared to that of neutral complex-1 (β = 0.276 × 10-30e.s.u.) which may be due to greater advantage of polarizability. Complex-2 is expected to be a potential material for optoelectronic and photonic technologies. Docking studies using AutodockVina revealed that complex-2 has higher binding energy for both G-Quadruplex DNA (-8.7 kcal/mol) and duplex DNA (-10.1 kcal/mol). It was also observed that structure plays an important role in binding efficiency.

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.

Diethylenetriamine/diamines/copper (II complexes [Cu(dien(NN]Br2: Synthesis, solvatochromism, thermal, electrochemistry, single crystal, Hirshfeld surface analysis and antibacterial activity

Directory of Open Access Journals (Sweden)

Fatima Abu Saleemh

2017-09-01

Full Text Available Two dicationic water soluble mixed triamine/diamine copper (II complexes, of general formula [Cu(dienNN]Br2 (1–2 [dien = diethelenetriamine and NN is en = ethylenediamine or Me4en = N,N′,N,N′-tetramethylethylenediamine] were prepared under ultrasonic mode with a relatively high yield. These complexes were characterized by elemental microanalysis, UV visible IR spectroscopy, and thermal and electrochemical techniques. In addition, complex 2 structure was solved by X-ray single crystal and Hirshfeld surface analysis. The complex exhibits a distorted square pyramidal coordination environment around Cu(II centre. The solvatochromism of the desired complexes was investigated in water and other suitable organic solvents. The results show that the Guttmann’s DN parameter values of the solvents have mainly contributed to the shift of the d–d absorption band towards the linear increase in the wavelength of the absorption maxima of the complexes. The complex 1 showed higher antibacterial activity against the studied microorganisms compared to complex 2. Both complexes revealed promising antibacterial activities.

Synthesis and studies on Cu(II), Co(II), Ni(II) complexes of Knoevenagel β-diketone ligands

Science.gov (United States)

Sumathi, S.; Tharmaraj, P.; Sheela, C. D.; Anitha, C.

2012-11-01

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, 1H NMR, Mass and ESR spectral studies. Conductivity measurements reveal that all the complexes are non-electrolytic in nature. Spectroscopic and other analytical data of the complexes suggest octahedral geometry for other metal(II) complexes. The redox behavior 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 the bacteria Pseudomonas aeruginosa, Escherichia coli and Staphylococcus aureus as well as the fungus Candida albicans by well diffusion method. The zone of inhibition value indicates that the most of 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 (L1-L3) was found to be considerable effect than that of urea and KDP (potassium dihydrogen phosphate).

Interaction between metals and nucleic acids. Part 3. Synthesis and structural studies of copper(II) complexes with Schiff base ligands derived from barbituric acid

Energy Technology Data Exchange (ETDEWEB)

Sasaki, I.; Gaudemer, A.; Chiaroni, A.; Riche, C.

1986-02-17

Schiff bases have been prepared from 5-formylbarbituric acid and 5-formyl-1,3-dimethyl-barbituric acid and various di- or tri-amines. The structure of the corresponding copper(II) complexes have been established by elemental analysis and spectroscopic methods. The molecular structure of one of the complexes, Cu(DiMeBardpt), was determined by X-ray diffraction. Electrochemical study shows that these complexes are reduced at slightly more negative potentials than the corresponding complexes obtained from uracil, which suggests that these new ligands are better electron-donors.

Towards a selective adsorbent for arsenate and selenite in the presence of phosphate: Assessment of adsorption efficiency, mechanism, and binary separation factors of the chitosan-copper complex.

Science.gov (United States)

Yamani, Jamila S; Lounsbury, Amanda W; Zimmerman, Julie B

2016-01-01

The potential for a chitosan-copper polymer complex to select for the target contaminants in the presence of their respective competitive ions was evaluated by synthesizing chitosan-copper beads (CCB) for the treatment of (arsenate:phosphate), (selenite:phosphate), and (selenate:sulfate). Based on work by Rhazi et al., copper (II) binds to the amine moiety on the chitosan backbone as a monodentate complex (Type I) and as a bidentate complex crosslinking two polymer chains (Type II), depending on pH and copper loading. In general, the Type I complex exists alone; however, beyond threshold conditions of pH 5.5 during synthesis and a copper loading of 0.25 mol Cu(II)/mol chitosan monomer, the Type I and Type II complexes coexist. Subsequent chelation of this chitosan-copper ligand to oxyanions results in enhanced and selective adsorption of the target contaminants in complex matrices with high background ion concentrations. With differing affinities for arsenate, selenite, and phosphate, the Type I complex favors phosphate chelation while the Type II complex favors arsenate chelation due to electrostatic considerations and selenite chelation due to steric effects. No trend was exhibited for the selenate:sulfate system possibly due to the high Ksp of the corresponding copper salts. Binary separation factors, α12, were calculated for the arsenate-phosphate and selenite-phosphate systems, supporting the mechanistic hypothesis. While, further research is needed to develop a synthesis method for the independent formation of the Type II complexes to select for target contaminants in complex matrices, this work can provide initial steps in the development of a selective adsorbent. Copyright © 2015 Elsevier Ltd. All rights reserved.

Sequestration of chelated copper by structural Fe(II): Reductive decomplexation and transformation of Cu{sup II}-EDTA

Energy Technology Data Exchange (ETDEWEB)

He, Hongping [State Key Laboratory of Pollution Control and Resources Reuse, School of Environmental Science & Engineering, Tongji University, Shanghai 200092 (China); Wu, Deli, E-mail: wudeli@tongji.edu.cn [State Key Laboratory of Pollution Control and Resources Reuse, School of Environmental Science & Engineering, Tongji University, Shanghai 200092 (China); Zhao, Linghui [State Key Laboratory of Pollution Control and Resources Reuse, School of Environmental Science & Engineering, Tongji University, Shanghai 200092 (China); Luo, Cong [School of Civil and Environmental Engineering, Georgia Institute of Technology, GA 30332 (United States); Dai, Chaomeng; Zhang, Yalei [State Key Laboratory of Pollution Control and Resources Reuse, School of Environmental Science & Engineering, Tongji University, Shanghai 200092 (China)

2016-05-15

Highlights: • Structural Fe(II) was found to reveal high sequestration potential in various chelated copper. • Chelated copper was reduced to Cu(0) and Cu{sub 2}O by =Fe(II), whcih was oxidized to Fe{sub 2}O{sub 3}·H{sub 2}O. • Both electron transfer and surface =Fe(II) were found to be crucial during chelated copper reduction. • The indispensible role of reductive decomplexation was identified in chelated copper sequestration. - Abstract: Chelated coppers, such as Cu{sup II}-EDTA, are characteristically refractory and difficult to break down because of their high stability and solubility. Cu{sup II}–EDTA sequestration by structural Fe(II) (=Fe(II)) was investigated intensively in this study. Up to 101.21 mgCu(II)/gFe(II) was obtained by =Fe(II) in chelated copper sequestration under near neutral pH condition (pH 7.70). The mechanism of Cu{sup II}-EDTA sequestration by =Fe(II) was concluded as follows: 3Cu{sup II}–EDTA + 7=Fe(II) + 9H{sub 2}O → Cu(0) ↓ + Cu{sub 2}O ↓ (the major product) + 2Fe{sub 2}O{sub 3}·H{sub 2}O ↓ + 3Fe{sup II}–EDTA +14H{sup +} Novel results strongly indicate that Cu{sup II} reductive transformation induced by surface =Fe(II) was mainly responsible for chelated copper sequestration. Cu(0) generation was initially facilitated, and subsequent reduction of Cu(II) into Cu(I) was closely combined with the gradual increase of ORP (Oxidation-Reduction Potential). Cu-containing products were inherently stable, but Cu{sub 2}O would be reoxidized to Cu(II) with extra-aeration, resulting in the release of copper, which was beneficial to Cu reclamation. Concentration diminution of Cu{sup II}–EDTA within the electric double layer and competitive adsorption were responsible for the negative effects of Ca{sup 2+}, Mg{sup 2+}. By generating vivianite, PO{sub 4}{sup 3−} was found to decrease surface =Fe(II) content. This study is among the first ones to identify the indispensible role of reductive decomplexation in chelated copper

Photochemical redox reactions of copper(II)-alanine complexes in aqueous solutions.

Science.gov (United States)

Lin, Chen-Jui; Hsu, Chao-Sheng; Wang, Po-Yen; Lin, Yi-Liang; Lo, Yu-Shiu; Wu, Chien-Hou

2014-05-19

The photochemical redox reactions of Cu(II)/alanine complexes have been studied in deaerated solutions over an extensive range of pH, Cu(II) concentration, and alanine concentration. Under irradiation, the ligand-to-metal charge transfer results in the reduction of Cu(II) to Cu(I) and the concomitant oxidation of alanine, which produces ammonia and acetaldehyde. Molar absorptivities and quantum yields of photoproducts for Cu(II)/alanine complexes at 313 nm are characterized mainly with the equilibrium Cu(II) speciation where the presence of simultaneously existing Cu(II) species is taken into account. By applying regression analysis, individual Cu(I) quantum yields are determined to be 0.094 ± 0.014 for the 1:1 complex (CuL) and 0.064 ± 0.012 for the 1:2 complex (CuL2). Individual quantum yields of ammonia are 0.055 ± 0.007 for CuL and 0.036 ± 0.005 for CuL2. Individual quantum yields of acetaldehyde are 0.030 ± 0.007 for CuL and 0.024 ± 0.007 for CuL2. CuL always has larger quantum yields than CuL2, which can be attributed to the Cu(II) stabilizing effect of the second ligand. For both CuL and CuL2, the individual quantum yields of Cu(I), ammonia, and acetaldehyde are in the ratio of 1.8:1:0.7. A reaction mechanism for the formation of the observed photoproducts is proposed.

Syntheses, structures, and properties of imidazolate-bridged Cu(II)-Cu(II) and Cu(II)-Zn(II) dinuclear complexes of a single macrocyclic ligand with two hydroxyethyl pendants.

Science.gov (United States)

Li, Dongfeng; Li, Shuan; Yang, Dexi; Yu, Jiuhong; Huang, Jin; Li, Yizhi; Tang, Wenxia

2003-09-22

The imidazolate-bridged homodinuclear Cu(II)-Cu(II) complex, [(CuimCu)L]ClO(4).0.5H(2)O (1), and heterodinuclear Cu(II)-Zn(II) complex, [(CuimZnL(-)(2H))(CuimZnL(-)(H))](ClO(4))(3) (2), of a single macrocyclic ligand with two hydroxyethyl pendants, L (L = 3,6,9,16,19,22-hexaaza-6,19-bis(2-hydroxyethyl)tricyclo[22,2,2,2(11,14)]triaconta-1,11,13,24,27,29-hexaene), have been synthesized as possible models for copper-zinc superoxide dismutase (Cu(2),Zn(2)-SOD). Their crystal structures analyzed by X-ray diffraction methods have shown that the structures of the two complexes are markedly different. Complex 1 crystallizes in the orthorhombic system, containing an imidazolate-bridged dicopper(II) [Cu-im-Cu](3+) core, in which the two copper(II) ions are pentacoordinated by virtue of an N4O environment with a Cu.Cu distance of 5.999(2) A, adopting the geometry of distorted trigonal bipyramid and tetragonal pyramid, respectively. Complex 2 crystallizes in the triclinic system, containing two similar Cu-im-Zn cores in the asymmetric unit, in which both the Cu(II) and Zn(II) ions are pentacoordinated in a distorted trigonal bipyramid geometry, with the Cu.Zn distance of 5.950(1)/5.939(1) A, respectively. Interestingly, the macrocyclic ligand with two arms possesses a chairlike (anti) conformation in complex 1, but a boatlike (syn) conformation in complex 2. Magnetic measurements and ESR spectroscopy of complex 1 have revealed the presence of an antiferromagnetic exchange interaction between the two Cu(II) ions. The ESR spectrum of the Cu(II)-Zn(II) heterodinuclear complex 2 displayed a typical signal for mononuclear trigonal bipyramidal Cu(II) complexes. From pH-dependent ESR and electronic spectroscopic studies, the imidazolate bridges in the two complexes have been found to be stable over broad pH ranges. The cyclic voltammograms of the two complexes have been investigated. Both of the two complexes can catalyze the dismutation of superoxide and show rather high activity.

Electrochemical behaviour of alkaline copper complexes

Indian Academy of Sciences (India)

Abstract. A search for non-cyanide plating baths for copper resulted in the development of alkaline copper complex baths containing trisodium citrate [TSC] and triethanolamine [TEA]. Voltammetric studies were carried out on platinum to understand the electrochemical behaviour of these complexes. In TSC solutions, the.

Complexação da tetraciclina, da oxitetraciclina e da clortetraciclina com o catião cobre (II. Estudo potenciométrico Tetracycline, oxytetracycline and chlortetracycline complexation with copper (II. Potentiometric study

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Cristina M. C. M. Couto

2000-08-01

Full Text Available Stability constants of complexes formed by copper (II with three different tetracyclines (tetracycline, oxytetracycline and chlortetracycline have been determined potentiometrically with an automatic system in aqueous medium at 25,0 ± 0,2 ºC and I = 0,1 mol L-1 NaNO3. The protonation constants of the three tetracyclines were also determined under the same conditions. The distribution of the complexes was then simulated at therapeutic levels of the drugs.

Structural measurements and cell line studies of the copper-PEG-Rifampicin complex against Mycobacterium tuberculosis.

Science.gov (United States)

Manning, Thomas; Mikula, Rachel; Wylie, Greg; Phillips, Dennis; Jarvis, Jackie; Zhang, Fengli

2015-02-01

The bacterium responsible for tuberculosis is increasing its resistance to antibiotics resulting in new multidrug-resistant Mycobacterium tuberculosis (MDR-TB) and extensively drug-resistant tuberculosis (XDR-TB). In this study, several analytical techniques including NMR, FT-ICR, MALDI-MS, LC-MS and UV/Vis are used to study the copper-Rifampicin-Polyethylene glycol (PEG-3350) complex. The copper (II) cation is a carrier for the antibiotic Rifampicin as well as nutrients for the bacterium. The NIH-NIAID cell line containing several Tb strains (including antibiotic resistant strains) is tested against seven copper-PEG-RIF complex variations. Copyright © 2014 Elsevier Ltd. All rights reserved.

Spectrophotometric determination of cobalt(II), nickel(II) and copper (II) with 1-(2 pyridylazo)-2-naphthol in micellar medium

International Nuclear Information System (INIS)

Shar, G.A.; Soomro, G.A.

2004-01-01

Spectrophotometric determination of cobalt(II), nickel(II) and copper(II) is carried out with 1-(2 pyridylazo)-2-naphthol as a complexing reagent in aqueous phase using non-ionic surfactant Tween 80. Beer's law is obeyed for Co(II), Ni(II) and Cu(II) over the range 0.5 - 4.0, 0.5 - 4.0 and 0.5 - 3.0 ngmL/sup -1/ with detection limit (2 σ) of 6.7, 3.2 and 3.9 ngmL/sup -1/. The max molar absorption, molar absorptivity, Sandell's sensitivity of Co(II), Ni(II) and Cu(II) are 580 nm, 570 nm and 555 nm; max (104 mol/sup -1/ cm /sup -1/) is 0.87, 1.8 and 1.6 and 6.8, 3.3 and 3.9 ng cm-2 respectively. The pH at which complex is formed for Co(II), Ni(II) and Cu(II) is 5, 5.5 and 6.5 respectively. The critical micelle concentration (CMC) of Tween 80 is 5%. The present method is compared with that of atomic absorption spectroscopy and no significant difference is noted between the two methods at 95% confidence level. The method has been applied to the determination of Co(II), Ni(II) and Cu(II) in industrial waste water and pharmaceutical samples. (author)

Preconcentration and extraction of copper(II) on activated carbon using ethyl-2-quinolyl-β (p-carboxyphenyl hydrazone)dioxo propionate

OpenAIRE

Mehrorang Ghaedi; Farshid Ahmadi; M.R. Baezat; J. Safari

2008-01-01

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 ethyl-2-quinolyl-β(p-carboxyphenyl hydrazone)dioxo propionate (EQCPDP). The adsorbed copper(II) ion on solid phase was eluted quantitatively by using nitric acid. The important parameter...

Nitrite to nitric oxide interconversion by heme FeII complex assisted by [CuI(tmpa)]+

KAUST Repository

Turias, Francesc; Solà , Miquel; Falivene, Laura; Cavallo, Luigi; Poater, Albert

2015-01-01

The present computational study complements the recent experimental efforts by Karlin and coworkers to describe the interconversion of nitrite to nitric oxide by means of an iron porphyrin complex together with a Cu chemical system, i.e., the iron(II) complex (F8TPP)FeII [F8TPP = tetrakis(2,6-difluorophenyl)porphyrinate(2−)] and a preformed copper(II)–nitrito complex [(tmpa)CuII(NO2)][B(C6F5)4] [tmpa = tris(2-pyridylmethyl)amine], being the latter an oxidized species of [(tmpa)CuI(MeCN)]+. By DFT calculations, we unravel how the reduction of nitrite to nitric oxide takes place through a μ-oxo heme-FeIII–O–CuII complex, following a mimetic path as in the cytochrome c oxidase. Mayer bond order (MBO) and energy decomposition analyses are used to analyze the bonding strength of such nitro derivatives to either copper or iron. © 2015 Springer Science+Business Media New York

Nitrite to nitric oxide interconversion by heme FeII complex assisted by [CuI(tmpa)]+

KAUST Repository

Turias, Francesc

2015-09-09

The present computational study complements the recent experimental efforts by Karlin and coworkers to describe the interconversion of nitrite to nitric oxide by means of an iron porphyrin complex together with a Cu chemical system, i.e., the iron(II) complex (F8TPP)FeII [F8TPP = tetrakis(2,6-difluorophenyl)porphyrinate(2−)] and a preformed copper(II)–nitrito complex [(tmpa)CuII(NO2)][B(C6F5)4] [tmpa = tris(2-pyridylmethyl)amine], being the latter an oxidized species of [(tmpa)CuI(MeCN)]+. By DFT calculations, we unravel how the reduction of nitrite to nitric oxide takes place through a μ-oxo heme-FeIII–O–CuII complex, following a mimetic path as in the cytochrome c oxidase. Mayer bond order (MBO) and energy decomposition analyses are used to analyze the bonding strength of such nitro derivatives to either copper or iron. © 2015 Springer Science+Business Media New York

Evidence for organic complexed copper in sea water

Energy Technology Data Exchange (ETDEWEB)

Slowey, J F; Jeffrey, L M; Hood, D W

1967-04-22

A few attempts have been made to characterize the chemical components contributing to the copper content of seawater. About 0.3 mu/liter of particulate copper in 2 stations in the English Channel and 15 mu/liter of ultrafilterable (10 mu) but non-dialyzable copper in a sample from Texas Bay has been reported. Also the evidence has been shown for copper in the organic form in waters of the Florida Current. The occasional presence of non- dialyzable copper for many samples from the Gulf of Mexico suggests that strongly complexed copper-organic compounds are present in seawater. This communication presents evidence for such complexes that are extractable into a nonpolar solvent in the absence of any added chelating agent. Preliminary results have shown that the copper- organic complex isolated by chloroform extraction occurs in the eighth fraction of the Hirsch and Ahrens lipid separation method using silica gel chromatography. This would indicate that copper complex is associated with the phospholipid, amino lipid, or porphyrin fraction of the lipids.

Copper (II)

African Journals Online (AJOL)

CLEMENT O BEWAJI

Valine (2 - amino - 3 – methylbutanoic acid), is a chemical compound containing .... Stability constant (Kf). Gibb's free energy. ) (. 1. −. ∆. Mol. JG. [CuL2(H2O)2] ... synthesis and characterization of Co(ii), Ni(ii), Cu (II), and Zn(ii) complexes with ...

Fe (III), Co(II), Ni(II), Cu(II) and Zn(II) complexes of schiff bases based-on glycine and phenylalanine: Synthesis, magnetic/thermal properties and antimicrobial activity

Science.gov (United States)

Sevgi, Fatih; Bagkesici, Ugur; Kursunlu, Ahmed Nuri; Guler, Ersin

2018-02-01

Zinc (II), copper (II), nickel (II), cobalt (II) and iron (III) complexes of Schiff bases (LG, LP) derived from 2-hydroxynaphthaldehyde with glycine and phenylalanine were reported and characterized by 1H NMR, 13C NMR, elemental analyses, melting point, FT-IR, magnetic susceptibility and thermal analyses (TGA). TGA data show that iron and cobalt include to the coordinated water and metal:ligand ratio is 1:2 while the complex stoichiometry for Ni (II), Cu (II) and Zn (II) complexes is 1:1. As expected, Ni (II) and Zn (II) complexes are diamagnetic; Cu (II), Co (II) and Fe (III) complexes are paramagnetic character due to a strong ligand of LG and LP. The LG, LP and their metal complexes were screened for their antimicrobial activities against five Gram-positive (Staphylococcus aureus, Methicillin resistant Staphylococcus aureus (MRSA), Bacillus cereus, Streptococcus mutans and Enterococcus faecalis) and three Gram-negative (Escherichia coli, Klebsiella pneumoniae and Pseudomonas aeruginosa) and one fungi (Candida albicans) by using broth microdilution techniques. The activity data show that ligands and their metal complexes exhibited moderate to good activity against Gram-positive bacteria and fungi.

Luminescence properties of copper(I), zinc(II) and cadmium(II) coordination compounds with picoline ligands

Energy Technology Data Exchange (ETDEWEB)

Małecki, Jan Grzegorz, E-mail: gmalecki@us.edu.pl; Maroń, Anna

2017-06-15

Mononuclear coordination compounds of copper(I) – [Cu(PPh{sub 3}){sub 2}(picoline)(NO{sub 3})], zinc(II) – [ZnCl{sub 2}(picoline){sub 2}] (picoline=3– and 4–methylpyridine) and polymeric cadmium(II) – [CdCl{sub 2}(β-picoline){sub 2}]{sub n} were prepared and their luminescence properties in solid state and acetonitrile solutions were determined. Single crystal X-ray crystallography revealed distorted tetrahedral geometry around the central ions of the compounds. The compounds exhibit green photoluminescence in solid state and in acetonitrile solutions. The emission of copper(I) compounds originated from metal-to-ligand charge transfer state combined with nitrato-to-picoline charge transfer state i.e. ({sup 1}(M+X)LCT). The presence of nitrato ligand in the coordination sphere of copper(I) compounds quenches the emission. Luminescence of zinc(II) and cadmium(II) compounds results from chloride-to-picoline charge transfer state and the quantum efficiency in the case of the polymeric Cd(II) compound reaches 39%. The photoluminescence quantum yields of the mononuclear zinc(II) compounds vary from 10 to 16% depending on the conditions (solid state, solution). - Graphical abstract: Coordination compounds of copper(I), zinc(II) and polymeric cadmium(II) with picoline ligands were prepared and their luminescence properties in solid state and acetonitrile solutions were determined. The compounds exhibit green photoluminescence in solid state and in acetonitrile solutions. Emission of copper(I) compounds originated from {sup 1}(M+X)LCT state. Luminescence of zinc(II) and cadmium(II) compounds results from chloride-to-picoline charge transfer state and the quantum efficiency in the case of the polymeric Cd(II) compound reaches 39%. The photoluminescence quantum yields of the mononuclear zinc(II) compounds vary from 10 to 16% depending on the conditions (solid state, solution).

Synthesis and Characterization of Cu(II), Co(II) and Ni(II) Complexes of Trithiocyanuric Acid: The Structure of {N,N'-Bis(3-Aminopropyl)-1,3-Propanediamine}-(Trithiocyanurato)Nickel(II)

Czech Academy of Sciences Publication Activity Database

Kopel, P.; Trávníček, Zdeněk; Kvítek, L.; Černošek, Z.; Wrzeszcz, G.; Marek, J.

2003-01-01

Roč. 56, č. 1 (2003), s. 1-11 ISSN 0095-8972 R&D Projects: GA ČR GA203/00/0152; GA AV ČR IBS5038351 Institutional research plan: CEZ:AV0Z5038910 Keywords : Copper(II) * cobalt(II) and nickel(II) complexes * Trithiocyanuric acid Subject RIV: CE - Biochemistry Impact factor: 0.841, year: 2003

Formation of a dinuclear copper(II) complex through the cleavage of CN bond of 1-benzoyl-3-(pyridin-2-yl)-1H-pyrazole

Energy Technology Data Exchange (ETDEWEB)

Shardin, Rosidah; Pui, Law Kung; Yamin, Bohari M. [School of Chemical Sciences and Food Technology, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, UKM 43600 Bangi, Selangor (Malaysia); Kassim, Mohammad B. [School of Chemical Sciences and Food Technology, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, UKM 43600 Bangi, Selangor, Malaysia and Fuel Cell Institute, Universiti Kebangsaan Malaysia, UKM 43600 Bangi, Selangor (Malaysia)

2014-09-03

A simple mononuclear octahedral copper(II) complex was attempted from the reaction of three moles of 1-benzoyl-3-(pyridin-2-yl)-1H-pyrazole and one mole of copper(II) perchlorate hexahydrate in methanol. However, the product of the reaction was confirmed to be a dinuclear copper(II) complex with μ-(3-(pyridin-2-yl)-pyrazolato) and 3-(pyridin-2-yl)-1H-pyrazole ligands attached to each of the Cu(II) centre atom. The copper(II) ion assisted the cleavage of the C{sub benzoyl}N bond afforded a 3-(pyridin-2-yl)-1H-pyrazole molecule. Deprotonation of the 3-(pyridin-2-yl)-1H-pyrazole gave a 3-(pyridin-2-yl)-pyrazolato, which subsequently reacted with the Cu(II) ion to give the (3-(pyridin-2-yl)-pyrazolato)(3-(pyridin-2-yl)-1H-pyrazole)Cu(II) product moiety. The structure of the dinuclear complex was confirmed by x-ray crystallography. The complex crystallized in a monoclinic crystal system with P2(1)/n space group and cell dimensions of a = 12.2029(8) Å, b = 11.4010(7) Å, c = 14.4052(9) Å and β = 102.414(2)°. The compound was further characterized by mass spectrometry, CHN elemental analysis, infrared and UV-visible spectroscopy and the results concurred with the x-ray structure. The presence of d-d transition at 671 nm (ε = 116 dm{sup 3} mol{sup −1} cm{sup −1}) supports the presence of Cu(II) centres.

Syntheses, crystal structures and spectroscopic properties of copper(II)-tetracyanometallate(II) complexes with nicotinamide and isonicotinamide ligands

Science.gov (United States)

Sayın, Elvan; Kürkçüoğlu, Güneş Süheyla; Yeşilel, Okan Zafer; Hökelek, Tuncer

2015-09-01

Four new one dimensional (1D) cyanide complexes, namely {[Cu(NH3)4(μ-na)][M‧(CN)4]}n and {[Cu(NH3)2(ina)2M‧(μ-CN)2(CN)2]}n (M‧(II) = Pd (1 and 3) or Pt (2 and 4), na:nicotinamide and ina:isonicotinamide) have been synthesized and characterized by elemental, spectral (FT-IR and Raman), and thermal (TG, DTG and DTA) analyses. The crystal structures of complexes 1-3 have been determined by single crystal X-ray diffraction technique. In complexes 1 and 2, na ligand is coordinated to the adjacent Cu(II) ions as a bridging ligand, giving rise to 1D linear cationic chain and the [M‧(CN)4]2- anionic complex acts as a counter ion. Complexes 3 and 4 are also 1D linear chain in which two cyanide ligands bridged neighboring M‧(II) and Cu(II) ions, while ina ligand is coordinated Cu(II) ion through nitrogen atom of pyridine ring. In the complexes, the Cu(II) ions adopt distorted octahedral geometries, while M‧(II) ions are four coordinated with four carbon atoms from cyanide ligands in square-planar geometries. The adjacent chains are further stacked through intermolecular hydrogen bond, Nsbnd Hṡṡṡπ, Csbnd H⋯M‧ and M‧⋯π interactions to form 3D supramolecular networks. Vibration assignments are given for all the observed bands. In addition, thermal stabilities of the compounds are also discussed.

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

) 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...... with the inorganic ligands at cis positions. The coordination polyhedron around the metal ion in [Co([3(5)]adz)][ZnCl4] (10b) and [Zn([3(5)]adz)][ZnCl4] (12) is a slightly distorted tetrahedron. Anation equilibrium constants were determined spectrophotometrically for complexes 2-6 at 25 and 40 degreesC and fall...

(Metformin-κ2N,N′(salicylato-κ2O,O′copper(II trihydrate

Directory of Open Access Journals (Sweden)

Sandra Julieta Gutiérrez Ojeda

2018-02-01

Full Text Available The hydrous title complex [systematic name: (1,1-dimethylbiguanide-κ2N2,N4(2-oxidobenzoato-κ2O,O′copper(II trihydrate], [Cu(C7H4O3(C4H11N5]·3H2O, was synthesized electrolytically from an ethanolic solution of metformin hydrochloride, acetylsalicylic acid, Pepto-Bismol and a copper sacrificial anode. Diffraction data were collected at 0.56 Å resolution, allowing the accurate determination of H-atom positions in the neutral metformin ligand. Both imine groups in metformin have very similar N=C bond lengths, 1.2978 (17 and 1.3033 (17 Å, and the salicylate dianion behaves as a chelating ligand. The coordination sphere of the copper(II cation deviates marginally from a square-planar arrangement. In the crystal, short Cu...Cu separations of 3.5476 (3 Å are observed, along with classical hydrogen-bonding interactions.

Copper complexes as 'radiation recovery' agents

International Nuclear Information System (INIS)

Sorenson, J.R.J.

1989-01-01

Copper and its compounds have been used for their remedial effects since the beginning of recorded history. As early as 3000 BC the Egyptians used copper as an antiseptic for healing wounds and to sterilise drinking water; and later, ca 1550 BC, the Ebers Papyrus reports the use of copper acetate, copper sulphate and pulverised metallic copper for the treatment of eye infections. These historical uses of copper and its compounds are particularly interesting in the light of modern evidence concerning the use of certain copper complexes for the treatment of radiation sickness and more recently as an adjunct to radiotherapy for cancer patients. (author)

Study on the interaction of a copper(II) complex containing the artificial sweetener aspartame with human serum albumin.

