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Sample records for schiff base complexes

  1. schiff base complexes

    African Journals Online (AJOL)

    DR. AMINU

    ABSTRACT. The complexes of iron (II) and nickel (II) with schiff base derived from benzoin and 2-amino benzoic acid have been prepared. Solubility, melting point, decomposition temperature, conductance measurement, infrared (IR) and UV – Visible spectrophotometric studies were used in characterizing the compounds.

  2. unsymmetrical Schiff base complexes

    Indian Academy of Sciences (India)

    The kinetics of thermal decomposition was stud- ied using thermal gravimetric method (TG) and Coats-Redfern equation. According to Coats-Redfern plots, the kinetics of thermal decomposition of the studied complexes is first-order in all stages. Also the kinetics and mechanism of the exchange reaction of the coordinated ...

  3. Synthesis of liquid-crystal vanadyl complex with Schiff base

    Energy Technology Data Exchange (ETDEWEB)

    Galyametdinov, Yu.G.; Ivanova, G.I.; Ovchinnikov, I.V. (AN SSSR, Kazan. Fiziko-Tekhnicheskij Inst.)

    1984-12-01

    The paramagnetic Schiff base vanadyl (4) complex (4-octiloxy-N-(2-hydroxy-4-heptyloxybenziliden aniline) possessing liquid-crystal properties is obtained. The complex is synthesized by heating Schiff base with vanadyl acetate in absolute ethanol with the 65% yield. The IR and EPR spectra are measured.

  4. Ruthenium(II) complexes containing bidentate Schiff bases and ...

    Indian Academy of Sciences (India)

    Unknown

    expensive Schiff base ligands, in this paper, we de- scribe the synthesis, characterisation and catalytic studies of stable ruthenium(II) complexes. The general structure of the Schiff base ligands used in this study is shown in scheme 1. 2. Experimental. RuCl3.3H2O was purchased from Loba-Chemie and used as supplied.

  5. Schiff base complex-catalysed enantioselective epoxidation of ...

    Indian Academy of Sciences (India)

    Administrator

    Chiral Ru(II) Schiff base complex-catalysed enantioselective epoxidation of styrene derivatives. R I KURESHY, N H KHAN, S H R ABDI, S T PATEL, P IYER and. R V JASRA. Silicates and Catalysis Discipline, Central Salt and Marine Chemicals. Research Institute, Bhavnagar 364 002, India. Ruthenium(II) chiral Schiff base ...

  6. Chalcogenated Schiff bases: Complexation with palladium(II) and ...

    Indian Academy of Sciences (India)

    The Pd–complexes (3–4) of L6–L7 were explored for Suzuki–Miyaura coupling and found promising as 0.006 mol % of 3 is sufficient to obtain good conversion with TON up to 1.58 × 104. Keywords. Chalcogenated Schiff base; palladium; Suzuki coupling; crystal structure. 1. Introduction. Schiff bases and related compounds ...

  7. (Ii) Complexes with Schiff Bases Derived From 2 – Hydroxy

    African Journals Online (AJOL)

    Schiff base ligands derived from 2-hydroxy-1-naphthaldehyde and some aliphatic diamines were synthesized and characterized. Each of the ligands was used to form complex with Mn (II). Solubility, elemental analyses and IR spectra were carried evaluated. Elemental analyses of the complexes for C, N and H revealed 1:1 ...

  8. Complex with a Schiff base Derived from 2 – Hydroxy

    African Journals Online (AJOL)

    ABSTRACT. Synthesis of Copper (II) complex with a Schiff base derived from the condensation of 2 – hydroxyl-1- naphthaldehyde and ethylenediammine was carried out. Solubility, melting/decomposition temperature, molar conductance, potentiometric as well as uv-visible spectrophotometric studies were carried out.

  9. Synthesis and Characterization of a Schiff Base Cobalt (III) Complex ...

    African Journals Online (AJOL)

    2017-12-18

    Dec 18, 2017 ... Synthesis and Characterization of a Schiff Base Cobalt (III) Complex and. Assessment of its Anti-Cancer Activity. Gwaram, N. S.. Department of Pure and Industrial Chemistry, Umaru Musa Yar'Adua University. P.M.B. 2211, Katsina, ... compounds of cobalt, copper, nickel, manganese, zinc, palladium ...

  10. synthesis, characterization an complexes with schiff base co ...

    African Journals Online (AJOL)

    userpc

    Aspergillus niger, Aspergillus flavus nd. Rhizoctoni abataicola cultured on potato dextrose agar as medium. The stock solution was prepared by dissolving .... Table 5:Antifungal activity of the Schiff base and its Ru(II) complexes. Compounds. Zone of Inhibition (mm). Aspergillus niger Aspergillus flavus Rhizoctonia bataicola.

  11. Schiff base transition metal complexes for Suzuki–Miyaura cross ...

    Indian Academy of Sciences (India)

    Schiff base ligand and its complex with iron (Fe), cobalt (Co), nickel (Ni) and copper (Cu) ions were synthesized using 4-aminoacetophenone and salicylaldehyde and characterized. FTIR spectrum shows that bidentate coordination of metal ions with ligand where O, N are electron donating sites of azomethine group.

  12. Lanthanide(III) complexes with tridentate Schiff base ligand ...

    African Journals Online (AJOL)

    The tridentate N4-type Schiff base was synthesized from the condensation reaction of 2-hydrazinopyridine and pyridine-2-carbaldehyde. Neodymium and Samarium complexes were isolated when the corresponding nitrate salt was added to the solution of the ligand. The isolated compounds were characterized by ...

  13. complexes with a tetradentate Schiff Base

    Indian Academy of Sciences (India)

    SMART software was used for data acquisition and the. SAINT-Plus software ... 8. Calculated density (g cm−3). 1.560. 1.274. Absorption coefficient (mm−1). 1.431. 1.601. Reflections collected. 35070. 29912. Unique reflections. 6495. 7474. Reflections [I .... action involving the babh2− phenyl ortho C−H of a second complex ...

  14. and Ni (II) complexes with Schiff base derived from 2-amino benzoic

    African Journals Online (AJOL)

    CLEMENT O BEWAJI

    ABSTRACT: The complexes of Mn (II) and Ni (II) with Schiff base derived from salicylaldehyde and 2-amino benzoic acid have been prepared and characterized by gravimetry, potentiometry, molar conductance and infrared analyses. The solubility test on the Schiff base and its nickel(II) complex revealed their solubility in ...

  15. Manganese-Schiff base complexes as catalysts for water photolysis.

    Science.gov (United States)

    González-Riopedre, Gustavo; Fernández-García, M Isabel; González-Noya, Ana M; Vázquez-Fernández, M Ángeles; Bermejo, Manuel R; Maneiro, Marcelino

    2011-10-28

    Four manganese(III)-Schiff base complexes (1-4) of formula [MnL(n)(H(2)O)(2)](2)(ClO(4))(2)·mH(2)O (n = 1-4; m = 0, 1) have been prepared. The multidentate H(2)L(n) Schiff base ligands consist of 3R,5R-substituted N,N'-bis(salicylidene)-1,2-diimino-2,2-dimethylethane, where R = OEt, OMe, Br or Cl. The complexes have been thoroughly characterized by elemental analysis, mass spectrometry, magnetic susceptibility measurements, IR, UV, paramagnetic (1)H NMR and EPR spectroscopies. Other properties, including redox studies and molar conductivity measurements, have also been assessed. The crystal structure of 1 was solved by X-ray diffraction, which revealed the dimeric nature of the compound through μ-aqua bridges. The ability of these complexes to split water has been studied by water photolysis experiments, with the oxygen evolution measured in aqueous media in the presence of a hydrogen acceptor (p-benzoquinone), the reduction of which was followed by UV-spectroscopy. The discussion of the photolytic behaviour includes advances in the knowledge of the structural motifs and the chemical activity of this type of complex, as revealed by the development of several characterization techniques in the last decade. Parallel-mode Mn(III) EPR shows that complexes 1-4 not only mimic reactivity but also share some structural characteristics from partially assembled natural OEC clusters. This journal is © the Owner Societies 2011

  16. Synthesis, characterization and antimicrobial studies of Schiff base complexes

    Science.gov (United States)

    Zafar, Hina; Ahmad, Anis; Khan, Asad U.; Khan, Tahir Ali

    2015-10-01

    The Schiff base complexes, MLCl2 [M = Fe(II), Co(II), Ni(II), Cu(II) and Zn(II)] have been synthesized by the template reaction of respective metal ions with 2-acetylpyrrole and 1,3-diaminopropane in 1:2:1 M ratio. The complexes have been characterized by elemental analyses, ESI - mass, NMR (1H and 13C), IR, XRD, electronic and EPR spectral studies, magnetic susceptibility and molar conductance measurements. These studies show that all the complexes have octahedral arrangement around the metal ions. The molar conductance measurements of all the complexes in DMSO indicate their non-electrolytic nature. The complexes were screened for their antibacterial activity in vitro against Gram-positive (Streptococcus pyogenes) and Gram-negative (Klebsiella pneumoniae) bacteria. Among the metal complexes studied the copper complex [CuLCl2], showed highest antibacterial activity nearly equal to standard drug ciprofloxacin. Other complexes also showed considerable antibacterial activity. The relative order of activity against S. Pyogenes is as Cu(II) > Zn(II) > Co(II) = Fe(II) > Ni(II) and with K. Pneumonia is as Cu(II) > Co(II) > Zn(II) > Fe(II) > Ni(II).

  17. Characterisation of covalent copper and manganese organometallic complexes with Schiff bases by ionspray mass spectrometry

    NARCIS (Netherlands)

    Raffaelli, A.; Minutolo, F.; Feringa, B.L.; Salvadori, P.

    1998-01-01

    Copper and manganese complexes containing Schiff bases as ligands, having potential interest in homogeneous catalysis, have been characterised by mass spectrometry using ionspray ionisation. Single stage mass spectrometry allowed us to confirm the molecular weight of complexes in all cases,

  18. Schiff base transition metal complexes for Suzuki–Miyaura cross ...

    Indian Academy of Sciences (India)

    RASHEEDA M ANSARI

    2017-08-19

    Aug 19, 2017 ... research study is to throw more light on the chelation behavior of Schiff base ligand towards the chosen metal ions and their catalytic activity in the coupling of various substituted aryl halides with phenylboronic acid. 2. Experimental. 2.1 Materials and reagents. All chemicals were of analytical reagent (AR) ...

  19. Tridentate Schiff base (ONO) transition metal complexes: Synthesis ...

    Indian Academy of Sciences (India)

    from the Schiff base ligand, the oxygen atom of a water molecule, and two nitrogen atoms from tmen. Inter- molecular hydrogen bonding stabilizes ... Mosquitoes are the best known disease vector, trans- mit harmful diseases such as filariasis, ... mosquito borne diseases every year. Hence it is most urgent to discover new ...

  20. Synthesis and Characterization of Metal Complexes with Schiff Base Ligands

    Science.gov (United States)

    Wilkinson, Shane M.; Sheedy, Timothy M.; New, Elizabeth J.

    2016-01-01

    In order for undergraduate laboratory experiments to reflect modern research practice, it is essential that they include a range of elements, and that synthetic tasks are accompanied by characterization and analysis. This intermediate general chemistry laboratory exercise runs over 2 weeks, and involves the preparation of a Schiff base ligand and…

  1. Ruthenium (II) complexes containing bidentate Schiff bases and ...

    Indian Academy of Sciences (India)

    The products were characterized by analytical, IR, electronic and 1H-NMR spectral studies and are formulated as [Ru(X)(CO) (L)(EPh3)(B)] (L = Schiff base anion ... Department of Chemistry, Periyar University, Salem 636 011, India; Department of Chemistry (PG), Kongunadu Arts and Science College, Coimbatore 641 029, ...

  2. Synthesis, structural, spectroscopic and biological studies of Schiff base complexes

    Science.gov (United States)

    Diab, M. A.; El-Sonbati, A. Z.; Shoair, A. F.; Eldesoky, A. M.; El-Far, N. M.

    2017-08-01

    Schiff base ligand 4-((pyridin-2- yl)methyleneamino)-1,2-dihydro-2,3-dimethyl-1-phenylpyrazol-5-one (PDMP) and its complexes were prepared and characterized on the basis of elemental analysis, IR, mass spectra and thermogravimetric analysis. All results confirm that the complexes have 1:1 (M: PMDP) stoichiometric formula [M(PMDP)Cl2H2O ] (M = Cu(II), Co(II), Ni(II) and Mn(II)), [Cd(PMDP)Cl2] and the ligand behaves as a bi/tridentate forming five-membered chelating ring towards the metal ions, bonding through azomethine nitrogen/exocyclic carbonyl oxygen, azomethine pyridine nitrogen and exocyclic carbonyl oxygen. The shift in the band positions of the groups involved in coordination has been utilized to estimate the metal-nitrogen and/or oxygen bond lengths. The complexes of Co(II), Ni(II) and Cu(II) are paramagnetic and the magnetic as well as spectral data suggest octahedral geometry, whereas the Cd(II) complex is tetrahedral. The XRD studies show that both the ligand and its metal complexes (1 and 3) show polycrystalline with crystal structure. Molecular docking was used to predict the binding between PMDP ligand and the receptors. The corrosion inhibition of mild steel in 2 M HCl solution by PDMP was explored utilizing potentiodynamic polarization, electrochemical impedance spectroscopy (EIS) and (EFM) electrochemical frequency modulation method. Potentiodynamic polarization demonstrated that PDMP compound is mixed-type inhibitor. EIS spectra exhibit one capacitive loop and confirm the protective ability. The percentage of inhibition efficiency was found to increase with increasing the inhibitor concentration.

  3. New strategy for chemically attachment of Schiff base complexes on Multiwalled Carbon Nanotubes surfaces

    Directory of Open Access Journals (Sweden)

    Leila Moradi

    2014-06-01

    Full Text Available Chemically attachment of Schiff base complexes on multiwalled carbon nanotubes (MWCNTs surfaces through a convenient and simple method was studied. In the first step of this method, we present a new method for preparation of aminated MWCNTs in order to attachment of (new chlorinated salen Schiff bases. Amination of multiwalled carbon nanotubes performed under microwave (MW irradiation through a one pot two step reaction. The chemically attachment of salen Schiff bases on functionalized MWCNTs (salen@MWCNTs performed under a facile simple nucleophilic substitution reaction and complexation of attached salen Schiff bases (salen complex@MWCNTs in last step, have been occurred with reaction of transition metal salts and salen@MWCNTs. The obtained products were characterized in detail, using FTIR, XRD, UV-Vis absorption, SEM and EDX methods.

  4. Chitosan-based Schiff base-metal complexes (Mn, Cu, Co) as ...

    Indian Academy of Sciences (India)

    improvement especially for an industrially important synthesis. We have presented here a systematic study involving the use of chitosan-based chemically modi- fied chitosan Schiff base-metal complex as a heteroge- neous catalyst for the oxidation of β-isophorone with excellent activity. The role of acetyl acetone and tri-.

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

    Science.gov (United States)

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

    2015-01-01

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

  6. Synthesis and photoluminescence properties of novel Schiff base type polymer-rare earth complexes containing furfural-based bidentate Schiff base ligands

    Science.gov (United States)

    Gao, Baojiao; Zhang, Dandan; Li, Yanbin

    2018-03-01

    Luminescent polymer-rare earth complexes are an important class of photoluminescence and electroluminescence materials. Via molecular design, two furfural-based bidentate Schiff base ligands, furfural-aniline (FA) type ligand and furfural-cyclohexylamine (FC) type ligand, were bonded on the side chains of polysulfone (PSF), respectively, forming two functionalized macromolecules, PSF-FA and PSF-FC. And then through respective coordination reactions of the two functionalized macromolecules with Eu(Ⅲ) ion and Tb(Ⅲ) ion, novel luminescent binary and ternary (with 1,10-phenanthroline as the second ligand) polymer-rare earth complexes were synthesized. For these complexes, on basis of the characterization of their chemical structures, they photoluminescence properties were main researched, and the relationship between their luminescent properties and structures was explored. The experimental results show that the complexes coming from PSF-FA and Eu(Ⅲ) ion including binary and ternary complexes emit strong red luminescence, indicating that the bonded bidentate Schiff base ligand FA can sensitize the fluorescence emission of Eu(III) ion. While the complexes coming from PSF-FC and Tb(Ⅲ) ion produce green luminescence, displaying that the bonded bidentate Schiff base ligand FC can sensitize the fluorescence emission of Tb(Ⅲ) ion. The fluorescence emission intensities of the ternary complexes were stronger than that of binary complexes, reflecting the important effect of the second ligand. The fluorescence emission of the solid film of complexes is much stronger than that of the solutions of complexes. Besides, by comparison, it is found that the furfural (as a heteroaromatic compound)-based Schiff base type polymer-rare earth complexes have stronger fluorescence emission and higher energy transfer efficiency than salicylaldehyde (as a common aromatic compound)-based Schiff base type polymer-rare earth complexes.

  7. Condensation Polymers of Terephthalic Acid and 1,4-Diaminobutane and Their Schiff Base Complexes

    Directory of Open Access Journals (Sweden)

    Sandeep Rai

    2013-01-01

    Full Text Available Amino-terminated oligomeric poly(tetramethylene terephthalamide (PTTA was prepared by condensation of terephthalic acid and 1,4-diaminobutane using phosphorylation technique. Schiff base complexes of this polyamide were synthesized with salicylaldehyde and 2-hydroxy-1-naphthaldehyde complexes of Co(II, Ni(II, and Cu(II. The polyamide as well as Schiff base complexes were characterized by elemental analysis, IR spectroscopy, and magnetic susceptibility measurements. Thermal stabilities of ligand and its various complexes were compared by thermogravimetric analysis.

  8. Schiff base ligand

    Indian Academy of Sciences (India)

    Unknown

    Schiff base; dicopper (II/II) complexes; imidazolidine-bridged; molecular mechanics; cy- ... nuclear complex of copper(II)–zinc(II) held by an ... ineffectiveness of the imidazolidine bridges in im- porting any magnetic communication between the two copper(II) centres has also been here established through EPR study. 2.

  9. Preparation and characterization of Schiff base Cu(II) complex and its applications on textile materials

    Science.gov (United States)

    Oylumluoglu, G.; Oner, J.

    2017-10-01

    Schiff base ligands are regarded as an important class of organic compounds on account of the fact that their complexation ability with transition metal ions. A new monomeric Schiff base Cu(II) complex, [Cu(HL)2], 1 [H2L = 2–((E)–(2–hydroxypropylimino)methyl)–4–nitrophenol] has been synthesized and characterized by elemental analysis, UV and IR spectroscopy, single crystal X-ray diffraction and photoluminescence study. While the Schiff base ligand and its Cu(II) complex are excited at λex = 349 nm in UV region, the Schiff base ligand shows a blue emission band at λmax = 480 nm whereas its Cu(II) complex shows a strong green emission band at λmax = 520 nm in the solid state at room temperature. The luminescent properties showed that the Schiff base ligand and its Cu(II) complex can be used as novel potential candidates for applications in textile such as UV-protection, antimicrobial, laundry and functional bleaching treatments.

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

    Science.gov (United States)

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

    2017-10-01

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

  11. Synthesis, spectroscopic characterization, DFT optimization and biological activities of Schiff bases and their metal (II) complexes

    Science.gov (United States)

    Rauf, Abdur; Shah, Afzal; Munawar, Khurram Shahzad; Khan, Abdul Aziz; Abbasi, Rashda; Yameen, Muhammad Arfat; Khan, Asad Muhammad; Khan, Abdur Rahman; Qureshi, Irfan Zia; Kraatz, Heinz-Bernhard; Zia-ur-Rehman

    2017-10-01

    A Novel Schiff base, 3-(((4-chlorophenyl)imino)methyl)benzene-1,2-diol (HL1) was successfully synthesized along with a structurally similar Schiff base 3-(((4-bromophenyl)imino)methyl)benzene-1,2-diol (HL2). Both the Schiff bases were used to synthesize their zinc (II) and cobalt (II) complexes. These compounds were characterized by FTIR, 1H NMR, 13C NMR and elemental analysis. Metal complexes were confirmed by TGA. Crystals of Schiff bases were also characterized by X-ray analysis and experimental parameters were found in line with the theoretical parameters. Quantum mechanical approach was also used to fine useful structural parameters and to ensure the geometry of metal complexes. The photometric behaviors of all the synthesized compounds were investigated in a wide pH range using BR buffers. The appearance of isosbestic points indicated the existence of Schiff bases in more than one isomeric form. Moreover, these compounds were screened for enzyme inhibition; antibacterial, cytotoxic and in vivo antidiabetic activities and compounds were found active against one or other activity. Results indicate that ZnL22 is a good inhibitor of alkaline phosphatase enzyme and possess highest potential against diabetes, blood cholesterol level and cancer cells. This effort just provides preliminary data for some biological properties. Further investigations are required to precisely determine mechanistic pathways of their use towards drug development.

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

    Indian Academy of Sciences (India)

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

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

    Indian Academy of Sciences (India)

    Copper(II) Schiff base complexes and their mixed thin layers with ZnO nanoparticles. MAGDALENA ... Keywords. Thin layer; ZnO nanoparticles; copper complexes; AFM; SEM; fluorescence. ... Zinc oxide was synthesized using a simple homogeneous precipitation method with zinc acetate as a starting material. Thin layers ...

  14. SCHIFF-BASE

    African Journals Online (AJOL)

    Preferred Customer

    Schiff bases due to structural varieties and unique characteristics are the most versatile studied ligands in coordination chemistry [1, 2] and their metal complexes play an important role in the development of inorganic chemistry [3]. A variety of applications, including biological [4, 5], analytical [6, 7] and industrial use as.

  15. Preparation, Characterization and Antibacterial Activity of Schiff base Ligand and their Complexes

    Directory of Open Access Journals (Sweden)

    Batool qusai

    2016-03-01

    Full Text Available A new Schiff base ligand has been synthesized from condensed 6.Amino Penicillinic acid with Benzyldehyde , then it mixed with number of the transition metal to form complexes. The newly prepared Schiff base ligand and metal complexes have been characterized by various techniques such as 1H NMR, 13C NMR , UV/ Visible, FT IR , Mass spectral ,Magnetic moment, molar conductance method , and it tested the effectiveness of inhibitory compounds prepared against four types of bacteria S.aureus , pseudomonas aeruginosa , Streptococcus Facials and Proteus Mirabils then it isolated from different classes of ulcerative infections.