Science.gov (United States)

Shahabadi, Nahid; Khodaei, Mohammad Mehdi; Kashanian, Soheila; Kheirdoosh, Fahimeh; Filli, Soraya Moradi

2014-05-01

A copper(II) complex containing aspartame (APM) as ligand, Cu(APM)2Cl2·2H2O, was synthesized and characterized. In vitro binding interaction of this complex with human serum albumin (HSA) was studied at physiological pH. Binding studies of this complex with HSA are useful for understanding the Cu(APM)2Cl2·2H2O-HSA interaction mechanism and providing guidance for the application and design of new and more efficient artificial sweeteners drive. The interaction was investigated by spectrophotometric, spectrofluorometric, competition experiment and circular dichroism. Hyperchromicity observed in UV absorption band of Cu(APM)2Cl2·2H2O. A strong fluorescence quenching reaction of HSA to Cu(APM)2Cl2·2H2O was observed and the binding constant (Kf) and corresponding numbers of binding sites (n) were calculated at different temperatures. Thermodynamic parameters, enthalpy change (∆H) and entropy change (∆S) were calculated to be -458.67 kJ mol(-1) and -1,339 J mol(-1 )K(-1) respectively. According to the van't Hoff equation, the reaction is predominantly enthalpically driven. In conformity with experimental results, we suggest that Cu(APM)2Cl2·2H2O interacts with HSA. In comparison with previous study, it is found that the Cu(II) complex binds stronger than aspartame.

Determining the Amount of Copper(II) Ions in a Solution Using a Smartphone

Science.gov (United States)

Montangero, Marc

2015-01-01

When dissolving copper in nitric acid, copper(II) ions produce a blue-colored solution. It is possible to determine the concentration of copper(II) ions, focusing on the hue of the color, using a smartphone camera. A free app can be used to measure the hue of the solution, and with the help of standard copper(II) solutions, one can graph a…

Hexacoordinated mixed-ligand complexes of vanadium(IV) and copper(II)

International Nuclear Information System (INIS)

Islam, M.S.; Motahera Begum; Roy, H.N.; Haroon, S.A.Q.M.

1996-01-01

The literature reports simple complexes of metal ions with Schiff bases derived from amino acids. But their mixed-ligand complexes are very rare. Keeping this fact in mind, some new mixed ligand complexes of V IV and Cu II with tridentate Schiff bases derived from glycine, salicylaldehyde and amino bases, e.g. quinoline (Q), isoquinoline (IQ), 2-picoline (2-pic), 4-picoline (4-pic) and pyridine (Py) were prepared and studied. 6 refs., 1 tab

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

A new copper(II) Schiff base complex containing asymmetrical tetradentate N.sub.2./sub.O.sub.2./sub. Schiff base ligand: Synthesis, characterization, crystal structure and DFT study

Czech Academy of Sciences Publication Activity Database

Grivani, G.; Baghan, S.H.; Vakili, M.; Khalaji, A.D.; Tahmasebi, V.; Eigner, Václav; Dušek, Michal

2015-01-01

Roč. 1082, Feb (2015), 91-96 ISSN 0022-2860 R&D Projects: GA ČR(CZ) GA14-03276S Institutional support: RVO:68378271 Keywords : Schiff-base * copper (II) * complex * single-crystal * thermal decomposition * DFT Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.780, year: 2015

Synthesis, characterization, DNA binding and cleavage studies of mixed-ligand copper (II complexes

Directory of Open Access Journals (Sweden)

M. Sunita

2017-05-01

Full Text Available New two copper complexes of type [Cu(Bzimpy(LH2O]SO4 (where L = 2,2′ bipyridine (bpy, and ethylene diamine (en, Bzimpy = 2,6-bis(benzimidazole-2ylpyridine have been synthesized and characterized by elemental analyses, molar conductance measurements, magnetic susceptibility measurements, mass, IR, electronic and EPR spectral studies. Based on elemental and spectral studies six coordinated geometries were assigned to the two complexes. DNA-binding properties of these metal complexes were investigated using absorption spectroscopy, fluorescence spectroscopy, viscosity measurements and thermal denaturation methods. Experimental studies suggest that the complexes bind to DNA through intercalation. These complexes also promote the cleavage of plasmid pBR322, in the presence of H2O2.

Geometric control of nuclearity in copper(I)/dioxygen chemistry.

Science.gov (United States)

Abe, Tsukasa; Morimoto, Yuma; Tano, Tetsuro; Mieda, Kaoru; Sugimoto, Hideki; Fujieda, Nobutaka; Ogura, Takashi; Itoh, Shinobu

2014-08-18

Copper(I) complexes supported by a series of N3-tridentate ligands bearing a rigid cyclic diamine framework such as 1,5-diazacyclooctane (L8, eight-membered ring), 1,4-diazacycloheptane (L7, seven-membered ring), or 1,4-diazacyclohexane (L6, six-membered ring) with a common 2-(2-pyridyl)ethyl side arm were synthesized and their reactivity toward O2 were compared. The copper(I) complex of L8 preferentially provided a mononuclear copper(II) end-on superoxide complex S as reported previously [Itoh, S., et al. J. Am. Chem. Soc. 2009, 131, 2788-2789], whereas a copper(I) complex of L7 gave a bis(μ-oxido)dicopper(III) complex O at a low temperature (-85 °C) in acetone. On the other hand, no such active-oxygen complex was detected in the oxygenation reaction of the copper(I) complex of L6 under the same conditions. In addition, O2-reactivity of the copper(I) complex supported by an acyclic version of the tridentate ligand (LA, PyCH2CH2N(CH3)CH2CH2CH2N(CH3)2; Py = 2-pyridyl) was examined to obtain a mixture of a (μ-η(2):η(2)-peroxido)dicopper(II) complex (S)P and a bis(μ-oxido)dicopper(III) complex O. Careful inspection of the crystal structures of copper(I) and copper(II) complexes and the redox potentials of copper(I) complexes has revealed important geometric effects of the supporting ligands on controlling nuclearity of the generated copper active-oxygen complexes.

Strong copper(II) species in estuarine and sea waters investigated by a method with high detection window.

Science.gov (United States)

Alberti, Giancarla; Biesuz, Raffaela; D'Agostino, Girolamo; Scarponi, Giuseppe; Pesavento, Maria

2007-02-15

The distribution of copper(II) in species of different stability in some estuarine and sea water samples (Adriatic Sea) was investigated by a method based on the sorption of the metal ion on a strongly sorbing resin, Chelex 100, whose sorbing properties have been previously characterized. From them, it is possible to predict very high values of detection windows at the considered conditions, for example side reaction coefficient as high as 10(10) at pH 7.5. Strong copper(II) species in equilibrium with Chelex 100 were detected, at concentration 2-20nM, with a reaction coefficient approximately 10(10.6) at pH 7.45 in sea water, strictly depending on the acidity. They represent 50-70% of the total metal ion and are the strongest copper(II) complexes found in sea water. Weak complexes too were detected in all the samples, with reaction coefficient lower than ca. 10(9) at the same pH. The method applied, named resin titration (RT), was described in a previous investigation, and is here modified in order to be carried out on oceanographic boat during a cruise in the Adriatic Sea.

A Schiff base-derived copper (II) complex is a potent inducer of apoptosis in colon cancer cells by activating the intrinsic pathway.

Science.gov (United States)

Hajrezaie, Maryam; Paydar, Mohammadjavad; Moghadamtousi, Soheil Zorofchian; Hassandarvish, Pouya; Gwaram, Nura Suleiman; Zahedifard, Maryam; Rouhollahi, Elham; Karimian, Hamed; Looi, Chung Yeng; Ali, Hapipah Mohd; Abdul Majid, Nazia; Abdulla, Mahmood Ameen

2014-01-01

Metal-based drugs with extensive clinical applications hold great promise for the development of cancer chemotherapeutic agents. In the last few decades, Schiff bases and their complexes have become well known for their extensive biological potential. In the present study, we examined the antiproliferative effect of a copper (II) complex on HT-29 colon cancer cells. The Cu(BrHAP)2 Schiff base compound demonstrated a potent antiproliferative effect in HT-29 cells, with an IC50 value of 2.87  μg/ml after 72 h of treatment. HT-29 cells treated with Cu (II) complexes underwent apoptosis death, as exhibited by a progressive elevation in the proportion of the G1 cell population. At a concentration of 6.25  μg/ml, the Cu(BrHAP)2 compound caused significant elevation in ROS production following perturbation of mitochondrial membrane potential and cytochrome c release, as assessed by the measurement of fluorescence intensity in stained cells. Furthermore, the activation of caspases 3/7 and 9 was part of the Cu (II) complex-induced apoptosis, which confirmed the involvement of mitochondrial-mediated apoptosis. Meanwhile, there was no significant activation of caspase-8. Taken together, these results imply that the Cu(BrHAP)2 compound is a potential candidate for further in vivo and clinical colon cancer studies to develop novel chemotherapeutic agents derived from metal-based agents.

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.

Development of pyridine-containing macrocyclic copper(II) complexes: potential role in the redox modulation of oxaliplatin toxicity in human breast cells.

Science.gov (United States)

Fernandes, Ana S; Costa, Judite; Gaspar, Jorge; Rueff, José; Cabral, M Fátima; Cipriano, Madalena; Castro, Matilde; Oliveira, Nuno G

2012-09-01

The unique redox and catalytic chemistry of Cu has justified the development of novel Cu complexes for different therapeutic uses including cancer therapy. In this work, four pyridine-containing aza-macrocyclic copper(II) complexes were prepared (CuL1-CuL4) varying in ring size and/or substituents and their superoxide scavenging activity evaluated. CuL3, the most active superoxide scavenger, was further studied as a modulator of the cytotoxicity of oxaliplatin in epithelial breast MCF10A cells and in MCF7 breast cancer cells. Our results show that CuL3 enhances the therapeutic window of oxaliplatin, by both protecting non-tumour cells and increasing its cytotoxic effect in breast carcinoma cells. CuL3 is thus a promising complex to be further studied and to be used as a lead compound for the optimization of novel chemotherapy sensitizers.

Copper(I) in fogwater: Determination and interactions with sulfite

Energy Technology Data Exchange (ETDEWEB)

Hanbin Xue; Reutlinger, M.; Sigg, L.; Stumm, W. (Swiss Federal Inst. of Tech., Duebendorf (Switzerland)); Lurdes S. Goncalves, M. de (Inst. Superior Tecnico, Lisbon (Portugal))

1991-10-01

The copper(I)/(II) redox system was examined in fogwater with respect to the occurrence of Cu(I), the role of sulfite as a reductant of Cu(II) and as a complexing ligand, and the speciation of Cu(I) and Cu(II). Copper(I) was measured in fogwater by the bathocuproine method, which was evaluated for the conditions typically encountered in atmospheric water droplets. Concentrations of Cu(I) in the range 0.1-1 {mu}M were found, which represented between 4 and > 90% of the total copper in these samples. In experiments using concentration ranges of copper and S(IV) close to that of fogwater, the reduction of copper(II) to copper(I) by sulfite was shown to be pH-dependent and to occur rapidly at pH > 6. Calculations of the equilibrium complexation of Cu(I) and Cu(II) under fogwater conditions show that complexes of Cu(I) with sulfite predominate, while for Cu(II) oxalato complexes are important. Sulfite plays an important role as a ligand for Cu(I) in fogwater; Cu(I) may be produced by various reduction reactions, e.g., by organic compounds, and appears to be oxidized only slowly in the presence of S(IV).

Structural influence in the interaction of cysteine with five coordinated copper complexes: Theoretical and experimental studies

Science.gov (United States)

Huerta-Aguilar, Carlos Alberto; Thangarasu, Pandiyan; Mora, Jesús Gracia

2018-04-01

Copper complexes of N,N,N‧,N‧-tetrakis(pyridyl-2-ylmethyl)-1,2-diaminoethane (L1) and N,N,N‧,N‧-tetrakis(pyridyl-2-ylmethyl)-1,3-diaminopropane (L2) prepared were characterized completely by different analytical methods. The X-structure of the complexes shows that Cu(II) presents in trigonal bi-pyramidal (TBP) geometry, consisting with the electronic spectra where two visible bands corresponding to five coordinated structure were observed. Thus TD-DFT was used to analyze the orbital contribution to the electronic transitions for the visible bands. Furthermore, the interaction of cysteine with the complexes was spectrally studied, and the results were explained through DFT analysis, observing that the geometrical parameters and oxidation state of metal ions play a vital role in the binding of cysteine with copper ion. It appears that the TBP structure is being changed into octahedral geometry during the addition of cysteine to the complexes as two bands (from complex) is turned to a broad band in visible region, signifying the occupation of cysteine molecule at sixth position of octahedral geometry. In the molecular orbital analysis, the existence of a strong overlapping of HOMOs (from cysteine) with LUMOs of Cu ion was observed. The total energy of the systems calculated by DFT shows that cysteine binds favorably with copper (I) than that with Cu(II).

Surface characteristics, copper release, and toxicity of nano- and micrometer-sized copper and copper(II) oxide particles: a cross-disciplinary study.

OpenAIRE

Midander, Klara; Cronholm, Pontus; Karlsson, Hanna L.; Elihn, Karine; Moller, Lennart; Leygraf, Christofer; Wallinder, Inger Odnevall

2009-01-01

An interdisciplinary and multianalytical research effort is undertaken to assess the toxic aspects of thoroughly characterized nano- and micrometer-sized particles of oxidized metallic copper and copper(II) oxide in contact with cultivated lung cells, as well as copper release in relevant media. All particles, except micrometer-sized Cu, release more copper in serum-containing cell medium (supplemented Dulbecco's minimal essential medium) compared to identical exposures in phosphate-buffered ...

A serials of sandwich-like trinuclear and one-dimensional chain cyanide-bridged iron(III)-copper(II) complexes: Syntheses, crystal structures and magnetic properties

Science.gov (United States)

Shi, Jingwen; Lan, Wenlong; Ren, Yanjie; Liu, Qingyun; Liu, Hui; Dong, Yunhui; Zhang, Daopeng

2018-04-01

Four pyridinecarboxamide trans-dicyanideiron(III) building blocks and one macrocyclic copper(II) compound have been employed to assemble cyanide-bridged heterometallic complexes, resulting in a serials of cyanide-bridged FeIII-CuII complexes with different structure types. The series of complexes can be formulated as: {[Cu(Cyclam)][Fe(bpb)(CN)2]2}·4H2O (1), {{[Cu(Cyclam)][Fe(bpb)(CN)2]}ClO4}n·nH2O (2), and {[Cu(Cyclam)][Fe(bpmb)(CN)2]2}·4H2O (3), {[Cu(Cyclam)][Fe(bpClb)(CN)2]2}·4H2O (4) and {{[Cu(Cyclam)][Fe(bpdmb)(CN)2]}ClO4}n·2nCH3OH (5) (bpb2- = 1,2-bis(pyridine-2-carboxamido)benzenate, bpmb2- = 1,2-bis(pyridine-2-carboxamido)-4-methyl-benzenate, bpClb2- = 1,2-bis(pyridine-2-carboxamido)-4-chloro-benzenate, bpdmb2- = 1,2-bis(pyridine-2-carboxamido)-4,5-dimethyl-benzenate, Cyclam = 1,4,8,11-tetraazacyclotetradecane). All the complexes have been characterized by elemental analysis, IR spectra and structural determination. Single X-ray diffraction analysis shows the similar neutral sandwich-like structures for complexes 1, 3 and 4, in which the two cyano precursors acting as monodentate ligand through one of their two cyanide groups were coordinated face to face to central Cu(II) ion. The complexes 2 and 5 can be structurally characterized as one-dimensional cationic single chain consisting of alternating units of [Cu(Cyclam)]2+ and [Fe(bpb/bpdmb)(CN)2]- with free ClO4- as balanced anion. Investigation over magnetic properties of the whole serials of complexes reveals the antiferromagnetic magnetic coupling between the neighboring cyanide-bridged Fe(III) and Cu(II) ions in complexes 3 and 4 and the ferromagnetic interaction in complexes 1, 2 and 5, respectively.

Efficient electron-induced removal of oxalate ions and formation of copper nanoparticles from copper(II oxalate precursor layers

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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.

Synthesis of 2D polymeric dicyanamide bridged hexa-coordinated Cu(II) complex: Structural characterization, spectral studies and TDDFT calculation

Science.gov (United States)

Konar, Saugata; Saha, Urmila; Dolai, Malay; Chatterjee, Sudipta

2014-10-01

A rare 2D polymeric dicyanamide bridged hexa-coordinated copper(II) complex [Cu(L1‧)(μ1,5-dca)2]n (1) (L1‧ = 2-carboxypyrazine) has been synthesized from the reaction of Cu(NO3)2ṡ6H2O, 2-pyrazinecarbonitrile (L1) and sodium dicyanamide (Nadca) in methanolic medium. Single crystal X-ray analysis reveals that the complex has a 2D infinite zigzag chain structure in which copper(II) ions are bridged by single dicyanamide ligand in an end-to-end fashion. Such 2-carboxypyrazine can be obtained on the way of metal-assisted nitrile hydrolysis which well connected with Cu(NO3)2ṡ6H2O and dicyanamide (dca) to give rare 2D Cu(II) polymeric complex due to the flexibility in the coordination ability of the copper(II) ions within the polymeric chain. The geometry of the asymmetric unit of the complex was optimized in singlet state by DFT method with multilayer ONIOM model at doublet spin state accordance with repeating asymmetric unit only. The electronic spectrum of the complex is explained using TDDFT calculation.

Preconcentration and extraction of copper(II on activated carbon using ethyl-2-quinolyl-β (p-carboxyphenyl hydrazonedioxo propionate

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Mehrorang Ghaedi

2008-12-01

Full Text Available 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 ethyl-2-quinolyl-β(p-carboxyphenyl hydrazonedioxo propionate (EQCPDP. The adsorbed copper(II ion on solid phase was eluted quantitatively by using nitric acid. The important parameters such as pH, amount of carrier, flow rate, amount of activated carbon and type and concentration of eluting agent for obtaining maximum recovery were optimized. The method at optimum conditions gives linear concentration range of 0.05-1.0 μg mL-1 of copper(II with correlation coefficient of 0.9994 and the detection limit of 0.99 ng mL-1. The preconcentration leads to enrichment factor of 175 and break through volume of 1750 mL. The method has good tolerance limit of interfering ions and selectivity and it has been successfully applied for determination of copper content in real sample such as blood, wastewater and river sample.

Synthesis and characterization of Ni(II, Cu(II and Co(III complexes with polyamine-containing macrocycles bearing an aminoethyl pendant arm

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K. S. SIDDIQI

2004-09-01

Full Text Available Reaction of [M(ppn2]X2 (where M = Cu(II, Ni(II, Co(II and ppn = 1,3-diaminopropane with formaldehyde and ethylenediamine in methanol results in the ready formation of a 16-membered macrocyclic complex. The complexes were characterized by elemental anlysis, IR, EPR, electronic spectral data, magnetic moments and conductance measurements. The Cu(II, Ni(II and Co(III complexes are coordinated axially with both pendant groups of the hexadentate macrocycle. These pendant donors are attached to the macrocycle by a carbon chain. The electrical conductivities of the Cu(II and Ni(II chelates indicated them to be 1:2 electrolytes whilst those of Co(III is a 1:3 electrolyte in DMSO. The EPR spectrum of the copper complex exhibited G at 3.66, which indicates a considerable exchange interaction in the complex. Spectroscopic evidence suggests that in all of the complexes the metal ion is in an octahedral environment.

Synthesis, characterization and behaviour to gamma radiation of the bis-L-alaninato-copper (II)

International Nuclear Information System (INIS)

Passos, B.F.T.

1985-01-01

The behaviour of coordinated compound obtained from the copper (II) and the L-(+)- alanine to gamma radiation was determined. A study of synthesis and characterization of this complex was made with elementary analysis, ultraviolet and visible electronic spectroscopy, infrared vibrational spectroscopy, proton magnetic resonance spectroscopy and thermo-gravimetric analysis. (C.G.C.)

Synthesis, structures, spectroscopy and antimicrobial properties of complexes of copper(II) with salicylaldehyde N-substituted thiosemicarbazones and 2,2'-bipyridine or 1,10-phenanthroline.

Science.gov (United States)

Lobana, Tarlok S; Indoria, Shikha; Jassal, Amanpreet Kaur; Kaur, Harpreet; Arora, Daljit S; Jasinski, Jerry P

2014-04-09

Among the biometals (Cu, Co, Ni-cofactors in many enzymes), copper derivatives of O, N, S-donor salicylaldehyde thiosemicarbazones have received considerable attention owing to their potential biological applications. Eight new complexes of salicylaldehyde-N-substituted thiosemicarbazones [5-MeO-2-HO-C₆H₄-C(2)(H)N(3)-N(2)H-C(1)(S)-N(1)HR; R = Me, H2L(1); Et, H₂L(1), Ph, H₂L(3), H, H₂L(4)] with copper(II), namely, [Cu(κ(3)-O,N,S-L)( κ(2)-N,N-L')] {(L)(2-) = (L(1))(2-), L' = bipy, 1, phen, 2; (L)(2-) = (L(2))(2-), L' = bipy, 3, phen, 4; (L)(2-) = (L(3))(2-), L' = bipy, 5, phen, 6; (L)(2-) = (L(4))(2-), L' = bipy, 7, phen, 8} have been isolated. Complexes have slightly distorted square pyramidal geometry around the metal center (τ parameter = 0.243-0.357) and display weak to intense fluorescence in the region, 375-475 nm. These copper complexes have shown significant growth inhibitory activity (antimicrobial activity) against Staphylococcus aureus (MTCC740), methicillin resistant Staphylococcus aureus (MRSA), Klebsiella pneumoniae 1 (MTCC109), Shigella flexneri (MTCC1457), Pseudomonas aeruginosa (MTCC741) and Candida albicans (MTCC227). The activity against MRSA is an interesting observation as the commercially available gentamycin is found to be inactive against this bacterial strain. Specifically complex 5 formed by 5-methoxysalicylaldehyde-N-phenylthiosemicatbazone has shown novel antimicrobial activity against various bacteria and yeast investigated. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

Biosorption of copper (II) from aqueous solution by mycelial pellets ...

African Journals Online (AJOL)

The optimum diameter and pH for biosorption of copper (II) was found to be 1.0 to 1.2 mm and 4.0. Evaluation of the experimental data in terms of biosorption dynamics showed that the biosorption of copper (II) onto MPRO followed the pseudo-second-order kinetic model. The equilibrium data fitted very well to the Langmuir ...

Preconcentration and Determination of Copper and Zinc in Natural Water Samples by ICP-AES After Complexation and Sorption on Amberlite XAD-2

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Ferreira Sérgio Luis Costa

1998-01-01

Full Text Available The present paper describes a procedure for separation, preconcentration and sequential determination of trace amounts of copper and zinc in natural water samples, by Inductively Coupled Plasma Atomic Emission Spectrometry (ICP-AES. The proposed method is based on the complexation of copper(II and zinc(II ions by 1-(2-thiazolylazo-2-naphthol (TAN and sorption on to Amberlite XAD-2 resin. Parameters such as: TAN amount, pH effect on the complexation and sorption of TAN complexes, agitation time for complete sorption, concentration of metal ion, mass of Amberlite XAD-2, desorption of metal ions from XAD-2 resin and sample volume were studied. The results demonstrated that the copper(II and zinc(II ions, in the range of 0.10 to 100.00 mug, contained in a solution sample volume of 400 mL, in the pH range of 5.7 to 8.3, on the form of TAN complexes had been quantitatively retained on to XAD-2 resin. The shaking time required for sorption is 1 h using a resin mass of 1.4 g. The solution for determination of copper and zinc by ICP-AES is obtained, after desorption of the ions from the XAD-2 resin, using 5 mL of 2 mol L-1 hydrochloric acid and shaking the system for 5 min. The procedure was applied to the determination of copper and zinc in several natural water samples. The standard addition technique was applied and the obtained recoveries revealed that the proposed procedure has a good accuracy. A high enrichment factor (80 and simplicity are the main advantages in this analytical protocol.

Copper(II hydrogenphosphate, CuHPO4

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Dörte Stachel

2009-12-01

Full Text Available The title compound, CuHPO4, has been synthesized from a mixture of phosphoric acid and copper oxide. It has the same composition as MHPO4 (M = Ca, Ba, Pb, Sr or Sn, but adopts a rhombohedral structure with all atoms on general positions. The structure features distorted PO4 tetrahedra linked by copper, forming 12-membered rings. The CuII atom is coordinated by five O atoms in a distorted square-pyramidal manner. O—H...O hydrogen bonding leads to an additional stabilization of the structure.

Investigation of the interaction of copper(II) oxide and electron beam irradiation crosslinkable polyethylene

International Nuclear Information System (INIS)

Bee, Soo-Tueen; Sin, Lee Tin; Ratnam, C.T.; Haraveen, K.J.S.; Tee, Tiam-Ting; Rahmat, A.R.

2015-01-01

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.

Investigation of the interaction of copper(II) oxide and electron beam irradiation crosslinkable polyethylene

Energy Technology Data Exchange (ETDEWEB)

Bee, Soo-Tueen, E-mail: direct.beest@gmail.com [Department of Chemical Engineering, Lee Kong Chian Faculty of Engineering and Science, Universiti Tunku Abdul Rahman, Jalan Sungai Long, Bandar Sungai Long, Cheras, 43000 Kajang, Selangor (Malaysia); Sin, Lee Tin, E-mail: direct.tinsin@gmail.com [Department of Chemical Engineering, Lee Kong Chian Faculty of Engineering and Science, Universiti Tunku Abdul Rahman, Jalan Sungai Long, Bandar Sungai Long, Cheras, 43000 Kajang, Selangor (Malaysia); Ratnam, C.T. [Radiation Processing Technology Division, Malaysian Nuclear Agency, Bangi, 43000 Kajang, Selangor (Malaysia); Haraveen, K.J.S.; Tee, Tiam-Ting [Department of Chemical Engineering, Lee Kong Chian Faculty of Engineering and Science, Universiti Tunku Abdul Rahman, Jalan Sungai Long, Bandar Sungai Long, Cheras, 43000 Kajang, Selangor (Malaysia); Rahmat, A.R. [Department of Polymer Engineering, Faculty of Chemical Engineering, Universiti Teknologi Malaysia, 81310 UTM Skudai, Johor (Malaysia)

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.

Determination of sub-parts per billion levels of copper in complex matrices by adsorptive string voltammetry on a mercury electrode

International Nuclear Information System (INIS)

Shahbaazi, H.R.; Shahbaazi, H.R.; Safavi, A.; Maleki, N.

2008-01-01

The voltammetric characteristics of Cu(II)-SSA complex at the mercury electrode were investigated. An analytical method that based on the adsorptive accumulation of Cu(II)-SSA complex followed by the reduction of the complexed copper was developed for the copper determination in complex matrices in presence of the large amount of foreign ions. Adsorptive voltammetry determination showed that the Cu(II)-SSA complex behaves irreversibly exchanging two electrons on the hanging mercury drop electrode (HMDE). Factor affecting on the complextion, accumulation and stripping steps were studied and a procedure was developed. The instrumental parameters in the measurement step were also tested. The optimum conditions of pH, SSA concentration, accumulation potential and accumulation time were studied. Under optimal conditions (pH=12.9 glycin Buffer, 7 x 10 - '3 M SSA and accumulation potential -100 mV vs. Ag/ AgCl), a linear calibration graph in the range 1.25 μg L -1 to 42.5 μg L'- 1 and a detection limit of 0.8 μ L -1 were obtained. The average relative standard deviation (RSD) for seven determinations was calculated as 7 %, 5.5 % and 3 % for the concentrations between 3, 15 and 23 μg L'- 1 . The effect of foreign ions and surfactants on the peak height of Cu(II)-SSA complex was evaluated. The method was applied for the determination of the copper in different real samples such as crude oil, crude oil tank button sludge, waste water and tap water samples. The accuracy of the results was checked by ICP. (author)

The oxidative p-dichlorobenzene dechlorinating in the presence of copper (ΙΙ complexes and nitrogen (ΙΙ, ΙV oxides

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Valentina Yemelyanova

2012-12-01

Full Text Available The results of dechlorination in the solution CuCl2–TBP–NaNO2–О2–Н2О kinetics research are presented in the article. All system components influence to the dechlorination process is studied and quantitatively described. The composition of copper intermediate complexes participating in reaction is studied by the instrumentality of UV-spectroscopy. Established part of binuclear copper complexes in the catalytic intermediate complex constants of formation were estimated and compared with the kinetic and spectrophotometric methods. The composition of the intermediate complexes responsible for process is defined, the mechanism scheme is offered, the p-dichlorobenzene dechlorination limiting stage including redox-disintegration of the intermediate complex consisting of dimeric complex of copper (II, I chloride, nitrogen oxide and p-dichlorobenzene is defined.

Copper(II) catalysis in cyanide conversion into ethyl carbamate in spirits and relevant reactions.

Science.gov (United States)

Aresta, M; Boscolo, M; Franco, D W

2001-06-01

The role of copper(II) species in the oxidation of inorganic cyanide to cyanate and in the conversion of cyanate or urea into ethyl carbamate was investigated. The oxidation process has been shown to be independent from the dissolved oxygen. Elemental analysis and infrared spectroscopy have shown the formation of a mixed copper carbonate/hydroxide in the process of oxidation of cyanide to cyanate in water/ethanol. The complexation to Cu(II) of cyanate formed upon cyanide oxidation makes the former more susceptible to nucleophilic attack from ethanol, with conversion into ethyl carbamate. Comparatively, urea has a minor role with respect to cyanide in the formation of ethyl carbamate. Therefore, the urea present in some samples of Brazilian sugar cane spirit (cachaça) has been shown to have almost no influence on the ethyl carbamate content of cachaças, which comes essentially from cyanide. Fe(II,III) affords results similar to those found with Cu(II). Some suggestions are presented to avoid ethyl carbamate formation in spirits during distillation.