  16. Synthesis, characterization and antibacterial studies of ruthenium(III) complexes derived from chitosan schiff base.

    Science.gov (United States)

    Vadivel, T; Dhamodaran, M

    2016-09-01

    Chitosan can be modified chemically by condensation reaction of deacetylated chitosan with aldehyde in homogeneous phase. This condensation is carried by primary amine (NH2) with aldehyde (CHO) to form corresponding schiff base. The chitosan biopolymer schiff base derivatives are synthesized with substituted aldehydes namely 4-hydroxy-3-methoxy benzaldehyde, 2-hydroxy benzaldehyde, and 2-hydroxy-3-methoxy benzaldehyde, becomes a complexing agent or ligand. The Ruthenium(III) complexes were obtained by complexation of Ruthenium with schiff base ligands and this product exhibits as an excellent solubility and more biocompatibility. The novel series of schiff base Ruthenium(III) complexes are characterized by Elemental analysis, FT-IR spectroscopy, and Thermo-gravimetric analysis (TGA). The synthesized complexes have been subjected to antibacterial study. The antibacterial results indicated that the antibacterial activity of the complexes were more effective against Gram positive and Gram negative pathogenic bacteria. These findings are giving suitable support for developing new antibacterial agent and expand our scope for applications. Copyright © 2015 Elsevier B.V. All rights reserved.

  17. A dinuclear dysprosium complex based on schiff base ligand: synthesis, structure and magnetic property

    Science.gov (United States)

    Hu, Peng; Xiao, Fengping; Wu, Lihuan; Chen, Zhisheng

    2017-12-01

    A novel dinuclear dysprosium complex, namely [Dy2 (L) 4 (COO) 2 (CH3OH)2] (1) (L = 2-hydroxy-3-methodxybenzaldehyde-5-bromo oxime), was synthesized, structurally and magnetically characterized. Single-crystal X-ray structural analysis reveals that complex 1 is neutral dinuclear complex, in which two Dy(III) ions with nine-coordinated environment are bridged by two phenoxide groups from two schiff base ligands and four O ions from two molecules of methanoic acid. The magnetic study of complex 1 indicates the slow relaxation of magnetization.

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

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Chemical Sciences; Volume 127; Issue 7. A novel dinuclear schiff base copper complex as an efficient and cost effective catalyst for oxidation of alcohol: Synthesis, crystal structure and theoretical studies. Atena Naeimi Samira Saeednia Mehdi Yoosefian Hadi Amiri Rudbari Viviana Mollica Nardo.

  19. STUDIES OF MN (II) AND NI (II) COMPLEXES WITH SCHIFF BASE ...

    African Journals Online (AJOL)

    DR. AMINU

    2010-06-01

    Jun 1, 2010 ... Department of Chemistry Bayero University, P. M. B. 3011, Kano, Nigeria. Correspondence author: hnuhu2000@yahoo.com. ABSTRACT. The complexes of Mn (II) and Ni (II) with Schiff base derived from salicylaldehyde and 2- aminobenzoic acid have been prepared and characterized by gravimetry, ...

  20. Vibration spectra of complexes of rare earth nitrate with some Schiff bases

    Science.gov (United States)

    Guofa, Liu

    1994-06-01

    Infrared and Raman spectra of complexes of rare earth nitrate with Schiff bases derived from vanillin (3-methoxy-4-hydroxy-benzaldehyde) or o-vanillin (2-hydroxy-3-methoxy-benzaldehyde) and p-toluidine, 1-naphthylamine, 2-naphthylamine are reported.

  1. Some Transition Metal Complexes of NO Type Schiff Base: Preparation and Characterization

    Directory of Open Access Journals (Sweden)

    Erdal CANPOLAT

    2016-04-01

    Full Text Available Metal complexes of Schiff base ligand (5-bromo-3-methoxysalicyliden-p-iminoacetophenone oxime derived from 5-bromo-3-methoxsalicylaldehyde and p-aminoacetophenoneoxime is reported. Schiff base was found to be bidentate ligand involving the imino nitrogen and carboxyl oxygen atoms in the complexes. Metal to ligand ratio were found to be 1:2 for all of the complexes. Co(II, Ni(II, and Zn(II complexes have been found tetrahedral geometry and Cu(II complex has been found four coordinated geometry. The complexes are found to have the formulae [M(L2]. The compounds obtained have been characterized by their elemental analyses, IR, 1H-NMR, 13C-NMR, UV spectra, magnetic susceptibility and thermogravimetric analyses (TGA.

  2. Transition Metal(II) Complexes with Cefotaxime-Derived Schiff Base: Synthesis, Characterization, and Antimicrobial Studies

    Science.gov (United States)

    Amzoiu, Emilia; Spînu, Cezar Ionuţ

    2014-01-01

    New [ML2(H2O)2] complexes, where M = Co(II), Ni(II), Cu(II), and Zn(II) while L corresponds to the Schiff base ligand, were synthesized by condensation of cefotaxime with salicylaldehyde in situ in the presence of divalent metal salts in ethanolic medium. The complexes were characterized by elemental analyses, conductance, and magnetic measurements, as well as by IR and UV-Vis spectroscopy. The low values of the molar conductance indicate nonelectrolyte type of complexes. Based on spectral data and magnetic moments, an octahedral geometry may be proposed for Co(II), Ni(II), and Zn(II) complexes while a tetragonal geometry for Cu(II) complex. Molecular structure of the Schiff base ligand and its complexes were studied using programs dedicated to chemical modeling and quantomolecular calculation of chemical properties. All the synthesized complexes were tested for in vitro antibacterial activity against some pathogenic bacterial strains, namely Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Bacillus subtilis, and Staphylococcus aureus. The MIC values shown by the complexes against these bacterial strains revealed that the metal complexes possess superior antibacterial activity than the Schiff base. PMID:24688454

  3. Studies of Some Lanthanide(III Nitrate Complexes of Schiff Base Ligands

    Directory of Open Access Journals (Sweden)

    Kishor Arora Mukesh Sharma

    2009-01-01

    Full Text Available The studies of 16 new lanthanide(III nitrate complexes of Schiff base ligands are discussed. Schiff bases were obtained by the condensation of 2–methyl–4–N,N–bis–2' –cyanoethyl aminobenzaldehyde with aniline and 3 different substituted anilines. Lanthanide(III nitrates, viz. gadolinium(III nitrate, lanthanum(III nitrate, samarium(III nitrate and cerium(III nitrate were chosen to synthesize new complexes. The complexes were characterized on the basis of physicochemical studies viz. elemental analysis, spectral, viz. IR and electronic spectral and magnetic studies. TGA studies of some of the representative complexes were also done. Some of the representative complexes were also screened for the anti microbial studies.

  4. Synthesis, physical characterization and biological evaluation of Schiff base M(II complexes

    Directory of Open Access Journals (Sweden)

    Mahasin Alias

    2014-04-01

    Full Text Available Metal (II complexes of Cu, Ni, and Co with Schiff base derived from potassium 2-N (4-N,N-dimethylaminobenzyliden- 4-trithiocarbonate 1,3,4-thiadiazole (L were synthesized and characterized by standard physico-chemical procedures i.e. (metal analysis A.A, elemental chemical analysis C.H.N.S, FTIR, UV–vis, thermal analysis TGA, magnetic susceptibility and conductometric measurements. On the basis of these studies, a six coordinated octahedral geometry for all these complexes has been proposed. The Schiff base ligand and its complexes were also tested for their antibacterial activity to assess their inhibiting potential against Pseudomonas aeruginosa (as gram negative bacteria and Staphylococcus aureus (as gram positive bacteria using two different concentrations (5 and 10 mM. The results showed the Ni(II complex have the higher rate in antibacterial activity than other complexes and ligand when compared them with ampicillin as standard drug.

  5. Synthesis and characterization of nickel complexes derived from Schiff-Bases

    Directory of Open Access Journals (Sweden)

    Mirian Y. Matsumoto

    2012-06-01

    Full Text Available Aromatic Schiff-Bases constitute a large class of organic compounds containing the imine group (C=N [1-3]. 2-hydroxybenzaldehyde (salicylaldehyde which has been frequently used for the synthesis of aromatic Schiff-Bases, it has many biological applications, such as analgesics, anti-inflammatory, antibacterial, antiviral and bactericidal activities [4-6]. From above, this project proposed the synthesis of three Schiff bases derived from salicylaldehyde prepared by condensation between salicylaldehyde with different p-substituted anilines (H, NO2 and MeO. Schiff-Bases synthesized were used as starting compound for the synthesis of nickel complexes. The synthesis of nickel complexes were carried out by adding of alcoholic solution of ligands (2 eq. in aqueous solution of NiCl2.6 H2O (1 eq. contain KOH (1eq. 3 hours. After thisMatsumoto et al. time, the reaction was kept to r.t. to obtain a precipitates. The precipitates were filtered under vacuum and they were characterized by GC-MS, FT-IR and UV-Vis

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

    Science.gov (United States)

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

    2014-12-01

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

  7. Tuning cobalt(III) Schiff base complexes as activated protein inhibitors.

    Science.gov (United States)

    Heffern, Marie C; Reichova, Viktorie; Coomes, Joseph L; Harney, Allison S; Bajema, Elizabeth A; Meade, Thomas J

    2015-09-21

    Cobalt(III) Schiff base complexes ([Co(acacen)(L)2](+), where L = NH3) inhibit histidine-containing proteins through dissociative exchange of the labile axial ligands (L). This work investigates axial ligand exchange dynamics of [Co(acacen)(L)2](+) complexes toward the development of protein inhibitors that are activated by external triggers such as light irradiation. We sought to investigate ligand exchange dynamics to design a Co(III) complex that is substitutionally inert under normal physiological conditions for selective activation. Fluorescent imidazoles (C3Im) were prepared as axial ligands in [Co(acacen)(L)2](+) to produce complexes (CoC3Im) that could report on ligand exchange and, thus, complex stability. These fluorescent imidazole reporters guided the design of a new dinuclear Co(III) Schiff base complex containing bridging diimidazole ligands, which exhibits enhanced stability to ligand exchange with competing imidazoles and to hydrolysis within a biologically relevant pH range. These studies inform the design of biocompatible Co(III) Schiff base complexes that can be selectively activated for protein inhibition with spatial and temporal specificity.

  8. Synthesis, characterization, and biological evaluation of Schiff base-platinum(II) complexes.

    Science.gov (United States)

    Shiju, C; Arish, D; Bhuvanesh, N; Kumaresan, S

    2015-06-15

    The platinum complexes of Schiff base ligands derived from 4-aminoantipyrine and a few substituted aldehydes were synthesized and characterized by elemental analysis, mass, (1)H NMR, IR, electronic spectra, molar conductance, and powder XRD. The structure of one of the ligands L5 was confirmed by a single crystal XRD analysis. The Schiff base ligand crystallized in the triclinic, space group P-1 with a=7.032(2)Ǻ, b=9.479(3)Ǻ, c=12.425(4)Ǻ, α=101.636(3)°, β=99.633(3)°, γ=94.040(3)°, V=795.0(4)Ǻ(3), Z=2, F(000)=352, Dc=1.405 mg/m(3), μ=0.099 mm(-1), R=0.0378, and wR=0.0967. The spectral results show that the Schiff base ligand acts as a bidentate donor coordinating through the azomethine nitrogen and the carbonyl oxygen atoms. The geometrical structures of these complexes are found to be square planar. Antimicrobial studies indicate that these complexes exhibit better activity than the ligand. The anticancer activities of the complexes have also been studied towards human cervical cancer cell line (HeLa), Colon Cancer Cells (HCT116) and Epidermoid Carcinoma Cells (A431) and it was found that the [Pt(L3)Cl2] complex is more active. Copyright © 2015 Elsevier B.V. All rights reserved.

  9. Synthesis and spectral studies of metal complexes of a Schiff base derived from (2-amino-5-chlorophenyl)phenyl methanone.

    Science.gov (United States)

    Mini, S; Sadasivan, V; Meena, S S; Bhatt, Pramod

    2015-01-01

    Some new complexes of Mn(II), Co(II), Ni(II), Cu(II), Zn(II), and Fe(III) with the Schiff base 5-chloro-2-(furan-2-yl methylamino)phenyl)phenyl methanone has been synthesized and characterized by elemental analysis, spectroscopic data including FT-IR, (1)H NMR, Electronic, ESI mass, Mössbauer & ESR. It has been found that the Schiff base behaves as a neutral bidentate N, O donor which chelates with the metal ions in 1:2 stoichiometry. Magnetic moment and electrolytic conductance data confirms this. The Schiff base and selected complexes were screened for antimicrobial activity. The complexes and the Schiff base were subjected to antioxidant study. The antitumor activity of Co(II) complex was tested by MTT assay. The result indicates the viability of the complex against tested cell lines. Copyright © 2015 Elsevier B.V. All rights reserved.

  10. ESI MS and PM5 semiempirical studies of gossypol schiff base with ( R)-tetrahydrofurfurylamine complexes and monovalent cations

    Science.gov (United States)

    Przybylski, Piotr; Włodarz, Magdalena; Schroeder, Grzegorz; Pankiewicz, Radosław; Brzezinski, Bogumil; Bartl, Franz

    2004-05-01

    Complexation of monovalent cations by a new Schiff base of gossypol with ( R)-tetrahydrofurfurylamine (GSTF) has been studied by ESI mass spectrometry as well as by PM5 semiempirical method. On the basis of ESI spectra it has been found that the new gossypol Schiff base forms only 1:1 complexes with all monovalent metal cations. With H + cation the Schiff base forms 1:1, 1:2 and 1:4 complexes. In the 1:1 and 1:2 complexes with protons, they are localised on the N atoms of the Schiff base. In the 1:4 complex two protons are localised on the N atoms and two other on the O atoms of the furan ring. In all complexes with protons the molecule exists in the imine-imine tautomeric form. The new Schiff base forms 1:1 complexes with monovalent cations, which occur in the enamine-enamine tautomeric form. The Li + and Na + cations in the complexes with GSTF are coordinated by oxygen atoms and N atoms of the Schiff base, whereas the K +, Rb + and Cs + cations are only coordinated by oxygen atoms. The structures of the complexes are calculated by PM5 semiempirical method and discussed.

  11. Cationic schiff base amphiphiles and their metal complexes: Surface and biocidal activities against bacteria and fungi.

    Science.gov (United States)

    Negm, N A; Zaki, M F; Salem, M A I

    2010-05-01

    A series of cationic surfactants containing schiff base groups was synthesized by condensation of four fatty amines namely: dodecyl, tetradecyl, hexadecyl and octadecyl amine and 4-diethyl aminobenzaldehyde (1-4), as well as their metal complexes with divalent transition metal ions including Co, Cu and Mn (5-16). The surface activities of the synthesized surfactants were influenced by their chemical structures and the type of the transition metals. The biological activity measurements of the parent cationic schiff bases showed high efficacy against Gram positive and Gram negative bacterial strains and fungi. While on complexation, the biocidal activity was increased remarkably. The biocidal activity of the tested compounds against sulfur reducing bacteria showed promising results in the field of biocide applications. 2010 Elsevier B.V. All rights reserved.

  12. Synthesis and DNA interaction of a Sm(III) complex of a Schiff base ...

    African Journals Online (AJOL)

    The interaction between the Sm(III) complex of an ionic Schiff base [HL]-, derived from vanillin and L-tryptophan, and herring sperm DNA at physiological pH (7.40) has been studied by UV-Vis absorption, fluorescence and viscosity methods. The binding ratios nSm(III) : nK[HL] = 1:1 and nSm(III)L: nDNA =5:1 were confirmed ...

  13. Lewis acidic zn(ii) schiff base complexes in homogeneous catalysis

    OpenAIRE

    Anselmo, Daniele

    2013-01-01

    The work described in this thesis shows studies towards new applications of Schiff base complexes in homogeneous catalysis . Specifically, we investigated “salen” ligands (including N2S2 chelating systems) and also examined other aspects that are generally considered important in the context of increasing the sustainability of chemical processes. Studies on the use of these Lewis acidic compounds in the catalysis of the fixation of carbon dioxide, multicomponent reactions for the synthesis of...

  14. Oxidation of benzoin catalyzed by oxovanadium(IV) schiff base complexes.

    Science.gov (United States)

    Alsalim, Tahseen A; Hadi, Jabbar S; Ali, Omar N; Abbo, Hanna S; Titinchi, Salam Jj

    2013-01-07

    The oxidative transformation of benzoin to benzil has been accomplished by the use of a wide variety of reagents or catalysts and different reaction procedures. The conventional oxidizing agents yielded mainly benzaldehyde or/and benzoic acid and only a trace amount of benzil. The limits of practical utilization of these reagents involves the use of stoichiometric amounts of corrosive acids or toxic metallic reagents, which in turn produce undesirable waste materials and required high reaction temperatures.In recent years, vanadium complexes have attracted much attention for their potential utility as catalysts for various types of reactions. Active and selective catalytic systems of new unsymmetrical oxovanadium(IV) Schiff base complexes for the oxidation of benzoin is reported. The Schiff base ligands are derived between 2-aminoethanol and 2-hydroxy-1-naphthaldehyde (H2L1) or 3-ethoxy salicylaldehyde (H2L3); and 2-aminophenol and 3-ethoxysalicylaldehyde (H2L2) or 2-hydroxy-1-naphthaldehyde (H2L4). The unsymmetrical Schiff bases behave as tridentate dibasic ONO donor ligands. Reaction of these Schiff base ligands with oxovanadyl sulphate afforded the mononuclear oxovanadium(IV) complexes (VIVOLx.H2O), which are characterized by various physico-chemical techniques.The catalytic oxidation activities of these complexes for benzoin were evaluated using H2O2 as an oxidant. The best reaction conditions are obtained by considering the effect of solvent, reaction time and temperature. Under the optimized reaction conditions, VOL4 catalyst showed high conversion (>99%) with excellent selectivity to benzil (~100%) in a shorter reaction time compared to the other catalysts considered. Four tridentate ONO type Schiff base ligands were synthesized. Complexation of these ligands with vanadyl(IV) sulphate leads to the formation of new oxovanadium(IV) complexes of type VIVOL.H2O.Elemental analyses and spectral data of the free ligands and their oxovanadium(IV) complexes were

  15. One-step electrochemical deposition of Schiff base cobalt complex as effective water oxidation catalyst

    Science.gov (United States)

    Huang, Binbin; Wang, Yan; Zhan, Shuzhong; Ye, Jianshan

    2017-02-01

    Schiff base metal complexes have been applied in many fields, especially, a potential homogeneous catalyst for water splitting. However, the high overpotential, time consumed synthesis process and complicated working condition largely limit their application. In the present work, a one-step approach to fabricate Schiff base cobalt complex modified electrode is developed. Microrod clusters (MRC) and rough spherical particles (RSP) can be obtained on the ITO electrode through different electrochemical deposition condition. Both of the MRC and RSP present favorable activity for oxygen evolution reaction (OER) compared to the commercial Co3O4, taking an overpotential of 650 mV and 450 mV to drive appreciable catalytic current respectively. The highly active and stable RSP shows a Tafel plot of 84 mV dec-1 and negligible decrease of the current density for 12 h bulk electrolysis. The synthesis strategy of effective and stable catalyst in this work provide a simple method to fabricate heterogeneous OER catalyst with Schiff base metal complex.

  16. Antibacterial evaluation of some Schiff bases derived from 2-acetylpyridine and their metal complexes.

    Science.gov (United States)

    Gwaram, Nura Suleiman; Ali, Hapipah Mohd; Khaledi, Hamid; Abdulla, Mahmood Ameen; Hadi, A Hamid A; Lin, Thong Kwai; Ching, Chai Lay; Ooi, Cher Lin

    2012-05-18

    A series of Schiff bases derived from 2-acetylpyridne and their metal complexes were characterized by elemental analysis, NMR, FT-IR and UV-Vis spectral studies. The complexes were screened for anti-bacterial activity against Methicillin-resistant Staphylococcus aureus (MRSA), Acinetobacter baumanni (AC), Klebsiella pneumonie (KB) and Pseudomonas aeruginosa (PA) using the disc diffusion and micro broth dilution assays. Based on the overall results, the complexes showed the highest activities against MRSA while a weak antibacterial activity was observed against A. baumanii and P. aeruginosa.

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

    Science.gov (United States)

    Singh, Lok P; Bhatnagar, Jitendra M

    2004-10-08

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

  18. Synthesis, characterization and biological activity of some unsymmetrical Schiff base transition metal complexes.

    Science.gov (United States)

    Esmadi, Fatima T; Khabour, Omar F; Abbas, Khamis; Mohammad, Abdel Elah; Obeidat, Ra'ad T; Mfady, Doa'a

    2016-01-01

    In this study, several unsymmetrical Schiff bases and their cobalt and manganese complexes have been synthesized and characterized. The unsymmetrical Schiff bases were prepared from reaction of o-phenylendiamine derivatives with 1-hydroxy-2-acetonaphthone and then the product was reacted with the following aldehydes: salicyaldehyde, 2-hydroxynaphthaldehyde, 2-pyridinecarboxaldehyde and 2-qinolinecarboxaldehyde to produce the desired tetradentate unsymmetrical Schiff base ligands H2SL, H2NL, HPYL and HQN, respectively. Reaction of these ligands with cobalt and manganese salts produced complexes of the general formula [M(SL)], [(NL)], [M(PYL)] and [M(QL)]. All the complexes were characterized by elemental analysis, infrared spectroscopy, UV-visible spectroscopy, electrical conductivity and magnetic susceptibility measurements. The prepared complexes were examined for their anti-bacterial activity using gram-positive and gram-negative pathogens. The following complexes showed strong antibacterial activity against Staphylococcus aureus: MnSL1, MnSL2 and MnSL3. The genotoxic activity of four complexes, which are MnNL1, MnSL1, CoNL1 and CoSL1, were examined using 8-hydroxy-2-deoxy guanosine (8-OHdG) assay in cultured human blood lymphocytes. All examined complexes were found to be genotoxic at examined concentrations (0.1-100 µg/mL), but with variable magnitudes (p  MnNL1 > CoSL1 > CoNL1. In conclusion, some of the prepared complexes showed some biological activities that might be of interest for future research.

  19. Zinc (II) complex with a cationic Schiff base ligand: synthesis, characterization, and biological studies.

    Science.gov (United States)

    Lee, Sze Koon; Tan, Kong Wai; Ng, Seik Weng; Ooi, Kah Kooi; Ang, Kok Pian; Abdah, Md Akim

    2014-01-01

    A cationic Schiff base ligand, TSB (L) and its Zn (II) complex (1) were synthesized and characterized by using CHN, (1)H-NMR, FT-IR, UV, LC-MS, and X-ray methods. Their ability to inhibit topoisomerase I, DNA cleavage activities, and cytotoxicity were studied. X-ray diffraction study shows that the mononuclear complex 1 is four coordinated with distorted tetrahedral geometry. The singly deprotonated Schiff base ligand L acts as a bidentate ON-donor ligand. Complexation of L increases the inhibitory strength on topoisomerase I activity. Complex 1 could fully inhibit topoisomerase I activity at 250 μM, while L did not show any inhibitory effect on topoisomerase I activity. In addition, L and complex 1 could cleave pBR322 DNA in a concentration and time dependent profile. Surprisingly, L has better DNA cleavage activity than complex 1. The cleavage of DNA by complex 1 is altered in the presence of hydrogen peroxide. Furthermore, L and complex 1 are mildly cytotoxic towards human ovarian cancer A2780 and hepatocellular carcinoma HepG2. Copyright © 2013 Elsevier B.V. All rights reserved.