Molecular structure, spectroscopic studies, and coppersbnd oxygen bond strength of α-methyl and α-ethyl derivatives of copper (II) acetylacetonate; Experimental and theoretical approach

Science.gov (United States)

Seyedkatouli, Seyedabdollah; Vakili, Mohammad; Tayyari, Sayyed Faramarz; Afzali, Raheleh

2018-05-01

This paper presents a combined experimental and theoretical study on the Cusbnd O bond strength of copper (II) α-methylacetylacetonate, Cu(3-Meacac)2, and copper (II) α-ethylacetylacetonate, Cu(3-Etacac)2, complexes in comparison to that in copper (II) acetylacetonate, Cu(acac)2. For this purpose, the molecular structure, UV spectra, and complete vibrational assignment of target molecules were investigated by DFT, Natural Bond Orbital (NBO) theory, and Atoms-in-Molecules (AIM) analysis at the B3LYP/6-311G* level of theory. The mentioned results are compared with those in Cu(acac)2. Fourier transform-Raman, IR, and UV spectra of these complexes have been also recorded. A complete assignment of the observed band frequencies has been done. All theoretical and experimental spectroscopic results are consisting with a stronger metal-oxygen bond in Cu(3-Meacac)2 and Cu(3-Etacac)2 complexes compared with Cu(acac)2. In addition, these results confirm that there is no significant difference between the Cusbnd O bond strength of the Cu(3-Meacac)2 and Cu(3-Etacac)2 complexes.

Structural characterization of copper (II tetradecanoate with 2,2′-bipyridine and 4,4′-bipyridine to study magnetic properties

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Noha Said Bedowr

2018-03-01

Full Text Available This paper presents synthesis, structural characterization and spintronic applications of copper (II tetradecanoate derived magnetic complexes. The complexes were prepared by a chemical reaction between [Cu2(CH3(CH212COO4](EtOH2 and 2,2′-bipyridine-4,4′-bipyridine ligands respectively. The complexes were further reacted between the product of the first reaction and 4,4′-bipyridine-2,2′-bipyridine respectively. The structural characterization techniques included elemental analysis, Fourier transformed infrared spectroscopy (FTIR, Ultra-violet–Visible (UV–Vis spectroscopy, polarized optical microscopy, magnetic moment and thermogravimetric analysis. The structural and characterization results suggested that the synthesized complexes were binuclear and mononuclear covalent complexes of copper(II with structural formulas [Cu2(η2-(OOCR4](4,4′-bpy2H2O] and [Cu(η1-(OOCR2(2,2′-bpy (4,4′-bpy] respectively.

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 ·H 2 O]·H 2 O, 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.

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.

Effect of glutamic acid on copper sorption onto kaolinite. Batch experiments and surface complexation modeling

Energy Technology Data Exchange (ETDEWEB)

Karimzadeh, Lotfallah; Barthen, Robert; Gruendig, Marion; Franke, Karsten; Lippmann-Pipke, Johanna [Helmholtz-Zentrum Dresden-Rossendorf e.V., Dresden (Germany). Reactive Transport; Stockmann, Madlen [Helmholtz-Zentrum Dresden-Rossendorf e.V., Dresden (Germany). Surface Processes

2017-06-01

In this work, we study the mobility behavior of Cu(II) under conditions related to an alternative, neutrophile biohydrometallurgical Cu(II) leaching approach. Sorption of copper onto kaolinite influenced by glutamic acid (Glu) was investigated in the presence of 0.01 M NaClO{sub 4} by means of binary and ternary batch adsorption measurements over a pH range of 4 to 9 and surface complexation modeling.

Effect of glutamic acid on copper sorption onto kaolinite. Batch experiments and surface complexation modeling

International Nuclear Information System (INIS)

Karimzadeh, Lotfallah; Barthen, Robert; Gruendig, Marion; Franke, Karsten; Lippmann-Pipke, Johanna; Stockmann, Madlen

2017-01-01

In this work, we study the mobility behavior of Cu(II) under conditions related to an alternative, neutrophile biohydrometallurgical Cu(II) leaching approach. Sorption of copper onto kaolinite influenced by glutamic acid (Glu) was investigated in the presence of 0.01 M NaClO_4 by means of binary and ternary batch adsorption measurements over a pH range of 4 to 9 and surface complexation modeling.

Synthesis, structural characterization, superoxide dismutase and antimicrobial activities studies of copper (II) complexes with 2-(E)-(2-(2-aminoethylamino) methyl)-4-bromophenol and (19E, 27E)-N1, N2-bis (phenyl (pyridine-2-yl)-methylene)-ethane-1, 2-diamine as ligands

Science.gov (United States)

Choudhary, Mukesh; Patel, R. N.; Rawat, S. P.

2014-07-01

Three new copper (II) complexes, [Cu(L)(H2O)]ClO4 (1), [Cu(L1)(ClO4)]+ (2) and [Cu(L1)]2+ (3), where HL = 2-(E)-(2-(2-aminoethylamino)methyl)-4-bromophenol, L1 =(19E, 27E)-N1,N2-bis(phenyl(pyridine-2-yl)-methylene)-ethane-1, 2-diamine, have been synthesized and characterized by using various physic-chemical and spectroscopic methods. The solid-state structures of 1 and 2 were determined by single crystal X-ray crystallography. Infrared spectra, ligand field spectra and magnetic susceptibility measurements agree with the observed crystal structures. The molecular structure of copper complexes showed that the ligands occupies the basal plane of square pyramidal geometry with the H2O of 1 or the ClO4 of 2 occupying the remaining apical position. Complexes 1 and 2 crystallize in the monoclinic system of the space group P21/c, a = 10.5948(6)Å, b = 19.6164(11)Å, c = 8.6517(5)Å, α = 90°, β = 108.213(2)°, γ = 90° and Z = 4 for 1, a = 9.5019(3)Å, b = 11.3 801(3)Å, c = 25.3168(14)Å, α = 90°, β = 100.583(4)°, γ = 90°, and Z = 4 for 2. The synthesized Schiff base (HL/L1) was behaves as tetradentate ON3/N4 ligands with donor groups suitable placed for forming 2 or 3 five membered chelate rings. Copper (II) complexes display X-band EPR spectra in 100% DMSO at 77 K giving g|| > g⊥ > 2.0023 indicating dx2-y2 ground state. The half-wave potential values for Cu (II)/Cu (I) redox couple obtained in the reaction of the copper (II) complexes with molecular oxygen and superoxide radical (O2-) electronegated in DMSO are in agreement with the SOD-like activity of the copper (II) complexes. In vitro antimicrobial activities of the complexes against the two bacteria (Escherichia coli, Salmonella typhi) and the two fungi (Penicillium, Aspergillus sp.) have been investigated comparing with the Schiff base ligands.

Synthesis, characterization and anti-fungal evaluation of Ni(II and Cu(II complexes with a derivative of 4-aminoantipyrine

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Monika Tyagi

2017-01-01

Full Text Available Transition metal complexes of Ni(II and Cu(II metal ions with the general stoichiometry [M(LX]X and [M(LSO4], where M = Ni(II and Cu(II, L = (1E-N-((5-((E-(2,3-dimethyl-1-phenyl-4-pyrazolineiminomethylthiophen-2-ylmethylene-2,3-dimethyl-1-phenyl-4-pyrazolineamine and X = Cl−, NO3− and SO42−, have been synthesized and characterized. The synthesized ligand and metal complexes were characterized by 1H NMR, IR, mass spectrometry, UV–Vis spectra and EPR. In molecular modelling, the geometries of the Schiff's base and metal complexes were fully optimized with respect to the energy using the 6-31g(d,p basis set. The nickel(II complexes were found to have octahedral geometry, whereas the copper(II complexes were of tetragonal geometry. The covalency factor (β and orbital reduction factor (k suggest the covalent nature of the complexes. To develop broad spectrum new molecules against seed-borne fungi, the minimum inhibitory concentration (MIC of the ligand and its metal complexes was evaluated by the serial dilution method.

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

2010-09-01

The interaction of taurine-salicylaldehyde Schiff base copper(II) (Cu(TSSB) 22+) 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) 22+ complex interaction with DNA was 3.49 × 10 4 L mol -1. Moreover, due to the fluorescence enhancing of Cu(TSSB) 22+ complex in the presence of DNA, a method for determination of DNA with Cu(TSSB) 22+ 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 μg mL -1 for calf thymus DNA (CT-DNA), 0.10-36 μg mL -1 for yeast DNA and 0.01-10.01 μg 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.

Metal complex derivatives of hydrogen uranyl phosphate

International Nuclear Information System (INIS)

Grohol, D.; Blinn, E.L.

1994-01-01

Derivatives of hydrogen uranyl phosphate were prepared by incorporating transition metal complexes into the uranyl phosphate matrix. The transition metal complexes employed include bis(ethylenediamine)copper(II), bis(1,3-propanediamine)copper(II) chloride, (triethylenetetramine)copper(II), (1,4,8,11-tetraazacyclotetradecane)copper(II), (1,4,8,12-tetraazacyclopentadecane)copper(II), (1,4,8,11-tetraazacyclotetradecane)nickel(II) chloride, (triethylenetetramine)nickel(II) and others. The chemical analyses of these derivatives indicated that the incorporation of the transition metal complexes into the uranyl phosphate matrix via ion exchange was not stoichiometric. The extent of ion exchange is dependent on the size and structure of the transition metal complex. All complexes were characterized by X-ray powder diffractometry, electronic and infrared spectra, thermal analyses and chemical analysis. An attempt was made to correlate the degree of quenching of the luminescence of the uranyl ion to the spacing between the uranyl phosphate layers in the derivatives

Effect of Phosphorylation and Copper(II or Iron(II Ions Enrichment on Some Physicochemical Properties of Spelt Starch

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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.

Theoretical investigation, biological evaluation and VEGFR2 kinase studies of metal(II) complexes derived from hydrotris(methimazolyl)borate.

Science.gov (United States)

Jayakumar, S; Mahendiran, D; Srinivasan, T; Mohanraj, G; Kalilur Rahiman, A

2016-02-01

The reaction of soft tripodal scorpionate ligand, sodium hydrotris(methimazolyl)borate with M(ClO4)2·6H2O [MMn(II), Ni(II), Cu(II) or Zn(II)] in methanol leads to the cleavage of B-N bond followed by the formation of complexes of the type [M(MeimzH)4](ClO4)2·H2O (1-4), where MeimzH=methimazole. All the complexes were fully characterized by spectro-analytical techniques. The molecular structure of the zinc(II) complex (4) was determined by X-ray crystallography, which supports the observed deboronation reaction in the scorpionate ligand with tetrahedral geometry around zinc(II) ion. The electronic spectra of complexes suggested tetrahedral geometry for manganese(II) and nickel(II) complexes, and square-planar geometry for copper(II) complex. Frontier molecular orbital analysis (HOMO-LUMO) was carried out by B3LYP/6-31G(d) to understand the charge transfer occurring in the molecules. All the complexes exhibit significant antimicrobial activity against Gram (-ve) and Gram (+ve) bacterial as well as fungal strains, which are quite comparable to standard drugs streptomycin and clotrimazole. The copper(II) complex (3) showed excellent free radical scavenging activity against DPPH in all concentration with IC50 value of 30μg/mL, when compared to the other complexes. In the molecular docking studies, all the complexes showed hydrophobic, π-π and hydrogen bonding interactions with BSA. The cytotoxic activity of the complexes against human hepatocellular liver carcinoma (HepG2) cells was assessed by MTT assay, which showed exponential responses toward increasing concentration of complexes. Copyright © 2015 Elsevier B.V. All rights reserved.

Synthesis and characterization of chromium(III), manganese(II), iron(III), cobalt(II), nickel(II), copper(II), cadmium(II) and dioxouranium(VI) complexes of 4(2-pyridyl)-1-(2,4-dihydroxybenzaldehyde)-3-thiosemicarbazone

International Nuclear Information System (INIS)

Abu El-Reash, G.M.; Ibrahim, M.M.; Kenawy; El-Ayaan, Usama; Khattab, M.A.

1994-01-01

A few complexes of Cr(III), Mn(II), Fe(III), Co(II), Ni(II), Cu(II), Zn(II), Cd(II) and dioxouranium(VI) with 4(2-pyridyl)-1-(2,4-dihydroxybenzaldehyde)-3-thiosemicarbazone have been synthesised and characterized on the basis of elemental analysis, IR, electronic NMR, and magnetic moment data. An octahedral structure is proposed for the Cr(III), Fe(III), Co(II) and Ni(H 3 PBT) 2 Cl 2 .2H 2 O complexes; a tetrahedral structure for the Mn(II) and Ni 2 (PBT)OAc.H 2 0 complexes and a square planar structure for the Cu(II) complexes. The antimicrobial and antifungal activities of H 3 PBT and of its metal(II) complexes are investigated. The results reveal that H 3 PBT exhibits greater antimicrobial activities than its complexes. (author). 34 refs., 4 figs., 2 tabs

Spectrophotometric Determination of Metoprolol Tartrate in Pharmaceutical Dosage Forms on Complex Formation with Cu(II

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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.

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

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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.

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.

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

Adsorption of 2-mercaptobenzothiazole on copper surface from phosphate solutions

International Nuclear Information System (INIS)

Kazansky, L.P.; Selyaninov, I.A.; Kuznetsov, Yu.I.

2012-01-01

Analysis of the electrochemical and XPS results has shown that adsorption of 2-mercaptobenzothiazole (MBT) on copper electrodes in neutral phosphate solutions proceeds through the formation of the chemical bonds by copper (I) cations with exo-sulfur and nitrogen atoms. A protection layer formed of Cu(I)MBT complex prevents precipitation of copper (II) phosphate on a copper surface. The thickness of the surface film consisting of a complex [Cu(I)MBT] n (having probably polymeric nature), where MBT acts as at least three-dentate ligand, increases depending on the exposure time, reaching 8-9 nm after immersing for 12 h in test solution. Even in a case of the preliminary formation of copper (II) phosphate on the copper electrode at the anodic potential addition of small amounts of MBT results in complete removal of copper (II) phosphate from the surface.

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

CONSIDERATIONS ON THE INFLUENCE OF COMPLEXATION IN THE COPPER UPTAKE AND TRANSLOCATION

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SEMAGHIUL BIRGHILA

2014-07-01

Full Text Available The actual knowledge about food and the environment underlines the fact that agricultural and environmental sciences must solve various problems regarding copper uptake from soil to plants and its bioaccumulation, being important issues for copper concentration in crops and also for phytoremediation of polluted soils. We studied the relation between the form in which copper is applied to soil and the consequential copper bioavailability, uptake and translocation, using as examples simple and complex copper compounds. The copper concentration in basil plants harvested from soils treated with copper compounds and the calculated values of transfer coefficient, translocation factor, bioaccumulation factor, and uptake coefficient demonstrated that the ionic copper (from simple salts is not necessarily easier to uptake than complex ions, but is easier translocated in plants, while the copper given as complex ions is most likely to be retained by roots. The results indicated that the involvement of copper complexes in agricultural treatments is a solution for soils phytoremediation, concerning the phytostabilization technology.

Leaching behavior and chemical stability of copper butyl xanthate complex under acidic conditions.

Science.gov (United States)

Chang, Yi Kuo; Chang, Juu En; Chiang, Li Choung

2003-08-01

Although xanthate addition can be used for treating copper-containing wastewater, a better understanding of the leaching toxicity and the stability characteristics of the copper xanthate complexes formed is essential. This work was undertaken to evaluate the leaching behavior of copper xanthate complex precipitates by means of toxicity characteristics leaching procedure (TCLP) and semi-dynamic leaching test (SDLT) using 1 N acetic acid solution as the leachant. Also, the chemical stability of the copper xanthate complex during extraction has been examined with the studying of variation of chemical structure using UV-vis, Fourier transform infrared and X-ray photoelectron spectroscopies (XPS). Both TCLP and SDLT results showed that a negligible amount of copper ion was leached out from the copper xanthate complex precipitate, indicating that the complex exhibited a high degree of copper leaching stability under acidic conditions. Nevertheless, chemical structure of the copper xanthate complex precipitate varied during the leaching tests. XPS data suggested that the copper xanthate complex initially contained both cupric and cuprous xanthate, but the unstable cupric xanthate change to the cuprous form after acid extraction, indicating the cuprous xanthate to be the final stabilizing structure. Despite that, the changes of chemical structure did not induce the rapid leaching of copper from the copper xanthate complex.

(II) complexes

African Journals Online (AJOL)

activities of Schiff base tin (II) complexes. Neelofar1 ... Conclusion: All synthesized Schiff bases and their Tin (II) complexes showed high antimicrobial and ...... Singh HL. Synthesis and characterization of tin (II) complexes of fluorinated Schiff bases derived from amino acids. Spectrochim Acta Part A: Molec Biomolec.

Structures of nitrato-(2-hydroxybenzaldehydo) (2,2 Prime -bipyridyl)copper and nitrato-(2-hydroxy-5-nitrobenzaldehydo)(2,2 Prime -bipyridyl)copper

Energy Technology Data Exchange (ETDEWEB)

Chumakov, Yu. M. [Academy of Sciences of Moldova, Institute of Applied Physics (Moldova, Republic of); Paladi, L. G. [Moldova State University (Moldova, Republic of); Antosyak, B. Ya.; Simonov, Yu. A. [Academy of Sciences of Moldova, Institute of Applied Physics (Moldova, Republic of); Tsapkov, V. I., E-mail: vtsapkov@gmail.com [Moldova State University (Moldova, Republic of); Bocelli, G. [Institute of Materials for Electronics and Magnetism (Italy); Gulea, A. P. [Moldova State University (Moldova, Republic of); Ginju, D. [Alexandru Ioan Cuza University of Iasi (Romania); Palomares-Sanchez, S. A. [Autonomous University of San Luis Potosi (Mexico)

2011-03-15

Nitrato-(2-hydroxy-5-nitrobenzaldehydo)(2,2 Prime -bipyridyl)copper (I) and nitrato-(2-hydroxybenzaldehydo)(2,2 Prime -bipyridyl)copper (II) were synthesized and characterized by X-ray diffraction. The coordination polyhedron of the central copper atom in complex I can be described as a distorted tetragonal pyramid whose base is formed by the phenol and carbonyl oxygen atoms of the monodeprotonated 2-hydroxy-5nitrobenzaldehyde molecule and the nitrogen atoms of the 2,2 Prime -bipyridyl ligand and whose apex is occupied by the oxygen atom of the nitrato group. In the crystal structure, complexes I are linked by the acido ligands and the NO{sub 2} groups of the aldehyde molecule into infinite chains. In complex II, the central copper atom is coordinated by 2-hydroxybenzaldehyde, 2,2 Prime -bipyridyl, and the nitrato group, resulting in the formation of centrosymmetric dimers. The coordination polyhedron of the central copper atom can be described as a bipyramid (4 + 1 + 1) with the same base as in complex I. The axial vertices of the bipyramid are occupied by the oxygen atom of the nitrato group and the bridging phenol oxygen atom of the adjacent complex related to the initial complex by a center of symmetry. In the crystal structure, complexes II are hydrogen bonded into infinite chains.

Synthesis, structure, and magnetic properties of two 1-D helical coordination polymeric Cu(II) complexes

Science.gov (United States)

Bian, He-Dong; Yang, Xiao-E.; Yu, Qing; Chen, Zi-Lu; Liang, Hong; Yan, Shi-Ping; Liao, Dai-Zheng

2008-01-01

Two helical coordination polymeric copper(II) complexes bearing amino acid Schiff bases HL or HL', which are condensed from 2-hydroxy-1-naphthaldehyde with 2-aminobenzoic acid or L-valine, respectively, have been prepared and characterised by X-ray crystallography. In [CuL] n ( 1) the copper(II) atoms are bridged by syn- anti carboxylate groups giving infinite 1-D right-handed helical chains which are further connected by weak C-H⋯Cu interactions to build a 2-D network. While in [CuL'] n ( 2) the carboxylate group acts as a rare monatomic bridge to connect the adjacent copper(II) atoms leading to the formation of a left-handed helical chain. Magnetic susceptibility measurements indicate that 1 exhibits weak ferromagnetic interactions whereas an antiferromagnetic coupling is established for 2. The magnetic behavior can be satisfactorily explained on the basis of the structural data.

EPR study of complex formation between copper (II) ions and sympathomimetic amines in aqueous solution

Energy Technology Data Exchange (ETDEWEB)

Preoteasa, E.A. [Inst. of Atomic Physics, IFIN, Bucharest (Romania); Duliu, O.G.; Grecu, V.V. [Bucharest, Univ. (Romania). Dept. of Atomic and Nuclear Physics

1997-07-01

The complex formation between sympathomimetic amines (SA): adrenaline (AD), noradrenaline (NA), dopamine (DA), ephedrine (ED) and p-tyramine (pTA), and Cu(II) ion in aqueous solution has been studied by X-band EPR at room temperature. Excepting pTA, all investigated SA yielded two types of complexes in different pH domains. All complexes consistent with a ligand fields having a distorted octahedral symmetry, i.e., hexacoordination of Cu(II). The covalence coefficient calculated from the isotropic g and A values has shown strong ionic sigma-type ligand bonds. A structural model with the Cu(II) ion bound by four catecholic O(hydroxy) atoms for the low pH complexes of AD, NA and DA is proposed. For the high pH complexes of the former compounds as well as for both Ed complexes, the authors suppose Cu(II) bound by two N (amino) and two O (hydroxy) atoms. The spectra are consistent to water binding on the longitudinal octahedron axis in all compounds excepting the high pH complex of Ed, where OH2- ions are bound. Possible implications for the SA-cell receptors interactions are discussed.

Ferromagnetic interaction in an asymmetric end-to-end azido double-bridged copper(II) dinuclear complex: a combined structure, magnetic, polarized neutron diffraction and theoretical study.

Science.gov (United States)

Aronica, Christophe; Jeanneau, Erwann; El Moll, Hani; Luneau, Dominique; Gillon, Béatrice; Goujon, Antoine; Cousson, Alain; Carvajal, Maria Angels; Robert, Vincent

2007-01-01

A new end-to-end azido double-bridged copper(II) complex [Cu(2)L(2)(N(3))2] (1) was synthesized and characterized (L=1,1,1-trifluoro-7-(dimethylamino)-4-methyl-5-aza-3-hepten-2-onato). Despite the rather long Cu-Cu distance (5.105(1) A), the magnetic interaction is ferromagnetic with J= +16 cm(-1) (H=-JS(1)S(2)), a value that has been confirmed by DFT and high-level correlated ab initio calculations. The spin distribution was studied by using the results from polarized neutron diffraction. This is the first such study on an end-to-end system. The experimental spin density was found to be localized mainly on the copper(II) ions, with a small degree of delocalization on the ligand (L) and terminal azido nitrogens. There was zero delocalization on the central nitrogen, in agreement with DFT calculations. Such a picture corresponds to an important contribution of the d(x2-y2) orbital and a small population of the d(z2) orbital, in agreement with our calculations. Based on a correlated wavefunction analysis, the ferromagnetic behavior results from a dominant double spin polarization contribution and vanishingly small ionic forms.

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

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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.

Unsymmetrical Mesoporphyrinic Complexes of Copper (II and Zinc (II. Microwave-Assisted Synthesis, Spectral Characterization and Cytotoxicity Evaluation

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Rica Boscencu

2011-06-01

Full Text Available New unsymmetrical mesoporphyrinic complexes, namely 5-(4-hydroxyphenyl-10,15,20–tris-(4-carboxymethylphenyl–21,23-Zn(II-porphine and 5-(4-hydroxyphenyl-10,15,20–tris-(4-carboxymethylphenyl–21,23-Cu(II-porphine, were synthesized using a microwave irradiation method. The structures of the porphyrinic complexes were confirmed using FT-IR, UV–Vis, EPR and NMR spectral data. The spectral absorption and emission properties of the porphyrinic complexes were studied in organic solvents of different polarities and the influence of solvent polarity on the wavelengths of the absorbance and fluorescence band maxima is described. The cytotoxicity evaluation of the porphyrinic complexes was performed on human colon adenocarcinoma cell line HT29 for different doses and incubation times. The obtained result indicates a lack of or low toxicity for both compounds, thus recommending them for further testing in light activation protocols.

2-Organoselenomethyl-1H-benzimidazole Complexes of Copper(II) and Copper(I)

Czech Academy of Sciences Publication Activity Database

Leboschka, M.; Sieger, M.; Sarkar, B.; Heck, J.; Niemeyer, M.; Bubrin, D.; Lissner, F.; Schleid, T.; Záliš, Stanislav; Su, Ch. Y.; Kaim, W.

2009-01-01

Roč. 635, 13-14 (2009), s. 2177-2184 ISSN 0044-2313 R&D Projects: GA MŠk OC 139; GA AV ČR KAN100400702 Institutional research plan: CEZ:AV0Z40400503 Keywords : coordination models * copper * imidazole ligands * selenoether ligands Subject RIV: CG - Electrochemistry Impact factor: 1.226, year: 2009

Synthesis and DNA binding/cleavage of mononuclear copper(II) phenanthroline/bipyridine proline complexes.

Science.gov (United States)

Reddy, Pulimamidi R; Raju, Nomula; Manjula, Pallerla; Reddy, Karnati V G

2007-07-01

The complexes [Cu(II)(phen)(L-Pro)(H2O)]+ ClO4(-) (1; phen = 1,10-phenanthroline) and [Cu(II)(bipy)(L-Pro)(H2O)]+ ClO4(-) (2; bipy = 2,2'-bipyridine) were synthesized and characterized by IR, magnetic susceptibility, UV/VIS, EPR, ESI-MS, elemental analysis, and theoretical calculations. The metal center was found in a square-pyramidal geometry. UV/VIS, thermal-denaturation, and fluorescence-spectroscopic studies were conducted to assess the interaction of the complexes with CT-DNA. An intercalative mode of binding was found, with intrinsic binding constants (Kb) of 3.86x10(3) and 4.6x10(3) M(-1) and Stern-Volmer quenching constants (K) of 0.15 and 0.11 for 1 and 2, respectively. Interestingly, none of the Cu(II) complexes was able to cleave pUC-19 DNA, which is attributed to the absence of a Pro amide H-atom and inhibition of the formation of an OH radical from the axially coordinated H2O molecule.

Synthesis, NMR characterization, X-ray crystal structure of Co(II) Ni(II) and Cu(II) complexes of a pyridine containing self-assembling

International Nuclear Information System (INIS)

Ranjbar, M.; Taghavipour, M.; Moghimi, A.; Aghabozorg, H.

2002-01-01

In the recent years, the self-assembling systems have been attracted chemists. The intermolecular bond in such systems mainly consists of ion pairing and hydrogen bonding [1,2]. The reaction between self-assembling system liquid LH 2 (py dc=2,6-pyridinedicarboxylic acid and py da=2,6- pyridine diamin) with cobalt (II) nitrate, nickel (II) chloride, and copper (II) acetate in water leads to the formation of self- assemble coordination complexes, [py da.H] 2 [M(py dc) 2 ]. H 2 O, M=Co(II),Ni(II), and Cu(II). The characterization was performed using elemental analysis, ESI mass spectroscopy, 1 H and 13 C NMR and X-ray crystallography. The crystal systems are monoclinic with space group P2 1 /n and four molecules per unit cell. These complexes shows 13 C NMR resonances of cationic counter ion [(py dc,H)] + in DMSO- d 6 but no signal corresponding to the two coordinated ligands [py dc] 2- The metal atoms are six-coordinated with a distorted octahedral geometry. The two [py de] 2- units are almost perpendicular to each other

Enhancement of antimicrobial activities of whole and sub-fractionated white tea by addition of copper (II sulphate and vitamin C against Staphylococcus aureus; a mechanistic approach

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Holloway Andrew C

2011-11-01

Full Text Available Abstract Background Enhancement of antimicrobial plant products e.g. pomegranate extract by copper (II sulphate is known. Such combinations have applications in various settings, including the identification of novel compositions to study, treat and control infection. Methods A combination of white tea (WT (made allowing 10 minutes infusion time at 100°C was combined with 4.8 mM copper (II sulphate and tested for antimicrobial effect on the viability of Staphylococcus aureus NCTC 06571. Comparisons were made with green (GT and black (BT teas. A WT sub-fraction (WTF Results A 30 minute incubation at room temperature of copper (II sulphate alone and combined with WT reduced the viability of S. aureus NCTC 06571 by c.a 1 log10 cfu mL-1. GT and BT with copper (II sulphate negated activity to buffer values. Combined with copper (II sulphate, vitamin C, WTF and, vitamin C plus WTF all reduced the viability of S. aureus NCTC 06571 by c.a. 3.5 log10 cfu mL-1. Independent experiments showed the results were not due to pH effects. Adding WT or WTF to copper (II sulphate resulted in increased acidity. Copper (II sulphate alone and combined with WT required c.a 300 μg mL-1 (final concentration catalase to restore S. aureus viability, WTF with copper (II sulphate and added vitamin C required c.a 600 μg mL-1. WT and WTF UV-visible spectra were similar. Conclusions WT showed no efficacy in the combinations tested. WTF was enhanced with copper (II sulphate and further with vitamin C. WT and WTF increased acidity of copper (II sulphate possibly via the formation of chemical complexes. The difference in WT/WTF absorbance possibly represented substances less concentrated or absent in WTF. Investigations to establish which WTF component/s and in what proportions additives are most effective against target organisms are warranted.

Iodometric determination of peroxydiphosphate in the presence of copper(II) or iron(II) as catalyst.

Science.gov (United States)

Kapoor, S; Sharma, P D; Gupta, Y K

1975-09-01

Peroxydiphosphate can be determined iodometrically in the presence of a large excess of potassium iodide with copper(II) or iron(II) as catalyst through the operation of the Cu(II)/Cu(I) or Fe(II)/Fe(III) cycle. The method is applicable in HClO(4), H(2)SO(4), HCl and CH(3)COOH acid media in the range 0.1-1.0M studied. Nickel, manganese(II), cobalt(II), silver, chloride and phosphate are without effect.

The DFT Calculations of Structures and EPR Parameters for the Dinuclear Paddle-Wheel Copper(II) Complex {Cu2(μ2-O2CCH3)4}(OCNH2CH3) as Powder or Single Crystal

Science.gov (United States)

Ding, Chang-Chun; Wu, Shao-Yi; Xu, Yong-Qiang; Zhang, Li-Juan; Zhang, Zhi-Hong; Zhu, Qin-Sheng; Wu, Ming-He; Teng, Bao-Hua

2017-10-01

Density functional theory (DFT) calculations of the structures and the Cu2+ g factors (gx, gy and gz ) and hyperfine coupling tensor A (Ax , Ay and Az ) were performed for the paddle-wheel (PW)-type binuclear copper(II) complex {Cu2(μ2-O2CCH3)4}(OCNH2CH3) powder and single crystal. Calculations were carried out with the ORCA software using the functionals BHandHlyp, B3P86 and B3LYP with five different basis sets: 6-311g, 6-311g(d,p), VTZ, def-2 and def2-TZVP. Results were tested by the MPAD analysis to find the most suitable functional and basis sets. The electronic structure and covalency between copper and oxygen were investigated by the electron localisation function and the localised orbital locator as well as the Mayer bond order for the [CuO5] group. The optical spectra were theoretically calculated by the time-dependent DFT module and plotted by the Multiwfn program for the [CuO5] group and reasonably associated with the local structure in the vicinity of the central ion copper. In addition, the interactions between the OCNH2CH3, NH3 and H2O molecules and the uncoordinated PW copper(II) complex were studied, and the corresponding adsorption energies, the frequency shifts with respect to the free molecules and the changes of the Cu-Cu distances were calculated and compared with the relevant systems.

Validation data supporting the characterization of novel copper complexes as anticancer agents

Directory of Open Access Journals (Sweden)

Ceyda Acilan

2016-12-01

Full Text Available Three copper(II complexes, Cu(Sal-Gly(phen, Cu(Sal-Glypheamine, Cu(Sal-Glyphepoxy were synthesized and characterized for their anticancer properties and mechanism of action (Acilan et al., in press [1]. Here, we provide supporting data on colon cancer cell lines complementing our previous findings in cervix cells. This paper also contains a data table for the fold changes and p-values of all genes analyzed in this study via a custom RT-qPCR array. All compounds induced DNA damage (based on 8-oxo-guanidine, ɣH2AX staining in cells and apoptosis (based on elevated DNA condensation/fragmentation, Annexin V staining, caspase 3/7 activity and mitochondrial membrane depolarization in HCT-116 colon cancer cells. The increase in oxidative stress was also further confirmed in these cells. Further interpretation of the data presented here can be found in the article entitled “Synthesis, biological characterization and evaluation of molecular mechanisms of novel copper complexes as anticancer agents” (Acilan et al., in press [1].

Fabrication of copper-selective PVC membrane electrode based on newly synthesized copper complex of Schiff base as carrier

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Sulekh Chandra

2016-09-01

Full Text Available The newly synthesized copper(II complex of Schiff base p-hydroxyacetophenone semicarbazone was explored as neutral ionophore for the fabrication of poly(vinylchloride (PVC based membrane electrode selective to Cu(II ions. The electrode shows a Nernstian slope of 29.8 ± 0.3 mV/decade with improved linear range of 1.8 × 10−7 to 1.0 × 10−1 M, comparatively lower detection limit 5.7 × 10−8 M between pH range of 2.0–8.0, giving a relatively fast response within 5s and can be used for at least 16 weeks without any divergence in potential. The selectivity coefficient was calculated using the fixed interference method (FIM. The electrode can also be used in partially non-aqueous media having up to 25% (v/v methanol, ethanol or acetone content with no significant change in the value of slope or working concentration range. It was successfully applied for the direct determination of copper content in water and tea samples with satisfactory results. The electrode has been used in the potentiometric titration of Cu2+ with EDTA.

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.

Synthesis, characterization and biological activities of semicarbazones and their copper complexes.

Science.gov (United States)

Venkatachalam, Taracad K; Bernhardt, Paul V; Noble, Chris J; Fletcher, Nicholas; Pierens, Gregory K; Thurecht, Kris J; Reutens, David C

2016-09-01

Substituted semicarbazones/thiosemicarbazones and their copper complexes have been prepared and several single crystal structures examined. The copper complexes of these semicarbazone/thiosemicarbazones were prepared and several crystal structures examined. The single crystal X-ray structure of the pyridyl-substituted semicarbazone showed two types of copper complexes, a monomer and a dimer. We also found that the p-nitrophenyl semicarbazone formed a conventional 'magic lantern' acetate-bridged dimer. Electron Paramagnetic Resonance (EPR) of several of the copper complexes was consistent with the results of single crystal X-ray crystallography. The EPR spectra of the p-nitrophenyl semicarbazone copper complex in dimethylsulfoxide (DMSO) showed the presence of two species, confirming the structural information. Since thiosemicarbazones and semicarbazones have been reported to exhibit anticancer activity, we examined the anticancer activity of several of the derivatives reported in the present study and interestingly only the thiosemicarbazone showed activity while the semicarbazones were not active indicating that introduction of sulphur atom alters the biological profile of these thiosemicarbazones. Copyright © 2016 Elsevier Inc. All rights reserved.

Copper Recovery from Yulong Complex Copper Oxide Ore by Flotation and Magnetic Separation

Science.gov (United States)

Han, Junwei; Xiao, Jun; Qin, Wenqing; Chen, Daixiong; Liu, Wei

2017-09-01

A combined process of flotation and high-gradient magnetic separation was proposed to utilize Yulong complex copper oxide ore. The effects of particle size, activators, Na2S dosage, LA (a mixture of ammonium sulfate and ethylenediamine) dosage, activating time, collectors, COC (a combination collector of modified hydroxyl oxime acid and xanthate) dosage, and magnetic intensity on the copper recovery were investigated. The results showed that 74.08% Cu was recovered by flotation, while the average grade of the copper concentrates was 21.68%. Another 17.34% Cu was further recovered from the flotation tailing by magnetic separation at 0.8 T. The cumulative recovery of copper reached 91.42%. The modifier LA played a positive role in facilitating the sulfidation of copper oxide with Na2S, and the combined collector COC was better than other collectors for the copper flotation. This technology has been successfully applied to industrial production, and the results are consistent with the laboratory data.

Induction of Laccase, Lignin Peroxidase and Manganese Peroxidase Activities in White-Rot Fungi Using Copper Complexes

Directory of Open Access Journals (Sweden)

Martina Vrsanska

2016-11-01

Full Text Available Ligninolytic enzymes, such as laccase, lignin peroxidase and manganese peroxidase, are biotechnologically-important enzymes. The ability of five white-rot fungal strains Daedaleopsis confragosa, Fomes fomentarius, Trametes gibbosa, Trametes suaveolens and Trametes versicolor to produce these enzymes has been studied. Three different copper(II complexes have been prepared ((Him[Cu(im4(H2O2](btc·3H2O, where im = imidazole, H3btc = 1,3,5-benzenetricarboxylic acid, [Cu3(pmdien3(btc](ClO43·6H2O and [Cu3(mdpta3(btc](ClO43·4H2O, where pmdien = N,N,N′,N′′,N′′-pentamethyl-diethylenetriamine and mdpta = N,N-bis-(3-aminopropylmethyl- amine, and their potential application for laccase and peroxidases induction have been tested. The enzyme-inducing activities of the complexes were compared with that of copper sulfate, and it has been found that all of the complexes are suitable for the induction of laccase and peroxidase activities in white-rot fungi; however, the newly-synthesized complex M1 showed the greatest potential for the induction. With respect to the different copper inducers, this parameter seems to be important for enzyme activity, which depends also on the fungal strains.

New Cu (II), Co(II) and Ni(II) complexes of chalcone derivatives: Synthesis, X-ray crystal structure, electrochemical properties and DFT computational studies

Science.gov (United States)

Tabti, Salima; Djedouani, Amel; Aggoun, Djouhra; Warad, Ismail; Rahmouni, Samra; Romdhane, Samir; Fouzi, Hosni

2018-03-01

The reaction of nickel(II), copper(II) and cobalt(II) with 4-hydroxy-3-[(2E)-3-(1H-indol-3-yl)prop-2-enoyl]-6-methyl-2H-pyran-2-one (HL) leads to a series of new complexes: Ni(L)2(NH3), Cu(L)2(DMF)2 and Co(L)2(H2O). The crystal structure of the Cu(L)2(DMF)2 complex have been determined by X-ray diffraction methods. The Cu(II) lying on an inversion centre is coordinated to six oxygen atoms forming an octahedral elongated. Additionally, the electrochemical behavior of the metal complexes were investigated by cyclic voltammetry at a glassy carbon electrode (GC) in CH3CN solutions, showing the quasi-reversible redox process ascribed to the reduction of the MII/MI couples. The X-ray single crystal structure data of the complex was matched excellently with the optimized monomer structure of the desired compound; Hirschfeld surface analysis supported the packed crystal lattice 3D network intermolecular forces. HOMO/LUMO energy level and the global reactivity descriptors quantum parameters are also calculated. The electrophilic and nucleophilic potions in the complex surface are theoretically evaluated by molecular electrostatic potential and Mulliken atomic charges analysis.

The Cu(II) affinity of the N-terminus of human copper transporter CTR1: Comparison of human and mouse sequences.

Science.gov (United States)

Bossak, Karolina; Drew, Simon C; Stefaniak, Ewelina; Płonka, Dawid; Bonna, Arkadiusz; Bal, Wojciech

2018-05-01

Copper Transporter 1 (CTR1) is a homotrimeric membrane protein providing the main route of copper transport into eukaryotic cells from the extracellular milieu. Its N-terminal extracellular domain, rich in His and Met residues, is considered responsible for directing copper into the transmembrane channel. Most of vertebrate CTR1 proteins contain the His residue in position three from N-terminus, creating a well-known Amino Terminal Cu(II)- and Ni(II)-Binding (ATCUN) site. CTR1 from humans, primates and many other species contains the Met-Asp-His (MDH) sequence, while some rodents including mouse have the Met-Asn-His (MNH) N-terminal sequence. CTR1 is thought to collect Cu(II) ions from blood copper transport proteins, including albumin, but previous reports indicated that the affinity of N-terminal peptide/domain of CTR1 is significantly lower than that of albumin, casting serious doubt on this aspect of CTR1 function. Using potentiometry and spectroscopic techniques we demonstrated that MDH-amide, a tripeptide model of human CTR1 N-terminus, binds Cu(II) with K of 1.3 × 10 13  M -1 at pH 7.4, ~13 times stronger than Human Serum Albumin (HSA), and MNH-amide is even stronger, K of 3.2 × 10 14  M -1 at pH 7.4. These results indicate that the N-terminus of CTR1 may serve as intermediate binding site during Cu(II) transfer from blood copper carriers to the transporter. MDH-amide, but not MNH-amide also forms a low abundance complex with non-ATCUN coordination involving the Met amine, His imidazole and Asp carboxylate. This species might assist Cu(II) relay down the peptide chain or its reduction to Cu(I), both steps necessary for the CTR1 function. Copyright © 2018 Elsevier Inc. All rights reserved.

Blue copper model complexes with distorted tetragonal geometry acting as effective electron-transfer mediators in dye-sensitized solar cells.

Science.gov (United States)

Hattori, Shigeki; Wada, Yuji; Yanagida, Shozo; Fukuzumi, Shunichi

2005-07-06

The electron self-exchange rate constants of blue copper model complexes, [(-)-sparteine-N,N'](maleonitriledithiolato-S,S')copper ([Cu(SP)(mmt)])(0/)(-), bis(2,9-dimethy-1,10-phenanthroline)copper ([Cu(dmp)(2)](2+/+)), and bis(1,10-phenanthroline)copper ([Cu(phen)(2)](2+/+)) have been determined from the rate constants of electron transfer from a homologous series of ferrocene derivatives to the copper(II) complexes in light of the Marcus theory of electron transfer. The resulting electron self-exchange rate constant increases in the order: [Cu(phen)(2)](2+/+) geometry. The dye-sensitized solar cells (DSSC) were constructed using the copper complexes as redox couples to compare the photoelectrochemical responses with those using the conventional I(3)(-)/I(-) couple. The light energy conversion efficiency (eta) values under illumination of simulated solar light irradiation (100 mW/cm(2)) of DSSCs using [Cu(phen)(2)](2+/+), [Cu(dmp)(2)](2+/+), and [Cu(SP)(mmt)](0/)(-) were recorded as 0.1%, 1.4%, and 1.3%, respectively. The maximum eta value (2.2%) was obtained for a DSSC using the [Cu(dmp)(2)](2+/+) redox couple under the light irradiation of 20 mW/cm(2) intensity, where a higher open-circuit voltage of the cell was attained as compared to that of the conventional I(3)(-)/I(-) couple.

PROMETHEE II: A knowledge-driven method for copper exploration

Science.gov (United States)

Abedi, Maysam; Ali Torabi, S.; Norouzi, Gholam-Hossain; Hamzeh, Mohammad; Elyasi, Gholam-Reza

2012-09-01

This paper describes the application of a well-known Multi Criteria Decision Making (MCDM) technique called Preference Ranking Organization METHod for Enrichment Evaluation (PROMETHEE II) to explore porphyry copper deposits. Various raster-based evidential layers involving geological, geophysical, and geochemical geo-datasets are integrated to prepare a mineral prospectivity mapping (MPM). In a case study, thirteen layers of the Now Chun copper deposit located in the Kerman province of Iran are used to explore the region of interest. The PROMETHEE II technique is applied to produce the desired MPM, and the outputs are validated using twenty-one boreholes that have been classified into five classes. This proposed method shows a high performance when providing the MPM while reducing the cost of exploratory drilling in the study area.

Sulfonato-imino copper(ii) complexes: fast and general Chan-Evans-Lam coupling of amines and anilines.

Science.gov (United States)

Hardouin Duparc, V; Schaper, F

2017-10-14

Sulfonato-imine copper complexes with either chloride or triflate counteranions were prepared in a one-step reaction followed by anion-exchange. They are highly active in Chan-Evans-Lam couplings under mild conditions with a variety of amines or anilines, in particular with sterically hindered substrates. No optimization of reaction conditions other than time and/or temperature is required.

Synthesis, characterization and polymerization of methacrylates of copper (II), cobalt (II) and molybdenum (II). Generation of new materials

International Nuclear Information System (INIS)

Rojas Bolanos, Omar

2006-01-01

Coordination compounds of the species copper (II), cobalt (II) and molybdenum (II) with methacrylic acid were synthesized and characterized. Besides, it realized reactions of bromine addition to the doubles links of the species obtained previously, also too like reactions with dry HCl. Finally, it got hybrids materials by polymerization of the first compounds in an acrylic matrix. Research concluded with the characterization of all the products. (author) [es

The crystal structure of paramagnetic copper(ii) oxalate (CuC2O4):

DEFF Research Database (Denmark)

Christensen, Axel Nørlund; Lebech, Bente; Andersen, Niels Hessel

2014-01-01

Synthetic copper(ii) oxalate, CuC2O4, was obtained in a precipitation reaction between a copper(ii) solution and an aqueous solution of oxalic acid. The product was identified from its conventional X-ray powder patterns which match that of the copper mineral Moolooite reported to have...... the composition CuC2O4·0.44H2O. Time resolved in situ investigations of the thermal decomposition of copper(ii) oxalate using synchrotron X-ray powder diffraction showed that in air the compound converts to Cu2O at 215 °C and oxidizes to CuO at 345 °C. Thermo gravimetric analysis performed in an inert Ar....... The crystal structure consists of a random stacking of CuC2O4 micro-crystallites where half the Cu-atoms are placed at (2a) and the other half at (2b) positions with the corresponding oxalate molecules centred around the corresponding (2b) and (2a) site positions, respectively. The diffraction patterns...

[Biohydrometallurgical technology of a complex copper concentrate process].

Science.gov (United States)

Murav'ev, M I; Fomchenko, N V; Kondrat'eva, T F

2011-01-01

Leaching of sulfide-oxidized copper concentrate of the Udokan deposit ore with a copper content of 37.4% was studied. In the course of treatment in a sulfuric acid solution with pH 1.2, a copper leaching rate was 6.9 g/kg h for 22 h, which allowed extraction of 40.6% of copper. As a result of subsequent chemical leaching at 80 degrees C during 7 h with a solution of sulphate ferric iron obtained after bio-oxidation by an association of microorganisms, the rate of copper recovery was 52.7 g/kg h. The total copper recovery was 94.5% (over 29 h). Regeneration of the Fe3+ ions was carried out by an association of moderately thermophilic microorganisms, including bacteria of genus Sulfobacillus and archaea of genus Ferroplasma acidiphilum, at 1.0 g/l h at 40 degrees C in the presence of 3% solids obtained by chemical leaching of copper concentrate. A technological scheme of a complex copper concentrate process with the use of bacterial-chemical leaching is proposed.

Hydrothermal growth of cross-linked hyperbranched copper dendrites using copper oxalate complex

Science.gov (United States)

Truong, Quang Duc; Kakihana, Masato

2012-06-01

A facile and surfactant-free approach has been developed for the synthesis of cross-linked hyperbranched copper dendrites using copper oxalate complex as a precursor and oxalic acid as a reducing and structure-directing agent. The synthesized particles are composed of highly branched nanostructures with unusual cross-linked hierarchical networks. The formation of copper dendrites can be explained in view of both diffusion control and aggregation-based growth model accompanied by the chelation-assisted assembly. Oxalic acid was found to play dual roles as reducing and structure-directing agent based on the investigation results. The understanding on the crystal growth and the roles of oxalic acid provides clear insight into the formation mechanism of hyperbranched metal dendrites.

Silver(I), Copper(I) and Copper(II) Complex of the New N,Se-Chelate Ligand 2-Phenylselenomethyl-1H-benzimidazole: Electrochemistry and Structure

Czech Academy of Sciences Publication Activity Database

Leboschka, M.; Sieger, M.; Sarkar, B.; Niemeyer, M.; Schurr, T.; Fiedler, Jan; Záliš, Stanislav; Kaim, W.

2009-01-01

Roč. 635, 6-7 (2009), s. 1001-1007 ISSN 0044-2313 R&D Projects: GA AV ČR KAN100400702; GA MŠk OC 139 Institutional research plan: CEZ:AV0Z40400503 Keywords : copper compounds * solid-state structures * electrochemistry * selenother ligand * silver complex Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 1.226, year: 2009

The removal of hydrogen sulfide from gas streams using an aqueous metal sulfate absorbent : Part II. the regeneration of copper sulfide to copper oxide - An experimental study

NARCIS (Netherlands)

Ter Maat, H.; Hogendoorn, J. A.; Versteeg, G. F.

2005-01-01

Aim of this study was to investigate the possibilities for a selective and efficient method to convert copper(II) sulfide (CuS) into copper(II) oxide (CuO). The oxidation of copper sulfide has been studied experimentally using a thermogravimetric analyzer (TGA) at temperatures ranging from 450 to

Synthesis, spectroscopic and antimicrobial properties of Co(II), Ni (II ...

African Journals Online (AJOL)

The objective of this study is to investigate the antimicrobial activity of novel Schiff base metal complexes. The resistance of micro-organisms to classical antimicrobial compounds poses a challenge to effective management and treatment of some diseases. In line with this, copper (II), nickel (II) and cobalt (II) complexes of ...

Trinuclear Schiff base complexes with uranium(V) and copper(II) or zinc(II) ions

Energy Technology Data Exchange (ETDEWEB)

Salmon, L.; Thuery, P.; Ephritikhine, M. [CEA Saclay, DSM, DRECAM, Serv Chim Mol, Lab Claude Frejacques, CNRS URA 331, F-91191 Gif Sur Yvette, (France)

2007-07-01

Treatment of the uranium(IV) complexes [{l_brace}ML{sup 1}(py){r_brace}{sub 2}U(IV)] (M = Cu, Zn; L{sup 1} = N, N'-bis(3-hydroxy-salicylidene)-1,3-propane-diamine) with silver nitrate in pyridine led to the formation of the corresponding cationic uranium(V) species which were found to be thermally unstable and were converted back into the parent U(IV) complexes; no electron transfer was observed in solution between the U(IV) and U(V) compounds. In the crystals of [{l_brace}ML{sup 1}(py){r_brace}{sub 2}U(IV)][{l_brace}ML{sup 1}(py){r_brace}{sub 2}U(V)][NO{sub 3}], the neutral U(IV) and cationic U(V) species are clearly identified by the distinct U-O distances. Similar reaction of [{l_brace}ZnL{sup 2}(py){r_brace}{sub 2}U(IV)] [L{sup 2} N,N'-bis(3-hydroxy-salicylidene)-1,4-butane-diamine] with AgNO{sub 3} gave crystals of [{l_brace}ZnL{sup 2}(py){r_brace}U(V){l_brace}ZnL{sup 2}(py){sub 2}{r_brace}][NO{sub 3}] but the copper counterpart was not isolated. Crystals of [{l_brace}ZnL{sup 1}(py){r_brace}{sub 2}U(V)][OTf].THF (OTf = OSO{sub 2}CF{sub 3}) were obtained fortuitously from the reaction of [Zn(H{sub 2}L{sup 1})] and U(OTf){sub 3}. (authors)

Metal complexation in near field conditions of nuclear waste repository - stability constant of copper complexation with cellulose degradation products, in alkaline conditions

International Nuclear Information System (INIS)

Guede, Kipre Bertin

2005-11-01

Copper is a stable element and spent fuel component which constitutes the radioactive waste. The reaction of Copper with cellulose degradation products in alkaline conditions was performed to mimic what occurs in near field conditions of nuclear waste repository. From the characteristics of Cu (II), this thesis aims at inferring the behaviour of radionuclides vis a vis the degradation products of cellulose. The contribution of the present work is therefore the assessment of the stability of the major cellulose degradation product, its affinity for Copper and the extent of the complexation function 13 between Cu (II) and the organic moieties. The formation of cellulose degradation products was followed by measurement of p11, Conductivity, Angle of rotation, relative abundance of aliphatics and aromatics (E4/E6 ) aid by UV-visible spectroscopy. The TOC was determined using the Walkley and Black titration after respectively 31 weeks and 13 weeks of degradation for the reaction mixtures T and A, N. The stability of the major degradation products gave the following figures: ISA(A): - 13 43.39 <ΔG -10639.88 ISA(N): - Ii 436.45<ΔG< -9103.6. The study of the characteristics of Gluconic Acid, as a model compound, was carried out in an attempt to give a general picture of the roper ties of cellulose degradation products. The Complexation between Cu (II) and the organic ligand (Cellulose degradation products) was performed using UV-visible spectroscopy and Ion Distribution technique. The Log B value obtained from the complexation studies at 336 nm for 1 = 0. I Ni NaClO4 and I = 0.01 M NaClO4, falls within a range of 3.48 to 3.74 for the standard reference material (Gluconic Acid), and within I .87 to 2.3 I, and I .6 to 2.01, respectively for the degradation Products ISA (A) and ISA(N). The ion distribution studies showed that: • In (he absence of the degradation product ISA and at pH = 3.68. 56. 17 % of Cu (II) was bound to the resin. • In the presence of ISA and at 2

Synthesis and spectral studies of manganese(II), cobalt(II), nickel(II), copper(II), zinc(II), cadmium(II) and mercury(II) complexes of 4-oxo-4H-1-benzopyran-3-carboxaldehyde hydrazone derivatives

International Nuclear Information System (INIS)

Nawar, N.; Khattab, M.A.; Bekheit, M.M.; El-Kaddah, A.H.

1996-01-01

A few complexes of Mn(II), Co(II), Ni(II), Cu(II), Zn(II), Cd(II) and Hg(II) with 4-oxo-4H-1-benzopyran-3-(carboxaldehyde-4-chlorobenzylhydrazone) (BCBH) and 4-oxo-4H-1-benzopyran-3-(carboxaldehyde-4-methylbenzylhydrazone) (BMBH) have been synthesised and characterized by elemental analysis, molar conductivities, magnetic measurements and infrared (IR) and visible spectral studies. The IR spectra show that BCBH and BMBH behave as bidentate ligands either in the keto or enol form. (author). 24 refs., 2 tabs

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

African Journals Online (AJOL)

Activated carbon modified method was used for the preconcentration and ... in real samples such as tap water, wastewater and a synthetic water sample by flame ... KEY WORDS: Copper(II), Solid phase extraction, Activated carbon, Flame ...

Copper Complexes of Nicotinic-Aromatic Carboxylic Acids as Superoxide Dismutase Mimetics

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Virapong Prachayasittikul

2008-12-01

Full Text Available Nicotinic acid (also known as vitamin B3 is a dietary element essential for physiological and antihyperlipidemic functions. This study reports the synthesis of novel mixed ligand complexes of copper with nicotinic and other select carboxylic acids (phthalic, salicylic and anthranilic acids. The tested copper complexes exhibited superoxide dismutase (SOD mimetic activity and antimicrobial activity against Bacillus subtilis ATCC 6633, with a minimum inhibition concentration of 256 μg/mL. Copper complex of nicotinic-phthalic acids (CuNA/Ph was the most potent with a SOD mimetic activity of IC50 34.42 μM. The SOD activities were observed to correlate well with the theoretical parameters as calculated using density functional theory (DFT at the B3LYP/LANL2DZ level of theory. Interestingly, the SOD activity of the copper complex CuNA/Ph was positively correlated with the electron affinity (EA value. The two quantum chemical parameters, highest occupied molecular orbital (HOMO and lowest unoccupied molecular orbital (LUMO, were shown to be appropriate for understanding the mechanism of the metal complexes as their calculated energies show good correlation with the SOD activity. Moreover, copper complex with the highest SOD activity were shown to possess the lowest HOMO energy. These findings demonstrate a great potential for the development of value-added metallovitamin-based therapeutics.

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)

Determination of Cu(III) and Cu(II)+Cu(III) in superconducting copper ceramics

International Nuclear Information System (INIS)

Nedelcheva, T.; Kostadinova, L.; Stoyanova-Ivanova, A.; Ivanova, I.

1992-01-01

Copper(III) and total copper in superconducting Y-Ba-Cu oxide and related compounds can be determinated by two successive iodimetric titrations after the sample has been dissolved under Ar in HCl/KI medium. First, the iodine equivalent to copper(III) is titrated with Na 2 S 2 O 3 solution at pH 4.8, copper(II) being masked with EDTA. The total copper is then determined in the same solution by demasking with acid and iodide, followed by iodimetric titration. The method is both accurate and reproducible. The relative standard deviations for 1.074% copper(III) and 23.37% total copper are 0.8% and 0.3%, respectively. (orig.)

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.

Structural characterization of copper (II) tetradecanoate with 2,2′-bipyridine and 4,4′-bipyridine to study magnetic properties

OpenAIRE

Noha Said Bedowr; Rosiyah Binti Yahya; Nesrain Farhan

2018-01-01

This paper presents synthesis, structural characterization and spintronic applications of copper (II) tetradecanoate derived magnetic complexes. The complexes were prepared by a chemical reaction between [Cu2(CH3(CH2)12COO)4](EtOH)2 and 2,2′-bipyridine-4,4′-bipyridine ligands respectively. The complexes were further reacted between the product of the first reaction and 4,4′-bipyridine-2,2′-bipyridine respectively. The structural characterization techniques included elemental analysis, Fourier...

Spectroscopic, thermal, catalytic and biological studies of Cu(II) azo dye complexes

Science.gov (United States)

El-Sonbati, A. Z.; Diab, M. A.; El-Bindary, A. A.; Shoair, A. F.; Hussein, M. A.; El-Boz, R. A.

2017-08-01

New complexes of copper(II) with azo compounds of 5-amino-2-(aryl diazenyl)phenol (HLn) are prepared and investigated by elemental analyses, molar conductance, IR, 1H NMR, UV-Visible, mass, ESR spectra, magnetic susceptibility measurements and thermal analyses. The complexes have a square planar structure and general formula [Cu(Ln)(OAc)]H2O. Study the catalytic activities of Cu(II) complexes toward oxidation of benzyl alcohol derivatives to carbonyl compounds were tested using H2O2 as the oxidant. The intrinsic binding constants (Kb) of the ligands (HLn) and Cu(II) complexes (1-4) with CT-DNA are determined. The formed compounds have been tested for biological activity of antioxidants, antibacterial against Gram-positive (Staphylococcus aureus) and Gram-negative (Escherichia coli) bacteria and yeast Candida albicans. Antibiotic (Ampicillin) and antifungal against (Colitrimazole) and cytotoxic compounds HL1, HL2, HL3 and complex (1) showed moderate to good activity against S. aureus, E. coli and Candida albicans, and also to be moderate on antioxidants and toxic substances. Molecular docking is used to predict the binding between the ligands with the receptor of breast cancer (2a91).

Aqua[bis(pyrimidin-2-yl-kappa N)amine](carbonato-kappa 2O,O')copper(II) dihydrate.

Science.gov (United States)

van Albada, Gerard A; Mutikainen, Ilpo; Turpeinen, Urho; Reedijk, Jan

2002-03-01

The title mononuclear complex, [Cu(CO(3))(C(8)H(7)N(5))(H(2)O)] x 2H(2)O, was obtained by fixation of CO(2) by a mixture of copper(II) tetrafluoroborate and the ligand bis(pyrimidin-2-yl)amine in ethanol/water. The Cu(II) ion of the complex has a distorted square-pyramidal environment, with a basal plane formed by two N atoms of the ligand and two chelating O atoms of the carbonate group, while the apical position is occupied by the O atom of the coordinating water molecule. In the solid state, hydrogen-bonding interactions are dominant, the most unusual being the Watson-Crick-type coplanar ligand pairing through two N--H...N bonds. Lattice water molecules also participate in hydrogen bonding.