  20. Metal complexes of Schiff base: Preparation, characterization and antibacterial activity

    Directory of Open Access Journals (Sweden)

    Emad Yousif

    2017-05-01

    Full Text Available A total of five new metal complex derivatives of 2N-salicylidene-5-(p-nitro phenyl-1,3,4-thiadiazole, HL with the metal ions Vo(II, Co(II, Rh(III, Pd(II and Au(III have been successfully prepared in alcoholic medium. The complexes obtained are characterized quantitatively and qualitatively by using micro elemental analysis, FTIR spectroscopy, UV–Vis spectroscopy, mass spectroscopy, 1H & 13C NMR, magnetic susceptibility and conductivity measurements. From the spectral study, all the complexes obtained as monomeric structure and the metals center moieties are four-coordinated with square planar geometry except VO(II and Co complexes which existed as a square pyramidal and tetrahedral geometry respectively. The preliminary in vitro antibacterial screening activity revealed that complexes 1–5 showed moderate activity against tested bacterial strains and slightly higher compared to the ligand, HL.

  1. Schiff base ligands and their transition metal complexes in the mixtures of ionic liquid + organic solvent: a thermodynamic study.

    Science.gov (United States)

    Shekaari, Hemayat; Kazempour, Amir; Khoshalhan, Maryam

    2015-01-21

    Schiff bases and their metal complexes in the mixtures of ionic liquid (IL) + organic solvent have shown great potential in attractive oxidation catalytic processes. The efficiency of such a process is strongly dependent on the various molecular interactions occurring between components. Thermodynamic properties of these systems can provide valuable information about structural interactions. Therefore, in this work, the interactions of the IL 1-hexyl-3-methylimidazolium chloride ([HMIm]Cl) with Schiff bases in organic solvents were studied through the measurements of density, viscosity, and electrical conductivity. The effect of solvent on the interactions was examined by the solutions of IL + BPIC Schiff base + solvent (C2H6O-C3H8O-C4H10O). Moreover, the influence of Schiff base ligand and Schiff base complex structures was probed by the solutions of IL + DMA + ligand (salcn/salpr/salen) and IL + DMA + complex (VO(3-OMe-salen)/VO(salophen)/VO(salen)), respectively. Using the experimental data, some important thermodynamic properties, such as standard partial molar volume (V(0)(φ,IL)), experimental slope (Sv), viscosity B-coefficient, solvation number (B/V(0)(φ,IL) and limiting molar conductivity (Λ0) were calculated and discussed in terms of solute-solvent (IL-DMF/alcohol) and solute-cosolute (IL-Schiff base) interactions.

  2. Syntheses and Characterization of Some Tetradentate Schiff-Base Complexes and Their Heteroleptic Analogues

    OpenAIRE

    Osowole, A. A.

    2008-01-01

    VO(IV), Ni(II) and Cu(II) complexes of the asymmetric Schiff base [(HOC6H3(OCH3)C(C6H5):N(CH2CH2)N:C(CH3)CH:C(C6H5)OH)], and their heteroleptic analogues with triphenyl phosphine and 2,2’-bipyridine have been synthesized and characterized by elemental analyses, conductance, magnetic, infrared and electronic spectral measurements. The ligand is tetradentate coordinating via the imine N and enolic O atoms. The Ni(II) and Cu(II) complexes adopt a four coordinate square planar geometry, the VO(I...

  3. Synthesis and characterization of chromium(III) Schiff base complexes: antimicrobial activity and its electrocatalytic sensing ability of catechol.

    Science.gov (United States)

    Kumar, S Praveen; Suresh, R; Giribabu, K; Manigandan, R; Munusamy, S; Muthamizh, S; Narayanan, V

    2015-03-15

    A series of acyclic Schiff base chromium(III) complexes were synthesized with the aid of microwave irradiation method. The complexes were characterized on the basis of elemental analysis, spectral analysis such as UV-Visible, Fourier transform infrared (FT-IR), nuclear magnetic resonance (NMR), electron paramagnetic resonance (EPR) spectroscopies and electrospray ionization (ESI) mass spectrometry. Electrochemical analysis of the complexes indicates the presence of chromium ion in +3 oxidation state. Cr (III) ion is stabilized by the tetradentate Schiff base ligand through its nitrogen and phenolic oxygen. From the spectral studies it is understood that the synthesized chromium(III) complexes exhibits octahedral geometry. Antimicrobial activity of chromium complexes was investigated towards the Gram positive and Gram negative bacteria. In the present work, an attempt was made to fabricate a new kind of modified electrode based on chromium Schiff base complexes for the detection of catechol at nanomolar level. Copyright © 2014 Elsevier B.V. All rights reserved.

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

    Indian Academy of Sciences (India)

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

  5. Synthesis and characterization of a Schiff base Cobalt (III) complex ...

    African Journals Online (AJOL)

    Cobalt (III) tris(azido)-2-Morpholino-N-(1-(2-pyridyl)ethylidene)ethanamine complex was synthesized, characterized and evaluated for in vitro anticancer activities. The chemical structure of the compound was assessed by elemental analysis, single crystal x-ray crystallography, FT-IR and UV-Visible spectroscopy.

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

    Indian Academy of Sciences (India)

    ARC

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

  7. Synthesis, characterization, anticancer activity, thermal and electrochemical studies of some novel uranyl Schiff base complexes

    Energy Technology Data Exchange (ETDEWEB)

    Asadi, Zahra; Asadi, Mozaffar; Firuzabadi, Fahimeh Dehghani [Shiraz Univ. (Iran, Islamic Republic of). Dept. of Chemistry; Yousefi, Reza; Jamshidi, Mehrnaz [Shiraz Univ. (Iran, Islamic Republic of). Protein Chemistry Lab. (PCL)

    2014-04-15

    Some tetradentate N{sub 2}O{sub 2} Schiff base ligands, such as N,N{sup '}-bis(naphtalidene)-1,2-phenylenediamine, N,N{sup '}-bis(naphtalidene)-4-methyl-1,2-phenylenediamine, N,N{sup '}-bis(naphtalidene)-4-chloro-1,2-phenylenediamine, N,N{sup '}-bis(naphtalidene)-4-nitro-1,2-phenylenediamine, N,N{sup '}-bis(naphtalidene)-4-carboxyl-1,2-phenylenediamine, and their uranyl complexes were synthesized and characterized by {sup 1}H NMR, IR, UV-Vis spectroscopy, TG (thermogravimetry), and elemental analysis (C.H.N.). Thermogravimetric analysis shows that uranyl complexes have very different thermal stabilities. This method is used also to establish that only one solvent molecule is coordinated to the central uranium ion and this solvent molecule does not coordinate strongly and is removed easier than the tetradentate ligand and also trans oxides. The electrochemical properties of the uranyl complexes were investigated by cyclic voltammetry. Electrochemistry of these complexes showed a quasireversible redox reaction without any successive reactions. Also, the kinetic parameters of thermal decomposition were calculated using Coats-Redfern equation. According to Coats-Redfern plots the kinetics of thermal decomposition of the studied complexes is first-order in all stages. Anticancer activity of the uranyl Schiff base complexes against cancer cell lines (Jurkat) was studied and determined by MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazoliumbromide) assay.

  8. Synthesis, characterization and biological studies on some metal complexes with Schiff base ligand containing pyrazolone moiety

    Directory of Open Access Journals (Sweden)

    M. Sivasankaran Nair

    2016-09-01

    Full Text Available 1:2 Complexes of Co(II, Ni(II, Cu(II and Zn(II with the Schiff base ligand Indal-4-AAP, derived from indole-3-carboxaldehyde and 4-aminoantipyrine were synthesized and characterized by elemental analyses, mass, IR, electronic spectra, magnetic moment, molar conductance and cyclic voltammetry. The complexes were found to have the general formulae [ML2Cl2] (M = Co(II, Ni(II, Cu(II and Zn(II. The IR results demonstrate that the co-ordination sites are the azomethine nitrogen and carbonyl oxygen atoms of the Schiff base ligand. The electronic spectral and magnetic measurement data indicate that the complexes exhibit octahedral geometry around the metal center. The in vitro biological screening effects of the synthesized compounds were tested against various microbial species and the results show that the metal complexes are more biologically active than the ligand. The DNA cleavage activity of the ligand and its complexes was assayed on pUC18 DNA using gel electrophoresis. The result shows that Ni(II, Cu(II, and Zn(II complexes have completely cleaved the DNA.

  9. Antimicrobial, spectral and thermal studies of divalent cobalt, nickel, copper and zinc complexes with triazole Schiff bases

    Directory of Open Access Journals (Sweden)

    Kiran Singh

    2017-02-01

    Full Text Available Co(II, Ni(II, Cu(II and Zn(II complexes of bidentate Schiff bases derived from the condensation of 4-amino-5-mercapto-3-methyl/ethyl-1,2,4-triazole with 5-nitrofurfuraldehyde were synthesized and tested as antimicrobial agents. The Schiff bases and their metal complexes were characterized by elemental analyses, magnetic moment measurements, spectroscopic (IR, Electronic, 1H NMR, ESR and thermogravimetric analyses. A square planar geometry for Cu(II and octahedral geometry for Co(II, Ni(II and Zn(II complexes have been proposed. The presence of coordinated water in metal complexes was confirmed by thermal and IR data of the complexes. The Schiff bases and their metal complexes have been screened for antibacterial [Pseudomonas aeruginosa, Bacillus subtilis, Escherichia coli, Staphylococcus aureus] and antifungal activities [Aspergillus niger, A. flavus].

  10. Effect of Schiff base Cu(II) complexes on signaling pathways in HT-29 cells.

    Science.gov (United States)

    Koňariková, Katarína; Perdikaris, Georgios A; Gbelcova, Helena; Andrezálová, Lucia; Švéda, Martin; Ruml, Tomáš; Laubertová, Lucia; Žitňanová, Ingrid

    2016-11-01

    Schiff base copper (II) complexes are known for their anticancer, antifungal, antiviral and anti‑inflammatory activities. The aim of the current study was to investigate biological effects of Schiff base Cu (II) complexes (0.001‑100 µmol/l)‑[Cu2(sal‑D, L‑glu)2(isoquinoline)2]·2C2H5OH (1), [Cu(sal‑5‑met‑L‑glu)(H2O)].H2O (2), [Cu(ethanol)2(imidazole)4][Cu2(sal‑D, L-glu)2(imidazole)2] (3), [Cu(sal‑D,L‑glu)(2‑methylimidazole)] (4) on the human colon carcinoma cells HT‑29, the mouse noncancerous cell line NIH‑3T3 and the human noncancerous fibroblast cell line VH10. The results suggested that Cu (II) complexes exhibit cytotoxic effects against the HT‑29 cell line, while complexes 3 and 4 were the most effective. Subsequent to 72 h of incubation, apoptosis was observed in the HT‑29 cells induced by Cu (II) complexes 1 (0.1, 1, 10 and 50 µmol/l), 2 (1, 10, 50 and 100 µmol/l), 3 (0.01, 1, 10 and 50 µmol/l) and 4 (0.01, 0.1, 1 and 10 µmol/l). The apoptotic pathways activated by the Cu (II) complexes were identified. The results indicated that complexes 2, 3 and 4 were able to induce the mitochondria‑dependent pathway of apoptosis in HT‑29 cells, while complex 1 was obsered to activate the extrinsic pathway of apoptosis. The levels of the anti‑apoptotic protein Bcl‑2 were reduced and those of the pro‑apoptotic protein Bax increased following treatment with complexes 2, 3 and 4. Complex 1 had no effect on Bax protein expression. Complexes 2 and 3 induced elevation of cytochrome c (cyt c), while complex 4 induced a time‑dependent elevation of cyt c levels. No cyt c was detected in HT‑29 cells exposed to complex 1, suggesting that Cu (II) complexes activated the extrinsic pathway of apoptosis. The results from the current study in addition to previous studies suggest that Schiff base Cu (II) complexes have potential as novel anticancer drugs.

  11. Synthesis, spectroscopic characterization and antibacterial studies of lanthanide(III) Schiff base complexes containing N, O donor atoms

    Science.gov (United States)

    Lekha, L.; Raja, K. Kanmani; Rajagopal, G.; Easwaramoorthy, D.

    2014-01-01

    A series of six Ln(III) Schiff base complexes, Pr(III), Sm(III), Gd(III), Tb(III), Er(III) and Yb(III), were synthesized using sodium salt of Schiff base, 2-[(5-bromo-2-hydroxy-benzylidene)-amino]-3-hydroxy-propionic acid, derived from L-serine and 5-bromosalicylaldehyde. These complexes having general formula [Ln(L)(NO3)2(H2O)]·NO3 were characterized by elemental analysis, conductivity measurements, UV-Vis, FT-IR, mass spectrometry and fluorescence studies. Elemental analysis and conductivity measurements suggest the complexes have a 1:1 stoichiometry. From the spectral studies it has been concluded that Ln(III) complexes display eight coordination. The Schiff base and its Ln(III) metal complexes have also been screened for their antibacterial activities by Agar diffusion method.

  12. Exploring DNA binding and nucleolytic activity of few 4-aminoantipyrine based amino acid Schiff base complexes: a comparative approach.

    Science.gov (United States)

    Raman, N; Sakthivel, A; Pravin, N

    2014-05-05

    A series of novel Co(II), Cu(II), Ni(II) and Zn(II) complexes were synthesized from Schiff base(s), obtained by the condensation of 4-aminoantipyrine with furfural and amino acid (glycine(L1)/alanine(L2)/valine(L3)) and respective metal(II) chloride. Their structural features and other properties were explored from the analytical and spectral methods. The binding behaviors of the complexes to calf thymus DNA were investigated by absorption spectra, viscosity measurements and cyclic voltammetry. The intrinsic binding constants for the above synthesized complexes are found to be in the order of 10(2) to 10(5) indicating that most of the synthesized complexes are good intercalators. The binding constant values (Kb) clearly indicate that valine Schiff-base complexes have more intercalating ability than alanine and glycine Schiff-base complexes. The results indicate that the complexes bind to DNA through intercalation and act as efficient cleaving agents. The in vitro antibacterial and antifungal assay indicates that these complexes are good antimicrobial agents against various pathogens. The IC50 values of [Ni(L1)2] and [Zn(L1)2] complexes imply that these complexes have preferable ability to scavenge hydroxyl radical. Copyright © 2014 Elsevier B.V. All rights reserved.

  13. Design, spectral characterization and biological studies of transition metal(II) complexes with triazole Schiff bases

    Science.gov (United States)

    Hanif, Muhammad; Chohan, Zahid H.

    2013-03-01

    A new series of three biologically active triazole derived Schiff base ligands L1-L3 have been synthesized in equimolar reaction of 3-amino-1H-1,2,4-triazole with pyrrol-2-carboxaldehyde, 4-bromo-thiophene-2-carboxaldehyde, and 5-iodo-2-hydroxy benzaldehyde. The prepared Schiff bases were used for further complex formation reaction with different metal elements like Co(II), Ni(II), Cu(II) and Zn(II) as chlorides by using a molar ratio of ligand:metal as 2:1. The structure and bonding nature of all the compounds were identified by their physical, spectral and analytical data. All the metal(II) complexes possessed an octahedral geometry except the Cu(II) complexes which showed a distorted octahedral geometry. All the synthesized compounds, were studied for their in vitro antibacterial, and antifungal activities, against four Gram-negative (Escherichia coli, Shigella sonnei, Pseudomonas aeruginosa and Salmonella typhi) and two Gram-positive (Bacillus subtilis and Staphylococcus aureus) bacterial strains and against six fungal strains (Trichophyton longifusus, Candida albicans, Aspergillus flavus, Microsporum canis, Fusarium solani and Candida glabrata) by using agar-well diffusion method. It has been shown that all the synthesized compounds showed moderate to significant antibacterial activity against one or more bacterial strains. In vitro Brine Shrimp bioassay was also carried out to investigate the cytotoxic properties of these compounds. The data also revealed that the metal complexes showed better activity than the ligands due to chelation/coordination.

  14. The Zinc-Schiff Base-Novicidin Complex as a Potential Prostate Cancer Therapy

    Science.gov (United States)

    Milosavljevic, Vedran; Haddad, Yazan; Merlos Rodrigo, Miguel Angel; Moulick, Amitava; Polanska, Hana; Hynek, David; Heger, Zbynek; Kopel, Pavel; Adam, Vojtech

    2016-01-01

    Prostate cancer cells control energy metabolism by chelating intracellular zinc. Thus, zinc delivery has been a popular therapeutic approach for prostate cancer. Here, we propose the use of the membrane-penetrating peptide Novicidin connected to zinc-Schiff base as a carrier vehicle for the delivery of zinc to prostate cells. Mass spectrometry, electrochemistry and spectrophotometry confirmed the formation/stability of this complex and provided insight regarding the availability of zinc for complex interactions. This delivery system showed minor toxicity in normal PNT1A cells and high potency towards PC3 tumor cells. The complex preferentially penetrated PC3 tumor cells in contrast to confinement to the membranes of PNT1A. Furthermore, zinc uptake was confirmed in both cell lines. Molecular analysis was used to confirm the activation of zinc stress (e.g., ZnT-1) and apoptosis (e.g., CASP-1). Our results strongly suggest that the zinc-Schiff base-Novicidin complex has great potential as a novel anticancer drug. PMID:27727290

  15. Synthesis, characterization and toxicity studies of pyridinecarboxaldehydes and L-tryptophan derived Schiff bases and corresponding copper (II) complexes

    Science.gov (United States)

    Malakyan, Margarita; Babayan, Nelly; Grigoryan, Ruzanna; Sarkisyan, Natalya; Tonoyan, Vahan; Tadevosyan, Davit; Matosyan, Vladimir; Aroutiounian, Rouben; Arakelyan, Arsen

    2016-01-01

    Schiff bases and their metal-complexes are versatile compounds exhibiting a broad range of biological activities and thus actively used in the drug development process. The aim of the present study was the synthesis and characterization of new Schiff bases and their copper (II) complexes, derived from L-tryptophan and isomeric (2-; 3-; 4-) pyridinecarboxaldehydes, as well as the assessment of their toxicity in vitro. The optimal conditions of the Schiff base synthesis resulting in up to 75-85% yield of target products were identified. The structure-activity relationship analysis indicated that the location of the carboxaldehyde group at 2-, 3- or 4-position with regard to nitrogen of the pyridine ring in aldehyde component of the L-tryptophan derivative Schiff bases and corresponding copper complexes essentially change the biological activity of the compounds. The carboxaldehyde group at 2- and 4-positions leads to the higher cytotoxic activity, than that of at 3-position, and the presence of the copper in the complexes increases the cytotoxicity. Based on toxicity classification data, the compounds with non-toxic profile were identified, which can be used as new entities in the drug development process using Schiff base scaffold. PMID:28344771

  16. Synthesis, experimental and theoretical characterizations of a new Schiff base derived from 2-pyridincarboxaldehyde and its Ni (II) complex

    Science.gov (United States)

    Habibi, Mohammad; Beyramabadi, S. Ali; Allameh, Sadegh; Khashi, Maryam; Morsali, Ali; Pordel, Mehdi; Khorsandi-Chenarboo, Mahdi

    2017-09-01

    In this work, a tridentate Schiff base of 2-pyridinecarboxaldehyde and its Ni(II) complex have been newly synthesized and characterized by the IR and NMR spectroscopies together with the elemental analysis. In addition, optimized geometries, the Natural Bond Orbital (NBO) analyses, assignment of the IR bands and NMR chemical shifts of the synthesized compounds were computed by using density functional theory (DFT) methods. In the optimized geometry of the free ligand, the aromatic rings are not in the same plane. But, the Ni complex is square planar, where the deprotonated Schiff base acts as a N3-tridentate ligand. The chloro ligand occupies another coordination position of the complex. The DFT-calculated vibrational wavenumbers and NMR chemical shifts are in agreement with the experimental values, confirming suitability of the optimized geometries for the Schiff base and Ni(II) complex.

  17. A gallium(III) Schiff base-curcumin complex that binds to amyloid-β plaques.

    Science.gov (United States)

    Lange, Jaclyn L; Hayne, David J; Roselt, Peter; McLean, Catriona A; White, Jonathan M; Donnelly, Paul S

    2016-09-01

    Gallium-68 is a positron-emitting isotope that can be used in positron-emission tomography imaging agents. Alzheimer's disease is associated with the formation of plaques in the brain primarily comprised of aggregates of a 42 amino acid protein called amyloid-β. With the goal of synthesising charge neutral, low molecular weight, lipophilic gallium complexes with the potential to cross the blood-brain barrier and bind to Aβ plaques we have used an ancillary tetradentate N2O2 Schiff base ligand and the β-diketone curcumin as a bidentate ligand to give a six-coordinate Ga3+ complex. The tetradentate Schiff base ligand adopts the cis-β configuration with deprotonated curcumin acting as a bidentate ligand. The complex binds to amyloid-β plaques in human brain tissue and it is possible that extension of this chemistry to positron-emitting gallium-68 could provide useful imaging agents for Alzheimer's disease. Copyright © 2016 Elsevier Inc. All rights reserved.

  18. Synthesis and characterization of thorium(IV) and uranium(IV) complexes with Schiff bases

    Energy Technology Data Exchange (ETDEWEB)

    Radoske, Thomas; Maerz, Juliane; Kaden, Peter; Patzschke, Michael; Ikeda-Ohno, Atsushi [Helmholtz-Zentrum Dresden-Rossendorf e.V., Dresden (Germany). Chemistry of the F-Elements

    2017-06-01

    We report herein the synthesis and characterization of several imine complexes of tetravalent thorium (Th(IV)) and uranium (U(IV)). The ligands investigated in this study are a Schiff base type, including the well-known salen ligand (H{sub 2}Le, Fig. 1). The complexation in solution was investigated by NMR measurements indicating paramagnetic effects of unpaired f-electrons of U(IV) on the ligand molecule. We also determined the solid-state molecular structures of the synthesized complexes by single crystal X-ray diffraction. The synthesized complexes show an eight-fold coordination geometry around the actinide center surrounded by two tetradentate ligands with 2N- and 2O-donor atoms.

  19. Syntheses and Characterization of Some Tetradentate Schiff-Base Complexes and Their Heteroleptic Analogues

    Directory of Open Access Journals (Sweden)

    A. A. Osowole

    2008-01-01

    Full Text Available VO(IV, Ni(II and Cu(II complexes of the asymmetric Schiff base [(HOC6H3(OCH3C(C6H5:N(CH2CH2N:C(CH3CH:C(C6H5OH], and their heteroleptic analogues with triphenyl phosphine and 2,2’-bipyridine have been synthesized and characterized by elemental analyses, conductance, magnetic, infrared and electronic spectral measurements. The ligand is tetradentate coordinating via the imine N and enolic O atoms. The Ni(II and Cu(II complexes adopt a four coordinate square planar geometry, the VO(IV complex is five coordinate square-pyramidal and the heteroleptic complexes are 6-coordinate, octahedral. The assignment of geometry is collaborated by magnetic moments and electronic spectra measurements. The compounds are non-electrolyte in nitromethane and are magnetically dilute.