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

Indian Academy of Sciences (India)

BISWAJIT CHOWDHURY

2017-10-03

Oct 3, 2017 ... made with a Jasco model V-730 UV-Vis spectrophotometer. ..... Ligand-induced coordination changes ... Fet3 protein from yeast, a multinuclear copper oxidase ... of mutants of the multicopper oxidase Fet3p Biochem-.

RECOVERY OF COPPER(II) AND CHROMIUM(III) FROM NITRATE ...

African Journals Online (AJOL)

Guerdouh A and Barkat D

2016-05-01

May 1, 2016 ... The ionic strength of the aqueous medium was ... phases were separated completely, concentrations of the copper(II) and chromium(III) ..... [18] Huff M M, Otu E O. Solvent Extraction and Ion Exchange, 2004, 22(4), 695-712.

Estudo voltamétrico do complexo de cobre(II com o ligante vermelho de alizarina S, adsorvido na superfície do eletrodo de grafite pirolítico Voltammetric study of complex of copper (II with alizarin red S ligand, absorbed on surface of pyrolytic graphite electrode

Directory of Open Access Journals (Sweden)

Victor E. Mouchrek Filho

1999-06-01

Full Text Available The alizarin red S (ARS has been used as a spectrophotometric reagent of several metals for a long time. Now this alizarin has been used as modifier agent of electrodes, for voltammetric analyses. In this work cyclic voltammetry experiments was accomplished on closed circuit, with the objective of studying the voltammetric behavior of alizarin red S adsorbed and of its copper complex, on the surface of the pyrolytic graphite electrode. These studies showed that ARS strongly adsorbs on the surface of this electrode. This adsorption was used to immobilize ions copper(II from the solution.

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.

catena-Poly[copper(II)-mu-L-tyrosyl-L-leucinato].

Science.gov (United States)

Baggio, Ricardo; Casado, Nieves M C; Calvo, Rafael; Rapp, Raul E; Garland, María Teresa

2005-05-01

In the title compound, [Cu(C15H20N2O4)]n, the copper(II) coordination is square planar. The anionic L-tyrosyl-L-leucinate ligand binds in an N,N',O-tridentate mode to one Cu(II) cation on one side and in an O-monodentate mode to a second Cu(II) cation on the other side, thus defining -Cu-O-C-O-Cu'- chains which run along the a axis. These chains are held together by a strong hydrogen bond involving the hydroxy H atom.

Reconnaissance and economic geology of Copper Mountain metamorphic complex, Owl Creek Mountains, Wyoming

International Nuclear Information System (INIS)

Hausel, W.D.

1983-01-01

The Copper Mountain metamorphic complex lies within a westerly trending belt of Precambrian exposures known as the Owl Creek Mountains uplift. The metamorphic complex at Copper Mountain is part of a larger complex known as the Owl Creek Mountains greenstone belt. Until more detailed mapping and petrographic studies can be completed, the Copper Mountain area is best referred to as a complex, even though it has some characteristics of a greestone belt. At least three episodes of Precambrian deformation have affected the supracrustals, and two have disturbed the granites. The final Precambrian deformation event was preceded by a weak thermal event expressed by retrogressive metamorphism and restricted metasomatic alteration. During this event, a second phase of pegmatization was accompanied by hydrothermal solutions. During the Laramide orogeny, Copper Mountain was again modified by deformation. Laramide deformation produced complex gravity faults and keystone grabens. Uranium deposits were formed following major Laramide deformation. The genesis of these deposits is attributable to either the leaching of granites or the leaching of overlying tuffaceous sediments during the Tertiary. Production of metals and industrial minerals has been limited, although some gold, copper, silver, tungsten, beryl, feldspar, and lithium ore have been shipped from Copper Mountain. A large amount of uranium was produced from the Copper Mountain district in the 1950s

Two-dimensional layer architecture assembled by Keggin polyoxotungstate, Cu(II)-EDTA complex and sodium linker: Synthesis, crystal structures, and magnetic properties

International Nuclear Information System (INIS)

Liu Hong; Xu Lin; Gao Guanggang; Li Fengyan; Yang Yanyan; Li Zhikui; Sun Yu

2007-01-01

Reaction of Keggin polyoxotungstate with copper(II)-EDTA (EDTA=ethylenediamine tetraacetate) complex under mild conditions led to the formation of hybrid inorganic-organic compounds Na 4 (OH)[(Cu 2 EDTA)PW 12 O 40 ].17H 2 O (1) and Na 4 [(Cu 2 EDTA)SiW 12 O 40 ].19H 2 O (2). The single-crystal X-ray diffraction analyses reveal their two structural features: (1) one-dimensional chain structure consisting of Keggin polyoxotungstate and copper(II)-EDTA complex; (2) Two-dimensional layer architecture assembled by the one-dimensional chain structure and sodium linker. The results of magnetic measurements in the temperature range 300-2 K indicated the existence of ferromagnetic exchange interactions between the Cu II ions for both compounds. In addition, TGA analysis, IR spectra, and electrochemical properties were also investigated to well characterize these two compounds. - Graphical abstract: Two new polyoxometalate-based hybrids, Na 4 (OH)[Cu 2 (EDTA)PW 12 O 40 ].17H 2 O (1) and Na 4 [Cu 2 (EDTA)SiW 12 O 40 ].19H 2 O (2), have been synthesized and structurally characterized, which consist of one-dimensional chain structure assembled by Keggin polyoxotungstate and copper(II)-EDTA complex. The chains are further connected to form two-dimensional layer architecture assembled by the one-dimensional chain structure and sodium linker

The DFT calculations of structures and EPR parameters for the dinuclear paddle-wheel copper(II) complex {Cu_2(μ_2-O_2CCH_3)_4}(OCNH{sub 2}CH{sub 3}) as powder or single crystal

Energy Technology Data Exchange (ETDEWEB)

Ding, Chang-Chun; Wu, Shao-Yi; Xu, Yong-Qiang; Zhang, Li-Juan; Zhang, Zhi-Hong; Zhu, Qin-Sheng; Wu, Ming-He; Teng, Bao-Hua [Univ. of Electronic Science and Technology of China, Chengdu (China). School of Physical Electronics

2017-07-01

Density functional theory (DFT) calculations of the structures and the Cu{sup 2+} g factors (g{sub x}, g{sub y} and g{sub z}) and hyperfine coupling tensor A (A{sub x}, A{sub y} and A{sub z}) were performed for the paddle-wheel (PW)-type binuclear copper(II) complex {Cu_2(μ_2-O_2CCH_3)_4}(OCNH{sub 2}CH{sub 3}) powder and single crystal. Calculations were carried out with the ORCA software using the functionals BHandHlyp, B3P86 and B3LYP with five different basis sets: 6-311g, 6-311g(d,p), VTZ, def-2 and def2-TZVP. Results were tested by the MPAD analysis to find the most suitable functional and basis sets. The electronic structure and covalency between copper and oxygen were investigated by the electron localisation function and the localised orbital locator as well as the Mayer bond order for the [CuO{sub 5}] group. The optical spectra were theoretically calculated by the time-dependent DFT module and plotted by the Multiwfn program for the [CuO{sub 5}] group and reasonably associated with the local structure in the vicinity of the central ion copper. In addition, the interactions between the OCNH{sub 2}CH{sub 3}, NH{sub 3} and H{sub 2}O molecules and the uncoordinated PW copper(II) complex were studied, and the corresponding adsorption energies, the frequency shifts with respect to the free molecules and the changes of the Cu-Cu distances were calculated and compared with the relevant systems.

Improving the Response of Copper(II) Selective PVC Membrane Electrode by Modification of N2S2 Donor Ligand.

Science.gov (United States)

Brinić, Slobodan; Buzuk, Marijo; Generalić, Eni; Bralić, Marija

2010-06-01

S,S'-bis(2-aminophenyl)ethanebis(thioate), (APhET), is reported as N2S2 ligand which form chelate with copper of high stability as compared to the other metals. Two modification of APhET, simpler 1,2-di-(o-aminophenylthio)ethane (DAPhTE), and the complex one 1,2-di-(o-salicylaldiminophenylthio)ethane (SAPhTE), were examined as the active material for copper(II) ion selective PVC membrane electrodes, and observed results are correlated. The obtained results with DAPhTE based electrodes show that only coordination abilities of ligand are insufficient for preparing the efficient membrane material. On the other hand, the results that are achieved with electrodes based on SAPhTE actuate interaction of ligand with polymer membrane matrix and necessity of ionophore immobilization in membrane. Optimized SAPhTE based membrane electrode has a linear range down to 10-6 mol L-1, with slope of 27.0 mV per decade, very rapid response time (under 5 seconds) and detection limit of 5.1 × 10-7 mol L-1. Such electrode is suitable for determination of copper(II) in analytical measurements by direct potentiometry and in potentiometric titrations, within pH between 2 and 7. The electrode is selective for copper(II) ions over a large number of metal ions, with the exception on Hg2+ ion when is present in concentrations above 2 × 10-5 mol L-1.

Physicochemical, antioxidant, DNA cleaving properties and antimicrobial activity of fisetin-copper chelates.

Science.gov (United States)

Łodyga-Chruscińska, Elżbieta; Pilo, Maria; Zucca, Antonio; Garribba, Eugenio; Klewicka, Elżbieta; Rowińska-Żyrek, Magdalena; Symonowicz, Marzena; Chrusciński, Longin; Cheshchevik, Vitalij T

2018-03-01

Fisetin (3,3',4',7-tetrahydroxyflavone) metal chelates are of interest as this plant polyphenol has revealed broad prospects for its use as natural medicine in the treatment of various diseases. Metal interactions may change or enhance fisetin biological properties so understanding fisetin metal chelation is important for its application not only in medicine but also as a food additive in nutritional supplements. This work was aimed to determine and characterize copper complexes formed in different pH range at applying various metal/ligand ratios. Fisetin and Cu(II)-fisetin complexes were characterized by potentiometric titrations, UV-Vis (Ultraviolet-visible spectroscopy), EPR, ESI-MS, FTIR and cyclic voltammetry. Their effects on DNA were investigated by using circular dichroism, spectrofluorimetry and gel electrophoresis methods. The copper complex with the ratio of Cu(II)/fisetin 1/2 exhibited significant DNA cleavage activity, followed by complete degradation of DNA. The influence of copper(II) ions on antioxidant activity of fisetin in vitro has been studied using DPPH, ABTS and mitochondrial assays. The results have pointed out that fisetin or copper complexes can behave both as antioxidants or pro-oxidants. Antimicrobial activity of the compounds has been investigated towards several bacteria and fungi. The copper complex of Cu(II)/fisetin 1/2 ratio showed higher antagonistic activity against bacteria comparing to the ligand and it revealed a promising antifungal activity. Copyright © 2017 Elsevier Inc. All rights reserved.

40 CFR 721.2577 - Copper complex of (substituted sulfonaphthyl azo substituted phenyl) disulfonaphthyl azo, amine...

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Copper complex of (substituted... Copper complex of (substituted sulfonaphthyl azo substituted phenyl) disulfonaphthyl azo, amine salt... substances identified generically as copper complex of (substituted sulfonaphthyl azo substituted phenyl...

Silica functionalized Cu(II) acetylacetonate Schiff base complex: An efficient catalyst for the oxidative condensation reaction of benzyl alcohol with amines

Science.gov (United States)

Anbarasu, G.; Malathy, M.; Karthikeyan, P.; Rajavel, R.

2017-09-01

Silica functionalized Cu(II) acetylacetonate Schiff base complex via the one pot reaction of silica functionalized 3-aminopropyltriethoxysilane with acetyl acetone and copper acetate has been reported. The synthesized material was well characterized by analytical techniques such as FT-IR, UV-DRS, XRD, SEM-EDX, HR-TEM, EPR, ICP-AES and BET analysis. The characterization results confirmed the grafting of Cu(II) Schiff base complex on the silica surface. The catalytic activity of synthesized silica functionalized Cu(II) acetylacetonate Schiff base complex was evaluated through the oxidative condensation reaction of benzyl alcohol to imine.

Crystal structure of μ-oxalodi-hydroxamato-bis-[(2,2'-bipyrid-yl)(di-methyl sulfoxide-κO)copper(II)] bis-(perchlorate).

Science.gov (United States)

Odarich, Irina A; Pavlishchuk, Anna V; Kalibabchuk, Valentina A; Haukka, Matti

2016-02-01

The centrosymmetric binuclear complex, [Cu2(C2H2N2O4)(C10H8N2)2(C2H6OS)2](ClO4)2, contains two copper(II) ions, connected through an N-deprotonated oxalodi-hydroxamic acid dianion, two terminal 2,2'-bi-pyridine ligands, and two apically coordinating dimethylsulfoxide mol-ecules. Two non-coordinating perchlorate anions assure electrical neutrality. The copper(II) ions in the complex dication [Cu2(C10H8N2)2(μ-C2H2N2O4)(C2H6SO)2](2+) are in an O2N3 square-pyramidal donor environment, the Cu-Cu separation being 5.2949 (4) Å. Two hydroxamate groups in the deprotonated oxalodi-hydroxamic acid are located trans to one each other. In the crystal, O-H⋯O and C-H⋯O hydrogen bonds link the complex cations to the perchlorate anions. Further C-H⋯O hydrogen bonds combine with π-π contacts with a centroid-to-centroid separation of 3.6371 (12) Å to stack the mol-ecules along the a-axis direction.

A novel dinuclear schiff base copper complex as an efficient and ...

Indian Academy of Sciences (India)

effective catalyst for oxidation of alcohol: Synthesis, crystal structure and theoretical studies .... 0.01 mol dihydrate copper (II) chloride (1.704 g) in 10 mL methanol. .... propyl)imino)methyl)naphthalen-2-ol ligand is coordi- nated to the Cu(II) ion ...

Enhanced catalytic four-electron dioxygen (O2) and two-electron hydrogen peroxide (H2O2) reduction with a copper(II) complex possessing a pendant ligand pivalamido group.

Science.gov (United States)

Kakuda, Saya; Peterson, Ryan L; Ohkubo, Kei; Karlin, Kenneth D; Fukuzumi, Shunichi

2013-05-01

A copper complex, [(PV-tmpa)Cu(II)](ClO4)2 (1) [PV-tmpa = bis(pyrid-2-ylmethyl){[6-(pivalamido)pyrid-2-yl]methyl}amine], acts as a more efficient catalyst for the four-electron reduction of O2 by decamethylferrocene (Fc*) in the presence of trifluoroacetic acid (CF3COOH) in acetone as compared with the corresponding copper complex without a pivalamido group, [(tmpa)Cu(II)](ClO4)2 (2) (tmpa = tris(2-pyridylmethyl)amine). The rate constant (k(obs)) of formation of decamethylferrocenium ion (Fc*(+)) in the catalytic four-electron reduction of O2 by Fc* in the presence of a large excess CF3COOH and O2 obeyed first-order kinetics. The k(obs) value was proportional to the concentration of catalyst 1 or 2, whereas the k(obs) value remained constant irrespective of the concentration of CF3COOH or O2. This indicates that electron transfer from Fc* to 1 or 2 is the rate-determining step in the catalytic cycle of the four-electron reduction of O2 by Fc* in the presence of CF3COOH. The second-order catalytic rate constant (k(cat)) for 1 is 4 times larger than the corresponding value determined for 2. With the pivalamido group in 1 compared to 2, the Cu(II)/Cu(I) potentials are -0.23 and -0.05 V vs SCE, respectively. However, during catalytic turnover, the CF3COO(-) anion present readily binds to 2 shifting the resulting complex's redox potential to -0.35 V. The pivalamido group in 1 is found to inhibit anion binding. The overall effect is to make 1 easier to reduce (relative to 2) during catalysis, accounting for the relative k(cat) values observed. 1 is also an excellent catalyst for the two-electron two-proton reduction of H2O2 to water and is also more efficient than is 2. For both complexes, reaction rates are greater than for the overall four-electron O2-reduction to water, an important asset in the design of catalysts for the latter.

Mononuclear, trinuclear, and hetero-trinuclear supramolecular complexes containing a new tri-sulfonate ligand and cobalt(II)/copper(II)-(1,10-phenanthroline) 2 building blocks

Science.gov (United States)

Yu, Yunfang; Wei, Yongqin; Broer, Ria; Sa, Rongjian; Wu, Kechen

2008-03-01

Novel mononuclear, trinuclear, and hetero-trinuclear supermolecular complexes, [Co(phen) 2(H 2O)(HTST)]·2H 2O ( 1), [Co 3(phen) 6(H 2O) 2(TST) 2]·7H 2O ( 2), and [Co 2Cu(phen) 6(H 2O) 2(TST) 2]·10H 2O ( 3), have been synthesized by the reactions of a new tri-sulfonate ligand (2,4,6-tris(4-sulfophenylamino)-1,3,5-triazine, H 3TST) with the M2+ ( M=Co, Cu) and the second ligand 1,10-phenanthroline (phen). Complex 1 contains a cis-Co(II)(phen) 2 building block and an HTST as monodentate ligand; complex 2 consists of two TST as bidentate ligands connecting one trans- and two cis-Co(II)(phen) 2 building blocks; complex 3 is formed by replacing the trans-Co(II)(phen) 2 in 2 with a trans-Cu(II)(phen) 2, which is the first reported hetero-trinuclear supramolecular complex containing both the Co(II)(phen) 2 and Cu(II)(phen) 2 as building blocks. The study shows the flexible multifunctional self-assembly capability of the H 3TST ligands presenting in these supramolecular complexes through coordinative, H-bonding and even π- π stacking interactions. The photoluminescent optical properties of these complexes are also investigated and discussed as well as the second-order nonlinear optical properties of 1.

Effects of Copper Exchange Levels on Complexation of Ammonia in ...

African Journals Online (AJOL)

NJD

Cation exchange, catalysis, copper, complexation, copper ammines. 1. Introduction ... ammonia is able to de-link Cu2+ ions away from the influence of .... Figure 1 DRS of CuX at different concentration levels of Cu/UC: (a). 38 Cu/UC, (b) 24 ...

Radiochemical and thermal studies of the copper(II)-exchanged form of synthetic zeolite linde sieve A

International Nuclear Information System (INIS)

Banerjee, S.P.

1978-01-01

Synthetic zeolite Linde Sieve A displays a double ion-sieve action. Only small cations can penetrate the single 6-rings into the beta cages. The radiochemical and thermal studies of copper(II)-exchanges form of 4A shows evidence of hydrated copper(II) ions in the zeolite structure. (author)

Theoretical Proposal for the Whole Phosphate Diester Hydrolysis Mechanism Promoted by a Catalytic Promiscuous Dinuclear Copper(II) Complex.

Science.gov (United States)

Esteves, Lucas F; Rey, Nicolás A; Dos Santos, Hélio F; Costa, Luiz Antônio S

2016-03-21

The catalytic mechanism that involves the cleavage of the phosphate diester model BDNPP (bis(2,4-dinitrophenyl) phosphate) catalyzed through a dinuclear copper complex is investigated in the current study. The metal complex was originally designed to catalyze catechol oxidation, and it showed an interesting catalytic promiscuity case in biomimetic systems. The current study investigates two different reaction mechanisms through quantum mechanics calculations in the gas phase, and it also includes the solvent effect through PCM (polarizable continuum model) single-point calculations using water as solvent. Two mechanisms are presented in order to fully describe the phosphate diester hydrolysis. Mechanism 1 is of the S(N)2 type, which involves the direct attack of the μ-OH bridge between the two copper(II) ions toward the phosphorus center, whereas mechanism 2 is the process in which hydrolysis takes place through proton transfer between the oxygen atom in the bridging hydroxo ligand and the other oxygen atom in the phosphate model. Actually, the present theoretical study shows two possible reaction paths in mechanism 1. Its first reaction path (p1) involves a proton transfer that occurs immediately after the hydrolytic cleavage, so that the proton transfer is the rate-determining step, which is followed by the entry of two water molecules. Its second reaction path (p2) consists of the entry of two water molecules right after the hydrolytic cleavage, but with no proton transfer; thus, hydrolytic cleavage is the rate-limiting step. The most likely catalytic path occurs in mechanism 1, following the second reaction path (p2), since it involves the lowest free energy activation barrier (ΔG(⧧) = 23.7 kcal mol(-1), in aqueous solution). A kinetic analysis showed that the experimental k(obs) value of 1.7 × 10(-5) s(-1) agrees with the calculated value k1 = 2.6 × 10(-5) s(-1); the concerted mechanism is kinetically favorable. The KIE (kinetic isotope effect) analysis

Electronic Structural Analysis of Copper(II)–TEMPO/ABNO Complexes Provides Evidence for Copper(I)–Oxoammonium Character

International Nuclear Information System (INIS)

Walroth, Richard C.; Miles, Kelsey C.; Lukens, James T.; MacMillan, Samantha N.; Stahl, Shannon S.; Lancaster, Kyle M.

2017-01-01

Copper/aminoxyl species are proposed as key intermediates in aerobic alcohol oxidation. Several possible electronic structural descriptions of these species are possible, and here we probe this issue by examining four crystallographically characterized Cu/aminoxyl halide complexes by Cu K-edge, Cu L 2,3 - edge, and Cl K-edge X-ray absorption spectroscopy. The mixing coefficients between Cu, aminoxyl, and halide orbitals are determined via these techniques with support from density functional theory. The emergent electronic structure picture reveals that Cu coordination confers appreciable oxoammonium character to the aminoxyl ligand. The computational methodology is extended to one of the putative intermediates invoked in catalytic Cu/aminoxyl-driven alcohol oxidation reactions, with similar findings. On the whole, the results have important implications for the mechanism of alcohol oxidation and the underlying basis for cooperativity in this co- catalyst system.

A novel trinuclear copper(II) complex containing a symmetric tetradentate N.sub.2./sub.O.sub.2./sub. Schiff base ligand: synthesis, characterization, crystal structure and its usage as a new precursor for the preparation of CuO particles

Czech Academy of Sciences Publication Activity Database

Khalaji, A.D.; Ghorbani, M.; Feizi, N.; Akbari, A.; Eigner, Václav; Dušek, Michal

2017-01-01

Roč. 121, Jan (2017), s. 9-12 ISSN 0277-5387 R&D Projects: GA ČR(CZ) GA15-12653S; GA MŠk LO1603 EU Projects: European Commission(XE) CZ.2.16/3.1.00/24510 Institutional support: RVO:68378271 Keywords : trinuclear complex * copper(II) complex * Schiff base * crystal structure * thermal decomposition Subject RIV: CC - Organic Chemistry OBOR OECD: Organic chemistry Impact factor: 1.926, year: 2016

COMPOSITIONS BASED ON PALLADIUM(II AND COPPER(II COMPOUNDS, HALIDE IONS, AND BENTONITE FOR OZONE DECOMPOSITION

Directory of Open Access Journals (Sweden)

T. L. Rakitskaya

2017-05-01

bromide ion. For Cu(II-KBr/N-Bent composition, kinetic and calculation data show that, in the presence of bromide ions, copper(II inhibits the ozone decomposition. For Pd(II-KBr/NBent composition, it has been found that the maximum activity is attained at СPd(II = 1.02·10-5 mol/g. For bimetallic Pd(II- Cu(II-KBr/N-Bent composition, changes in τ0, τ1/2, k1/2, and Q1/2 parameters depending on a Pd(II content are similar to those for monometallic Pd(II-KBr/NBent composition; however, values of the parameters are higher for the monometallic system. Thus, the inhibiting effect of Cu(II is observed even in the presence of palladium(II.

Copper Complexes with Tetradentate Ligands for Enhanced Charge Transport in Dye-Sensitized Solar Cells

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Hannes Michaels

2018-05-01

Full Text Available In dye-sensitized solar cells (DSCs, the redox mediator is responsible for the regeneration of the oxidized dye and for the hole transport towards the cathode. Here, we introduce new copper complexes with tetradentate 6,6′-bis(4-(S-isopropyl-2-oxazolinyl-2,2′-bipyridine ligands, Cu(oxabpy, as redox mediators. Copper coordination complexes with a square-planar geometry show low reorganization energies and thus introduce smaller losses in photovoltage. Slow recombination kinetics of excited electrons between the TiO2 and CuII(oxabpy species lead to an exceptionally long electron lifetime, a high Fermi level in the TiO2, and a high photovoltage of 920 mV with photocurrents of 10 mA∙cm−2 and 6.2% power conversion efficiency. Meanwhile, a large driving force remains for the dye regeneration of the Y123 dye with high efficiencies. The square-planar Cu(oxabpy complexes yield viscous gel-like solutions. The unique charge transport characteristics are attributed to a superposition of diffusion and electronic conduction. An enhancement in charge transport performance of 70% despite the higher viscosity is observed upon comparison of Cu(oxabpy to the previously reported Cu(tmby2 redox electrolyte.

Hematotoxicity response in rats by the novel copper-based anticancer agent: casiopeina II

International Nuclear Information System (INIS)

Vizcaya-Ruiz, A. de; Rivero-Mueller, A.; Ruiz-Ramirez, L.; Howarth, J.A.; Dobrota, M.

2003-01-01

The in vivo toxicity of the novel copper-based anticancer agent, casiopeina II (Cu(4,7-dimethyl-1,10-phenanthroline)(glycine)NO 3 ) (CII), was investigated. Casiopeinas are a family of copper-coordinated complexes that have shown promising anticancer activity. The major toxic effect attributed to a single i.v. administration of CII (5 mg/kg dose) in the rat was an hemolytic anemia (reduced hemoglobin concentration (HB), red blood cell (RBC) count and packed cell volume (PCV) accompanied by a marked neutrophilic leukocytosis) 12 h and 5 days after administration, attributed to a direct erythrocyte damage. Increased reticulocyte levels and presence of normoblasts in peripheral blood 5 days post-administration indicated an effective erythropoietic response with recovery at 15 days. Increase in spleen weight and the morphological evidence of congestion of the red pulp (RP) with erythrocytes (E) resulting in a higher ratio of red to white pulp (WP) was consistent with increased uptake of damaged erythrocytes by the reticuloendothelial system observed by histopathology and electron microscopy. Extramedullary hemopoiesis was markedly increased at 5 days giving further evidence of a regenerative erythropoietic response that had an effective recovery by 15 days. Morphological changes in spleen cellularity were consistent with hematotoxicity, mainly a reduction of the red pulp/white pulp ratio, increase in erythrocyte content at 12 h, and an infiltration of nucleated cells in the red pulp at 5 days, with a tendency towards recovery 15 days after administration. The erythrocyte damage is attributed to generation of free radicals and oxidative damage on the membrane and within cells resulting from the reduction of Cu(II) and the probable dissociation of the CII complex

Synthesis, characterization and behaviour of trans-bis (argininate) copper (II) to gamma radiation

International Nuclear Information System (INIS)

Pereira, A.B.

1984-01-01

The synthesis, the characterization and the behaviour to gamma radiation of trans-bis (argininate) copper (II) are presented. The synthesis is made from copper sulfate, sodium hydroxide and hydrochloride of L (+) arginine, in aqueous medium, and the characterization by infrared spectroscopy, visible and ultraviolet spectroscopy and elementary analysis. (C.G.C.)

Removal of Copper(II) Ions in Aqueous Solutions Using Tannin-Rich Plants as Natural Bio-Adsorbents

Science.gov (United States)

Paksamut, J.; Boonsong, P.

2018-03-01

In this study, the purpose of our interest is to investigatethe adsorption behavior of copper (II) ions in aqueous solution using some tannin-rich plants as natural bio-adsorbents such as mangosteen peels (Garciniamangostana L.), cassava leaves (Manihotesculenta Crantz) and Thai copper pod leaves (Sennasiamea (Lam.)) as powder form in different dosage of adsorbent plant materials.The adsorption capacities at different pH of solution and contact time were performed.All the experiments in this studywere chosen at room temperature by batch technique. From the experimental results showed that cassava leaves gave better adsorbent properties than mangosteen peels and Thai copper pod leaves. The increasing dosage of all adsorbents and contact time have been found to increase adsorption capacities. In this respect, the adsorption capacities depend crucially on the adsorbents and contact time. The optimum pH of copper (II) ions adsorption was pH4. According to this work, it was observed that bioadsorbent materials from tannin-rich plants could be used to remove copper (II) ions from aqueous solutions.

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 ]Cl 2 , (compound 5) and tris(1,10-phenanthroline)cobalt(III) chloride ([Co(phen) 3 ]Cl 3 , (compound 6) that also showed enhanced DENV2 loads. Also, we found that copper(II) chloride dehydrate (CuCl 2 ·2H 2 O) or cobalt(II) chloride hexahydrate (CoCl 2 ·6H 2 O) alone had no effects as "free" cations

Crystal and Molecular Structure of Bis(2,2-diphenyl-N-(di-n-propylcarbamothioyl acetamidocopper(II Complex

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Hakan Arslan

2011-01-01

Full Text Available Bis(2,2-diphenyl-N-(di-n-propylcarbamothioyl acetamidocopper(II complex has been synthesized and characterized by elemental analysis and FT-IR spectroscopy. The crystal and molecular structure of the title compound has been determined from single crystal X-ray diffraction data. It crystallizes in the triclinic space group P-1, with a = 13.046(2 Å, b = 13.135(2 Å, c = 13.179(2 Å, α= 67.083(4°, β= 67.968(4°, γ = 84.756(4° and Dcalc =1.330 g/cm3 for Z = 2. The crystal structure confirms that the complex is a mononuclear copper(II complex and the 2,2-diphenyl-N-(di-n-propyl-carbamothioylacetamide ligand is a bidentate chelating ligand, coordinating to the copper atom through the thiocarbonyl and carbonyl groups. This coordination has a slightly distorted square-planar geometry (O1-Cu1-O2: 86.48(11°, O1-Cu1-S1: 93.85(9°, O2-Cu1-S2: 94.20(9° and S1-Cu1-S2: 91.21(4°. The title molecule shows a cis-arrangement and C–O, C–S and C–N bond lengths of the complex suggest considerable electronic delocalization in the chelate rings.