  20. In vitro antibacterial, antifungal and cytotoxic activities of some triazole Schiff bases and their oxovanadium(IV) complexes.

    Science.gov (United States)

    Sumrra, Sajjad H; Chohan, Zahid H

    2013-12-01

    The condensation reaction of 3,5-diamino-1,2,4-triazole with methoxy-, chloro-, bromo-, iodo- and nitro-substituted 2-hydroxybenzaldehydes formed triazole Schiff bases (L(1))-(L(6)). The synthesized ligands have been characterized through physical, spectral and analytical data. Furthermore, the reaction of synthesized Schiff bases with the oxovanadium(IV) sulphate in (1:2) (metal:ligand) molar ratio afforded the oxovanadium(IV) complexes (1)-(6). All the complexes were non-electrolytic and showed a square-pyramidal geometry. The synthesized compounds have been screened for in-vitro antibacterial, antifungal and brine shrimp bioassay. The bioactivity data showed the complexes to be more active than the original Schiff bases.

  1. Synthesis, characterization and antibacterial activity of a tridentate Schiff base derived from cephalothin and sulfadiazine, and its transition metal complexes.

    Science.gov (United States)

    Anacona, J R; Noriega, Natiana; Camus, Juan

    2015-02-25

    Metal(II) coordination compounds of a cephalothin Schiff base (H2L) derived from the condensation of cephalothin antibiotic with sulfadiazine were synthesized. The Schiff base ligand, mononuclear [ML(H2O)3] (M(II)=Mn,Co,Ni,Zn) complexes and magnetically diluted dinuclear copper(II) complex [CuL(H2O)3]2 were characterized by several techniques, including elemental and thermal analysis, molar conductance and magnetic susceptibility measurements, electronic, FT-IR, EPR and (1)H NMR spectral studies. The cephalothin Schiff base ligand H2L behaves as a dianionic tridentate NOO chelating agent. The biological applications of complexes have been studied on two bacteria strains (Escherichia coli and Staphylococcus aureus) by agar diffusion disc method. Copyright © 2014 Elsevier B.V. All rights reserved.

  2. Synthesis, characterization and antibacterial activity of a Schiff base derived from cephalexin and sulphathiazole and its transition metal complexes.

    Science.gov (United States)

    Anacona, J R; Rodriguez, Juan Luis; Camus, Juan

    2014-08-14

    Metal(II) coordination compounds of a cephalexin Schiff base (HL) derived from the condensation of cephalexin antibiotic with sulphathiazole were synthesized. The Schiff base ligand, mononuclear [ML(OAc)(H2O)2] (M(II)=Mn, Co, Ni, Zn) complexes and magnetically diluted trinuclear copper(II) complex [Cu3L(OH)5] were characterized by several techniques, including elemental and thermal analysis, molar conductance and magnetic susceptibility measurements, electronic, FT-IR, EPR and (1)H NMR spectral studies. The analytical and molar conductance values indicated that the acetate ions coordinate to the metal ions. The Schiff base ligand HL behaves as a monoanionic tridentate NNO and tetradentate NNOO chelating agent in the mono and trinuclear complexes respectively. Copyright © 2014 Elsevier B.V. All rights reserved.

  3. Antibacterial Evaluation of Some Schiff Bases Derived from 2-Acetylpyridine and Their Metal Complexes

    Directory of Open Access Journals (Sweden)

    Thong Kwai Lin

    2012-05-01

    Full Text Available A series of Schiff bases derived from 2-acetylpyridne and their metal complexes were characterized by elemental analysis, NMR, FT-IR and UV-Vis spectral studies. The complexes were screened for anti-bacterial activity against Methicillin-resistant Staphylococcus aureus (MRSA, Acinetobacter baumanni (AC, Klebsiella pneumonie (KB and Pseudomonas aeruginosa (PA using the disc diffusion and micro broth dilution assays. Based on the overall results, the complexes showed the highest activities against MRSA while a weak antibacterial activity was observed against A. baumanii and P. aeruginosa.

  4. Bioinorganic Relevance of Some Cobalt(II Complexes with Thiophene-2-glyoxal Derived Schiff Bases

    Directory of Open Access Journals (Sweden)

    Prashant Singh

    2009-01-01

    Full Text Available Complexes of Co(II with two new Schiff bases TEAB [2-hydroxy-4-{[2-oxo-2-(thiophen-2-ylethylidene]amino}benzoic acid] and TEPC [N-[2-oxo-2-(thiophen-2-ylethylidene]pyridine-3-carboxamide] have been synthesized and characterized with the help of elemental analysis, magnetic, mass, 1H-NMR, 13C-NMR, IR and electronic spectral data. IR spectra manifest the coordination of the ligand to the metal ion through the carbonyl oxygen, azomethine nitrogen and thienyl sulphur atoms. With the help of electronic spectral data various ligand field parameters were also calculated. All these studies reveal the distorted octahedral Co(II complexes. Synthesized compounds have also been screened against some micro organisms viz, Escherichia coli, Proteus vulgaris, Aspergillus niger and Aspergillus flavus with the help of ‘filter paper disc’ technique. It has been observed that the antimicrobial activities of metal complexes are higher than that of the free ligand.

  5. Antibacterial activity of Pd(II) complexes with salicylaldehyde-amino acids Schiff bases ligands.

    Science.gov (United States)

    Rîmbu, Cristina; Danac, Ramona; Pui, Aurel

    2014-01-01

    Palladium(II) complexes with Schiff bases ligands derived from salicylaldehyde and amino acids (Ala, Gly, Met, Ser, Val) have been synthesized and characterized by Fourier transform (FT)-IR, UV-Vis and (1)H-NMR spectroscopy. The electrospray mass spectrometry (ES-MS) spectrometry confirms the formation of palladium(II) complexes in 1/2 (M/L) molar ratio. All the Pd(II) complexes 1, [Pd(SalAla)2]Cl2; 2, [Pd(SalGly)2]Cl2; 3, [Pd(SalMet)2]Cl2; 4, [Pd(SalSer)2]Cl2; 5, [Pd(SalVal)2]Cl2; have shown antibacterial activity against Gram-positive bacteria Staphylococcus aureus and Gram-negative bacteria Escherichia coli.

  6. Mössbauer study of novel iron(II) complexes synthesized with Schiff bases

    Science.gov (United States)

    Várhelyi, Cs.; Lengyel, A.; Homonnay, Z.; Szalay, R.; Pokol, Gy.; Szilágyi, I.-M.; Huszthy, P.; Papp, J.; Goga, F.; Golban, L.-M.; Várhelyi, M.; Tomoaia-Cotisel, M.; Szőke, Á.; Kuzmann, E.

    2017-11-01

    Novel [Fe(4-benzyl-2-hydroxyphenyl-propylidene)2ethylene-diamine], and [Fe (2,4,6-trihydroxy-benzyl-4-metoxiphenyl-methylidene)2ethylene-diamine] complexes were synthesized by reacting FeII salt with the indicated Schiff-base ligands. The compounds were characterized by57Fe Mössbauer spectroscopy, FTIR, UV-VIS, TG-DTA-DTG, MS, AFM, XRD, cyclic voltammetry and biological activity measurements. 295 K and 78 K Mössbauer spectra revealed that iron is dominantly in high spin FeII state in both complexes while simultaneously a minor low spin FeII was also present in both complexes, furthermore a minor high spin FeIII was observed in [Fe(2,4,6-trihydroxy-benzyl-4-metoxiphenyl- methylidene) 2ethylene-diamine], too.

  7. Metal complexes of ONO donor Schiff base ligand as a new class of bioactive compounds: synthesis, characterization and biological evolution.

    Science.gov (United States)

    Kumar Naik, K H; Selvaraj, S; Naik, Nagaraja

    2014-10-15

    Present work reviews that, the synthesis of (E)-N'-((7-hydroxy-4-methyl-2-oxo-2H-chromen-8-yl)methylene)benzohydrazide [L] ligand and their metal complexes. The colored complexes were prepared of type [M(2+)L]X2, where M(2+)=Mn, Co, Ni, Cu, Sr and Cd, L=(7-hydroxy-4-methyl-2-oxo-2H-chromen-8-yl)methylene)benzohydrazide, X=Cl(-). Ligand derived from the condensation of 8-formyl-7-hydroxy-4-methylcoumarin and benzohydrazide in the molar ratio 1:1 and in the molar ratio 1:2 for metal complexes have been prepared. The chelation of the ligand to metal ions occurs through the both oxygen groups, as well as the nitrogen atoms of the azomethine group of the ligand. Reactions of the Schiff base ligand with Manganese(II), Cobalt(II), Nickel(II), Copper(II), Strontium(II), and Cadmium(II) afforded the corresponding metal complexes. The structures of the obtained ligand and their respective metal complexes were elucidated by infra-red, elemental analysis, Double beam UV-visible spectra, conductometric measurements, magnetic susceptibility measurements and also thermochemical studies. The metal complex exhibits octahedral coordination geometrical arrangement. Schiff base ligand and their metal complexes were tested against antioxidants, antidiabetic and antimicrobial activities have been studied. The Schiff base metal complexes emerges effective α-glucosidase inhibitory activity than free Schiff base ligand. Copyright © 2014 Elsevier B.V. All rights reserved.

  8. Metal complexes of ONO donor Schiff base ligand as a new class of bioactive compounds; Synthesis, characterization and biological evolution

    Science.gov (United States)

    Kumar Naik, K. H.; Selvaraj, S.; Naik, Nagaraja

    2014-10-01

    Present work reviews that, the synthesis of (E)-N";-((7-hydroxy-4-methyl-2-oxo-2H-chromen-8-yl)methylene)benzohydrazide [L] ligand and their metal complexes. The colored complexes were prepared of type [M2+L]X2, where M2+ = Mn, Co, Ni, Cu, Sr and Cd, L = (7-hydroxy-4-methyl-2-oxo-2H-chromen-8-yl)methylene)benzohydrazide, X = Cl-. Ligand derived from the condensation of 8-formyl-7-hydroxy-4-methylcoumarin and benzohydrazide in the molar ratio 1:1 and in the molar ratio 1:2 for metal complexes have been prepared. The chelation of the ligand to metal ions occurs through the both oxygen groups, as well as the nitrogen atoms of the azomethine group of the ligand. Reactions of the Schiff base ligand with Manganese(II), Cobalt(II), Nickel(II), Copper(II), Strontium(II), and Cadmium(II) afforded the corresponding metal complexes. The structures of the obtained ligand and their respective metal complexes were elucidated by infra-red, elemental analysis, Double beam UV-visible spectra, conductometric measurements, magnetic susceptibility measurements and also thermochemical studies. The metal complex exhibits octahedral coordination geometrical arrangement. Schiff base ligand and their metal complexes were tested against antioxidants, antidiabetic and antimicrobial activities have been studied. The Schiff base metal complexes emerges effective α-glucosidase inhibitory activity than free Schiff base ligand.

  9. Infrared and Raman spectra of complexes about rare earth nitrate with Schiff base from o-vanillin and 1-naphthylamine

    Science.gov (United States)

    Guofa, Liu; Tongshun, Shi; Yongnian, Zhao

    1997-07-01

    Infrared and Raman spectra are reported for 10 complexes of rare earth nitrate with Schiff base from o-vanillin (2-hydroxy-3-methoxy-benzaldehyde) and 1-naphthylamine in the range 100-4000 cm -1 and 100-1799 cm -1. Some absorption bands are assigned and the results of them are used to discuss the coordinated structure of the complexes.

  10. Derivatives of phosphate Schiff base transition metal complexes: synthesis, studies and biological activity

    Science.gov (United States)

    El-Wahab, Z. H. Abd; El-Sarrag, M. R.

    2004-01-01

    We report the synthesis and structural characterization of series of tetra- and hexacoordinate metal chelate complexes of phosphate Schiff base ligands having the general composition LMX n·H 2O and L 2MX n (L=phosphate Schiff base ligand; M=Ag +, Mn 2+, Cu 2+, Zn 2+, Cd 2+, Hg 2+, or Fe 3+ and X=NO 3-, Br - or Cl -). The structure of the prepared compounds was investigated using elemental analysis, IR, 1H and 31P NMR, UV-vis, mass spectra, solid reflectance, magnetic susceptibility and conductance measurements as well as conductometric titration. In all the complexes studied, the ligands act as a chelate ligand with coordination involving the phosphateO-atom and the azomethineN-atom. IR, solid reflectance spectra and magnetic moment measurement are used to infer the structure and to illustrate the coordination capacity of ligand. IR spectra show the presence of coordinated nitrate and water molecule, the magnetic moments of all complexes show normal magnetic behavior and the electronic spectra of the metal complexes indicate a tetra- and octahedral structure for Mn 2+, octahedral structure of Fe 3+ and both square-planar and distorted octahedral structure for Cu 2+ complexes. Antimicrobial activity of the ligands and their complexes were tested using the disc diffusion method and the chosen strains include Staphylococcus aureus, Pseudomonas aereuguinosa, Klebsiella penumoniae, Escherichia coli, Microsporum canis, Trichophyton mentagrophyte and Trichophyton rubrum. Some known antibiotics are included for the sake of comparison and the chosen antibiotic are Amikacin, Doxycllin, Augmantin, Sulperazon, Unasyn, Septrin, Cefobid, Ampicillin, Nitrofurantion, Traivid and Erythromycin.

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

    Directory of Open Access Journals (Sweden)

    Poomalai Jayaseelan

    2016-09-01

    Full Text Available A novel Schiff base ligand has been prepared by the condensation between butanedione monoxime with 3,3′-diaminobenzidine. The ligand and metal complexes have been characterized by elemental analysis, UV, IR, 1H NMR, conductivity measurements, EPR and magnetic studies. The molar conductance studies of Cu(II, Ni(II, Co(II and Mn(II complexes showed non-electrolyte in nature. The ligand acts as dibasic with two N4-tetradentate sites and can coordinate with two metal ions to form binuclear complexes. The spectroscopic data of metal complexes indicated that the metal ions are complexed with azomethine nitrogen and oxyimino nitrogen atoms. The binuclear metal complexes exhibit octahedral arrangements. DNA binding properties of copper(II metal complex have been investigated by electronic absorption spectroscopy. Results suggest that the copper(II complex bind to DNA via an intercalation binding mode. The nucleolytic cleavage activities of the ligand and their complexes were assayed on CT-DNA using gel electrophoresis in the presence and absence of H2O2. The ligand showed increased nuclease activity when administered as copper complex and copper(II complex behave as efficient chemical nucleases with hydrogen peroxide activation. The anti-microbial activities and thermal studies have also been studied. In anti-microbial activity all complexes showed good anti-microbial activity higher than ligand against gram positive, gram negative bacteria and fungi.

  12. New Cu(II) complexes with pyrazolyl derived Schiff base ligands: Synthesis and biological evaluation.

    Science.gov (United States)

    Ribeiro, Nádia; Roy, Somnath; Butenko, Nataliya; Cavaco, Isabel; Pinheiro, Teresa; Alho, Irina; Marques, Fernanda; Avecilla, Fernando; Costa Pessoa, João; Correia, Isabel

    2017-09-01

    Since the discovery of cisplatin there has been a continuous pursuit for new metallodrugs showing higher efficacies and lower side effects. In this work, new copper(II) complexes (C1-C6) of Schiff bases derived from pyrazolyl were developed. Through condensation of 5-methyl-1H-pyrazole-3-carbohydrazide with different aromatic aldehydes - pyridoxal, salicylaldehyde, 3-methoxy-2-hydroxybenzaldehyde, 3-ethoxy-2-hydroxybenzaldehyde and 2-hydroxynaphthene-1-carbaldehyde - a set of new pyrazole based "ONO" tridentate Schiff bases were obtained in moderate to good yields - L1-L6, as well as their Cu(II)-complexes. All compounds were characterized by analytical techniques and their molecular formulae established. The antioxidant potential of all compounds was tested, yielding low activity in most cases, with the exception of L1 and C5. The Cu(II) complexes were tested for their aqueous stability, and for their interaction with biological molecules, namely DNA and HSA (human serum albumin), through fluorescence quenching experiments (and electrophoresis for DNA). With the exception of C3, all the synthesized complexes were able to interact with DNA and HSA. Their cytotoxic activity against two cancer cell lines (MCF7 - breast and PC3 - prostate) was also evaluated. Complexes C5 and C6, with larger aromatic systems, showed much higher cytotoxicity (in the low μM range), than C1-C4, as well as IC50 values much lower than cisplatin. For C6 the results suggest that the mechanisms of cell death do not seem to be mediated by apoptosis, through caspases 3/7 activation, but by involving membrane potential and imbalance in physiological elements such as P, K and Ca. Copyright © 2017 Elsevier Inc. All rights reserved.

  13. Schiff base triphenylphosphine palladium (II) complexes: Synthesis, structural elucidation, electrochemical and biological evaluation

    Science.gov (United States)

    Shabbir, Muhammad; Akhter, Zareen; Ahmad, Iqbal; Ahmed, Safeer; Shafiq, Maryam; Mirza, Bushra; McKee, Vickie; Munawar, Khurram Shahzad; Ashraf, Ahmad Raza

    2016-08-01

    The complexes N-(2-oxidophenyl)salicylideneiminatotriphenylphosphine palladium(II) (1) and N-(2-sulfidophenyl)salicylideneiminato triphenylphosphine palladium(II) (2) of tridentate Schiff bases derived from salicylaldehyde and an amino- or thiophenol, have been synthesized and characterized by various spectroscopic, analytical and electro-analytical techniques. X-ray single crystal analysis of complex 1 has revealed its square planar geometry. The thermal analysis has shown the absence of coordinated water and final degradation product is PdO. The alkaline phosphatase studies have indicated that enzymatic activity is concentration dependent which is inversely proportional to the concentration of the compounds. The biological assays (brine shrimp cytotoxicity, DPPH) have reflected their biologically active and mild antioxidant nature. However, results of DNA protection assay have shown that they possess moderate protective activity against hydroxyl free radicals (rad OH). The voltammetric studies ascertain two-electron reduction of the compounds through purely diffusion controlled process and reveal intercalative mode of drug DNA interactions.

  14. Spectroscopic, Physical and Topography of Photochemical Process of PVC Films in the Presence of Schiff Base Metal Complexes

    Directory of Open Access Journals (Sweden)

    Emad Yousif

    2016-05-01

    Full Text Available The photostability of poly(vinyl chloride, PVC, containing various Schiff base metal complexes (0.5% by weight was investigated. Various indices corresponding to a number of functional groups were monitored with irradiation of polymeric films to determine their photostabilization activities. The quantum yield of the chain scission (Φcs of modified polymeric films was found to be (1.15–4.65 × 106. The surface morphology of a PVC sample was investigated by the use of atomic force microscope (AFM. The photostability of PVC films in the presence of Schiff base additives was found to follow the following order: PVC < PVC + CuL2 < PVC + CdL2 < PVC + ZnL2 < PVC + SnL2 < PVC + NiL2. Various mechanisms for PVC films photostability containing the Schiff base additives have been suggested.

  15. Synthesis, Characterization, Anticancer, and Antioxidant Studies of Ru(III) Complexes of Monobasic Tridentate Schiff Bases

    Science.gov (United States)

    Ejidike, Ikechukwu P.

    2016-01-01

    Mononuclear Ru(III) complexes of the type [Ru(LL)Cl2(H2O)] (LL = monobasic tridentate Schiff base anion: (1Z)-N′-(2-{(E)-[1-(2,4-dihydroxyphenyl)ethylidene]amino}ethyl)-N-phenylethanimidamide [DAE], 4-[(1E)-N-{2-[(Z)-(4-hydroxy-3-methoxybenzylidene)amino]ethyl}ethanimidoyl]benzene-1,3-diol [HME], 4-[(1E)-N-{2-[(Z)-(3,4-dimethoxybenzylidene)amino]ethyl}ethanimidoyl]benzene-1,3-diol [MBE], and N-(2-{(E)-[1-(2,4-dihydroxyphenyl)ethylidene]amino}ethyl)benzenecarboximidoyl chloride [DEE]) were synthesized and characterized using the microanalytical, conductivity measurements, electronic spectra, and FTIR spectroscopy. IR spectral studies confirmed that the ligands act as tridentate chelate coordinating the metal ion through the azomethine nitrogen and phenolic oxygen atom. An octahedral geometry has been proposed for all Ru(III)-Schiff base complexes. In vitro anticancer studies of the synthesized complexes against renal cancer cells (TK-10), melanoma cancer cells (UACC-62), and breast cancer cells (MCF-7) was investigated using the Sulforhodamine B assay. [Ru(DAE)Cl2(H2O)] showed the highest activity with IC50 valves of 3.57 ± 1.09, 6.44 ± 0.38, and 9.06 ± 1.18 μM against MCF-7, UACC-62, and TK-10, respectively, order of activity being TK-10 [Ru(HME)Cl2(H2O)] > [Ru(DAE)Cl2(H2O)] > [Ru(MBE)Cl2(H2O)]. PMID:27597814

  16. Synthesis, Spectral, and In Vitro Antibacterial Studies of Organosilicon(IV) Complexes with Schiff Bases Derived from Amino Acids.

    Science.gov (United States)

    Singh, Har Lal; Singh, Jangbhadur; Mukherjee, A

    2013-01-01

    The present work stems from our interest in the synthesis, characterization, and antibacterial evaluation of organosilicon(IV) complexes of a class of amino-acid-based Schiff base which have been prepared by the interaction of ethoxytrimethylsilane with the Schiff bases (N OH) in 1 : 1 molar ratio. These complexes have been characterized by elemental analysis, molar conductance, and spectroscopic studies including electronic IR and NMR ((1)H, (13)C, and (29)Si) spectroscopy. The analytical and spectral data suggest trigonal bipyramidal geometry around the silicon atom in the resulting complexes. The ligands and their organosilicon complexes have also been evaluated for in vitro antimicrobial activity against bacteria (Bacillus cereus, Nocardia spp., E. aerogenes, Escherichia coli, Klebsiella spp., and Staphylococcus spp.). The complexes were found to be more potent as compared to the ligands.

  17. Metal (II) Complexes Derived from Naphthofuran-2-carbohydrazide and Diacetylmonoxime Schiff Base: Synthesis, Spectroscopic, Electrochemical, and Biological Investigation

    Science.gov (United States)

    Sumathi, R. B.; Halli, M. B.

    2014-01-01

    A new Schiff base and a new series of Co(II), Ni(II), Cu(II), Cd(II), and Hg(II) complexes were synthesized by the condensation of naphthofuran-2-carbohydrazide and diacetylmonoxime. Metal complexes of the Schiff base were prepared from their chloride salts of Co(II), Ni(II), Cu(II), Cd(II), and Hg(II) in ethanol. The ligand along with its metal complexes have been characterized on the basis of analytical data, IR, electronic, mass, 1HNMR, ESR spectral data, thermal studies, magnetic susceptibility, and molar conductance measurements. The nonelectrolytic behaviour of the complexes was assessed from the measured low conductance data. The elemental analysis of the complexes confirm the stoichiometry of the type CuL2Cl2 and MLCl2 where M = Ni(II), Co(II), Cd(II), and Hg(II) and L = Schiff base. The redox property of the Cu(II) complex was investigated by electrochemical method using cyclic voltammetry. In the light of these results, Co(II), Ni(II), and Cu(II) complexes are assigned octahedral geometry, Cd(II), and Hg(II) complexes tetrahedral geometry. In order to evaluate the effect of metal ions upon chelation, both the ligand and its metal complexes were screened for their antibacterial and antifungal activities by minimum inhibitory concentration (MIC) method. The DNA cleaving capacity of all the complexes was analysed by agarose gel electrophoresis method. PMID:24592203

  18. Synthesis, Spectroscopic Characterization and Biological Activities of Transition Metal Complexes Derived from a Tridentate Schiff Base

    Directory of Open Access Journals (Sweden)

    J. Senthil Kumaran

    2013-01-01

    Full Text Available A new series of Cu (II, Ni (II, Co (II and Zn (II complexes have been synthesized from the Schiff base derived from 4-hydroxy-3-methoxybenzylidine-4-aminoantipyrine and 2-aminophenol. The structural features have been determined from their elemental analysis, magnetic susceptibility, molar conductance, Mass, IR, UV-Vis, 1H-NMR, 13C-NMR and ESR spectral studies. The redox behavior of the copper complex has been studied by cyclic voltammetry. The data confirm that the complexes have composition of ML2 type. The electronic absorption spectral data of the complexes propose an octahedral geometry around the central metal ion. All the metal complexes with DNA structure were guided by the presence of inter-molecular C–H⋯O and C–H⋯N hydrogen bonds. The biological activity of the synthesized compounds were tested against the bacterial species such as Bacillus subtilis, Staphylococcus aureus, Proteus vulgaris and fungal species such as Candida albicans by the well-diffusion method.

  19. Sulfonated Schiff base Sn(IV) complexes as potential anticancer agents.

    Science.gov (United States)

    Hazra, Susanta; Paul, Anup; Sharma, Gunjan; Koch, Biplob; da Silva, M Fátima C Guedes; Pombeiro, Armando J L

    2016-09-01

    Syntheses, crystal structures and biological activities of the diphenoxo-bridged diorgano dinuclear Sn(IV) compounds [Sn(Et)2(HL)(H2O)]2 (1) and [Sn(n-Bu)2(HL)(H2O)]2 (2) derived from the Schiff base 2-[(2,3-dihydroxyphenyl)methylideneamino]benzenesulfonic acid trihydrate (H3L·3H2O) are described. The monoprotonated form (HL2-) of the Schiff base behaves as O,O'-bidentate ligand, chelating the metal by the two phenoxo oxygen atoms. The hexacoordinated metal centres in 1 and 2 are bridged by a phenoxo oxygen and the remaining coordination positions are fulfilled by the other phenoxo oxygen, two organic groups (ethyl for 1 and n-butyl for 2) and a water molecule. A two dimensional zigzag sheet in 1 and three dimensional polymeric networks in H3L·3H2O and 2 are stabilized by a number of non-covalent, H-bonding and π⋯π stacking interactions. The DNA binding activities of these complexes have been studied by UV-vis and fluorescence spectroscopies. Their antiproliferative efficacies have been evaluated on A-549, HeLa and MDA-MB-231 cancer cell lines by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. IC50 values (1.35±0.23, 2.43±0.54 and 1.74±0.04μM for 2) are indicative of a substantial cytotoxicity of 2, mainly towards the A-549 lung cancer cell line. The greater antiproliferative efficacy of 2has further been studied by fluorescence activated cell sorting (FACS) and nuclear morphology by Hoechst/propidium iodide (PI) double staining method. The possible mode of the apoptotic pathway for 2has been substantiated by the reactive oxygen species (ROS) generation studies. Copyright © 2016 Elsevier Inc. All rights reserved.

  20. Mononuclear and tetranuclear Fe(III) complexes with two different types of N, O donor Schiff base ligands

    Science.gov (United States)

    Sutradhar, Manas; Roy Barman, Tannistha; Drew, Michael G. B.; Rentschler, Eva

    2013-06-01

    A mononuclear Fe(III) complex of a tetradentate N2O2 donor Schiff base ligand derived from 3-ethoxysalicaldehyde and ethylenediamine has been reported. In addition two tetranuclear Fe(III) complexes with discrete Fe4III(μ4-O) cores have been synthesized and characterized using two Schiff base ligands (H2L1-2) derived from two different aromatic acid hydrazides and diacetyl monoxime. The mononuclear Fe(III) and one of the tetranuclear Fe(III) complexes have been structurally characterized by single-crystal X-ray crystallography. The mononuclear complex has a highly distorted octahedral geometry. The tetranuclear Fe(III) complexes are found to be rare examples with discrete neutral alkoxido-oxido clusters with Fe4III(μ4-O) cores.

  1. Synthesis, crystal structure and thermodynamic properties of a new praseodymium Schiff-base complex

    Energy Technology Data Exchange (ETDEWEB)

    Li, Chuan-Hua, E-mail: lichuanhua0526@126.com [School of Chemistry and Chemical Engineering, Central South University, Changsha 410083, Hunan (China); Hunan Provincial Key Laboratory of Xiangnan Rare-Precious Metals Compounds and Applications, Department of Chemistry and Life Science, Xiangnan University, Chenzhou 423000, Hunan (China); Song, Xiang-Zhi, E-mail: xzsong@csu.edu.cn [School of Chemistry and Chemical Engineering, Central South University, Changsha 410083, Hunan (China); Jiang, Jian-Hong [Hunan Provincial Key Laboratory of Xiangnan Rare-Precious Metals Compounds and Applications, Department of Chemistry and Life Science, Xiangnan University, Chenzhou 423000, Hunan (China); Gu, Hui-Wen [State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082, Hunan (China); Tao, Li-Ming; Yang, Ping; Li, Xu; Xiao, Sheng-Xiong; Yao, Fei-Hong; Liu, Wen-Qi; Xie, Jin-Qi; Peng, Meng-Na; Pan, Lan; Wu, Xi-Bin; Jiang, Chao; Wang, Song; Xu, Man-Fen [Hunan Provincial Key Laboratory of Xiangnan Rare-Precious Metals Compounds and Applications, Department of Chemistry and Life Science, Xiangnan University, Chenzhou 423000, Hunan (China); Li, Qiang-Guo, E-mail: liqiangguo@163.com [Hunan Provincial Key Laboratory of Xiangnan Rare-Precious Metals Compounds and Applications, Department of Chemistry and Life Science, Xiangnan University, Chenzhou 423000, Hunan (China)

    2014-04-01

    Highlights: • A new mononuclear Schiff base praseodymium complex was synthesized. • Based on Hess's law, thermochemical cycles of two reactions were designed. • The dissolution enthalpies were measured by a solution–reaction calorimeter. • The standard molar enthalpy of formation of the complex was calculated. - Abstract: The title complex [Pr(H{sub 2}vanen)(NO{sub 3}){sub 2}(H{sub 2}O){sub 2}·NO{sub 3}] was synthesized reacting of Valen Schiff-base ligand [H{sub 2}vanen = N,N′-ethylene-bis(3-methoxysalicylideneimine)] and Pr(NO{sub 3}){sub 3}·6H{sub 2}O in ethanol at 60 °C. The complex was crystallized in the monoclinic crystal system with space group P21/c. The coordination polyhedron of Pr(III) ion was consisted of two bidentate nitrate ions, two molecules of water and one ligand which coordinated through oxygen atoms of the two phenolic and methoxy groups. After designing two reasonable thermochemical cycles according to Hess's law, the calorimetric experiments were conducted using isoperibol solution–reaction calorimeter at a constant temperature of 298.15 K. The standard molar enthalpy changes of two reactions were determined to be Δ{sub r}H{sub m}{sup θ}(1a)=−(51.94±1.26) kJ mol{sup −1} and Δ{sub r}H{sub m}{sup θ}(1b)=−(8.62±1.34) kJ mol{sup −1}. Then the standard molar enthalpies of formation of the ligand and the title complex were calculated to be Δ{sub f}H{sub m}{sup θ} [H{sub 2}vanen(s), 298.15 K] = −(517.75 ± 2.36) kJ mol{sup −1} and Δ{sub f}H{sub m}{sup θ} [Pr(H{sub 2}vanen)(NO{sub 3}){sub 2}(H{sub 2}O){sub 2}·NO{sub 3} (s), 298.15 K] = −(2454.8 ± 2.7) kJ mol{sup −1}, respectively. The rationality of two thermochemical cycles was verified by UV spectra and refractive indexes.

  2. A combined spectroscopic, docking and molecular dynamics simulation approach to probing binding of a Schiff base complex to human serum albumin.

    Science.gov (United States)

    Fani, N; Bordbar, A K; Ghayeb, Y

    2013-02-15

    The molecular mechanism of a Schiff base complex ((E)-((E)-2-(3-((E)-((E)-3(mercapto (methylthio) methylene)cyclopentylidene) amino) propylimino) cyclopentylidene) (methylthio) methanethiol) binding to Human Serum Albumin (HSA) was investigated by fluorescence quenching, absorption spectroscopy, molecular docking and molecular dynamics (MD) simulation procedures. The fluorescence emission of HSA was quenched by this Schiff base complex that has been analyzed for estimation of binding parameters. The titration of Schiff base solution by various amount of HSA was also followed by UV-Vis absorption spectroscopy and the corresponding data were analyzed by suitable models. The results revealed that this Schiff base has an ability to bind strongly to HSA and formed 1:1 complex. Energy transfer mechanism of quenching was discussed and the value of 5.45 ± 0.06 nm was calculated as the mean distance between the bound complex and the Trp residue. This is implying the high possibility of energy transfer from HSA to this Schiff base complex. Molecular docking results indicated that the main active binding site for this Schiff base complex is site III in subdomain IB. Moreover, MD simulation results suggested that this Schiff base complex can interact with HSA, without affecting the secondary structure of HSA but probably with a slight modification of its tertiary structure. MD simulations, molecular docking and experimental data reciprocally supported each other. Copyright © 2012 Elsevier B.V. All rights reserved.

  3. Unsymmetrical Schiff base (ON) ligand on complexation with some transition metal ions: synthesis, spectral characterization, antibacterial, fluorescence and thermal studies.

    Science.gov (United States)

    Ali, Omyma A M; El-Medani, Samir M; Abu Serea, Maha R; Sayed, Abeer S S

    2015-02-05

    A series of eight metal Schiff base complexes were synthesized by the thermal reaction of Cu(II), Ni(II), Fe(III), Co(II), Zn(II), Hg(II), La(III) or Sm(III) with a Schiff base "L" produced by the condensation of furfuraldehyde and 1,2-diaminobenzene. These compounds were characterized by elemental analysis, UV-Vis, FT-IR, molar conductance, mass spectrometry, thermal and fluorescence studies. The studies suggested the coordination of the ligand L to metal through azomethine imine nitrogen and furan oxygen atoms of Schiff base moiety. Thermogravimetric (TG/DTG) analyses data were studied and indicated high stability for all complexes and suggested the presence of lattice and/or coordinated water molecules in the complexes. Coats-Redfern method has been used to calculate the kinetic and thermodynamic parameters of the metal complexes. The spectral and thermal analysis reveal that all complexes have octahedral geometry except Cu(II) and Ni(II) complexes which can attain a square planner arrangements. The ligand and its complexes exhibited intraligand (π-π(∗)) fluorescence and can potentially serve as photoactive materials. Both the ligand and its complexes have been screened for antibacterial activities. Copyright © 2014 Elsevier B.V. All rights reserved.

  4. Synthesis and characterization of some metal complexes of a Schiff base derived from ninhydrin and α,L-alanine

    Directory of Open Access Journals (Sweden)

    Mehabaw Getahun Derebe

    2002-06-01

    Full Text Available Complexes of Mn(II, Fe(III, Co(II, Ni(II and Zn(II with an intermediate Schiff base derived from ninhydrin and α,L-alanine (indane-1,3-dione-2-imine-N-2-propionate, IDIP were successfully synthesized. All complexes were distinctly colored and were characterized by elemental analysis, molar conductance, magnetic susceptibility, infrared and electronic spectral studies. The ligand (Schiff base was shown to behave as a monobasic tridentate ONO donor. The Mn(II and Fe(III complexes contain only one ligand molecule plus water and chloride(s per metal ion, while all the others contain two ligand molecules per metal ion. An octahedral geometry is proposed for the metal complexes.

  5. Synthesis, Characterization and Spectroscopic Studies of A Novel 2-[(E-[(2,4-dichlorophenylimino]methyl]phenol Schiff Base and Its Metal Complexes

    Directory of Open Access Journals (Sweden)

    Eman Turky Shamkhy

    2012-01-01

    Full Text Available A novel Schiff base 2-{(E-[(2,4-dichlorophenylimino]methyl}phenol (LB was synthesized from the condensation reaction of 2,4-dichloroaniline with salicyladehyde in [1:1] ratio in the presence of glacial acetic acid as catalyst. Complexation reaction of this Schiff base with copper (II, cobalt (II as nitrate salts and with Rhodium (III as chloride salt to produce three coordinate metal complexes, with a Schiff base: Metal ion ratio of 2:1. These compounds have been characterized by a variety of physico-chemical and spectroscopic techniques. The ligand and its metal complexes were expected to show an interesting bioactivity and cytotoxicity.

  6. 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.

  7. Synthesis, characterization and the interaction of some new water-soluble metal Schiff base complexes with human serum albumin.

    Science.gov (United States)

    Asadi, Mozaffar; Asadi, Zahra; Sadi, Somaye Barzegar; Zarei, Leila; Baigi, Fatemeh Moosavi; Amirghofran, Zahra

    2014-03-25

    Some new water-soluble Schiff base complexes of Na2[M(L)(H2O)n]; (M=Zn, Cu, Ni, Mn) with a new water-soluble Schiff base ligand where L denotes an asymmetric N2O2 Schiff base ligands; N,N'-bis(5-sulfosalicyliden)-3,4-diaminobenzophenone (5-SO3-3,4-salbenz) were synthesized and characterized. The formation constants of the water soluble Schiff base complexes were calculated by Ketelaar's equation. The theoretical molecular structure for the complexes was computed by using the HF method and the 6-311G basis set. The mechanism of binding of Na2[M(L)(H2O)n] with human serum albumin (HSA) was studied by fluorescence spectroscopic technique. The results of fluorescence titration showed that the intrinsic fluorescence of HSA was quenched by the complexes; which was rationalized in terms of the dynamic quenching mechanism. The values of Stern-Volmer constants, quenching rate constants, binding constants, binding sites and average aggregation number of HSA have been determined. The thermodynamic parameters, were calculated by van't Hoff equation, indicate that the binding is entropy driven and enthalpically disfavored. Based on the Förster theory of non-radiation energy transfer, the efficiency of energy transfer and the distance between the donor (Trp residues) and the acceptor (complex) were obtained. Finally, the growth inhibitory effects of the complexes toward the K562 cancer cell line were measured. Copyright © 2013 Elsevier B.V. All rights reserved.

  8. New asymmetric heptaaza Schiff base macrocyclic complex of Mn(II): Crystal structure, biological and DFT studies

    Science.gov (United States)

    Khanmohammadi, Hamid; Amani, Saeid; Abnosi, Mohammad H.; Khavasi, Hamid R.

    2010-10-01

    A new asymmetric heptaaza Schiff base macrocyclic bis(pendant donor) manganese(II) complex, [MnL 1](ClO 4) 2·CH 3CN ( 1), has been prepared and characterized by X-ray diffraction and spectroscopic methods. The antimicrobial activity of 1 and a series of its familiar symmetric heptaaza [15]pydieneN 5, [16]pydieneN 5, and [17]pydieneN 5-based bis-(2-aminoethyl) pendant armed Schiff base macrocyclic complexes of Mn(II) were tested against Escherichia coli, Staphylococcus aureus and Candida albicans. The results showed that the symmetric heptaaza [16]pydieneN 5, and [17]pydieneN 5-based Schiff base macrocyclic complexes of Mn(II) had remarkable inhibition zone on the culture of S. aureus and E. coli as compared with standard drugs. The optimized geometry of the prepared complex has been obtained from density functional method, DFT, using B3LYP/6-31G* basis set.

  9. Synthesis, spectroscopic, coordination and biological activities of some organometallic complexes derived from thio-Schiff base ligands.

    Science.gov (United States)

    Abou-Hussein, Azza A; Linert, Wolfgang

    2014-01-03

    Two series of mono- and binuclear complexes cyclic or acyclic thio-ferocine Schiff base ligands, derived from the condensation of 2-aminobenzenthiol (L) with monoacetyl ferrocene in the molar ratio 1:1 or in the molar ratio 1:2 for diacetyl ferocine have been prepared. The condensation reactions yield the corresponding Schiff Base ligands, HLa-Maf and H2Lb-Daf. The chelation of the ligands to metal ions occurs through the sulfur of the thiol group as well as the nitrogen atoms of the azomethine group of the ligands. HLa-Maf acts as monobasic bidentate or dibasic tetradentate, while H2Lb-Daf behaves as twice negatively cargend tetradentate ligand. The structures of these ligands were elucidated by elemental analysis, infrared, ultraviolet-visible spectra, as well as (1)H NMR spectra. Reactions of the Schiff bases ligands with ruthenium(III), oxovanadium(IV) and dioxouranium(VI) afforded the corresponding transition metal complexes. The properties of the newly prepared complexes were analyse by elemental analyses, infrared, electronic spectra, (1)H NMR as well as the magnetic susceptibility and conductivity measurement. The metal complexes exhibits different geometrical arrangements such as octahedral and square pyramidal coordination. Schiff base ligands and their metal complexes were tested against two pathogenic bacteria as Gram-positive and Gram-negative bacteria as well as one kind of fungi to study their biological activity. All the complexes exhibit antibacterial and antifungal activities against these organisms. Copyright © 2013 The Authors. Published by Elsevier B.V. All rights reserved.

  10. A novel cationic cobalt(III) Schiff base complex: Preparation, crystal structure, Hirshfeld surface analysis, antimicrobial activities and molecular docking.

    Science.gov (United States)

    Yousef Ebrahimipour, S; Machura, Barbara; Mohamadi, Maryam; Khaleghi, Moj

    2017-12-01

    A novel Co(III) complex, [Co(L)(Imi)3]Cl incorporating 2-((3-methoxy-2-oxidobenzylidene)amino)-4-methylphenolate (L2-), as a dibasic deprotonated Schiff base ligand and imidazole (Imi) was synthesized and fully characterized using physicochemical and spectroscopic techniques including elemental analysis, conductance measurement, FT-IR, UV-Vis and X-ray single crystal diffraction. As the conductivity data showed, the synthesized complex had a 1:1 ionic nature. The structure of the complex was found to be distorted octahedral in which, O/N donor atoms of the Schiff base ligand and N atoms of three imidazole groups were involved. Antimicrobial activity of the Co(III) complex as well as the its parent Schiff base ligand against two Gram-positive bacteria (S. Aureus and M. luteus), two Gram-negative bacteria (E. coli and P. aeruginosa) and a fungus (C. Albicans) was studied. Moreover, the antimicrobial activity of [Co(L)(Imi)3]Cl was investigated using molecular docking of the complex with GlcN-6-P synthase. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. Silver(I) complexes of 2,4-dihydroxybenzaldehyde-amino acid Schiff bases-Novel noncompetitive α-glucosidase inhibitors.

    Science.gov (United States)

    Zheng, Jingwei; Ma, Lin

    2015-01-01

    A series of silver(I) complexes of 2,4-dihydroxybenzaldehyde-amino acid Schiff bases were designed and tested for α-glucosidase inhibition. Our results indicate that all the silver complexes (4a-18a) possessed strong inhibitory activity at μmolL(-1) level, especially glutamine (12a) and histidine (18a) Schiff base silver(I) complexes exhibited an IC50 value of less than 0.01μmolL(-1). This series of compounds exhibited noncompetitive inhibition characteristics in kinetic studies. In addition, we investigated the mechanism of inhibition and the structure-activity relationships of the amino acid Schiff base silver complexes. Our results reveal that Schiff base silver complexes may be explored for their therapeutic potential as alternatives of α-glucosidase inhibitors. Copyright © 2015 Elsevier Ltd. All rights reserved.

  12. Novel Organotin(IV) Schiff Base Complexes with Histidine Derivatives: Synthesis, Characterization, and Biological Activity

    Science.gov (United States)

    Garza-Ortiz, Ariadna; Camacho-Camacho, Carlos; Sainz-Espuñes, Teresita; Rojas-Oviedo, Irma; Gutiérrez-Lucas, Luis Raúl; Gutierrez Carrillo, Atilano; Vera Ramirez, Marco A.

    2013-01-01

    Five novel tin Schiff base complexes with histidine analogues (derived from the condensation reaction between L-histidine and 3,5-di-tert-butyl-2-hydroxybenzaldehyde) have been synthesized and characterized. Characterization has been completed by IR and high-resolution mass spectroscopy, 1D and 2D solution NMR (1H, 13C  and 119Sn), as well as solid state 119Sn NMR. The spectroscopic evidence shows two types of structures: a trigonal bipyramidal stereochemistry with the tin atom coordinated to five donating atoms (two oxygen atoms, one nitrogen atom, and two carbon atoms belonging to the alkyl moieties), where one molecule of ligand is coordinated in a three dentate fashion. The second structure is spectroscopically described as a tetrahedral tin complex with four donating atoms (one oxygen atom coordinated to the metal and three carbon atoms belonging to the alkyl or aryl substituents), with one molecule of ligand attached. The antimicrobial activity of the tin compounds has been tested against the growth of bacteria in vitro to assess their bactericidal properties. While pentacoordinated compounds 1, 2, and 3 are described as moderate effective to noneffective drugs against both Gram-positive and Gram-negative bacteria, tetracoordinated tin(IV) compounds 4 and 5 are considered as moderate effective and most effective compounds, respectively, against the methicillin-resistant Staphylococcus aureus strains (Gram-positive). PMID:23864839

  13. Synthesis, anticancer activity and molecular docking study of Schiff base complexes containing thiazole moiety

    Directory of Open Access Journals (Sweden)

    Mokhles M. Abd-Elzaher

    2016-03-01

    Full Text Available A Schiff base ligand 1 was prepared from condensation of salicyaldehyde with 2-amino-4-phenyl-5-methyl thiazole. The ligand forms complexes with CoII, NiII, CuII, and ZnII in good yield. The synthesized compounds were characterized by elemental analysis, magnetic susceptibility, molar conductance, infrared spectra, 1H and 13C NMR, mass, electronic absorption and ESR spectroscopy. The anticancer activity of the synthesized compounds was studied against different human tumor cell lines: breast cancer MCF-7, liver cancer HepG2, lung carcinoma A549 and colorectal cancer HCT116 in comparison with the activity of doxorubicin as a reference drug. The study showed that ZnII complex showed potent inhibition against human TRK in the four cell lines (HepG2, MCF7, A549, HCT116 by the ratio 80, 70, 61 and 64% respectively as compared to the inhibition in the untreated cells. Moreover, the molecular docking into TRK (PDB: 1t46 was done for the optimization of the aforementioned compounds as potential TRK inhibitors.