Synthesis, characterization and electrochemical investigations of mixed-ligand copper(II)-organic supramolecular frameworks

Science.gov (United States)

Singh, Sandeep K.; Srivastava, Ashish Kumar; Srivastava, Krishna; Banerjee, Rahul; Prasad, Jagdish

2017-11-01

Two mixed-ligand copper(II)-organic coordination compounds with 5,5‧-dimethyl-2,2‧-bipyridine (5,5‧-Me2bpy) as a primary ligand while aliphatic malonate (Hmal) and aromatic 2-hydroxynicotinate (2-OHNA) as secondary ligands, were synthesized. These complexes are formulated as: [Cu(Hmal)(5,5‧-Me2bpy)(H2O)](ClO4) 1 and [Cu2(2-OHNA)2(5,5‧-Me2bpy)2(NO3)](NO3) 2. These two complexes were structurally characterized by single crystal X-ray diffraction analysis. Characterization was further supported by powder X-ray diffraction analysis, elemental analyses, FT-IR, FAB-MASS and TGA, DSC studies. Cyclic voltammetric and UV-visible spectral studies of these two complexes have also been done. The electrochemical studies of complex 1 in DMSO and DMF have shown that this complex undergoes quasi-reversible diffusion-controlled one-electron transfer reaction without any chemical complication while complex 2 in DMSO undergoes quasi-reversible diffusion-controlled one electron transfer reaction, following EC mechanism. The electrochemical behaviour of complex 2 in DMF is complicated probably due to presence of more than one species in solution phase.

Titrimetric application of 2-bromo-bis-1,10-phenanthroline-copper (II) bromide as a titrant in determination of ascorbic acid in pure form, fruits and vegetables

International Nuclear Information System (INIS)

Oladeji, O.

2016-01-01

Ascorbic acid is very important to man and the consumption has been linked to the prevention of degenerative diseases such as scurvy and serves as an antioxidants. There have been different approaches in the determination of ascorbic acid in fruits and vegetable. In recent times, new methods were introduced by scientists. Therefore, in order to prove the authenticity of these methods, the concentrations obtained were compared with the conventional methods. The results show that orange has maximum ascorbic acid content when compared to cashew and in vegetables Vermonia baldwinii has maximum and Solanium incanum has low ascorbic acid content. The amount of ascorbic acid determined by 2, 6-dichlorophenol-indophenol and copper (II) complex (2-bromo-bis-1, 10 phenanthroline-copper (II) bromide) are comparable.Therefore, 2-bromo-bis-1, 10-phenanthroline-copper (II) bromide can serve as a titrant in titrimetric determination of ascorbic acid in pure form, fruits and vegetables. (author)

Structural characterization of copper(II) binding to α-synuclein: Insights into the bioinorganic chemistry of Parkinson's disease

Science.gov (United States)

Rasia, Rodolfo M.; Bertoncini, Carlos W.; Marsh, Derek; Hoyer, Wolfgang; Cherny, Dmitry; Zweckstetter, Markus; Griesinger, Christian; Jovin, Thomas M.; Fernández, Claudio O.

2005-01-01

The aggregation of α-synuclein (AS) is characteristic of Parkinson's disease and other neurodegenerative synucleinopathies. We demonstrate here that Cu(II) ions are effective in accelerating AS aggregation at physiologically relevant concentrations without altering the resultant fibrillar structures. By using numerous spectroscopic techniques (absorption, CD, EPR, and NMR), we have located the primary binding for Cu(II) to a specific site in the N terminus, involving His-50 as the anchoring residue and other nitrogen/oxygen donor atoms in a square planar or distorted tetragonal geometry. The carboxylate-rich C terminus, originally thought to drive copper binding, is able to coordinate a second Cu(II) equivalent, albeit with a 300-fold reduced affinity. The NMR analysis of AS–Cu(II) complexes reveals the existence of conformational restrictions in the native state of the protein. The metallobiology of Cu(II) in Parkinson's disease is discussed by a comparative analysis with other Cu(II)-binding proteins involved in neurodegenerative disorders. PMID:15767574

Repurposing of Copper(II)-chelating Drugs for the Treatment of Neurodegenerative Diseases.

Science.gov (United States)

Lanza, Valeria; Milardi, Danilo; Di Natale, Giuseppe; Pappalardo, Giuseppe

2018-02-12

There is mounting urgency to find new drugs for the treatment of neurodegenerative disorders. A large number of reviews have exhaustively described either the molecular or clinical aspects of neurodegenerative diseases such as Alzheimer's (AD) and Parkinson's (PD). Conversely, reports outlining how known drugs in use for other diseases can also be effective as therapeutic agents in neurodegenerative diseases are less reported. This review focuses on the current uses of some copper(II) chelating molecules as potential drug candidates in neurodegeneration. Starting from the well-known harmful relationships existing between the dyshomeostasis and mis-management of metals and AD onset, we surveyed the experimental work reported in the literature, which deals with the repositioning of metal-chelating drugs in the field of neurodegenerative diseases. The reviewed papers were retrieved from common literature and their selection was limited to those describing the biomolecular aspects associated with neuroprotection. In particular, we emphasized the copper(II) coordination abilities of the selected drugs. Copper, together with zinc and iron, are known to play a key role in regulating neuronal functions. Changes in copper homeostasis are crucial for several neurodegenerative disorders. The studies included in this review may provide an overview on the current strategies aimed at repurposing copper (II) chelating drugs for the treatment of neurodegenerative disorders. Starting from the exemplary case of clioquinol repurposing, we discuss the challenge and the opportunities that repurposing of other metal-chelating drugs may provide (e.g. PBT-2, metformin and cyclodipeptides) in the treatment of neurodegenerative disease. In order to improve the success rate of drug repositioning, comprehensive studies on the molecular mechanism and therapeutic efficacy are still required. The present review upholds that drug repurposing makes significant advantages over drug discovery since

Amplification of light emission of chiral pyridine Eu(III) complex by copper nanoparticles

Energy Technology Data Exchange (ETDEWEB)

Reisfeld, Renata; Levchenko, Viktoria [Institute of Chemistry, The Hebrew University of Jerusalem, Givat Ram, Jerusalem 91904 (Israel); Piccinelli, Fabio; Bettinelli, Marco [Laboratorio Materiali Luminescenti, DB, Universita di Verona and INSTM, UdR Verona, Strada Le Grazie 15, 37134 Verona (Italy)

2016-02-15

We outline the applications of lanthanides luminescence in a number of modern fields. The intensity of the luminescence of the expensive lanthanides can be increased by their interaction with nanoparticles of inexpensive copper. As a typical example the chiral pyridine-based Eu{sup 3+} complex was incorporated into amorphous films of polyvinyl alcohol with hydroxyethyl cellulose. The luminescence intensity of the complex is increased by three hundred percent by its interaction with copper nanoparticles. The synthesis and steady state spectroscopy of the materials are presented. - Highlights: • Nanoparticles of copper were for the first time synthesized at 80 °C. • Copper NPs were incorporated with a luminescent Eu{sup 3+} complex in a polymeric matrix. • The films produced were characterized by photoluminescence spectroscopy. • The luminescence of Eu{sup 3+} complex with Cu NPs is 3 times higher than the original one.

Copper Promoted Synthesis of Diaryl Ethers

OpenAIRE

Ghosh, Rajshekhar; Samuelson, Ashoka G

2004-01-01

An efficient protocol using copper based reagents for the coupling of aryl halides with phenols to generate diaryl ethers is described. Acopper( I) complex, [ Cu( CH3CN) (4)] ClO4, or the readily available copper( II) source, CuCO3 . Cu( OH) (2) . H2O ( in combination with potassium phosphate), can be used. Aryl halides and phenols with different steric and electronic demands have been used to assess the efficiency of the procedure. The latter source of copper gives better yields under all co...

Mononuclear, trinuclear, and hetero-trinuclear supramolecular complexes containing a new tri-sulfonate ligand and cobalt(II)/copper(II)-(1,10-phenanthroline)2 building blocks

International Nuclear Information System (INIS)

Yu Yunfang; Wei Yongqin; Broer, Ria; Sa Rongjian; Wu Kechen

2008-01-01

Novel mononuclear, trinuclear, and hetero-trinuclear supermolecular complexes, [Co(phen) 2 (H 2 O)(HTST)].2H 2 O (1), [Co 3 (phen) 6 (H 2 O) 2 (TST) 2 ].7H 2 O (2), and [Co 2 Cu(phen) 6 (H 2 O) 2 (TST) 2 ].10H 2 O (3), have been synthesized by the reactions of a new tri-sulfonate ligand (2,4,6-tris(4-sulfophenylamino)-1,3,5-triazine, H 3 TST) with the M 2+ (M=Co, Cu) and the second ligand 1,10-phenanthroline (phen). Complex 1 contains a cis-Co(II)(phen) 2 building block and an HTST as monodentate ligand; complex 2 consists of two TST as bidentate ligands connecting one trans- and two cis-Co(II)(phen) 2 building blocks; complex 3 is formed by replacing the trans-Co(II)(phen) 2 in 2 with a trans-Cu(II)(phen) 2 , which is the first reported hetero-trinuclear supramolecular complex containing both the Co(II)(phen) 2 and Cu(II)(phen) 2 as building blocks. The study shows the flexible multifunctional self-assembly capability of the H 3 TST ligands presenting in these supramolecular complexes through coordinative, H-bonding and even π-π stacking interactions. The photoluminescent optical properties of these complexes are also investigated and discussed as well as the second-order nonlinear optical properties of 1. - Graphical abstract: Novel mononuclear, trinuclear, and hetero-trinuclear supermolecular complexes, [Co(phen) 2 (H 2 O)(HTST)].2H 2 O (1), [Co 3 (phen) 6 (H 2 O) 2 (TST) 2 ].7H 2 O (2), and [Co 2 Cu(phen) 6 (H 2 O) 2 (TST) 2 ].10H 2 O (3), have been synthesized by the reactions of a new tri-sulfonate ligand (2,4,6-tris(4-sulfophenylamino)-1,3,5-triazine, H 3 TST) with the M 2+ (M=Co, Cu) and the second ligand 1,10-phenanthroline (phen). The study shows the flexible multifunctional self-assembly capability of H 3 TST ligand presenting in these supramolecular complexes

Self-reduction of a copper complex MOD ink for inkjet printing conductive patterns on plastics.

Science.gov (United States)

Farraj, Yousef; Grouchko, Michael; Magdassi, Shlomo

2015-01-31

Highly conductive copper patterns on low-cost flexible substrates are obtained by inkjet printing a metal complex based ink. Upon heating the ink, the soluble complex, which is composed of copper formate and 2-amino-2-methyl-1-propanol, decomposes under nitrogen at 140 °C and is converted to pure metallic copper. The decomposition process of the complex is investigated and a suggested mechanism is presented. The ink is stable in air for prolonged periods, with no sedimentation or oxidation problems, which are usually encountered in copper nanoparticle based inks.

Studies on Cementation of Tin on Copper and Tin Stripping from Copper Substrate

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Rudnik E.

2016-06-01

Full Text Available Cementation of tin on copper in acid chloride-thiourea solutions leads to the formation of porous layers with a thickness dependent on the immersion time. The process occurs via Sn(II-Cu(I mechanism. Chemical stripping of tin was carried out in alkaline and acid solutions in the presence of oxidizing agents. It resulted in the dissolution of metallic tin, but refractory Cu3Sn phase remained on the copper surface. Electrochemical tin stripping allows complete tin removal from the copper substrate, but porosity and complex phase composition of the tin coating do not allow monitoring the process in unambiguous way.

Biosorption of lead (II and copper (II by biomass of some marine algae

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Chaisuksant, Y.

2004-09-01

Full Text Available Biosorption of heavy metal ions by algae is a potential technology for treating wastewater contaminated with heavy metals. Adsorption of lead (II and copper (II in aqueous solutions by some marine algae available in large quantities in Pattani Bay including Gracilaria fisheri, Ulva reticulata and Chaetomorpha sp. were investigated. The effect of pH on metal sorption of the algal biomass and the metal uptake capacity of the algal biomass comparing to that of synthetic adsorbents including activated carbon and siliga gel were studied by using batch equilibrium experiments. Each dried adsorbent was stirred in metal ions solutions with different pH or different concentration at room temperature for 24 hours and the residual metal ions were analysed using atomic absorption spectrophotometer. The initial concentrations of lead and copper ionswere 70 µg/l and 20 mg/l, respectively. It was found that the effect of pH on metal sorption was similar in each algal biomass. The metal uptake capacity increased as pH of the solution increased from 2.0 to 4.0 and reached a plateau at pH 5.0-7.0. The metal uptake capacities of each algal biomass were similar. At low concentrations of metal ions, the metal adsorption occurred rapidly while at higher metal concentration less metal adsorption by each algal biomass was observed. The metal adsorption of activated carbon and silica gel occurred gradually and was less than those of algal biomass. The equilibrium data of copper and lead ions fitted well to the Langmuir and Freundlich isotherm models. The maximum sorption capacity (Qm values (mean±SD of Chaetomorpha sp., U. reticulata, G. fisheri, activated carbon and silica gel for lead ions were 1.26±0.14, 1.19±0.14, 1.18±0.15, 1.14±0.11 and 1.15±0.12 mg/g, respectively. For copper adsorption, the Qm values for G. fisheri, U. reticulata and Chaetomorpha biomass were 15.87±1.03, 14.71±1.02 and 12.35± 1.03 mg/g, respectively. While those of activated carbon and

Synthesis, spectral characterization and structural studies of a novel O, N, O donor semicarbazone and its binuclear copper complex with hydrogen bond stabilized lattice

Science.gov (United States)

Layana, S. R.; Saritha, S. R.; Anitha, L.; Sithambaresan, M.; Sudarsanakumar, M. R.; Suma, S.

2018-04-01

A novel O,N,O donor salicylaldehyde-N4-phenylsemicarbazone, (H2L) has been synthesized and physicochemically characterized. Detailed structural studies of H2L using single crystal X-ray diffraction technique reveals the existence of intra and inter molecular hydrogen bonding interactions, which provide extra stability to the molecule. We have successfully synthesized a binuclear copper(II) complex, [Cu2(HL)2(NO3)(H2O)2]NO3 with phenoxy bridging between the two copper centers. The complex was characterized by elemental analysis, magnetic susceptibility and conductivity measurements, FT-IR, UV-Visible, mass and EPR spectral methods. The grown crystals of the copper complex were employed for the single crystal X-ray diffraction studies. The complex possesses geometrically different metal centers, in which the ligand coordinates through ketoamide oxygen, azomethine nitrogen and deprotonated phenoxy oxygen. The extensive intermolecular hydrogen bonding interactions of the coordinated and the lattice nitrate groups interconnect the complex units to form a 2D supramolecular assembly. The ESI mass spectrum substantiates the existence of 1:1 complex. The g values obtained from the EPR spectrum in frozen DMF suggest dx2 -y2 ground state for the unpaired electron.

Decomposition of Copper (II) Sulfate Pentahydrate: A Sequential Gravimetric Analysis.

Science.gov (United States)

Harris, Arlo D.; Kalbus, Lee H.

1979-01-01

Describes an improved experiment of the thermal dehydration of copper (II) sulfate pentahydrate. The improvements described here are control of the temperature environment and a quantitative study of the decomposition reaction to a thermally stable oxide. Data will suffice to show sequential gravimetric analysis. (Author/SA)

Synthesis, characterization, anti-microbial, DNA binding and cleavage studies of Schiff base metal complexes

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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.

Oligo-m-phenyleneoxalamide copper(II) mesocates as electro-switchable ferromagnetic metal-organic wires.

Science.gov (United States)

Pardo, Emilio; Ferrando-Soria, Jesús; Dul, Marie-Claire; Lescouëzec, Rodrigue; Journaux, Yves; Ruiz-García, Rafael; Cano, Joan; Julve, Miguel; Lloret, Francesc; Cañadillas-Delgado, Laura; Pasán, Jorge; Ruiz-Pérez, Catalina

2010-11-15

Double-stranded copper(II) string complexes of varying nuclearity, from di- to tetranuclear species, have been prepared by the Cu(II)-mediated self-assembly of a novel family of linear homo- and heteropolytopic ligands that contain two outer oxamato and either zero (1 b), one (2 b), or two (3 b) inner oxamidato donor groups separated by rigid 2-methyl-1,3-phenylene spacers. The X-ray crystal structures of these Cu(II) (n) complexes (n=2 (1 d), 3 (2 d), and 4 (3 d)) show a linear array of metal atoms with an overall twisted coordination geometry for both the outer CuN(2)O(2) and inner CuN(4) chromophores. Two such nonplanar all-syn bridging ligands 1 b-3 b in an anti arrangement clamp around the metal centers with alternating M and P helical chiralities to afford an overall double meso-helicate-type architecture for 1 d-3 d. Variable-temperature (2.0-300 K) magnetic susceptibility and variable-field (0-5.0 T) magnetization measurements for 1 d-3 d show the occurrence of S=nS(Cu) (n=2-4) high-spin ground states that arise from the moderate ferromagnetic coupling between the unpaired electrons of the linearly disposed Cu(II) ions (S(Cu)=1/2) through the two anti m-phenylenediamidate-type bridges (J values in the range of +15.0 to 16.8 cm(-1)). Density functional theory (DFT) calculations for 1 d-3 d evidence a sign alternation of the spin density in the meta-substituted phenylene spacers in agreement with a spin polarization exchange mechanism along the linear metal array with overall intermetallic distances between terminal metal centers in the range of 0.7-2.2 nm. Cyclic voltammetry (CV) and rotating-disk electrode (RDE) electrochemical measurements for 1 d-3 d show several reversible or quasireversible one- or two-electron steps that involve the consecutive metal-centered oxidation of the inner and outer Cu(II) ions (S(Cu)=1/2) to diamagnetic Cu(III) ones (S(Cu)=0) at relatively low formal potentials (E values in the range of

Synthesis, Spectroscopic Characterization, and Biological Activities of Metal Complexes of 4-((4-Chlorophenyldiazenyl-2-((p-tolyliminomethylphenol

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C. Anitha

2013-01-01

Full Text Available Azo Schiff base complexes of VO(II, Mn(II, Co(II, Ni(II, Cu(II, and Zn(II have been synthesized from 4-((4-chlorophenyldiazenyl-2-((p-tolyliminomethylphenol (CDTMP. The nature of bonding and the structural features of the complexes have been deduced from elemental analysis, molar conductance, magnetic susceptibility measurements, IR, UV-Vis, 1H-NMR, EPR, mass, SEM, and fluorescence spectral studies. Spectroscopic and other analytical studies reveal square-planar geometry for copper, square-pyramidal geometry for oxovanadium, and octahedral geometry for other complexes. The EPR spectra of copper(II complex in DMSO at 300 K and 77 K were recorded, and its salient features are reported. Antimicrobial studies against several microorganisms indicate that the complexes are more potent bactericides and fungicides than the ligand. The electrochemical behavior of the copper(II complex was studied by cyclic voltammetry. All the synthesized compounds can serve as potential photoactive materials as indicated from their characteristic fluorescence properties. The second harmonic conversion efficiency of the synthesized azo Schiff base was found to be higher than that of urea and KDP (potassium dihydrogen phosphate. SEM image of copper(II complex implies the crystalline state and surface morphology of the complex.

Study of the Direct Red 81 Dye/Copper(II-Phenanthroline System

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Elsa Walger

2018-01-01

Full Text Available Recovered papers contain several chromophores, such as wood lignin and dyes. These have to be eliminated during paper recycling in order to produce white paper. Hydrogen peroxide under alkaline conditions is generally used to decolorize lignin, but its effect on dyes is limited. Copper(II-phenanthroline (Cu-Phen complexes can activate the oxidation of lignin by hydrogen peroxide. Hydrogen peroxide may also be activated during recycled fiber bleaching, thus enhancing its color-stripping efficiency towards unoxidizable azo dyes. The purpose of this paper was to determine the effect of Cu-Phen complexes on a model azo dye, Direct Red 81 (DR81, in aqueous solution. Different Cu-Phen solutions (with different initial Cu:Phen molar ratios were prepared and mixed with the dye at different pHs. The geochemical computer program PHREEQC allowed precise calculation of the theoretical distribution between different possible coordinates (CuPhenOH+, Cu(Phen22+, CuPhen(OH2, Cu(Phen32+, etc. depending on pH and initial concentrations. UV-vis spectroscopic measurements were correlated with the major species theoretically present in each condition. The UV absorbance of the system was mainly attributed to the Cu-Phen complex and the visible absorbance was only due to the dye. Cu-Phen appeared to reduce the color intensity of the DR81 dye aqueous solution under specific conditions (more effective at pH 10.7 with Cu:Phen = 1:1, probably owing to the occurrence of a coordination phenomenon between DR81 and Cu-Phen. Hence, the ligand competition between phenanthroline and hydroxide ions would be disturbed by a third competitor, which is the dye molecule. Further investigation proved that the DR81 dye is able to form a complex with copper-phenanthroline, leading to partial color-stripping. This new “color-stripping effect” may be a new opportunity in paper and textile industries for wastewater treatment.

A New Polynuclear Coordination Type for (Salicylaldoxime)copper(II) Complexes: Structure and Magnetic Properties of an (Oxime)Cu₆ Cluster

DEFF Research Database (Denmark)

Wenzel, Marco; Forgan, Ross S.; Faure, Anaëlle

2009-01-01

A previously unseen coordination mode is reported for (salicylaldoxime)copper complexes utilising a linked zwitterionic NO22- donor set. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)...

Nuclease-like activity of some Cu(II) complexes

International Nuclear Information System (INIS)

Durackova, Z.; Fenikova, L.; Svorenova, L.; Labudova, O.; Kollarova, M.; Labuda, J.

1995-01-01

The nuclease reaction of a copper complex with the macrocyclic Schiff base ligand tetrabenzo[b,f,j,n][a,3,9,13]tetraaza cyclohexadecine (TAAB) at the cleavage of DNA in aerobic conditions and the presence of ascorbic acid has been investigated and compared with that of the copper phenanthroline complex. The AT specifity of the Cu(TAAB) 2+ for both single-stranded and double-stranded DNA templates was observed. (authors), 4 figs., 6 refs

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.

The impact of tertiary wastewater treatment on copper and zinc complexation.

Science.gov (United States)

Constantino, C; Gardner, M; Comber, S D W; Scrimshaw, M D; Ellor, B

2015-01-01

Tightening quality standards for European waters has seen a move towards enhanced wastewater treatment technologies such as granulated organic carbon treatment and ozonation. Although these technologies are likely to be successful in degrading certain micro-organic contaminants, these may also destroy compounds which would otherwise complex and render metals significantly less toxic. This study examined the impact of enhanced tertiary treatment on the capacity of organic compounds within sewage effluents to complex copper and zinc. The data show that granulated organic carbon treatment removes a dissolved organic carbon (DOC) fraction that is unimportant to complexation such that no detrimental impact on complexation or metal bioavailability is likely to occur from this treatment type. High concentrations of ozone (>1 mg O3/mg DOC) are, however, likely to impact the complexation capacity for copper although this is unlikely to be important at the concentrations of copper typically found in effluent discharges or in rivers. Ozone treatment did not affect zinc complexation capacity. The complexation profiles of the sewage effluents show these to contain a category of non-humic ligand that appears unaffected by tertiary treatment and which displays a high affinity for zinc, suggesting these may substantially reduce the bioavailability of zinc in effluent discharges. The implication is that traditional metal bioavailability assessment approaches such as the biotic ligand model may overestimate zinc bioavailability in sewage effluents and effluent-impacted waters.

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

2018-04-01

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.

Benchmarking of copper(II) LFMM parameters for studying amyloid-β peptides.

Science.gov (United States)

Mutter, Shaun T; Deeth, Robert J; Turner, Matthew; Platts, James A

2018-04-01

Ligand field molecular mechanics (LFMM) parameters have been benchmarked for copper (II) bound to the amyloid-β 1-16 peptide fragment. Several density functional theory (DFT) optimised small test models, representative of different possible copper coordination modes, have been used to test the accuracy of the LFMM copper bond lengths and angles, resulting in errors typically less than 0.1 Å and 5°. Ligand field molecular dynamics (LFMD) simulations have been carried out on the copper bound amyloid-β 1-16 peptide and snapshots extracted from the subsequent trajectory. Snapshots have been optimised using DFT and the semi-empirical PM7 method resulting in good agreement against the LFMM calculated geometry. Analysis of substructures within snapshots shows that the larger contribution of geometrical difference, as measured by RMSD, lies within the peptide backbone, arising from differences in DFT and AMBER, and the copper coordination sphere is reproduced well by LFMM. PM7 performs excellently against LFMM with an average RMSD of 0.2 Å over 21 tested snapshots. Further analysis of the LFMD trajectory shows that copper bond lengths and angles have only small deviations from average values, with the exception of a carbonyl moiety from the N-terminus, which can act as a weakly bound fifth ligand.

The synthesis, spectroscopy and X-ray single crystal structure of catena-[(μ-anacardato)-copper(II)bipyridine][Cu2{(μ-O2CC6H3(o-OH)(o-C15H31)}4(NC5H5)2].

Science.gov (United States)

Malik, Mohammad Azad; O'Brien, Paul; Tuna, Floriana; Pritchard, Robin; Buchweishaija, Joseph; Kimambo, Elianaso; Mubofu, Egid B

2013-10-28

Hydrogenation of crude anacardic acid gave a transparent crystalline product on recrystallization. When reacted with copper nitrate in the presence of pyridine it produced green crystals of a pyridine adduct of a dimeric copper(II) anacardate with the copper acetate structure. The X-ray single crystal structures of both anacardic acid and the copper complex were determined. Magnetic studies have confirmed strong antiferromagnetic coupling between copper(II) centre in the dimer. The exchange coupling constant was determined to be J = -324 cm(-1). The EPR spectra of the polycrystalline product are consistent with spin S = 1. The zero-field splitting parameter and g tensor values are |D| = 0.36 cm(-1), g(||) = 2.36 and g(⊥) = 2.06.

RECOVERY OF COPPER(II AND CHROMIUM(III FROM NITRATE MEDIUM WITH SALICYLIDENEANILINE DISSOLVED IN 1-OCTANOL

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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.

Syntheses of polystyrene supported chelating resin containing the Schiff base derived from salicylaldehyde and triethylene tetramine and its copper(II), nickel(II), cobalt(II), iron(III), zinc(II), cadmium(II), molybdenum(VI), zirconium(IV) and uranium(VI) complexes

International Nuclear Information System (INIS)

Syamal, A.; Singh, M.M.

1998-01-01

A new polymer-anchored chelating ligand has been synthesized by the reaction of chloromethylated polystyrene (containing 0.94 mmol of Cl per gram of resin and 1% cross-linked with divinylbenzene) and the Schiff base derived from salicylaldehyde and triethylenetetramine. A new series of polystyrene supported, Cu(II), Ni(II), Co(II), Fe(III), Zn(II), Cd(II), Zr(IV), dioxomolybdenum (VI) and dioxouranium (VI) complexes of the formulae PS-LCu, PS-LNi, PS-LCo, PS-LFeCl.DMF, PS-LZn, PS-LCd, PS-LZr(OH) 2 . DMF, PS L MoO 2 and PS-LUO 2 (where PS-LH 2 = polymer-anchored Schiff base and DMF dimethyl-formamide) have been synthesized and characterised by elemental analysis, infrared, electronic spectra and magnetic susceptibility measurements. The complexes PS-LCu, PS-LNi and PS-LCo have square planar structure, PS-LFeCl.DMF, PS-LMoO 2 and PS-LUO 2 have octahedral structure, PS L Zn and PS-LCd are tetrahedral and PS-LZr(OH) 2 .DMF is pentagonal bipyramidal. The polymer-anchored Cu(II), Co(II) and Fe(III) complexes are paramagnetic while Ni(II), Zn(II), Cd(II), Zr(IV), dioxomolybdenum(VI) and dioxouranium(VI) complexes are diamagnetic. The negative shift of the v (C=N) (azomethine) and the positive shift of v (C--O)(phenolic) are indicative of ONNO donor behaviour of the polymer-anchored Schiff base. (author)

A THIOLATO-BRIDGED OCTANUCLEAR COPPER(I,II MIXED- VALENCE COMPLEX WITH N,N,S-TRIDENTATE LIGAND

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Takanori Kotera

2007-06-01

Full Text Available Thiolato-bridged complex [CuI4CuII4(peampt4Cl8]·2H2O (Hpeampt = 1-(2-pyridylethylamino methylpropane-2-thiol has been synthesized and characterized by the elemental analysis, IR and UV-vis spectroscopies and magnetic susceptibility measurement. The X-ray crystal structure analysis of this complex shows a localized mixed-valence octanuclear cage structure made up of four trigonal-bipyramidal CuIIN2SCl2, two trigonal CuIS2Cl, and two tetrahedral CuIS2Cl2 coordination sites. Temperature dependence of magnetic susceptibility (4.5— 300 K shows that a fairly strong antiferromagnetic interaction is operating between the four CuII ions.

Well-Defined Copper(I) Fluoroalkoxide Complexes for Trifluoroethoxylation of Aryl and Heteroaryl Bromides

KAUST Repository

Huang, Ronglu

2015-03-17

© 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Copper(I) fluoroalkoxide complexes bearing dinitrogen ligands were synthesized and the structure and reactivity of the complexes toward trifluoroethoxylation, pentafluoropropoxylation, and tetrafluoropropoxylation of aryl and heteroaryl bromides were investigated. Efficiency drive: A series of copper(I) fluoroalkoxide complexes bearing N,N ligands have been prepared and structurally characterized. These well-defined complexes serve as efficient reagents for the fluoroalkoxylation of aryl and heteroaryl bromides to produce a wide range of trifluoroethyl, pentafluoropropyl, and tetrafluoropropyl (hetero)aryl ethers in good to excellent yields.

Melanoidin formation in ethanolic monosaccharide – arylamine – copper (II systems

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Cherepanov I. S.