  14. Synthesis, Characterization and Spectroscopic Studies of A Novel 2-[(E)-[(2,4-dichlorophenyl)imino]methyl]phenol Schiff Base and Its Metal Complexes

    OpenAIRE

    Shamkhy, Eman Turky; Al-Karkhi, Isam Hussain T.

    2012-01-01

    A novel Schiff base 2-{(E)-[(2,4-dichlorophenyl)imino]methyl}phenol (LB) was synthesized from the condensation reaction of 2,4-dichloroaniline with salicyladehyde in [1:1] ratio in the presence of glacial acetic acid as catalyst. Complexation reaction of this Schiff base with copper (II), cobalt (II) as nitrate salts and with Rhodium (III) as chloride salt to produce three coordinate metal complexes, with a Schiff base: Metal ion ratio of 2:1. These compounds have been characterized by a vari...

  15. Microwave assisted synthesis and characterization of unsymmetrical tetradentate Schiff base complexes of VO(IV) and MoO(V)

    Science.gov (United States)

    Thaker, B. T.; Barvalia, R. S.

    2011-12-01

    Microwave synthesis, is green chemical method, simple, sensitive, reducing solvent amount and reaction time. The attempt was made to synthesize the unsymmetrical tetradentate N 2O 2 ligands and their VO(IV) and MoO(V) unsymmetrical tetradentate Schiff base complexes by classical and microwave techniques using domestic microwave oven. The resulting unsymmetrical Schiff base ligands L 1-L 3 characterized by different spectral methods. Their complexes with oxocations of VO(IV) and MoO(V) have been synthesized and characterized by elemental analyses, conductometric measurements, infrared and electronic absorption, 1H NMR spectra, mass spectrometry, ESR spectra, magnetic susceptibility measurement and thermal study. The study suggests that the oxo metal ion is bonded to the ligand through the oxygen and imino nitrogen and the geometry around metal ion is distorted octahedral.

  16. Potentiometric and spectrophotometric studies of the complexation of Schiff-base hydrazones containing the pyrimidine moiety

    Directory of Open Access Journals (Sweden)

    M. SHEBL

    2003-10-01

    Full Text Available Three Schiff-base hydrazones (ONN – donors were prepared by condensation of 2-amino-4-hydrazino-6-methylpyrimidine with 2-hydroxyacetophenone, 2-methoxybenzaldehyde and diacetyl to yield 2-OHAHP, 2-OMeBHP and DHP, respectively. The structures of these ligands were elucidated by elemental analysis, UV, IR, 1H-NMR and mass spectra. The metal–ligand stability constants of Mn2+, Fe3+, Co2+, Ni2+, Cu2+, Zn2+, Cd2+, UO22+ and Th4+ chelates were determined potentiometrically in two different media (75 % (v/v dioxane–water and ethanol–water at 283, 293, 303 and 313 K at an ionic strength of 0.05 M (KNO3. The thermodynamic parameters of the 1:1 and 1:2 complexes were evaluated and are discussed. The dissociation constants of 2-OHAHP, 2-OMeBHP and DHP ligands and the stability constants of Co2+, Ni2+ and Cu2+ with 2-OHAHP were determined spectrophotometrically in 75 % (v/v dioxane–water.

  17. "Half-sandwich" Schiff-base Ir(III) complexes as anticancer agents.

    Science.gov (United States)

    Mou, Ze-Dong; Deng, Ning; Zhang, Feng; Zhang, Jiaying; Cen, Juan; Zhang, Xia

    2017-09-29

    A series of "half-sandwich" Schiff-base Ir(III) complexes were synthesized and investigated for their in vitro activities against the leukemia K562 cell line. These compounds demonstrated antiproliferative activities against K562 cells with IC50 values of 0.26-4.77 μM. In particular, compound 10c showed cytotoxicity against five cancer cell lines/sublines and stronger activities than cisplatin in K562, K562/A02, MCF-7, MCF-7/ADM, and A549 cells. Mechanism studies illustrated that compound 10c increased the level of reactive oxygen species and induced apoptosis of K562 cells. This compound effectively decreased the mitochondrial membrane potential and the protein level of Bcl-2. It also increased the protein levels of Bax, caspase-3, and caspase-9, and led to release of cytochrome c in K562 cells, indicating that the apoptosis induced by compound 10c was mediated by the intrinsic mitochondria apoptosis pathway. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  18. Surfactant-copper(II) Schiff base complexes: synthesis, structural investigation, DNA interaction, docking studies, and cytotoxic activity.

    Science.gov (United States)

    Lakshmipraba, Jagadeesan; Arunachalam, Sankaralingam; Solomon, Rajadurai Vijay; Venuvanalingam, Ponnambalam; Riyasdeen, Anvarbatcha; Dhivya, Rajakumar; Akbarsha, Mohammad Abdulkader

    2015-01-01

    A series of surfactant-copper(II) Schiff base complexes (1-6) of the general formula, [Cu(sal-R2)2] and [Cu(5-OMe-sal-R2)2], {where, sal=salicylaldehyde, 5-OMe-sal=5-methoxy- salicylaldehyde, and R2=dodecylamine (DA), tetradecylamine (TA), or cetylamine (CA)} have been synthesized and characterized by spectroscopic, ESI-MS, and elemental analysis methods. For a special reason, the structure of one of the complexes (2) was resolved by single crystal X-ray diffraction analysis and it indicates the presence of a distorted square-planar geometry in the complex. Analysis of the binding of these complexes with DNA has been carried out adapting UV-visible-, fluorescence-, as well as circular dichroism spectroscopic methods and viscosity experiments. The results indicate that the complexes bind via minor groove mode involving the hydrophobic surfactant chain. Increase in the length of the aliphatic chain of the ligands facilitates the binding. Further, molecular docking calculations have been performed to understand the nature as well as order of binding of these complexes with DNA. This docking analysis also suggested that the complexes interact with DNA through the alkyl chain present in the Schiff base ligands via the minor groove. In addition, the cytotoxic property of the surfactant-copper(II) Schiff base complexes have been studied against a breast cancer cell line. All six complexes reduced the visibility of the cells but complexes 2, 3, 5, and 6 brought about this effect at fairly low concentrations. Analyzed further, but a small percentage of cells succumbed to necrosis. Of these complexes (6) proved to be the most efficient aptotoxic agent.

  19. Comparative Study of Aluminum Complexes Bearing N,O- and N,S-Schiff Base in Ring-Opening Polymerization of ε-Caprolactone and L-Lactide.

    Science.gov (United States)

    Chang, Meng-Chih; Lu, Wei-Yi; Chang, Heng-Yi; Lai, Yi-Chun; Chiang, Michael Y; Chen, Hsing-Yin; Chen, Hsuan-Ying

    2015-12-07

    A series of Al complexes bearing Schiff base and thio-Schiff base ligands were synthesized, and their application for the ring-opening polymerization of ε-caprolactone (CL) and l-lactide (LA) was studied. It was found that steric effects of the ligands caused higher polymerization rate and most importantly the Al complexes with N,S-Schiff base showed significantly higher polymerization rate than Al complexes with N,O-Schiff base (5-12-fold for CL polymerization and 2-7-fold for LA polymerization). The reaction mechanism of CL polymerization was investigated by density functional theory (DFT). The calculations predicted a lower activation energy for a process involved with an Al complex bearing an N,S-Schiff base ligand (17.6 kcal/mol) than for that of an Al complex bearing an N,O-Schiff base ligand (19.0 kcal/mol), and this magnitude of activation energy reduction is comparable to the magnitude of rate enhancement observed in the experiment. The reduction of activation energy was attributed to the catalyst-substrate destabilization effect. Using a sulfur-containing ligand to decrease the activation energy in the ring-opening polymerization process may be a new strategy to design a new Al complex with high catalytic activity.

  20. Cytogenotoxic effects of two potential anticancer Ruthenium(III Schiff Bases complexes

    Directory of Open Access Journals (Sweden)

    Izet Eminovic

    2016-10-01

    Full Text Available Introduction: Treatment of cancer has been subject of great interest. Researchers are continuously searching for new medicines. In this sense, ruthenium complexes have big potential. Some evidences suggest that ruthenium compounds possess anticancer activities. We synthesized two recently published ruthenium(III complexes with bidentate O,N and tridentate O,O,N Schiff bases derived from 5-substituted salicylaldehyde and aminophenol or anilineare. These compounds showed affinity for binding to the DNA molecule, however, insufficient data are available regarding their possible toxic effects on biological systems.Methods: In the present study we evaluated genotoxic, cytotoxic, and cytostatic effects of Na[RuCl2(L12] and Na[Ru(L22], using the Allium cepa assay.Results: Different toxic effects were observed depending on the substance, tested concentration, and endpoint measured. In general, the tested compounds significantly lowered the root growth and mitotic index values as compared to the control group. Additionally, a wide range of abnormal mitotic stages, both clastogenic and non-clastogenic were observed in the treated cells. Na[RuCl2(L12] significantly increased the frequency of sticky metaphases, chromosome bridges, micronuclei, impaired chromosome segregation, as well as number of apoptotic and necrotic cells over the controls. In contrast, Na[Ru(L22] did not show significant evidence of genotoxicity with regard to chromosome aberrations and micronuclei, however, significant differences were detected in the number of apoptotic and necrotic cells when the highest concentration was applied.Conclusions: In this study we demonstrated antiproliferative effects of Na[RuCl2(L12] and Na[Ru(L22]. At clinical level, these results could be interesting for further studies on anticancer potential of the ruthenium(III complexes using animal models.

  1. Two new Ni(II) Schiff base complexes : X-ray absolute structure determination, synthesis of a N-15-labelled complex and full assignment of its H-1 NMR and C-13 NMR spectra

    NARCIS (Netherlands)

    Langer, Vratislav; Popkov, Alexander; Nadvornik, Milan; Lycka, Antonin

    2007-01-01

    The Ni(II) complex of the Schiff base of (S)-N-(2-benzoyl-4-chlorophenyl)-1-benzylpyrrolidine-2-carboxamide and glycine (1) [GKCI] and the hemihydrate of the Ni(II) complex of the Schiff base of (S)-N-(2-benzoylphenyl)-1-benzylpyrrolidine-2-carboxamide and 2-aminoisobutiric acid (2) Me(2)GK] were

  2. Synthesis and luminescence properties of polymer-rare earth complexes containing salicylaldehyde-type bidentate Schiff base ligand.

    Science.gov (United States)

    Zhang, Dandan; Gao, Baojiao; Li, Yanbin

    2017-08-01

    Using molecular design and polymer reactions, two types of bidentate Schiff base ligands, salicylaldehyde-aniline (SAN) and salicylaldehyde-cyclohexylamine (SCA), were synchronously synthesized and bonded onto the side chain of polysulfone (PSF), giving two bidentate Schiff base ligand-functionalized PSFs, PSF-SAN and PSF-SCA, referred to as macromolecular ligands. Following coordination reactions between the macromolecular ligands and Eu(III) and Tb(III) ions (the reaction occurred between the bonded ligands SAN or SCA and the lanthanide ion), two series of luminescent polymer-rare earth complexes, PSF-SAN-Eu(III) and PSF-SCA-Tb(III), were obtained. The two macromolecular ligands were fully characterized by Fourier transform infrared (FTIR), 1 H NMR and UV absorption spectroscopy, and the prepared complexes were also characterized by FTIR, UV absorption spectroscopy and thermo-gravity analysis. On this basis, the photoluminescence properties of these complexes and the relationships between their structure and luminescence were investigated in depth. The results show that the bonded bidentate Schiff base ligands, SAN and SCA, can effectively sensitize the fluorescence emission of Eu(III) and Tb(III) ions, respectively. PSF-SAN-Eu(III) series complexes, namely the binary complex PSF-(SAN)3 -Eu(III) and the ternary complex PSF-(SAN)3 -Eu(III)-(Phen)1 (Phen is the small-molecule ligand 1,10-phenanthroline), produce strong red luminescence, suggesting that the triplet state energy level of SAN is lower and well matched with the resonant energy level of the Eu(III) ion. By contrast, PSF-SAN-Eu(III) series complexes, namely the binary complex PSF-(SCA)3 -Tb(III) and the ternary complex PSF-(SCA)3 -Tb(III)-(Phen)1 , display strong green luminescence, suggesting that the triplet state energy level of SCA is higher and is well matched with the resonant energy level of Tb(III). Copyright © 2017 John Wiley & Sons, Ltd.

  3. Synthesis and Biological Activities of Lanthanide (III) Nitrate Complexes with N-(2-hydroxynaphthalen-1-yl) methylene) Nicotinohydrazide Schiff Base.

    Science.gov (United States)

    Hijazi, Ahmed K; Taha, Ziyad A; Ajlouni, Abdulaziz M; Al-Momani, Waleed M; Idris, Idris M; Hamra, Eman A

    2016-01-01

    The field of coordination chemistry has registered a phenomenal growth during the last few decades. It is well known that precious metals have been used for medicinal purposes for at least 3500 years. At that time, precious metals were believed to benefit health because of their rarity, but research has now well established the link between medicinal properties of inorganic drugs and specific biological properties. The current study was designed to explain the synthesis and characterization of the lanthanide (III) nitrate complexes with N-(2-hydroxynaphthalen-1-yl) methylene) nicotinohydrazide schiff base and to evaluate the antibacterial and the antioxidant activities of the schiff base and it's lanthanide ion complexes. Antimicrobial activity of the Lanthanide (III) nitrate complexes with N-(2- hydroxynaphthalen-1-yl) methylene) nicotinohydrazide schiff base was estimated by minimum inhibitory concentration (MIC, µg/mL) using a micro-broth dilution method for different clinical isolates such as Eschereshia coli and Enterococcus faecalis. The antioxidant activities of the ligand and its lanthanide complexes were tested using a UV-Visible spectrophotometer by preparing 5x10-4M of all tested samples and DPPH in Dimethyl sulphoxide (DMSO). Our present study has shown that moderate antimicrobial activity exists against both ligand and its complexes. There was no significant difference between Gram-positive and Gram-negative bacteria towards the tested ligand and its complexes. The free ligand has scavenging activity between 13-21 % while all complexes are more efficient in quenching DPPH than free ligand. The results obtained herein indicate that the ligand and its complexes have a considerable antibacterial activity as well as antioxidant activity in quenching DPPH. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  4. Affinity to bovine serum albumin and anticancer activity of some new water-soluble metal Schiff base complexes.

    Science.gov (United States)

    Asadi, Mozaffar; Asadi, Zahra; Zarei, Leila; Sadi, Somaye Barzegar; Amirghofran, Zahra

    2014-12-10

    Metal Schiff-base complexes show biological activity but they are usually insoluble in water so four new water-soluble metal Schiff base complexes of Na2[M(5-SO3-1,2-salben]; (5-SO3-1,2-salben denoted N,N'-bis(5-sulphosalicyliden)-1,2-diaminobenzylamine and M=Mg, Mn, Cu, Zn) were synthesized and characterized. The formation constants of the metal complexes were determined by UV-Vis absorption spectroscopy. The interaction of these complexes with bovine serum albumin (BSA) was studied by fluorescence spectroscopy. Type of quenching, binding constants, number of binding sites and binding stoichiometries were determined by fluorescence quenching method. The results showed that the mentioned complexes strongly bound to BSA. Thermodynamic parameters indicated that hydrophobic association was the major binding force and that the interaction was entropy driven and enthalpically disfavoured. The displacement experiment showed that these complexes could bind to the subdomain IIA (site I) of albumin. Furthermore the synchronous fluorescence spectra showed that the microenvironment of the tryptophan residues was not apparently changed. Based on the Förster theory of non-radiation energy transfer, the distance between the donor (Trp residues) and the acceptor metal complexes was obtained. The growth inhibitory effect of complexes toward the K562 cancer cell line was measured. Published by Elsevier B.V.

  5. A new chitosan Schiff base supported Pd(II) complex for microwave-assisted synthesis of biaryls compounds

    Science.gov (United States)

    Baran, Talat

    2017-08-01

    In this study, a new heterogeneous palladium (II) catalyst that contains O-carboxymethyl chitosan Schiff base has been designed for Suzuki coupling reactions. The chemical structures of the synthesized catalyst were characterized with the FTIR, TG/DTG, ICP-OES, SEM/EDAX, 1H NMR, 13C NMR, GC/MS, XRD, and magnetic moment techniques. The reusability and catalytic behavior of heterogeneous catalyst was tested towards Suzuki reactions. As a result of the tests, excellent selectivity was obtained, and by-products of homo coupling were not seen in the spectra. The biaryls products were identified on a GC/MS. In addition, it was determined in the reusability tests that the catalysts could be used several times (seven runs). More importantly, with very low catalyst loading (6 × 10-3 mol %) in very short reaction time (5 min), chitosan Schiff base supported Pd(II) complex gave high TON and TOF values. These findings showed that Schiff base supported Pd(II) catalyst is suitable for Suzuki cross coupling reactions.

  6. Investigation of the oxygen affinity of manganese(II, cobalt(II and nickel(II complexes with some tetradentate Schiff bases

    Directory of Open Access Journals (Sweden)

    Adel A.A. Emara

    2014-12-01

    Full Text Available Oxygen absorption–desorption processes for square planar Mn(II, Co(II and Mn(II complexes of tetradentate Schiff base ligands in DMF and chloroform solvents were investigated. The tetradentate Schiff base ligands were obtained by condensation reaction of ethylenediamine with salcyldehyde, o-hydroxyacetophenone or acetylacetone in the molar ratio 1:2. The square planar complexes were prepared by the reaction of the Schiff base ligands with Mn(II acetate, Co(II nitrate and Ni(II nitrate in dry ethanol under nitrogen atmosphere. The sorption processes were undertaken in the presence and absence of (pyridine axial-base in 1:1 M ratio of (pyridine:metal(II complexes. Complexes in DMF indicate significant oxygen affinity than in chloroform solvent. Cobalt(II complexes showed significant sorption processes compared to Mn(II and Ni(II complexes. The presence of pyridine axial base clearly increases oxygen affinity.

  7. EPR interpretation, magnetism and biological study of a Cu(II) dinuclear complex assisted by a schiff base precursor.

    Science.gov (United States)

    Das, Kuheli; Patra, Chiranjit; Sen, Chandana; Datta, Amitabha; Massera, Chiara; Garribba, Eugenio; El Fallah, Mohamed Salah; Beyene, Belete B; Hung, Chen-Hsiung; Sinha, Chittaranjan; Askun, Tulin; Celikboyun, Pinar; Escudero, Daniel; Frontera, Antonio

    2017-06-01

    A new Cu(II) dinuclear complex, Cu2L2 (1) was afforded employing the potentially pentatentate Schiff base precursor H2L, a refluxed product of o-vanillin and diethylenetriamine in methanol. Complex 1 was systematically characterized by FTIR, UV-Vis, emission and EPR spectrometry. The single crystal X-ray diffraction analysis of 1 reveals that the copper atom exhibits a distorted square planar geometry, comprising two pairs of phenolato-O and imine-N donors from two different H2L ligands. The temperature dependent magnetic interpretation agrees with the existence of weak antiferromagnetic interactions between the bridging dinuclear Cu(II) ions. A considerable body of experimental evidence has been accumulated to elucidate the magneto-structural relationship in this dinuclear Cu(II) complex by DFT computation. Both the ligand and complex 1 exhibit anti-mycobacterial activity and considerable efficacy on M. tuberculosis H37Ra (ATCC 25177) and M. tuberculosis H37Rv (ATCC 25618) strains. The practical applicability of the ligand and complex 1 has been examined in living cells (African Monkey Vero Cells). The MTT assay proves the non-toxicity of the probe up to 100 mg mL-1. A new homometallic dinuclear Cu(II) complex is afforded with a tetradentate Schiff base precursor. EPR interpretation and temperature dependent magnetic studies show that complex 1 has weak antiferromagnetic coupling and DFT computation is governed to explain the magneto-structural correlation.

  8. Spectral characterization, electrochemical and anticancer studies on some metal(II) complexes containing tridentate quinoxaline Schiff base.

    Science.gov (United States)

    Chellaian, Justin Dhanaraj; Johnson, Jijo

    2014-06-05

    Co(II), Ni(II), Cu(II) and Zn(II) complexes of a tridentate ONO donor Schiff base ligand derived from 3-(2-aminoethylamino)quinoxalin-2(1H)-one were synthesized. The ligand and its metal complexes were characterized using elemental analysis, molar conductance, IR, (1)H NMR, mass, magnetic susceptibility, electronic spectra and ESR spectral studies. Electrochemical behavior of the synthesized compounds was studied using cyclic voltammetry. The grain size of the synthesized compounds was determined by powder XRD. The Schiff base and its complexes have been screened for their antimicrobial activities against the bacterial species E. coli, K. pneumoniae, P. aeruginosa and S. aureus; fungal species include, A. niger, and C. albicans by disc diffusion method. The results show that the complexes have higher activity than the free ligand. The interaction of the complexes with calf thymus DNA (CT DNA) has been investigated by electronic absorption method. Furthermore, the DNA cleavage activity of the complexes was studied using agarose gel electrophoresis. In vitro anticancer studies of the ligand and its complexes using MTT assay was also done. Copyright © 2014 Elsevier B.V. All rights reserved.

  9. Synthesis, spectroscopic, coordination and biological activities of some transition metal complexes containing ONO tridentate Schiff base ligand.

    Science.gov (United States)

    Belal, A A M; El-Deen, I M; Farid, N Y; Zakaria, Rosan; Refat, Moamen S

    2015-01-01

    The main target of this paper is to get an interesting data for the preparation and characterizations of metal oxide (MO) nanoparticles using H2L Schiff base complexes as precursors through the thermal decomposition procedure. Five Schiff base complexes of Mn(II), Co(II), Ni(II), Cu(II) and Zn(II) metal ions were synthesized from 2-[(2-hydroxy-naphthalen-1-ylmethylene)-amino]-benzoic acid new adduct (H2L). Theses complexes were characterized using infrared, electronic, mass and (1)H NMR spectroscopic techniques. The elemental analysis data was confirmed that the stoichiometry of (metal:H2L) is 1:1 molar ratio. The molar conductance indicates that all of complexes are non electrolytic. The general chemical formulas of these complexes is [M(L)(NH3)]·nH2O. All complexes are tetrahedral geometry. The thermal decomposition behavior of H2L hydrated and anhydrous complexes has been discussed using thermogravimetric analysis (TG/DTG) and differential thermal analyses (DTA) under nitrogen atmosphere. The crystalline phases of the reaction products were checked using X-ray diffractometer (XRD) and scanning electron microscopy (SEM). Copyright © 2015 Elsevier B.V. All rights reserved.

  10. Crystal structures of type I dehydroquinate dehydratase in complex with quinate and shikimate suggest a novel mechanism of Schiff base formation.

    Science.gov (United States)

    Light, Samuel H; Antanasijevic, Aleksandar; Krishna, Sankar N; Caffrey, Michael; Anderson, Wayne F; Lavie, Arnon

    2014-02-11

    A component of the shikimate biosynthetic pathway, dehydroquinate dehydratase (DHQD) catalyzes the dehydration of 3-dehydroquniate (DHQ) to 3-dehydroshikimate. In the type I DHQD reaction mechanism a lysine forms a Schiff base intermediate with DHQ. The Schiff base acts as an electron sink to facilitate the catalytic dehydration. To address the mechanism of Schiff base formation, we determined structures of the Salmonella enterica wild-type DHQD in complex with the substrate analogue quinate and the product analogue shikimate. In addition, we determined the structure of the K170M mutant (Lys170 being the Schiff base forming residue) in complex with quinate. Combined with nuclear magnetic resonance and isothermal titration calorimetry data that revealed altered binding of the analogue to the K170M mutant, these structures suggest a model of Schiff base formation characterized by the dynamic interplay of opposing forces acting on either side of the substrate. On the side distant from the substrate 3-carbonyl group, closure of the enzyme's β8-α8 loop is proposed to guide DHQ into the proximity of the Schiff base-forming Lys170. On the 3-carbonyl side of the substrate, Lys170 sterically alters the position of DHQ's reactive ketone, aligning it at an angle conducive for nucleophilic attack. This study of a type I DHQD reveals the interplay between the enzyme and substrate required for the correct orientation of a functional group constrained within a cyclic substrate.

  11. Synthesis, characterization, nano-sized binuclear nickel complexes, DFT calculations and antibacterial evaluation of new macrocyclic Schiff base compounds

    Science.gov (United States)

    Parsaee, Zohreh; Mohammadi, Khosro

    2017-06-01

    Some new macrocyclic bridged dianilines tetradentate with N4coordination sphere Schiff base ligands and their nickel(II)complexes with general formula [{Ni2LCl4} where L = (C20H14N2X)2, X = SO2, O, CH2] have been synthesized. The compounds have been characterized by FT-IR, 1H and 13C NMR, mass spectroscopy, TGA, elemental analysis, molar conductivity and magnetic moment techniques. Scanning electron microscopy (SEM) shows nano-sized structures under 100 nm for nickel (II) complexes. NiO nanoparticle was achieved via the thermal decomposition method and analyzed by FT-IR, SEM and X-ray powder diffraction which indicates closeaccordance to standard pattern of NiO nanoparticle. All the Schiff bases and their complexes have been detected in vitro both for antibacterial activity against two gram-negative and two gram-positive bacteria. The nickel(II) complexes were found to be more active than the free macrocycle Schiff bases. In addition, computational studies of three ligands have been carried out at the DFT-B3LYP/6-31G+(d,p) level of theory on the spectroscopic properties, including IR, 1HNMR and 13CNMR spectroscopy. The correlation between the theoretical and the experimental vibrational frequencies, 1H NMR and 13C NMR of the ligands were 0.999, 0.930-0.973 and 0.917-0.995, respectively. Also, the energy gap was determined and by using HOMO and LUMO energy values, chemical hardness-softness, electronegativity and electrophilic index were calculated.

  12. Antimicrobial efficacy of phenanthrenequinone based Schiff base complexes incorporating methionine amino acid: Structural elucidation and in vitro bio assay

    Science.gov (United States)

    Arun, Thesingu Rajan; Raman, Natarajan

    2014-06-01

    This work focuses the synthesis and characterization of few novel mixed ligand Schiff base metal complexes and their biological activities. For deriving the structural aspects, spectral techniques such as FT-IR, UV-Vis., 1H NMR, Raman, EPR and the physicochemical characterizations including elemental analysis, molar conductance and magnetic susceptibility method have been involved. All the complexes adopt square planar geometry. DNA binding ability of these complexes has been explored using diverse techniques viz. UV-Vis. absorption, fluorescence spectroscopy, viscometry and cyclic voltammetry. These studies prove that CT-DNA binding of the complexes follows the intercalation mode. Comparative DNA oxidative cleavage ability of the complexes has been done under ultraviolet photo radiation on pUC19 DNA. In addition, the biocidal action of the complexes has been investigated against few pathogenic bacteria and fungi by disc diffusion method. Importantly, the amylase inhibition activity of Cu(II) complex has been explored. The amylase inhibition property has been found to be increased upon increasing the complex concentration.

  13. Synthesis of metal complexes involving Schiff base ligand with methylenedioxy moiety: Spectral, thermal, XRD and antimicrobial studies

    Science.gov (United States)

    Sundararajan, M. L.; Jeyakumar, T.; Anandakumaran, J.; Karpanai Selvan, B.

    2014-10-01

    Metal complexes of Zn(II), Cd(II), Ni(II), Cu(II), Fe(III), Co(II), Mn(II) Hg(II), and Ag(I) have been synthesized from Schiff base ligand, prepared by the condensation of 3,4-(methylenedioxy)aniline and 5-bromo salicylaldehyde. All the compounds have been characterized by using elemental analysis, molar conductance, FT-IR, UV-Vis, 1H NMR, 13C NMR, mass spectra, powder XRD and thermal analysis (TG/DTA) technique. The elemental analysis suggests the stoichiometry to be 1:1 (metal:ligand). The FT-IR, 1H NMR, 13C NMR and UV-Vis spectral data suggest that the ligand coordinate to the metal atom by imino nitrogen and phenolic oxygen as bidentate manner. Mass spectral data further support the molecular mass of the compounds and their structure. Powder XRD indicates the crystalline state and morphology of the ligand and its metal complexes. The thermal behaviors of the complexes prove the presence of lattice as well as coordinated water molecules in the complexes. Melting point supports the thermal stability of all the compounds. The in vitro antimicrobial effects of the synthesized compounds were tested against five bacterial and three fungal species by well diffusion method. Antioxidant activities have also been performed for all the compounds. Metal complexes show more biological activity than the Schiff base.

  14. Modern spectroscopic technique in the characterization of biosensitive macrocyclic Schiff base ligand and its complexes: Inhibitory activity against plantpathogenic fungi

    Science.gov (United States)

    Tyagi, Monika; Chandra, Sulekh; Akhtar, Jameel; Chand, Dinesh

    2014-01-01

    Complexes of the type [M(L)Cl2], where M = Co(II), Ni(II) and Cu(II) have been synthesized with a macrocyclic Schiff base ligand (1,4,5,7,10,11,12,15-octaaza,5,11,16,18-tetraphenyl, 3,4,12,13-tetramethyl cyclo-octadecane) derived from Schiff base (obtained by the condensation of 4-aminoantipyrine and dibenzoyl methane) and ethylenediamine. The ligand was characterized on the basis of elemental analysis, IR, 1H NMR, EI Mass and molecular modeling studies while the complexes were characterized by elemental analysis, molar conductance measurements, magnetic susceptibility measurements, IR, electronic and EPR spectral studies. All the complexes are non-electrolyte in nature. The covalency factor (β) and coefficient factor (α) suggest the covalent nature of the complexes. The ligand and its metal complexes have shown antifungal activity with their LD50 values determined by probit analysis against two economically important fungal plant pathogens i.e. Macrophomina phaseolina and Fusarium solani.

  15. Synthesis of metal complexes involving Schiff base ligand with methylenedioxy moiety: spectral, thermal, XRD and antimicrobial studies.

    Science.gov (United States)

    Sundararajan, M L; Jeyakumar, T; Anandakumaran, J; Karpanai Selvan, B

    2014-10-15

    Metal complexes of Zn(II), Cd(II), Ni(II), Cu(II), Fe(III), Co(II), Mn(II) Hg(II), and Ag(I) have been synthesized from Schiff base ligand, prepared by the condensation of 3,4-(methylenedioxy)aniline and 5-bromo salicylaldehyde. All the compounds have been characterized by using elemental analysis, molar conductance, FT-IR, UV-Vis, (1)H NMR, (13)C NMR, mass spectra, powder XRD and thermal analysis (TG/DTA) technique. The elemental analysis suggests the stoichiometry to be 1:1 (metal:ligand). The FT-IR, (1)H NMR, (13)C NMR and UV-Vis spectral data suggest that the ligand coordinate to the metal atom by imino nitrogen and phenolic oxygen as bidentate manner. Mass spectral data further support the molecular mass of the compounds and their structure. Powder XRD indicates the crystalline state and morphology of the ligand and its metal complexes. The thermal behaviors of the complexes prove the presence of lattice as well as coordinated water molecules in the complexes. Melting point supports the thermal stability of all the compounds. The in vitro antimicrobial effects of the synthesized compounds were tested against five bacterial and three fungal species by well diffusion method. Antioxidant activities have also been performed for all the compounds. Metal complexes show more biological activity than the Schiff base. Copyright © 2014 Elsevier B.V. All rights reserved.

  16. Two Types of Anion-Induced Reconstruction of Schiff-Base Macrocyclic Zinc Complexes: Ring-Contraction and Self-Assembly of a Molecular Box.

    Science.gov (United States)

    Zhang, Kun; Zhang, Lei; Feng, Gen-Feng; Hu, Yong; Chang, Fei-Fan; Huang, Wei

    2016-01-04

    Two 46-membered [2 + 2] Schiff-base macrocyclic dinuclear Zn(II) complexes (1a and 1b) were investigated deeply by the postmodification strategy, and two types of supramolecular processes (ring-contraction and self-assembly) have been achieved after the addition of specific anions as stimulus for the equilibrium of Schiff-base macrocyclic complexes. Namely, in the presence of linear three-atom SCN(-), 1a was degraded into two 23-membered [1 + 1] Schiff-base macrocyclic complexes simultaneously (mononuclear Zn(II) complex 2 and dinuclear Zn(II) complex 3). In contrast, 1b was only transformed into the macrocyclic mononuclear complex 5. More interestingly, in the case of pseudolinear five-atom N(CN)2(-), supramolecular self-assembly took place instead of the above-mentioned ring-contraction. Finally, 1a was assembled into a unique molecular box 4 with two 46-membered [2 + 2] Schiff-base macrocyclic heteronuclear Zn4Na4 substrates and double μ2-N(CN)2(-) bridges, while no similar assembly process was observed for 1b. The geometry of anions and pH values slightly adjusted by the pendant arms on the macrocyclic skeletons are believed to be the critical factors for the different supramolecular processes originating from the dynamic covalent chemistry of Schiff-base imine bonds.

  17. Synthesis, characterization and biological activity of transition metal complexes with Schiff bases derived from 2-nitrobenzaldehyde with glycine and methionine

    Science.gov (United States)

    Singh, Bibhesh K.; Rajour, Hemant K.; Prakash, Anant

    Schiff bases derived from 2-nitrobenzaldehyde with amino acids (glycine, methionine) and their Co(II), Ni(II) and Cu(II) complexes have been synthesized and characterized by various physico-chemical techniques. From spectral studies, it has been concluded that the ligands acts as bidentate molecule, coordinates metal through azomethine nitrogen and carboxylate oxygen. Mass spectrum explains the successive degradation of the molecular species in solution and justifies ML2 complexes. X-ray powder diffraction helps to determine the cell parameters of the complexes. Molecular structure of the complexes has been optimized by MM2 calculations and suggests a square planar geometry. The ligands and their metal complexes have been tested in vitro against Streptococcus, Staph, Staphylococcus aureus and Escherchia coli bacteria in order to assess their antibacterial potential. The results indicate that the biological activity increases on complexation.

  18. L-glutamine Schiff base copper complex as a proteasome inhibitor and an apoptosis inducer in human cancer cells.

    Science.gov (United States)

    Xiao, Yan; Bi, Caifeng; Fan, Yuhua; Cui, Cindy; Zhang, Xia; Dou, Q Ping

    2008-11-01

    Interest in the use of metallic compounds for cancer treatment has been increasing since the discovery of cisplatin. Clinical studies suggest the use of proteasome inhibitors as potential novel anticancer agents. L-glutamine is the most abundant free amino acid in the body, and has been shown to play a regulatory role in several cellular processes, including metabolism, degradation, redox potential and cellular integrity. Although glutamine is reported to play a role in the regulation of apoptosis, the effect of glutamine copper complex on tumor cells and the involved molecular mechanism have not been investigated. Here, for the first time, we report that a newly synthesized L-glutamine-containing copper complex has proteasome-inhibitory activity in human breast cancer and leukemia cells. The inhibition of the tumor proteasomal activity results in the accumulation of ubiquitinated proteins and ubiquitinated form of IkappaB-alpha, a natural proteasome substrate, followed by induction of apoptosis. Furthermore, this glutamine Schiff base copper complex selectively inhibits the proteasomal activity and induces cell death in cultured breast cancer cells, but not normal, immortalized breast cells. Our data suggest that glutamine Schiff base copper complexes have a potential use for to be used in cancer treatment and prevention.

  19. Synthesis of Schiff bases of naphtha[1,2-d]thiazol-2-amine and metal complexes of 2-(2'-hydroxy)benzylideneaminonaphthothiazole as potential antimicrobial agents.

    Science.gov (United States)

    Azam, Faizul; Singh, Satendra; Khokhra, Sukhbir Lal; Prakash, Om

    2007-06-01

    A series of 2-benzylideneaminonaphthothiazoles were designed and synthesized incorporating the lipophilic naphthalene ring to render them more capable of penetrating various biomembranes. Schiff bases were synthesized by the reaction of naphtha[1,2-d]thiazol-2-amine with various substituted aromatic aldehydes. 2-(2'-Hydroxy)benzylideneaminonaphthothiazole was converted to its Co(II), Ni(II) and Cu(II) metal complexes upon treatment with metal salts in ethanol. All the compounds were evaluated for their antibacterial activities by paper disc diffusion method with Gram positive Staphylococcus aureus and Staphylococcus epidermidis and Gram negative Escherichia coli and Pseudomonas aeruginosa bacteria. The minimum inhibitory concentrations of all the Schiff bases and metal complexes were determined by agar streak dilution method. All the compounds moderately inhibited the growth of Gram positive and Gram negative bacteria. In the present study among all Schiff bases 2-(2'-hydroxy)benzylideneaminonaphthothiazole showed maximum inhibitory activity and among metal complexes Cu(II) metal complex was found to be most potent. The results obtained validate the hypothesis that Schiff bases having substitution with halogens, hydroxyl group and nitro group at phenyl ring are required for the antibacterial activity while methoxy group at different positions in the aromatic ring has minimal role in the inhibitory activity. The results also indicated that the metal complexes are better antibacterial agents as compared to the Schiff bases.

  20. Co(II), Ni(II) and Cu(II) complexes with coumarin-8-yl Schiff-bases: Spectroscopic, in vitro antimicrobial, DNA cleavage and fluorescence studies

    Science.gov (United States)

    Patil, Sangamesh A.; Unki, Shrishila N.; Kulkarni, Ajaykumar D.; Naik, Vinod H.; Badami, Prema S.

    2011-09-01

    A new series of Co(II), Ni(II) and Cu(II) complexes of the type ML·2H 2O of Schiff-bases derived from m-substituted thiosemicarbazides and 8-acetyl-7-hydroxy-4-methylcoumarin have been synthesized and characterized by spectroscopic studies. Schiff-bases exhibit thiol-thione tautomerism wherein sulphur plays an important role in the coordination. The coordination possibility of the Schiff-bases towards metal ions have been proposed in the light of elemental analyses, spectral (IR, UV-vis, FAB-mass, ESR and fluorescence), magnetic and thermal studies. The low molar conductance values in DMF indicate that, the metal complexes are non-electrolytes. The cyclic voltammetric studies suggested that, the Cu(II) and Ni(II) complexes are of single electron transfer quasi-reversible nature. The Schiff-bases and its metal complexes have been evaluated for their in vitro antibacterial ( Escherichia coli, Staphilococcus aureus, Bascillus subtilis and Salmonella typhi) and antifungal activities ( Candida albicans, Cladosporium and Aspergillus niger) by MIC method. The Schiff-base I and its metal complexes exhibited DNA cleavage activity on isolated DNA of A. niger.

  1. Synthesis, characterization and antibacterial studies of Mn(II and Co(II complexes of an ionic liquid tagged Schiff base

    Directory of Open Access Journals (Sweden)

    Saha Sanjoy

    2016-01-01

    Full Text Available Mn(II and Co(II complexes of an ionic liquid-based Schiff base, 1-{2-(2-hydroxybenzylideneaminoethyl}-3-methylimidazolium bromide, were synthesized and characterized by various analytical and spectroscopic methods such as elemental analysis, UV-Visible, FT-IR, 1H NMR, ESI-MS and magnetic susceptibility measurement. These studies indicated tetrahedral geometry for the complexes. The Schiff base ligand and its complexes were tested for in vitro antibacterial activities to assess their inhibiting potentials against Escherichia coli and Lactobacillus sp.

  2. Synthesis, Spectroscopic, and Magnetic Studies of Mono- and Polynuclear Schiff Base Metal Complexes Containing Salicylidene-Cefotaxime Ligand

    Directory of Open Access Journals (Sweden)

    J. R. Anacona

    2013-01-01

    Full Text Available Metal complexes of a Schiff base ligand derived from cefotaxime and salicylaldehyde were prepared. The salicilydene-cefotaxime ligand (H2L and mononuclear [M(L] (M(II = Co, Ni and Cu, dinuclear [Ag2(L(OAc2], and tetranuclear metal complexes [M4(L(OH6] (M(II = Ni, Cu were characterized on the basis of analytical, thermal, magnetic, and spectral studies (IR, UV-visible, 1H NMR, 13C NMR, and EPR. The electronic spectra of the complexes and their magnetic moments suggesttetrahedral geometry for the isolated complexes. The complexes are nonelectrolytes and insoluble in water and common organic solvents but soluble in DMSO.

  3. 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.

  4. All-optical switching and limiting properties of a Ru (II) Schiff-base complex for nonlinear optical applications

    Science.gov (United States)

    Manjunatha, K. B.; Rajarao, Ravindra; Umesh, G.; Ramachandra Bhat, B.; Poornesh, P.

    2017-08-01

    A salen-based ruthenium (Ru) (II) complex was synthesized for possible use in nonlinear optical device applications. The Ru complex was doped in a polymer matrix to fabricate films using a low-cost spin-coating technique. The third-order nonlinear optical parameters of the complex were investigated by Z-scan and degenerate four-wave mixing techniques. The study reveals two-order enhancement of third-order optical susceptibility χ (3) and exhibits superior limiting capability due to a reverse saturable absorption process. All-optical switching action for the films indicates that the sample can function as an optical inverter or a NOT gate. Hence, the Ru (II) Schiff-base complex materializes as a possible candidate for use in nonlinear optical devices.

  5. SOD activity and DNA binding properties of a new symmetric porphyrin Schiff base ligand and its metal complexes.

    Science.gov (United States)

    Çay, Sevim; Köse, Muhammet; Tümer, Ferhan; Gölcü, Ayşegül; Tümer, Mehmet

    2015-12-05

    4-Methoxy-2,6-bis(hydroxymethyl)phenol (1) was prepared from the reaction of 4-methoxyphenol and formaldehyde. The compound (1) was then oxidized to the 4-methoxy-2,6-diformylphenol (2) compound. Molecular structure of compound (2) was determined by X-ray diffraction method. A new symmetric porphyrin Schiff base ligand 4-methoxy-2,6-bis[5-(4-iminophenyl)-10,15,20-triphenylporphyrin]phenol (L) was prepared from the reaction of the 5-(4-aminophenyl)-10,15,20-triphenylporphyrin (TTP-NH2) and the compound (2) in the toluene solution. The metal complexes (Cu(II), Fe(III), Mn(III), Pt(II) and Zn(II)) of the ligand (L) were synthesized and characterized by the spectroscopic and analytical methods. The DNA (fish sperm FSdsDNA) binding studies of the ligand and its complexes were performed using UV-vis spectroscopy. Additionally, superoxide dismutase activities of the porphyrin Schiff base metal complexes were investigated. Additionally, electrochemical, photoluminescence and thermal properties of the compounds were investigated. Copyright © 2015 Elsevier B.V. All rights reserved.

  6. Synthesis of copper/nickel nanoparticles using newly synthesized Schiff-base metals complexes and their cytotoxicity/catalytic activities.

    Science.gov (United States)

    Aazam, Elham S; El-Said, Waleed Ahmed

    2014-12-01

    Transition metal complexes compounds with Schiff bases ligand representing an important class of compounds that could be used to develop new metal-based anticancer agents and as precursors of metal NPs. Herein, 2,3-bis-[(3-ethoxy-2-hydroxybenzylidene)amino]but-2-enedinitrile Schiff base ligand and its corresponding copper/nickel complexes were synthesized. Also, we reported a facile and rapid method for synthesis nickel/copper nanoparticles based on thermal reduction of their complexes. Free ligand, its metal complexes and metals nanoparticles have been characterized based on elemental analysis, transmission electron microscopy, powder X-ray diffraction, magnetic measurements and by various spectroscopic (UV-vis, FT-IR, (1)H NMR, GC-MS) techniques. Additionally, the in vitro cytotoxic activity of free ligand and its complexes compounds were assessed against two cancer cell lines (HeLa and MCF-7 cells)and one healthy cell line (HEK293 cell). The copper complex was found to be active against these cancer cell lines at very low LD50 than the free ligand, while nickel complex did not show any anticancer activity against these cell lines. Also, the antibacterial activity of as-prepared copper nanoparticles were screened against Escherichia coli, which demonstrated minimum inhibitory concentration and minimum bactericidal concentration values lower than those values of the commercial Cu NPs as well as the previous reported values. Moreover, the synthesized nickel nanoparticles demonstrated remarkable catalytic performance toward hydrogenation of nitrobenzene that producing clean aniline with high selectivity (98%). This reactivity could be attributed to the high degree of dispersion of Ni nanoparticles. Copyright © 2014 Elsevier Inc. All rights reserved.

  7. Synthesis, crystal structure, fluorescence and electrochemical studies of a new tridentate Schiff base ligand and its nickel(II) and palladium(II) complexes.

    Science.gov (United States)

    Shafaatian, Bita; Soleymanpour, Ahmad; Kholghi Oskouei, Nasim; Notash, Behrouz; Rezvani, Seyyed Ahmad

    2014-07-15

    A new unsymmetrical tridentate Schiff base ligand was derived from the 1:1M condensation of ortho-vanillin with 2-mercaptoethylamine. Nickel and palladium complexes were obtained by the reaction of the tridentate Schiff base ligand with nickel(II) acetate tetrahydrate and palladium(II) acetate in 2:1M ratio. In nickel and palladium complexes the ligand was coordinated to metals via the imine N and enolic O atoms. The S groups of Schiff bases were not coordinated to the metals and S-S coupling was occured. The complexes have been found to possess 1:2 Metal:Ligand stoichiometry and the molar conductance data revealed that the metal complexes were non-electrolytes. The complexes exhibited octahedral coordination geometry. The emission spectra of the ligand and its complexes were studied in methanol. Electrochemical properties of the ligand and its metal complexes were investigated in the CH3CN solvent at the 100 mV s(-1) scan rate. The ligand and metal complexes showed both reversible and quasi-reversible processes at this scan rate. The Schiff base and its complexes have been characterized by IR, (1)H NMR, UV/Vis, elemental analyses and conductometry. The crystal structure of nickel complex has been determined by single crystal X-ray diffraction. Copyright © 2014 Elsevier B.V. All rights reserved.