2017-09-01

Full Text Available Results of studying of melanoidin formation regularities at interaction of D-glucose and D-xylose with p-amino benzoic acid (PABA in acidic ethanolic media have been presented; features of the chosen threefold systems are, firstly, existence of the low-active amino-compound of benzene series, secondly, presence of catalytic amounts of the biogenic metal. Regularities of melanoidins structure formation from similar systems are almost not studied, at the same time some important biological properties are predicted for them that demands research of reactions' kinetics and development of techniques of their directional synthesis. Studying has been carried out by synthetic methods in total with a sample drawing technique with UV-Vis-spectrophotometry filing and engaging of FTIR-spectroscopy. Based on electronic spectra analysis more intensive melanoidin formation in case of reaction from D-xylose has been shown, this can be bound to steric hindrance and to ability of aldopentoses to give more reactionary capable intermediates in comparison with aldohexoses. The accelerating role of copper (II ions as the complexing center catalyzing both formation and degradation of the intermediate products at different reaction stages has been confirmed, at the same time the accelerating action is considerably shown since copper ion concentrations about 60 mg/l, but Cu(II chelation degree by final products is low. The effect of solvent has been noted, in particular the influence of ethanol on nature of amino-carbonyl interactions manifested in strengthening of carbohydrates tendency to re-cyclization, it also probably accelerates melanoidin formation. The data obtained have shown the percent of carbohydrates direct destruction (caramelization in the presented conditions is insignificant, that allows developing based on the present researches target synthetic techniques for melanoidin products' preparation.

Determination of HCl and VOC Emission from Thermal Degradation of PVC in the Absence and Presence of Copper, Copper(II Oxide and Copper(II Chloride

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Ahamad J. Jafari

2009-01-01

Full Text Available Polyvinyl chloride (PVC has played a key role in the development of the plastic industry over the past 40 years. Thermal degradation of PVC leads to formation of many toxic pollutants such as HCl, aromatic and volatile organic carbon vapors. Thermal degradation of PVC and PVC in the present of copper, cupric oxide and copper(II chloride were investigated in this study using a laboratory scale electrical furnace. HCl and Cl- ion were analyzed by a Dionex ion chromatograph and VOCs compounds were analyzed using GC or GC-MS. The results showed that HCl plus Cl- ion and benzene formed about 99% and 80% respectively in the first step of thermal degradation under air atmosphere. The presence of cupric oxide increases the percentage of short chain hydrocarbons more than 184% and decreases the amount of the major aromatic hydrocarbon and HCl plus Cl- ion to 90% and 65% respectively. The total aromatic hydrocarbon emitted less than when atmosphere was air and difference was statistically significant (Pvalue<0.000

Theoretical (in B3LYP/6-3111++G** level), spectroscopic (FT-IR, FT-Raman) and thermogravimetric studies of gentisic acid and sodium, copper(II) and cadmium(II) gentisates.

Science.gov (United States)

Regulska, E; Kalinowska, M; Wojtulewski, S; Korczak, A; Sienkiewicz-Gromiuk, J; Rzączyńska, Z; Swisłocka, R; Lewandowski, W

2014-11-11

The DFT calculations (B3LYP method with 6-311++G(d,p) mixed with LanL2DZ for transition metals basis sets) for different conformers of 2,5-dihydroxybenzoic acid (gentisic acid), sodium 2,5-dihydroxybenzoate (gentisate) and copper(II) and cadmium(II) gentisates were done. The proposed hydrated structures of transition metal complexes were based on the results of experimental findings. The theoretical geometrical parameters and atomic charge distribution were discussed. Moreover Na, Cu(II) and Cd(II) gentisates were synthesized and the composition of obtained compounds was revealed by means of elemental and thermogravimetric analyses. The FT-IR and FT-Raman spectra of gentisic acid and gentisates were registered and the effect of metals on the electronic charge distribution of ligand was discussed. Copyright © 2014 Elsevier B.V. All rights reserved.

Anti-inflammatory activity of copper-protein complexes with reference to rheumatoid arthritis

International Nuclear Information System (INIS)

Bibi, S.; Sajjad, I.; Akram, W.; Karim, H.M.A.; Iqbal, M.Z.

1996-01-01

Work was carried out on the serum of 100 healthy subjects and hundred Rheumatoid Arthritus patients by electrophoresis and atomic absorption model Hitachi-180-80. The different proteins fractions separated by electrophoresis were subjected for estimation of Cu-Concentration. It was found that only 5% copper is present in albumin which remains constant in normal and Rheumatoid Arthritus patients. The other important group of proteins were a2-globulins, in which Cu concentration was found high in Rheumatoid Arthritus patients as compared to normal subject. There was no copper detected in beta and gamma globulins. The study can be used for diagnostic purposes. Copper complexes of alpha 2-Globulins were found anti inflammatory in nature and this quality of self defense can bring revolution in the history of all infectious diseases including Rheumatoid Arthritus simply by separating the copper complexes of alpha 2-globulins (most probably ceruloplasmin) from the blood of donors and injecting into the body of patients. It is possible by this method that the disease-Rheumatoid Arthritus may be eradicated completely. These complexes have also shown antibiotic activity in gynae patients. (author)

Removal of copper (II) from aqueous solutions by adsorption onto granular activated carbon in the presence of competitor ions

International Nuclear Information System (INIS)

Almohammadi, S.; Mirzaei, M.

2016-01-01

In this work, the removal of copper from an aqueous solution by granular activated carbon (GAC) in the presence of competitor ions was studied. A batch adsorption was carried out and different parameters such as p H, contact time, initial copper concentration and competitor ions concentration were changed to determine the optimum conditions for adsorption. The optimum p H required for maximum adsorption was found to be 4.5 for copper. Equilibrium was evaluated at 144 h at room temperature. The removal efficiency of Cu(II) was 71.12% at this time. The kinetics of copper adsorption on activated carbon followed the pseudo second-order model. The experimental equilibrium sorption data were tested using the Langmuir, Freundlich, Temkin and Dubinin–Radushkevich (D-R) equations and the Langmuir model was found to be well fitted for copper adsorption onto GAC. The maximum adsorption capacity of the adsorbent for Cu(II) was calculated from the Langmuir isotherm and found to be 7.03 mg/g. Subsequently, the removal of copper by granular activated carbon in the presence of Ag 1 + and Mn 2 + as competitor ions was investigated. The removal efficiency of Cu(II) ions without the presence of the competitor ions was 46% at 6 h, while the removal efficiency of Cu(II) ions in the presence of competitor ions, Ag 1 + and Mn 2 + , was 34.76% and 31.73%, respectevely.

Competitive adsorption of copper(II), cadmium(II), lead(II) and zinc(II) onto basic oxygen furnace slag

International Nuclear Information System (INIS)

Xue Yongjie; Hou Haobo; Zhu Shujing

2009-01-01

Polluted and contaminated water can often contain more than one heavy metal species. It is possible that the behavior of a particular metal species in a solution system will be affected by the presence of other metals. In this study, we have investigated the adsorption of Cd(II), Cu(II), Pb(II), and Zn(II) onto basic oxygen furnace slag (BOF slag) in single- and multi-element solution systems as a function of pH and concentration, in a background solution of 0.01 M NaNO 3 . In adsorption edge experiments, the pH was varied from 2.0 to 13.0 with total metal concentration 0.84 mM in the single element system and 0.21 mM each of Cd(II), Cu(II), Pb(II), and Zn(II) in the multi-element system. The value of pH 50 (the pH at which 50% adsorption occurs) was found to follow the sequence Zn > Cu > Pb > Cd in single-element systems, but Pb > Cu > Zn > Cd in the multi-element system. Adsorption isotherms at pH 6.0 in the multi-element systems showed that there is competition among various metals for adsorption sites on BOF slag. The adsorption and potentiometric titrations data for various slag-metal systems were modeled using an extended constant-capacitance surface complexation model that assumed an ion-exchange process below pH 6.5 and the formation of inner-sphere surface complexes at higher pH. Inner-sphere complexation was more dominant for the Cu(II), Pb(II) and Zn(II) systems

Competitive adsorption of copper(II), cadmium(II), lead(II) and zinc(II) onto basic oxygen furnace slag

Energy Technology Data Exchange (ETDEWEB)

Xue Yongjie [School of Resource and Environment Science, Wuhan University, Hubei, Wuhan (China); Wuhan Kaidi Electric Power Environmental Protection Co. Ltd., Hubei, Wuhan (China)], E-mail: xueyj@mail.whut.edu.cn; Hou Haobo; Zhu Shujing [School of Resource and Environment Science, Wuhan University, Hubei, Wuhan (China)

2009-02-15

Polluted and contaminated water can often contain more than one heavy metal species. It is possible that the behavior of a particular metal species in a solution system will be affected by the presence of other metals. In this study, we have investigated the adsorption of Cd(II), Cu(II), Pb(II), and Zn(II) onto basic oxygen furnace slag (BOF slag) in single- and multi-element solution systems as a function of pH and concentration, in a background solution of 0.01 M NaNO{sub 3}. In adsorption edge experiments, the pH was varied from 2.0 to 13.0 with total metal concentration 0.84 mM in the single element system and 0.21 mM each of Cd(II), Cu(II), Pb(II), and Zn(II) in the multi-element system. The value of pH{sub 50} (the pH at which 50% adsorption occurs) was found to follow the sequence Zn > Cu > Pb > Cd in single-element systems, but Pb > Cu > Zn > Cd in the multi-element system. Adsorption isotherms at pH 6.0 in the multi-element systems showed that there is competition among various metals for adsorption sites on BOF slag. The adsorption and potentiometric titrations data for various slag-metal systems were modeled using an extended constant-capacitance surface complexation model that assumed an ion-exchange process below pH 6.5 and the formation of inner-sphere surface complexes at higher pH. Inner-sphere complexation was more dominant for the Cu(II), Pb(II) and Zn(II) systems.

Competitive adsorption of copper(II), cadmium(II), lead(II) and zinc(II) onto basic oxygen furnace slag.

Science.gov (United States)

Xue, Yongjie; Hou, Haobo; Zhu, Shujing

2009-02-15

Polluted and contaminated water can often contain more than one heavy metal species. It is possible that the behavior of a particular metal species in a solution system will be affected by the presence of other metals. In this study, we have investigated the adsorption of Cd(II), Cu(II), Pb(II), and Zn(II) onto basic oxygen furnace slag (BOF slag) in single- and multi-element solution systems as a function of pH and concentration, in a background solution of 0.01M NaNO(3). In adsorption edge experiments, the pH was varied from 2.0 to 13.0 with total metal concentration 0.84mM in the single element system and 0.21mM each of Cd(II), Cu(II), Pb(II), and Zn(II) in the multi-element system. The value of pH(50) (the pH at which 50% adsorption occurs) was found to follow the sequence Zn>Cu>Pb>Cd in single-element systems, but Pb>Cu>Zn>Cd in the multi-element system. Adsorption isotherms at pH 6.0 in the multi-element systems showed that there is competition among various metals for adsorption sites on BOF slag. The adsorption and potentiometric titrations data for various slag-metal systems were modeled using an extended constant-capacitance surface complexation model that assumed an ion-exchange process below pH 6.5 and the formation of inner-sphere surface complexes at higher pH. Inner-sphere complexation was more dominant for the Cu(II), Pb(II) and Zn(II) systems.

Performance Evaluation of Monolith Based Immobilized Acetylcholinesterase Flow-Through Reactor for Copper(II Determination with Spectrophotometric Detection

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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.

Recovery of copper(II) and chromium(III) from nitrate medium with ...

African Journals Online (AJOL)

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 ...

A novel dumbbell-like polyoxometalate assembled of copper(II)-disubstituted monovacant keggin polyoxoanions with a tetranuclear copper cluster.

Science.gov (United States)

Miao, Hao; Xu, Xiao; Ju, Wei-Wei; Wan, Hong-Xiang; Zhang, Yu; Zhu, Dun-Ru; Xu, Yan

2014-03-17

A dimeric Keggin polyoxometalate, [Cu(bpy)(μ2-OH)]4[(H2O)(bpy)2HPW11Cu2O39]2·2CH3CH2OH·10H2O (1), constructed from two dicopper(II)-substituted monovacant Keggin polyoxoanions bridged by a Cu4 cluster, has been hydrothermally synthesized. Magnetic analysis indicates predominantly an antiferromagnetic interaction between copper(II) centers. Compound 1 also shows very high catalytic activity for the esterification of phosphoric acid with equimolar lauryl alcohol to monoalkyl phosphate ester.

Degradation reaction of Diazo reactive black 5 dye with copper (II) sulfate catalyst in thermolysis treatment.

Science.gov (United States)

Lau, Yen-Yie; Wong, Yee-Shian; Ang, Tze-Zhang; Ong, Soon-An; Lutpi, Nabilah Aminah; Ho, Li-Ngee

2018-03-01

The theme of present research demonstrates performance of copper (II) sulfate (CuSO 4 ) as catalyst in thermolysis process to treat reactive black 5 (RB 5) dye. During thermolysis without presence of catalyst, heat was converted to thermal energy to break the enthalpy of chemical structure bonding and only 31.62% of color removal. With CuSO 4 support as auxiliary agent, the thermally cleaved molecular structure was further destabilized and reacted with CuSO 4 . Copper ions functioned to delocalize the coordination of π of the lone paired electron in azo bond, C=C bond of the sp 2 carbon to form C-C of the sp 3 amorphous carbon in benzene and naphthalene. Further, the radicals of unpaired electrons were stabilized and RB 5 was thermally decomposed to methyl group. Zeta potential measurement was carried out to analyze the mechanism of RB 5 degradation and measurement at 0 mV verified the critical chemical concentration (CCC) (0.7 g/L copper (II) sulfate), as the maximum 92.30% color removal. The presence of copper (II) sulfate catalyst has remarkably increase the RB 5 dye degradation as the degradation rate constant without catalyst, k 1 is 6.5224 whereas the degradation rate constant with catalyst, k 2 is 25.6810. This revealed the correlation of conversion of thermal energy from heat to break the chemical bond strength, subsequent fragmentation of RB 5 dye molecular mediated by copper (II) sulfate catalyst. The novel framework on thermolysis degradation of molecular structure of RB 5 with respect to the bond enthalpy and interfacial intermediates decomposition with catalyst reaction were determined.

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.

Determination of copper (II) in foodstuffs based on its quenching effect on the fluorescence of N,N'-bis(pyridoxal phosphate)-o-phenylenediamine.

Science.gov (United States)

Xu, Canhui; Liao, Lifu; He, Yunfei; Wu, Rurong; Li, Shijun; Yang, Yanyan

2015-01-01

A Schiff base-type fluorescence probe was prepared for the detection of copper (II) in foodstuffs. The probe is N,N'-bis(pyridoxal phosphate)-o-phenylenediamine (BPPP). It was synthesized by utilizing the Schiff base condensation reaction of pyridoxal 5-phosphate with 1,2-phenylenediamine. BPPP has the properties of high fluorescence stability, good water solubility and low toxicity. Its maximum excitation wavelength and maximum fluorescence emission wavelength are at 389 and 448 nm, respectively. When BPPP coexists with copper (II), its fluorescence is dramatically quenched. Under a certain condition, the fluorescence intensity decreased proportionally to the concentration of copper (II) by the quenching effect. Based on this fact, we established a fluorescence quenching method for the determination of copper (II). Under optimal conditions a linear range was found to be 0.5-50 ng/mL with a detection limit of 0.2 ng/mL. The method has been applied to determine copper (II) in foodstuff samples and the analytical results show good agreement with that obtained from atomic absorption spectrometry method. Copyright © 2015 Elsevier B.V. All rights reserved.

The in vivo behavior of copper-64-labeled azamacrocyclic complexes

International Nuclear Information System (INIS)

Jones-Wilson, Teresa M.; Deal, Kim A.; Anderson, Carolyn J.; McCarthy, Deborah W.; Kovacs, Zoltan; Motekaitis, Ramunas J.; Sherry, A. Dean; Martell, Arthur E.; Welch, Michael J.

1998-01-01

The use of copper radioisotopes in imaging and therapy applications has created a greater need for bifunctional chelates (BFCs) for complexing copper radioisotopes to biomolecules. It has been demonstrated that the charge and lipophilicity of the Cu-BFC complex has a significant effect on the in vivo behavior of the radiolabeled Cu-BFC-biomolecule conjugate. To evaluate the effects of charge, stability, and macrocyclic backbone size on the biological behavior of 64 Cu complexes, a series of macrocyclic 64 Cu complexes have been prepared, and the biodistributions of these agents were evaluated in normal Sprague-Dawley rats. Two macrocyclic backbones, dodecane and tetradecane, were evaluated; cyclen, DOTA, and DO2A were dodecane backbone derivatives, and cyclam, TETA, and et-cyclam were tetradecane backbone derivatives. The biodistributions of the 64 Cu-labeled complexes correlated with differences in the size of the macrocycle backbone and the formal charge of the complex. All compounds showed uptake and clearance through the liver and kidneys; however, the positively charged 64 Cu complexes showed significantly higher uptake in both of these organs than did the negatively charged or neutral complexes. 64 Cu-TETA, a negatively charged complex with the tetradecane backbone, had the most efficient clearance by 24 hours' postinjection. These data suggest that negatively charged complexes may have more favorable clearance properties when used as BFCs

Solar photocatalytic removal of Cu(II), Ni(II), Zn(II) and Pb(II): Speciation modeling of metal-citric acid complexes

International Nuclear Information System (INIS)

Kabra, Kavita; Chaudhary, Rubina; Sawhney, R.L.

2008-01-01

The present study is targeted on solar photocatalytic removal of metal ions from wastewater. Photoreductive deposition and dark adsorption of metal ions Cu(II), Ni(II), Pb(II) and Zn(II), using solar energy irradiated TiO 2 , has been investigated. Citric acid has been used as a hole scavenger. Modeling of metal species has been performed and speciation is used as a tool for discussing the photodeposition trends. Ninety-seven percent reductive deposition was obtained for copper. The deposition values of other metals were significantly low [nickel (36.4%), zinc (22.2%) and lead (41.4%)], indicating that the photocatalytic treatment process, using solar energy, was more suitable for wastewater containing Cu(II) ions. In absence of citric acid, the decreasing order deposition was Cu(II) > Ni(II) > Pb(II) > Zn(II), which proves the theoretical thermodynamic predictions about the metals

Proteomic and physiological responses of Kineococcus radiotolerans to copper.

Directory of Open Access Journals (Sweden)

Christopher E Bagwell

Full Text Available Copper is a highly reactive, toxic metal; consequently, transport of this metal within the cell is tightly regulated. Intriguingly, the actinobacterium Kineococcus radiotolerans has been shown to not only accumulate soluble copper to high levels within the cytoplasm, but the phenotype also correlated with enhanced cell growth during chronic exposure to ionizing radiation. This study offers a first glimpse into the physiological and proteomic responses of K. radiotolerans to copper at increasing concentration and distinct growth phases. Aerobic growth rates and biomass yields were similar over a range of Cu(II concentrations (0-1.5 mM in complex medium. Copper uptake coincided with active cell growth and intracellular accumulation was positively correlated with Cu(II concentration in the growth medium (R(2=0.7. Approximately 40% of protein coding ORFs on the K. radiotolerans genome were differentially expressed in response to the copper treatments imposed. Copper accumulation coincided with increased abundance of proteins involved in oxidative stress and defense, DNA stabilization and repair, and protein turnover. Interestingly, the specific activity of superoxide dismutase was repressed by low to moderate concentrations of copper during exponential growth, and activity was unresponsive to perturbation with paraquot. The biochemical response pathways invoked by sub-lethal copper concentrations are exceptionally complex; though integral cellular functions are preserved, in part, through the coordination of defense enzymes, chaperones, antioxidants and protective osmolytes that likely help maintain cellular redox. This study extends our understanding of the ecology and physiology of this unique actinobacterium that could potentially inspire new biotechnologies in metal recovery and sequestration, and environmental restoration.

Proteomic and physiological responses of Kineococcus radiotolerans to copper.

Science.gov (United States)

Bagwell, Christopher E; Hixson, Kim K; Milliken, Charles E; Lopez-Ferrer, Daniel; Weitz, Karl K

2010-08-26

Copper is a highly reactive, toxic metal; consequently, transport of this metal within the cell is tightly regulated. Intriguingly, the actinobacterium Kineococcus radiotolerans has been shown to not only accumulate soluble copper to high levels within the cytoplasm, but the phenotype also correlated with enhanced cell growth during chronic exposure to ionizing radiation. This study offers a first glimpse into the physiological and proteomic responses of K. radiotolerans to copper at increasing concentration and distinct growth phases. Aerobic growth rates and biomass yields were similar over a range of Cu(II) concentrations (0-1.5 mM) in complex medium. Copper uptake coincided with active cell growth and intracellular accumulation was positively correlated with Cu(II) concentration in the growth medium (R(2)=0.7). Approximately 40% of protein coding ORFs on the K. radiotolerans genome were differentially expressed in response to the copper treatments imposed. Copper accumulation coincided with increased abundance of proteins involved in oxidative stress and defense, DNA stabilization and repair, and protein turnover. Interestingly, the specific activity of superoxide dismutase was repressed by low to moderate concentrations of copper during exponential growth, and activity was unresponsive to perturbation with paraquot. The biochemical response pathways invoked by sub-lethal copper concentrations are exceptionally complex; though integral cellular functions are preserved, in part, through the coordination of defense enzymes, chaperones, antioxidants and protective osmolytes that likely help maintain cellular redox. This study extends our understanding of the ecology and physiology of this unique actinobacterium that could potentially inspire new biotechnologies in metal recovery and sequestration, and environmental restoration.

Structural and magnetic characterization of three tetranuclear Cu(II) complexes with face-sharing-dicubane/double-open-cubane like core framework

International Nuclear Information System (INIS)

Paul, Aparup; Bertolasi, Valerio; Figuerola, Albert; Manna, Subal Chandra

2017-01-01

Three novel tetranuclear copper(II) complexes namely [Cu 4 (L 1 ) 4 ]∙2(dmf) (1), [Cu 4 (L 1 ) 4 ] (2) and [Cu 4 (L 2 ) 2 (HL 2 ) 2 (H 2 O) 2 ]∙2(ClO 4 )·6(H 2 O) (3) (H 2 L 1 , (E)−2-((1-hydroxybutan-2-ylimino)methyl)phenol; H 2 L 2 , (E)−2-((1-hydroxybutan-2-ylimino)methyl)−6-methoxyphenol)) were synthesized from the self-assembly of copper(II) perchlorate and the tridentate Schiff base ligands. The structural determination reveals that crystallizes in the monoclinic system with space group C2/c, whereas both the and crystallize in the triclinic system with space group P-1. and possess face-sharing dicubane core, on the other hand complex 3 has double open cubane core structure. The copper(II) ions in the cubane core are in distorted square planar geometries, and weak π…π and C–H…π interactions lead to formation of a 2D supramolecular architecture for and . At room temperature and , exhibit fluorescence with a quantum yield (Φ s ) of 0.47, 0.49 and 0.38, respectively. Variable temperature magnetic susceptibility measurements in the range 2–300 K indicate an overall weak antiferromagnetic exchange coupling in all complexes. The PHI program was used to study their magnetic behaviour. In agreement with their face-sharing dicubane structure, a Hamiltonian of the type H =– J 1 (S 1 S 2 +S 1 S 2’ +S 1' S 2 +S 1' S 2’ ) – J 2 S 1 S 1’ , where S 1 = S 1’ = S 2 = S 2’ = S Cu =1/2, was used for studying and . Simulations performed suggest magnetic exchange constants with values close to J 1 =−20 cm −1 and J 2 =0 cm -1 for these complexes. On the other hand, the spin Hamiltonian H =– J 1 (S 1 S 4 +S 2 S 3 ) – J 2 (S 1 S 3 +S 2 S 4 ) – J 3 S 1 S 2 , where S 1 = S 2 = S 3 = S 4 = S Cu =1/2, was used to study the magnetic behaviour of the double open cubane core of and a good agreement between the experimental and simulated results was found by using the parameters g 1 = g 2 =2.20, g 3 = g 4 =2.18, J 1 =−36 cm -1 , J 2

Catecholase activity of dicopper(II)-bispidine complexes: stabilities and structures of intermediates, kinetics and reaction mechanism.

Science.gov (United States)

Born, Karin; Comba, Peter; Daubinet, André; Fuchs, Alexander; Wadepohl, Hubert

2007-01-01

A mechanism for the oxidation of 3,5-di-tert-butylcatechol (dtbc) with dioxygen to the corresponding quinone (dtbq), catalyzed by bispidine-dicopper complexes (bispidines are various mono- and dinucleating derivatives of 3,7-diazabicyclo[3.3.1]nonane with bis-tertiary-amine-bispyridyl or bis-tertiary-amine-trispyridyl donor sets), is proposed on the basis of (1) the stoichiometry of the reaction as well as the stabilities and structures [X-ray, density functional theory (B3LYP, TZV)] of the bispidine-dicopper(II)-3,4,5,6-tetrachlorcatechol intermediates, (2) formation kinetics and structures (molecular mechanics, MOMEC) of the end-on peroxo-dicopper(II) complexes and (3) kinetics of the stoichiometric (anaerobic) and catalytic (aerobic) copper-complex-assisted oxidation of dtbc. This involves (1) the oxidation of the dicopper(I) complexes with dioxygen to the corresponding end-on peroxo-dicopper(II) complexes, (2) coordination of dtbc as a bridging ligand upon liberation of H(2)O(2) and (3) intramolecular electron transfer to produce dtbq, which is liberated, and the dicopper(I) catalyst. Although the bispidine complexes have reactivities comparable to those of recently published catalysts with macrocyclic ligands, which seem to reproduce the enzyme-catalyzed process in various reaction sequences, a strikingly different oxidation mechanism is derived from the bispidine-dicopper-catalyzed reaction.

Synthesis and spectroscopic studies of biologically active tetraazamacrocyclic complexes of Mn(II, Co(II, Ni(II, Pd(II and Pt(II

Directory of Open Access Journals (Sweden)

Monika Tyagi

2014-01-01

Full Text Available Complexes of Mn(II, Co(II, Ni(II, Pd(II and Pt(II were synthesized with the macrocyclic ligand, i.e., 2,3,9,10-tetraketo-1,4,8,11-tetraazacycoletradecane. The ligand was prepared by the [2 + 2] condensation of diethyloxalate and 1,3-diamino propane and characterized by elemental analysis, mass, IR and 1H NMR spectral studies. All the complexes were characterized by elemental analysis, molar conductance, magnetic susceptibility measurements, IR, electronic and electron paramagnetic resonance spectral studies. The molar conductance measurements of Mn(II, Co(II and Ni(II complexes in DMF correspond to non electrolyte nature, whereas Pd(II and Pt(II complexes are 1:2 electrolyte. On the basis of spectral studies an octahedral geometry has been assigned for Mn(II, Co(II and Ni(II complexes, whereas square planar geometry assigned for Pd(II and Pt(II. In vitro the ligand and its metal complexes were evaluated against plant pathogenic fungi (Fusarium odum, Aspergillus niger and Rhizoctonia bataticola and some compounds found to be more active as commercially available fungicide like Chlorothalonil.

Removal of copper (II from aqueous solutions by adsorption onto granular activated carbon in the presence of competitor ions

Directory of Open Access Journals (Sweden)

Saeed Almohammadi

2016-04-01

Full Text Available In this work, the removal of copper from an aqueous solution by granular activated carbon (GAC in the presence of competitor ions was studied. A batch adsorption was carried out and different parameters such as pH, contact time, initial copper concentration and competitor ions concentration were changed to determine the optimum conditions for adsorption. The optimum pH required for maximum adsorption was found to be 4.5 for copper. Equilibrium was evaluated at 144 h at room temperature. The removal efficiency of Cu(II was 71.12% at this time. The kinetics of copper adsorption on activated carbon followed the pseudo second-order model. The experimental equilibrium sorption data were tested using the Langmuir, Freundlich, Temkin and Dubinin–Radushkevich (D-R equations and the Langmuir model was found to be well fitted for copper adsorption onto GAC. The maximum adsorption capacity of the adsorbent for Cu(II was calculated from the Langmuir isotherm and found to be 7.03 mg/g. Subsequently, the removal of copper by granular activated carbon in the presence of Ag1+ and Mn2+ as competitor ions was investigated. The removal efficiency of Cu(II ions without the presence of the competitor ions was 46% at 6 h, while the removal efficiency of Cu(II ions in the presence of competitor ions, Ag1+ and Mn2+ , was 34.76% and 31.73%, respectively.

Cyclam Derivatives with a Bis(phosphinate) or a Phosphinato-Phosphonate Pendant Arm: Ligands for Fast and Efficient Copper(II) Complexation for Nuclear Medical Applications

Czech Academy of Sciences Publication Activity Database

David, T.; Kubíček, V.; Gutten, Ondrej; Lubal, P.; Kotek, J.; Pietzsch, H.-J.; Rulíšek, Lubomír; Hermann, P.

2015-01-01

Roč. 54, č. 24 (2015), s. 11751-11766 ISSN 0020-1669 R&D Projects: GA ČR(CZ) GA14-31419S Grant - others:COST(XE) TD1004 Institutional support: RVO:61388963 Keywords : cyclam derivatives * radiolabelling * quantum chemical calculations * copper(II) chelation Subject RIV: CA - Inorganic Chemistry Impact factor: 4.820, year: 2015

Absorption and fluorescence spectroscopy of 3-hydroxy-3-phenyl-1-o-carboxyphenyltriazene and its copper (II), nickel (II) and zinc (II) complexes: a novel fluorescence sensor

International Nuclear Information System (INIS)

Ressalan, S.; Iyer, C.S.P.

2005-01-01

Absorption and fluorescence spectroscopic properties of 3-hydroxy-3-phenyl-1-o-carboxyphenyltriazene (HT) are studied. The mechanism of photo-induced electron transfer (PET) followed by energy transfer process of the ligand and the Cu (II), Ni (II) and Zn (II) metal complexes have been investigated. The excited state photo induced intramolecular hydrogen transfer from N-OH to triazene 1-nitrogen atom is explained. The effect of pH, solvent and concentration on the absorption and fluorescence of the ligand is studied and it has been found that the absorption and fluorescence of HT is highly pH, solvent and concentration dependent. Participation of the N-OH proton of HT in the solvent assisted O to N-proton transfer has also been proposed. The fluorescence band shift and changes in intensity is modulated by protonation and complexation with metal ions. This fluorophore can thus be used as a pH dependent and M (n+1)+ /M n+ redox on/off switchable molecular sensor

Syntheses and properties of binuclear copper(II) mixed-ligand complexes involving thiodiglycolic acid. The crystal structures of [(phen)2Cu(m-tdga)Cu(phen)](NO3)2x5H2O and [(H2O)(pmdien)Cu(micro-tdga)Cu(pmdien)(H2O)](ClO4)

Czech Academy of Sciences Publication Activity Database

Kopel, P.; Trávníček, Zdeněk; Marek, J.; Korabik, M.; Mrozinski, J.

2003-01-01

Roč. 22, - (2003), s. 411-418 ISSN 0277-5387 R&D Projects: GA ČR GA203/99/0067 Institutional research plan: CEZ:AV0Z5038910 Keywords : Copper(II) * Thiodiglycolic acid complexes * Crystal structures Subject RIV: CE - Biochemistry Impact factor: 1.584, year: 2003

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

Indian Academy of Sciences (India)

Unknown

measurements, ESR and electronic spectral data indicate the presence of six coordinated Cu(II) ion. The ligand ... the test solution was diffused into the plate and affected the growth of the inoculated. Pseudomonas aeroginosa. .... bacteria Pseudomonas aerogenosa using the diffusion method 4. The antibacterial activity.

Oxidation of aromatic alcohols on zeolite-encapsulated copper amino acid complexes

Energy Technology Data Exchange (ETDEWEB)

Ernst, S.; Teixeira Florencio, J.M. [Kaiserslautern Univ. (Germany). Dept. of Chemistry, Chemical Technology

1998-12-31

Copper complexes of the amino acids histidine, arginine and lysine have been introduced into the supercages of zeolite Y and, for the first time, into the large intracrystalline cavities of zeolites EMT and MCM-22. The resulting host/guest compounds are characterized by X-ray powder diffraction, UV/VIS-spectroscopy in the diffuse reflectance mode and by catalytic tests in the liquid-phase oxidation of aromatic alcohols (viz. benzyl alcohol, 2- and 3-methylbenzyl alcohol and 2,5-dimethylbenzyl alcohol) with tertiary-butylhydroperoxide as oxidant. It was observed that intracrystalline copper-amino acid complexes possess remarkable catalytic activity, yielding the corresponding aromatic aldehydes and acids. (orig.)

Leaching of copper concentrates using NaCl and soluble copper contributed by the own concentrate

International Nuclear Information System (INIS)

Herrero, O.; Bernal, N.; Quiroz, R.; Fuentes, G.; Vinals, J.

2005-01-01

Leaching of copper concentrates using cupric chloro complexes, generated in situ by the reaction between Cu(II), aported by the soluble copper content of the concentrate, and sodium chloride in acid media was studied. The concentrate samples were obtained from mineral processing plants from Antofagasta, Chile. Chemical and mineralogical characterization from original concentrates was made. Typical variable such as a chloride concentration, soluble copper concentration, leaching time, solid percentage and temperature were studied. DRX and EDS analyzed some of the residues. the experimental results indicated that it is possible to obtain solutions having high copper content (15 to 35 g/L) and 2 to 5 g/L free acid in order to submit this solution directly to a solvent extraction stage. The leaching tests use common reactive and low cost such as sodium chloride and sulfuric acid. (Author) 16 refs

Metal complexes of salicylhydroxamic acid (H2Sha), anthranilic hydroxamic acid and benzohydroxamic acid. Crystal and molecular structure of [Cu(phen)2(Cl)]Cl x H2Sha, a model for a peroxidase-inhibitor complex.

Science.gov (United States)

O'Brien, E C; Farkas, E; Gil, M J; Fitzgerald, D; Castineras, A; Nolan, K B

2000-04-01

Stability constants of iron(III), copper(II), nickel(II) and zinc(II) complexes of salicylhydroxamic acid (H2Sha), anthranilic hydroxamic acid (HAha) and benzohydroxamic acid (HBha) have been determined at 25.0 degrees C, I=0.2 mol dm(-3) KCl in aqueous solution. The complex stability order, iron(III) > copper(II) > nickel(II) approximately = zinc(II) was observed whilst complexes of H2Sha were found to be more stable than those of the other two ligands. In the preparation of ternary metal ion complexes of these ligands and 1,10-phenanthroline (phen) the crystalline complex [Cu(phen)2(Cl)]Cl x H2Sha was obtained and its crystal structure determined. This complex is a model for hydroxamate-peroxidase inhibitor interactions.

The piroxicam complex of copper(II), trans-[Cu(Pir)2(THF)2], and its interaction with DNA

Science.gov (United States)

Hadadzadeh, Hassan; Salimi, Mona; Weil, Matthias; Jannesari, Zahra; Darabi, Farivash; Abdi, Khatereh; Khalaji, Aliakbar Dehno; Sardari, Soroush; Ahangari, Reza

2012-08-01

The mononuclear Cu(II) complex, trans-[Cu(Pir)2(THF)2], where Pir is 4-hydroxy-2-methyl-N-2-pyridyl-2H-1,2-benzothiazine-3-carboxamide-1,1-dioxide (piroxicam), has been prepared and characterized by elemental analysis, spectroscopic methods (UV-Vis, IR, and 1H NMR) and single crystal X-ray structure analysis. The molecular structure of the centrosymmetric complex is made up of two monoanionic bidentate Pir ligands coordinated to the Cu(II) atom through the pyridyl N atom and the carbonyl O atom of the amide group in equatorial positions. The elongated rhombic octahedral (ERO) coordination of the CuNONOO2″ chromophore is completed by the O atoms of two THF molecules in axial positions. A strong intramolecular hydrogen bond between the amide N-H function and the enolate O atom confirms the ZZZ conformation of piroxicam. In addition, CD spectroscopy and gel electrophoresis assays have been used to investigate the interaction of the complex with DNA. The results revealed that the binding of the complex with DNA led to DNA backbone distortion.

Complexometric determination, Part II: Complexometric determination of Cu2+-ions

Directory of Open Access Journals (Sweden)

Rajković Miloš B.

2002-01-01

Full Text Available A copper-selective electrode of the coated wire type based on sulphidized copper wire was applied successfully for determining Cu(II ions by complexometric titration with the disodium salt of EDTA (complexon III. By the formation of internal complex compounds with the Cu(II ion, the copper concentration in the solution decreases, and all this is followed by a change of potential of the indicator system Cu-DWISE (or Cu-EDWISE/SCE. At the terminal point of titration, when all the Cu(II ions are already utilized for the formation of the complex with EDTA, there occurs a steep rise of potential, thus enabling us, through the first or second derivative to note the quantity of copper that is present in the solution. Copper-selective electrode showed a responsivity towards titration with EDTA as a complexing agent, with the absence of "fatigue" due to a great number of repeated measurings. Errors occurring during quantitative measurements were more a characteristic of the overall procedure which involve, because of the impossibility of the complete absence of subjectivity, a constant error, and the reproducibility of the results confirmed this fact. The disodium salt of EDTA appeared as a very efficient titrant in all titrations and with various concentrations ot Cu(II ions in the solution, with somewhat weaker response at lower concentrations in the solution.

(azo anils and oxalate ion) copper(ii)

African Journals Online (AJOL)

B. S. Chandravanshi

transition metal complexes compared to corresponding free ligands may be attributed to structural symmetry of ... C H, N contents in synthesized azo anils ligands and in Cu(II) complexes were found using. CHNS technique (Costech international-4100). Metal contents in synthesized complexes were. Compounds. Color.

Production of Copper-Plated Beamline Bellows and Spools for LCLS-II

Energy Technology Data Exchange (ETDEWEB)

Wilson, Katherine M. [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Carpenter, Brian C. [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Daly, Ed [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Huque, Naeem A. [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Peshehonoff, Ted [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Arkan, Tug [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Lunin, A. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Premo, K. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)

2017-05-01

The SLAC National Accelerator Laboratory is currently constructing a major upgrade to its accelerator, the Linac Coherent Light Source II (LCLS-II). Several Department of Energy national laboratories, including the Thomas Jefferson National Accelerator Facility (JLab) and Fermi National Accelerator Laboratory (FNAL), are participating in this project. The 1.3-GHz cryomodules for this project consist of eight cavities separated by bellows (expansion joints) and spools (tube sections), which are copper plated for RF conduction. JLab is responsible for procurement of these bellows and spools, which are delivered to JLab and FNAL for assembly into cryomodules. Achieving accelerator-grade copper plating is always a challenge and requires careful specification of requirements and application of quality control processes. Due to the demanding technical requirements of this part, JLab implemented procurement strategies to make the process more efficient as well as provide process redundancy. This paper discusses the manufacturing challenges that were encountered and resolved, as well as the strategies that were employed to minimize the impact of any technical issues.

Synthesis, characterization and antifungal efficacy of C-coordinated O-carboxymethyl chitosan Cu(II) complexes.

Science.gov (United States)

Liu, Weixiang; Qin, Yukun; Liu, Song; Xing, Ronge; Yu, Huahua; Chen, Xiaolin; Li, Kecheng; Li, Pengcheng

2017-03-15

A novel type of O-carboxymethyl chitosan Schiff bases (O-CSPX) was synthesized via a condensation reaction. After the coordination reaction of cupric ions, Cu(II) complexes (O-CSPX-Cu) were achieved. The theoretical structure of O-CSPX-Cu calculated by Gaussian 09 reveals that the copper ions underwent dsp 2 hybridization, coordinated by the carbon atom in the p-π conjugate group and the oxygen atoms in the acetate ion. Then, the structures were confirmed by FT-IR, 1 H NMR, CP-MAS 13 C NMR, elemental analysis, DSC and XRD. The antifungal properties of O-CSPX-Cu against Phytophthora capsici (P. capsici), Gibberella zeae (G. zeae) and Glomerella cingulata (G. cingulata) were evaluated at concentrations ranging from 0.05mg/mL to 0.20mg/mL. The experiments indicated that the derivatives have significantly enhanced antifungal activity after copper ion complexation compared with the original chitosan. Moreover, it was shown that 0.20mg/mL of O-CSP3-Cu and O-CSP4-Cu can 100% inhibit the growth of P. capsici. The experimental results reveal that the antifungal efficiency is related to the space steric hindrance on the benzene ring, which may provide a novel direction for the development of copper fungicides. Copyright © 2016 Elsevier Ltd. All rights reserved.

Synthesis, Spectroscopy, Thermal Analysis, Magnetic Properties and Biological Activity Studies of Cu(II and Co(II Complexes with Schiff Base Dye Ligands

Directory of Open Access Journals (Sweden)

Saeid Amani

2012-05-01

Full Text Available Three azo group-containing Schiff base ligands, namely 1-{3-[(3-hydroxy-propyliminomethyl]-4-hydroxyphenylazo}-4-nitrobenzene (2a, 1-{3-[(3-hydroxypropyl-iminomethyl]-4-hydroxyphenylazo}-2-chloro-4-nitrobenzene (2b and 1-{3-[(3-hydroxy-propyliminomethyl]-4-hydroxyphenylazo}-4-chloro-3-nitrobenzene (2c were prepared. The ligands were characterized by elemental analysis, FTIR spectroscopy, UV-Vis spectroscopy, ¹³C- and ¹H-NMR spectroscopy and thermogravimetric analysis. Next the corresponding copper(II and cobalt(II metal complexes were synthesized and characterized by the physicochemical and spectroscopic methods of elemental analysis, FTIR spectroscopy, UV-Vis spectroscopy, magnetic moment measurements, and thermogravimetric analysis (TGA and (DSC. The room temperature effective magnetic moments of complexes are 1.45, 1.56, 1.62, 2.16, 2.26 and 2.80 B.M. for complexes 3a, 3b, 3c, 4a 4b, and 4c, respectively, indicating that the complexes are paramagnetic with considerable electronic communication between the two metal centers.

Vectorization of copper complexes via biocompatible and biodegradable PLGA nanoparticles.

Science.gov (United States)

Courant, T; Roullin, V G; Cadiou, C; Delavoie, F; Molinari, M; Andry, M C; Gafa, V; Chuburu, F

2010-04-23

A double emulsion-solvent diffusion approach with fully biocompatible materials was used to encapsulate copper complexes within biodegradable nanoparticles, for which the release kinetics profiles have highlighted their potential use for a prolonged circulating administration.

Vectorization of copper complexes via biocompatible and biodegradable PLGA nanoparticles

Energy Technology Data Exchange (ETDEWEB)

Courant, T; Roullin, V G; Andry, M C [Institut de Chimie Moleculaire de Reims, CNRS UMR 6229, UFR Pharmacie Reims, 51 rue Cognacq-Jay, F-51100 Reims (France); Cadiou, C; Chuburu, F [Institut de Chimie Moleculaire de Reims, CNRS UMR 6229, UFR des Sciences Exactes et Naturelles, Batiment 18-Europol' Agro, BP 1039, F-51687 Reims Cedex 2 (France); Delavoie, F [Laboratoire de Microscopie Electronique Analytique, INSERM UMRS 926, 21 rue Clement Ader, F-51685 Reims Cedex 2 (France); Molinari, M [Laboratoire de Microscopies et d' Etudes des Nanostructures, UFR des Sciences, Universite de Reims Champagne-Ardenne, 21 rue Clement Ader, F-51685 Reims Cedex 2 (France); Gafa, V, E-mail: gaelle.roullin@univ-reims.fr, E-mail: francoise.chuburu@univ-reims.fr [EA4303 ' Inflammation et Immunite de l' Epithelium Respiratoire' , IFR53, UFR de Pharmacie, Universite de Reims Champagne-Ardenne, 51 rue Cognacq-Jay, F-51100 Reims (France)

2010-04-23

A double emulsion-solvent diffusion approach with fully biocompatible materials was used to encapsulate copper complexes within biodegradable nanoparticles, for which the release kinetics profiles have highlighted their potential use for a prolonged circulating administration.

Vectorization of copper complexes via biocompatible and biodegradable PLGA nanoparticles

International Nuclear Information System (INIS)

Courant, T; Roullin, V G; Andry, M C; Cadiou, C; Chuburu, F; Delavoie, F; Molinari, M; Gafa, V

2010-01-01

A double emulsion-solvent diffusion approach with fully biocompatible materials was used to encapsulate copper complexes within biodegradable nanoparticles, for which the release kinetics profiles have highlighted their potential use for a prolonged circulating administration.

EPR of Cu(II) in sarcosine cadmium chloride: probe into dopant site - symmetry and copper-sarcosine interaction

CERN Document Server

Pathinettam-Padiyan, D; Murugesan, R

2000-01-01

The electron paramagnetic resonance spectra of Cu(II) doped sarcosine cadmium chloride single crystals have been investigated at room temperature. Experimental results reveal that the Cu(II) ion enters the lattice interstitially. The observed superhyperfine lines indicate the superposition of two sets of quintet structure with interaction of nitrogen atoms and the two isotopes of copper. The spin Hamiltonian parameters are evaluated by Schonland method and the electric field symmetry around the copper ion is rhombic. An admixture of d sub z sup 2 orbital with the d sub x sub sup 2 sub - sub y sub sup 2 ground state is observed. Evaluation of MO coefficients reveals that the in-plane interaction between copper and nitrogen is strong in this lattice.

Thermal Degradation of Complexes Derived from Cu (II) Groundnut (Arachis hypogaea) and Sesame (Sesamum indicum) Soaps

Science.gov (United States)

Joram, Anju; Sharma, Rashmi; Sharma, Arun kumar

2018-05-01

The complexes have been synthesized from Cu (II) soaps of groundnut (Arachis hypogaea) and sesame (Sesamum indicum) oils, with ligand containing nitrogen and sulfur atoms like 2-amino-6-methyl benzothiazole. The complexes were greenish brown in color. In order to study TGA, first characterized them by elemental analysis, and spectroscopic technique such as IR, NMR and ESR. From the analytical data, the stoichiometry's of the complexes have been observed to be 1:1 (metal:ligand). These complexes have been thermally analyzed using TGA techniques to determine their energy of activation. These complexes show three step thermal degradation corresponding to fatty acid components of the edible oils and each complex has three decomposition steps in the range of 439-738 K. Various equations like Coats-Redfern (CR), Horowitz-Metzger (HM) and Broido equations (BE) were applied to evaluate the energy of activation. The values of energy of activation are observed to be in the following order for both copper groundnut benzothiazole (CGB) and copper sesame benzothiazole (CSeB) complexes: CGB > CSeB. CGB is observed to be more stable than CSeB due to its higher activation energy. The above studies would provide significant information regarding the applications of synthesized agrochemicals and their safe removal through parameters obtained in degradation curves and its relation with energy.

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.

Construction of a new functional platform by grafting poly(4-vinylpyridine) in multi-walled carbon nanotubes for complexing copper ions aiming the amperometric detection of L-cysteine

International Nuclear Information System (INIS)

Carvalho Castro e Silva, Cecília de; Breitkreitz, Márcia Cristina; Santhiago, Murilo; Crispilho Corrêa, Cátia; Tatsuo Kubota, Lauro

2012-01-01

Highlights: ► Construction of new nanostructured platform based on MWCNTs–PVP to complex copper(II) ions. ► Development of an amperometric sensor for highly selective determination of Cys in food supplement samples. ► Combination of nanocomposite and the copper(II) ions causes a dramatic enhancement in the sensitivity of Cys quantification at low overpotential. - Abstract: This work describes the preparation of an amperometric sensor for electrocatalytical detection of L-cysteine (Cys). The developed sensor is based on a functional platform to complex copper ions on multi-walled carbon nanotubes (MWCNTs) modified with poly-4-vinylpyridine (PVP) through an in situ polymerization. The obtained values for the kinetic constants of heterogeneous electron transfer rate (k s ) and for chemical reaction (k obs ) between Cu 2+ and cysteine were 5.78 s −1 and 6.96 L mol −1 s −1 , respectively. The analytical curve showed a linear response range for detecting L-cysteine in concentrations from 5 to 60 μmol L −1 . The detection and quantification limits obtained were 1.50 and 5.00 μmol L −1 , respectively with a response time of 0.10 s at an applied potential of 150 mV vs SCE.

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].

Modulating p-hydroxycinnamate behavior as a ditopic linker or photoacid in copper(ii) complexes with an auxiliary pyridine ligand.

Science.gov (United States)

Soldevila-Sanmartín, Joan; Calvet, Teresa; Font-Bardia, Merce; Domingo, Concepción; Ayllón, José A; Pons, Josefina

2018-05-08

The reaction of copper(ii) acetate monohydrate with p-hydroxycinnamic acid (HpOHcinn) and different pyridine derivatives (4-tert-butylpyridine, 4-tBupy; 4-acetylpyridine, 4-Acpy; 3-phenylpyridine, 3-Phpy; 4-phenylpyridine, 4-Phpy) was essayed in methanol solvent at room temperature. The crystal structures of the resulting compounds were elucidated. Their analysis shows that the choice of pyridine ligands determines different coordination modes of the pOHcinn ligand and the Cu(ii) coordination, nuclearity and geometry. The pOHcinn acts as a monodentate carboxylate ligand in combination with 4-tBupy or 4-Phpy, yielding monomers and dimers, associated by hydrogen bonds into supramolecular networks in which the phenol group plays a key role. Conversely, in combination with 4-Acpy or 3-Phpy, the phenol group coordinates directly to the Cu(ii), acting as a ditopic ligand and yielding 2D coordination polymers. The compound containing 3-Phpy shows interesting MeOH-H2O reversible exchange behavior. Not only has the pyridine auxiliary ligand had a tremendous effect on the coordination mode of pOHcinn, but also its reactivity is influenced. Particularly, in the case of the compound containing 4-Phpy, it undergoes a photoinduced process, in which the phenol group deprotonates and coordinates to Cu(ii) as a phenoxy ligand. This yields a coordination polymer in which two different dimers alternate, bridged by the resulting pOcinn ligand. The magneto-structural correlation of this compound is also discussed.

DNA damage by the cobalt (II) and zinc (II) complexes of ...

African Journals Online (AJOL)

Using the single cell gel electrophoresis method, the tetraazamacrocycle Zn(II) complex (Zn(II)-L) and the tetraazamacrocycle Co(II) complex (Co(II)-L) were investigated focusing on their DNA damage to Tetrahymena thermophila. When the cells were treated with the 0.05, 0.25 and 0.50 mg/ml Zn(II)-L, the tail length ...

Effect of copper (II) ion against elongation behavior of amyloid {beta} fibrils on liposome membranes

Energy Technology Data Exchange (ETDEWEB)

Shimanouchi, T.; Onishi, R.; Kitaura, N.; Umakoshi, H.; Kuboi, R. [Division of Chemical Engineering, Graduate School of Engineering Science, Osaka University, 1-3 Machikaneyama-cho, Toyonaka, Osaka (Japan)

2012-01-15

The fibril growth behavior of amyloid {beta} protein (A{beta}) on cell membranes is relating to the progression of Alzheimer's disease. This growth behavior of A{beta} fibrils is sensitively affected by the metal ions, neurotransmitters, or bioreactive substrate. The inhibitory effect of those materials was quantitatively estimated from the viewpoints of ''crystal growth''. In a bulk aqueous solution, copper (II) ion showed the strong inhibitory effect on the growth of A{beta} fibrils. Meanwhile, the addition of a closed-phospholipid bilayer membrane (liposome) could reduce the above inhibitory effect of copper (II) ion. (copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

Well-Defined Copper(I) Fluoroalkoxide Complexes for Trifluoroethoxylation of Aryl and Heteroaryl Bromides

KAUST Repository

Huang, Ronglu; Huang, Yangjie; Lin, Xiaoxi; Rong, Mingguang; Weng, Zhiqiang

2015-01-01

© 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Copper(I) fluoroalkoxide complexes bearing dinitrogen ligands were synthesized and the structure and reactivity of the complexes toward trifluoroethoxylation, pentafluoropropoxylation

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

Adsorptive stripping voltammetric behaviour of copper complexes of some heterocyclic azo compounds.

Science.gov (United States)

Farias, P A; Ferreira, S L; Ohara, A K; Bastos, M B; Goulart, M S

1992-10-01

Controlled adsorptive accumulation of copper complexed with TAN, TAC, TAR and TAM (heterocyclic azo-compounds) on a static mercury drop electrode provides the basis for the direct stripping measurement of this element in the nanomolar concentration level. The ligand TAN exhibited great sensitivity and better separation of the peak current of the ligand in relation to the complex. The reduction current of adsorbed complex ions of copper is measured by linear scan cathodic stripping voltammetry, preceded by a period of accumulation of a few minutes. The peak potential is at approximately -0.37 V vs. Ag/AgCl. Optimal experimental parameters were found to be a TAN concentration of 1 x 10(-5)M, an accumulation potential of -0.22 V, and a solution pH of 3.7 (acetate buffer). The detection limit is 0.8nM after a 5-min accumulation with a stirred solution, and the response is linear up to 50 mug/l. Many common cations and anions do not interfere in the determination of copper. The interference of titanium is eliminated by addition of fluoride ion. Results are reported for a fresh water sample.

High sensitive detection of copper II ions using D-penicillamine-coated gold nanorods based on localized surface plasmon resonance

Science.gov (United States)

Hong, Yoochan; Jo, Seongjae; Park, Joohyung; Park, Jinsung; Yang, Jaemoon

2018-05-01

In this paper, we describe the development of a nanoplasmonic biosensor based on the localized surface plasmon resonance (LSPR) effect that enables a sensitive and selective recognition of copper II ions. First, we fabricated the nanoplasmonics as LSPR substrates using gold nanorods (GNR) and the nano-adsorption method. The LSPR sensitivity of the nanoplasmonics was evaluated using various solvents with different refractive indexes. Subsequently, D-penicillamine (DPA)—a chelating agent of copper II ions—was conjugated to the surface of the GNR. The limit of detection (LOD) for the DPA-conjugated nanoplasmonics was 100 pM. Furthermore, selectivity tests were conducted using various divalent cations, and sensitivity tests were conducted on the nanoplasmonics under blood-like environments. Finally, the developed nanoplasmonic biosensor based on GNR shows great potential for the effective recognition of copper II ions, even in human blood conditions.

DNA damage by the cobalt (II) and zinc (II) complexes of ...

African Journals Online (AJOL)

STORAGESEVER

2008-09-03

Sep 3, 2008 ... distributed in grade 3. The results indicated that Co(II)-L induced a relatively high level of DNA damage in comparison with the level of damage induced by Zn(II)-L. Key words: Tetraazamacrocycle Zn(II) complex, tetraazamacrocycle Co(II) complex, Tetrahymena thermophila, DNA damage, the comet assay.

Electron transfer reactions in structural units of copper proteins

International Nuclear Information System (INIS)

Faraggi, M.

1975-01-01

In previous pulse radiolysis studies it was suggested that the reduction of the Cu(II) ions in copper proteins by the hydrated electron is a multi-step electron migration process. The technique has been extended to investigate the reduction of some structural units of these proteins. These studies include: the reaction of the hydrated electron with peptides, the reaction of the disulphide bridge with formate radical ion and radicals produced by the reduction of peptides, and the reaction of Cu(II)-peptide complex with esub(aq)sup(-) and CO 2 - . Using these results the reduction mechanism of copper and other proteins will be discussed. (author)

Spectroscopy of Cu(II)-PcoC and the multicopper oxidase function of PcoA, two essential components of Escherichia coli pco copper resistance operon.

Science.gov (United States)

Huffman, David L; Huyett, Jennifer; Outten, F Wayne; Doan, Peter E; Finney, Lydia A; Hoffman, Brian M; O'Halloran, Thomas V

2002-08-06

The plasmid-encoded pco copper resistance operon in Escherichia coli consists of seven genes that are expressed from two pco promoters in response to elevated copper; however, little is known about how they mediate resistance to excess environmental copper. Two of the genes encode the soluble periplasmic proteins PcoA and PcoC. We show here that inactivation of PcoC, and PcoA to a lesser extent, causes cells to become more sensitive to copper than wild-type nonresistant strains, consistent with a tightly coupled detoxification pathway. Periplasmic extracts show copper-inducible oxidase activity, attributed to the multicopper oxidase function of PcoA. PcoC, a much smaller protein than PcoA, binds one Cu(II) and exhibits a weak electronic transition characteristic of a type II copper center. ENDOR and ESEEM spectroscopy of Cu(II)-PcoC and the (15)N- and Met-CD(3)-labeled samples are consistent with a tetragonal ligand environment of three nitrogens and one aqua ligand "in the plane". A weakly associated S-Met and aqua are likely axial ligands. At least one N is a histidine and is likely trans to the in-plane aqua ligand. The copper chemistry of PcoC and the oxidase function of PcoA are consistent with the emerging picture of the chromosomally encoded copper homeostasis apparatus in the E. coli cell envelope [Outten, F. W., Huffman, D. L., Hale, J. A., and O'Halloran, T. V. (2001) J. Biol. Chem. 276, 30670-30677]. We propose a model for the plasmid system in which Cu(I)-PcoC functions in this copper efflux pathway as a periplasmic copper binding protein that docks with the multiple repeats of Met-rich domains in PcoA to effect oxidation of Cu(I) to the less toxic Cu(II) form. The solvent accessibility of the Cu(II) in PcoC may allow for metal transfer to other plasmid and chromosomal factors and thus facilitate removal of Cu(II) from the cell envelope.

Infrared spectroscopy of copper-resveratrol complexes: A joint experimental and theoretical study

Energy Technology Data Exchange (ETDEWEB)

Chiavarino, B.; Crestoni, M. E.; Fornarini, S. [Dipartimento di Chimica e Tecnologie del Farmaco, Sapienza - Universita di Roma, Piazzale A. Moro 5, 00185 Rome (Italy); Taioli, S. [Interdisciplinary Laboratory for Computational Science, FBK-CMM and University of Trento, Via Sommarive 18, 38123 Trento (Italy); Department of Physics, University of Trento, Via Sommarive 14, 38123 Trento (Italy); Istituto Nazionale di Fisica Nucleare, Sezione di Perugia (Italy); Department of Chemistry, University of Bologna, Via F. Selmi 2, I-40126 Bologna (Italy); Mancini, I.; Tosi, P. [Department of Physics, University of Trento, Via Sommarive 14, 38123 Trento (Italy)

2012-07-14

Infrared multiple-photon dissociation spectroscopy has been used to record vibrational spectra of charged copper-resveratrol complexes in the 3500-3700 cm{sup -1} and 1100-1900 cm{sup -1} regions. Minimum energy structures have been determined by density functional theory calculations using plane waves and pseudopotentials. In particular, the copper(I)-resveratrol complex presents a tetra-coordinated metal bound with two carbon atoms of the alkenyl moiety and two closest carbons of the adjoining resorcinol ring. For these geometries vibrational spectra have been calculated by using linear response theory. The good agreement between experimental and calculated IR spectra for the selected species confirms the overall reliability of the proposed geometries.

Spectroscopic and structural study of the newly synthesized heteroligand complex of copper with creatinine and urea.

Science.gov (United States)

Gangopadhyay, Debraj; Singh, Sachin Kumar; Sharma, Poornima; Mishra, Hirdyesh; Unnikrishnan, V K; Singh, Bachcha; Singh, Ranjan K

2016-02-05

Study of copper complex of creatinine and urea is very important in life science and medicine. In this paper, spectroscopic and structural study of a newly synthesized heteroligand complex of copper with creatinine and urea has been discussed. Structural studies have been carried out using DFT calculations and spectroscopic analyses were carried out by FT-IR, Raman, UV-vis absorption and fluorescence techniques. The copper complex of creatinine and the heteroligand complex were found to have much increased water solubility as compared to pure creatinine. The analysis of FT-IR and Raman spectra helps to understand the coordination properties of the two ligands and to determine the probable structure of the heteroligand complex. The LIBS spectra of the heteroligand complex reveal that the complex is free from other metal impurities. UV-visible absorption spectra and the fluorescence emission spectra of the aqueous solution of Cu-Crn-urea heteroligand complex at different solute concentrations have been analyzed and the complex is found to be rigid and stable in its monomeric form at very low concentrations. Copyright © 2015 Elsevier B.V. All rights reserved.