  8. Fast O2 Binding at Dicopper Complexes Containing Schiff-Base Dinucleating Ligands

    Science.gov (United States)

    Company, Anna; Gómez, Laura; Mas-Ballesté, Rubén; Korendovych, Ivan V.; Ribas, Xavi; Poater, Albert; Parella, Teodor; Fontrodona, Xavier; Benet-Buchholz, Jordi; Solà, Miquel; Que, Lawrence; Rybak-Akimova, Elena; Costas, Miquel

    2008-01-01

    A new family of dicopper(I) complexes [CuI2RL](X)2, (R = H, 1X, R = tBu, 2X and R = NO2, 3X, X = CF3SO3, ClO4, SbF6 or BArF, BArF = [B{3,5-(CF3)2-C6H3}4]−), where RL is a Schiff-base ligand containing two tridentate binding sites linked by a xylyl spacer have been prepared, characterized, and their reaction with O2 studied. The complexes were designed with the aim of reproducing structural aspects of the active site of type 3 dicopper proteins; they contain two three-coordinate copper sites and a rather flexible podand ligand backbone. The solid state structures of 1ClO4, 2CF3SO3, 2ClO4 and 3BArF·CH3CN have been established by single crystal X-ray diffraction analysis. 1ClO4 adopts a polymeric structure in solution while 2CF3SO3, 2ClO4 and 3BArF·CH3CN are monomeric. The complexes have been studied in solution by means of 1H and 19F NMR spectroscopy, which put forward the presence of dynamic processes in solution. 1-3BArF and 1-3CF3SO3 in acetone react rapidly with O2 to generate metaestable [CuIII2(μ-O)2(RL)]2+ 1-3(O2) and [CuIII2(μ-O)2(CF3SO3)(RL)]+ 1-3(O2)(CF3SO3) species, respectively that have been characterized by UV-vis spectroscopy and resonance Raman analysis. Instead, reaction of 1-3BArF with O2 in CH2Cl2 results in intermolecular O2 binding. DFT methods have been used to study the chemical identities and structural parameters of the O2 adducts, and the relative stability of the CuIII2(μ-O)2 form with respect to the CuII2(μ-η2: η2-peroxo) isomer. The reaction of 1X, X = CF3SO3 and BArF with O2 in acetone has been studied by stopped-flow exhibiting an unexpected very fast reaction rate (k = 3.82(4) × 103 M−1s−1, ΔH‡ = 4.9 ± 0.5 kJ·mol−1, ΔS‡ = −148 ± 5 J·K−1·mol−1), nearly three orders of magnitude faster than in the parent [CuI2(m-XYLMeAN)]2+. Thermal decomposition of 1-3(O2) does not result in aromatic hydroxylation. The mechanism and kinetics of O2 binding to 1X (X = CF3SO3 and BArF) is discussed and compared with those

  9. synthesis of schiff bases derived from 2-hydroxy-1-naphth

    African Journals Online (AJOL)

    KEY WORDS: Schiff base, 2-Hydroxy-1-naphthaldehyde, L-Histidine and sulfamethazine, Tin(II) complexes,. Antimicrobial activities ... be involved in copper transport in blood [12]. Sulfonamides are an ..... activity and thermodynamic studies of five coordinate cobalt(III) Schiff base complexes. Bull. Chem. Soc. Ethiop. 2016 ...

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

    Science.gov (United States)

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

    2012-08-15

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

  11. Herbo-mineral based Schiff base ligand and its metal complexes: Synthesis, characterization, catalytic potential and biological applications.

    Science.gov (United States)

    Kareem, Abdul; Laxmi; Arshad, Mohammad; Nami, Shahab A A; Nishat, Nahid

    2016-07-01

    Schiff base ligand, (L), derived from condensation reaction of 1,7-bis-(4-hydroxy-3-methoxyphenyl)-1,6-heptadiene-3,5-dione, (curcumin), with pyridine-3-carboxamide, (nicotinamide), and its complexes of Co(II), Ni(II) and Cu(II) ions, containing 1,10-phenanthroline as auxiliary ligand were synthesized and characterized by various physico-chemical techniques. From the micro analytical data, the stoichiometry of the complexes 1:1 (metal: ligand) was ascertained. The Co(II) and Cu(II) forms octahedral complexes, while the geometric structure around Ni(II) atom can be described as square planar. The catalytic potential of the metal complexes have been evaluated by recording the rate of decomposition of hydrogen peroxide. The results reveal that the percent decomposition of H2O2increases with time and the highest value (50.50%) was recorded for Co(II) complex. The ligand and its complexes were also screened for their in vitro antibacterial activity against Escherichia coli, Staphylococcus aureus, Klebsiella pneumoniae, Streptococcus pyogenes and Pseudomonas aeruginosa. The relative order of antibacterial activity against S. Pyogenes, S. aureus and E. coli is Cu(II)>Ni(II)>Co(II)>(L); while with P. aeruginosa, K. pneumoniae the order of activity is Cu(II)>Co(II)>Ni(II)>(L). The anthelmintic screening was performed using Pheretima posthuma. The order of anthelmintic activity of ligand and its complexes is [(Phen)CuLCl2]>[(Phen)CoLCl2]>[(Phen)NiL]Cl2>(L). Copyright © 2016 Elsevier B.V. All rights reserved.

  12. Synthesis, X-ray crystal structures, electrochemistry and theoretical investigation of a tetradentate nickel and copper Schiff base complexes

    Science.gov (United States)

    Rahmouni, Samra; Djedouani, Amel; Anak, Barkahem; Tabti, Salima; Bendaas, Abderrahmen; Bencharif, Mustapha; François, Michel; Fleutot, Solenne; Rabilloud, Franck

    2017-11-01

    New tetradentate mononuclear nickel(II) [NiL] and pentadentate binuclear copper(II) [Cu2L2H2O], H2O Schiff base complexes have been synthesized. The crystal structures of [NiL] and [Cu2L2H2O], H2O have been determined by X-ray diffraction method showing distorted square-planar geometry for [NiL] and distorted tetragonal pyramid geometry for [Cu2L2H2O], H2O. In both complexes, the dehydroacetic acid functional group engages in a deprotonated manner and coordination occurs through the nitrogen atoms of the imine function and the phenolic oxygen. Density Functional Theory calculations are carried out for the determination of the optimized structures. The fundamental vibrational wave numbers are calculated and a good agreement between observed and calculated wave numbers is achieved.

  13. Steric effects in the design of Co-Schiff base complexes for the catalytic oxidation of lignin models to para-benzoquinones

    Science.gov (United States)

    Berenger Biannic; Joseph J. Bozell; Thomas Elder

    2014-01-01

    New Co-Schiff base complexes that incorporate a sterically hindered ligand and an intramolecular bulky piperazine base in close proximity to the Co center are synthesized. Their utility as catalysts for the oxidation of para-substituted lignin model phenols with molecular oxygen is examined. Syringyl and guaiacyl alcohol, as models of S and G units in lignin, are...

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

    Science.gov (United States)

    Shebl, Magdy

    2014-01-03

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

  15. Schiff Bases: A Short Survey on an Evergreen Chemistry Tool

    Directory of Open Access Journals (Sweden)

    Mauro Panunzio

    2013-10-01

    Full Text Available The review reports a short biography of the Italian naturalized chemist Hugo Schiff and an outline on the synthesis and use of his most popular discovery: the imines, very well known and popular as Schiff Bases. Recent developments on their “metallo-imines” variants have been described. The applications of Schiff bases in organic synthesis as partner in Staudinger and hetero Diels-Alder reactions, as “privileged” ligands in the organometallic complexes and as biological active Schiff intermediates/targets have been reported as well.

  16. DNA binding, BSA interaction and SOD activity of two new nickel(II) complexes with glutamine Schiff base ligands.

    Science.gov (United States)

    Wei, Qiang; Dong, Jianfang; Zhao, Peiran; Li, Manman; Cheng, Fengling; Kong, Jinming; Li, Lianzhi

    2016-08-01

    Two hexacoordinated octahedral nickel(II) complexes, [Ni(o-van-gln)(phen)(H2O)](1) and [Ni(sal-gln)(phen)(H2O)](2) [o-van-gln=a Schiff base derived from o-vanillin and glutamine, sal-gln=a Schiff base derived from salicylaldehyde and glutamine, phen=1,10-phenanthroline], have been synthesized and characterized by elemental analysis, IR spectra and single crystal X-ray diffraction. X-ray studies showed that nickel atoms of both 1 and 2 exhibit distorted NiN3O3 octahedral geometry. In each crystal, intermolecular hydrogen bonds form a two-dimensional network structure. DNA-binding properties of these two nickel(II) complexes were investigated by using UV-Vis absorption, fluorescence, circular dichroism (CD) spectroscopies and viscosity measurements. Results indicated that the two complexes can bind to calf thymus DNA (CT-DNA) via an intercalative mode, and complex 1 exhibits higher interaction with CT-DNA than complex 2. Furthermore, the interactions between the nickel(II) complexes with bovine serum albumin (BSA) have been studied by spectroscopies. The results indicated that both complexes could quench the intrinsic fluorescence of BSA in a static quenching process. The binding constants (Kb) and the numbers of binding sites (n) obtained are 1.10×10(5)M(-1) and 1.05 for complex 1 and 5.05×10(4)M(-1) and 0.997 for complex 2, respectively. Site-selective competitive binding investigation indicated that the binding sites of both the complexes are located in site I of sub-domains IIA of BSA. Assay of superoxide dismutase (SOD) activity of the nickel(II) complexes revealed that they exhibit significant superoxide scavenging activity with IC50=3.4×10(-5)M for complex 1 and 4.3×10(-5)M for complex 2, respectively. Copyright © 2016 Elsevier B.V. All rights reserved.

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

    Directory of Open Access Journals (Sweden)

    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.

  18. Synthesis, interaction with DNA and antiproliferative activities of two novel Cu(II) complexes with Schiff base of benzimidazole

    Science.gov (United States)

    Song, Wen-Ji; Cheng, Jian-Ping; Jiang, Dong-Hua; Guo, Li; Cai, Meng-Fei; Yang, Hu-Bin; Lin, Qiu-Yue

    2014-03-01

    Two novel copper(II) complexes with Schiff base of benzimidazole [Cu(L)Cl]2·CH3OH have been synthesized. HL1 (N-(benzimidazol-2-ymethyl)-5-chlorosalicylideneimine, C15H11ClN3O) and HL2 (N-(benzimidazol-2-ymethyl)-salicylideneimine, C15H12N3O) are ligands of complex (1) and complex (2), respectively. The complexes were characterized by elemental analysis, IR, UV-Vis, TGA and X-ray diffraction. Within the complexes, Cu(II) ions were four coordinated by two nitrogen atom of azomethine and imine, one phenolic oxygen atom from HL and one chloride atom. A distorted quadrilateral structure was formed. Complex (1) crystallized in the triclinic crystal system. Results showed that π-π stacking effect occurred due to the existence of aromatic ring from Schiff base and hydrogen bonding between methanol and adjacent atoms. The DNA binding properties of the complexes were investigated by electronic absorption spectra, fluorescence spectra and viscosity measurements. Results indicated that complexes bound to DNA via partial intercalation mode. The DNA binding constants Kb/(L mol-1) were 1.81 × 104 (1), 1.37 × 104 (2), 6.27 × 103 (HL1) and 3.14 × 103 (HL2) at 298 K. The title complexes could quench the emission intensities of EB-DNA system significantly. The results of agarose gel electrophoresis indicated complex (1) could cleave supercoiled DNA through the oxidative mechanism. The inhibition ratios revealed that complex (1) and HL1 had strong antiproliferative activities against human breast cancer cells (MCF-7) lines and human colorectal cancer cells (COLO205) lines in vitro. The antiproliferative activities of complex (1) against MCF-7 lines (IC50 = 16.9 ± 1.5 μmol L-1) and against COLO205 lines (IC50 = 16.5 ± 3.4 μmol L-1) is much stronger than that of HL1, which had the potential to develop anti-cancer drug.

  19. Synthesis, interaction with DNA and antiproliferative activities of two novel Cu(II) complexes with Schiff base of benzimidazole.

    Science.gov (United States)

    Song, Wen-Ji; Cheng, Jian-Ping; Jiang, Dong-Hua; Guo, Li; Cai, Meng-Fei; Yang, Hu-Bin; Lin, Qiu-Yue

    2014-01-01

    Two novel copper(II) complexes with Schiff base of benzimidazole [Cu(L)Cl]2·CH3OH have been synthesized. HL(1) (N-(benzimidazol-2-ymethyl)-5-chlorosalicylideneimine, C15H11ClN3O) and HL(2) (N-(benzimidazol-2-ymethyl)-salicylideneimine, C15H12N3O) are ligands of complex (1) and complex (2), respectively. The complexes were characterized by elemental analysis, IR, UV-Vis, TGA and X-ray diffraction. Within the complexes, Cu(II) ions were four coordinated by two nitrogen atom of azomethine and imine, one phenolic oxygen atom from HL and one chloride atom. A distorted quadrilateral structure was formed. Complex (1) crystallized in the triclinic crystal system. Results showed that π-π stacking effect occurred due to the existence of aromatic ring from Schiff base and hydrogen bonding between methanol and adjacent atoms. The DNA binding properties of the complexes were investigated by electronic absorption spectra, fluorescence spectra and viscosity measurements. Results indicated that complexes bound to DNA via partial intercalation mode. The DNA binding constants Kb/(L mol(-1)) were 1.81×10(4) (1), 1.37×10(4) (2), 6.27×10(3) (HL(1)) and 3.14×10(3) (HL(2)) at 298 K. The title complexes could quench the emission intensities of EB-DNA system significantly. The results of agarose gel electrophoresis indicated complex (1) could cleave supercoiled DNA through the oxidative mechanism. The inhibition ratios revealed that complex (1) and HL(1) had strong antiproliferative activities against human breast cancer cells (MCF-7) lines and human colorectal cancer cells (COLO205) lines in vitro. The antiproliferative activities of complex (1) against MCF-7 lines (IC50=16.9±1.5 μmol L(-1)) and against COLO205 lines (IC50=16.5±3.4 μmol L(-1)) is much stronger than that of HL(1), which had the potential to develop anti-cancer drug. Copyright © 2013 Elsevier B.V. All rights reserved.

  20. Synthesis of α-Amino Acids via Asymmetric Phase Transfer-Catalyzed Alkylation of Achiral Nickel(II) Complexes of Glycine-Derived Schiff Bases

    NARCIS (Netherlands)

    Belokon, Yuri N.; Bespalova, Natalia B.; Churkina, Tatiana D.; Císařová, Ivana; Ezernitskaya, Marina G.; Harutyunyan, Syuzanna R.; Hrdina, Radim; Kagan, Henri B.; Kočovský, Pavel; Kochetkov, Konstantin A.; Larionov, Oleg V.; Lyssenko, Konstantin A.; North, Michael; Polášek, Miroslav; Peregudov, Alexander S.; Prisyazhnyuk, Vladimir V.; Vyskočil, Štěpán

    2003-01-01

    Achiral, diamagnetic Ni(II) complexes 1 and 3 have been synthesized from Ni(II) salts and the Schiff bases, generated from glycine and PBP and PBA, respectively, in MeONa/MeOH solutions. The requisite carbonyl-derivatizing agents pyridine-2-carboxylic acid(2-benzoyl-phenyl)-amide (PBP) and

  1. Synthesis, spectral characterization and biological activity of zinc(II) complexes with 3-substituted phenyl-4-amino-5-hydrazino-1, 2, 4-triazole Schiff bases

    Science.gov (United States)

    Singh, A. K.; Pandey, O. P.; Sengupta, S. K.

    New Zn(II) complexes have been synthesized by the reactions of zinc(II) acetate with Schiff bases derived from 3-substituted phenyl-4-amino-5-hydrazino-1, 2, 4-triazole and benzaldehyde, 2-hydroxyacetophenone or indoline-2,3-dione. All these complexes are soluble in DMF and DMSO; low molar conductance values indicate that they are non-electrolytes. Elemental analyses suggest that the complexes have 1:1 stoichiometry of the type [ZnL(H 2O) 2], [ZnL'(OAc) 2(H 2O) 2] (L = dianionic Schiff bases derived from 3-(substituted phenyl)-4-amino-5-hydrazino-1, 2, 4-triazole and 2-hydroxyacetophenone or indoline-2,3-dione; L' = neutral Schiff bases derived from 3-(substituted phenyl)-4-amino-5-hydrazino-1, 2, 4-triazole and benzaldehyde) and they were characterized by FT-IR, 1H NMR, 13C NMR and FAB mass. All these Schiff bases and their complexes have also been screened for their antibacterial activities against Bacillus subtilis, Escherichia coli and antifungal activities against Colletotrichum falcatum, Aspergillus niger, Fusarium oxysporium and Carvularia pallescence by petriplates methods.

  2. Studies on DNA binding behaviour of biologically active transition metal complexes of new tetradentate N2O2 donor Schiff bases: Inhibitory activity against bacteria

    Science.gov (United States)

    Sobha, S.; Mahalakshmi, R.; Raman, N.

    A series of Cu(II), Ni(II) and Zn(II) complexes of the type ML have been synthesized with Schiff bases derived from o-acetoacetotoluidide, 2-hydroxybenzaldehyde and o-phenylenediamine/1,4-diaminobutane. The complexes are insoluble in common organic solvents but soluble in DMF and DMSO. The measured molar conductance values in DMSO indicate that the complexes are non-electrolytic in nature. All the six metal complexes have been fully characterized with the help of elemental analyses, molecular weights, molar conductance values, magnetic moments and spectroscopic data. The analytical data helped to elucidate the structure of the metal complexes. The Schiff bases are found to act as tetradentate ligands using N2O2 donor set of atoms leading to a square-planar geometry for the complexes around all the metal ions. The binding properties of metal complexes with DNA were investigated by absorption spectra, viscosity measurements and cyclic voltammetry. Detailed analysis reveals that the metal complexes intercalate into the DNA base stack as intercalators. All the metal complexes cleave the pUC19 DNA in presence of H2O2. The Schiff bases and their complexes have been screened for their antibacterial activity against five bacterial strains (Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, Staphylococcus epidermidis, Klebsiella pneumoniae) by disk diffusion method. All the metal complexes have potent biocidal activity than the free ligands.

  3. Antitumor activity of a Trans-thiosemicarbazone schiff base palladium (II) complex on human gastric adenocarcinoma cells.

    Science.gov (United States)

    Zhang, Bingchang; Luo, Haiqing; Xu, Qinjuan; Lin, Lirong; Zhang, Bing

    2017-02-21

    The development of transition-metal-based antitumor drug candidates increases the metallopharmaceuticals study dramatically. Two trans-thiosemicarbazone-based, Schiff base palladium (Pd) (II) complexes, DMABTSPd (TSPd) and DMABPTSPd (PTSPd), were prepared and characterized as described in our previous study. Here, we investigated whether the two complexes have antitumor effect on human gastric adenocarcinoma cell lines, BGC-823 and SGC-7901, compared with normal human gastric mucosal epithelial cell line, Ges-1. The results show that the Pd complex with the bare amino group (DMABTSPd(TSPd)) can inhibit cell viabilities and induce apoptosis in human gastric carcinoma cells, rather than the Pd complex without the bare amino group (DMABPTSPd (PTSPd)). This occurs via a mitochondrial-related pathway by down-regulating the level of Bcl-2 expression and up-regulating the level of Bid expression. Meanwhile, DMABTSPd (TSPd) suppressed tumor growth via a mitochondrial-related pathway in a nude mouse tumor xenograft model derived from BGC-823 cells. These findings demonstrate that DMABTSPd (TSPd) is worthy of further structural optimization and representing a promising Pd complex for the development of a new antitumor therapeutic agent.

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

    Science.gov (United States)

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

    2016-09-01

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

  5. Synthesis, Characterisation, and Biological Evaluation of Zn(II Complex with Tridentate (NNO Donor Schiff Base Ligand

    Directory of Open Access Journals (Sweden)

    Nayaz Ahmed

    2015-01-01

    Full Text Available The present paper deals with the synthesis and characterization of metal complex of tridentate Schiff base ligand derived from the inserted condensation of 2-aminobenzimidazole (1H-benzimidazol-2-amine with salicylaldehyde (2-hydroxybenzaldehyde in a 1 : 1 molar ratio. Using this tridentate ligand, complex of Zn(II with general formula ML has been synthesized. The synthesized complex was characterized by several techniques using molar conductance, elemental analysis, FT-IR, and mass and 1HNMR spectroscopy. The elemental analysis data suggest the stoichiometry to be 1 : 1 [M : L]. The complex is nonelectrolytic in nature as suggested by molar conductance measurements. Infrared spectral data indicate the coordination between the ligand and the central metal ion through deprotonated phenolic oxygen, imidazole nitrogen of benzimidazole ring, and azomethine nitrogen atom. Spectral studies suggest tetrahedral geometry for the complex. The pure compound, synthesized ligand, and metal complex were screened for their antimicrobial activity.

  6. Designing, synthesis and spectral characterization of Schiff base transition metal complexes: DNA cleavage and antimicrobial activity studies

    Directory of Open Access Journals (Sweden)

    N. RAMAN

    2008-10-01

    Full Text Available A new series of transition metal complexes of Cu(II, Ni(II, Co(II and Zn(II have been designed and synthesized using a Schiff base (L derived from 4-aminoantipyrine, benzaldehyde and o-phenylenediamine. The structural features were derived from their elemental analyses, magnetic susceptibility and molar conductivity, as well as from mass, IR, UV–Vis, 1H-NMR and ESR spectral studies. The FAB mass spectral data and elemental analyses showed that the complexes had a composition of the ML type. The UV–Vis and ESR spectral data of the complexes suggested a square-planar geometry around the central metal ion. The magnetic susceptibility values of the complexes indicated that they were monomeric in nature. Antimicrobial screening tests were also performed against four bacteria, viz. Salmonella typhi, Staphylococcus aureus, Escherichia coli, and Bacillus subtilis and three fungi, viz. Aspergillus niger, Aspergillus flavus and Rhizoctonia bataicola. These data gave good results in the presence of metal ion in the ligand system. The nuclease activity of the above metal complexes shows that only the copper complex cleaves CT DNA in the presence of an oxidant.

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

    Science.gov (United States)

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

    2016-05-31

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

  8. Mn(II) and Cu(II) complexes of a bidentate Schiff's base ligand: Spectral, thermal, molecular modelling and mycological studies

    Science.gov (United States)

    Tyagi, Monika; Chandra, Sulekh; Tyagi, Prateek

    2014-01-01

    Complexes of manganese(II) and copper(II) of general composition M(L)2X2 have been synthesized [L = 2-acetyl thiophene thiosemicarbazone and X = Cl- and NO3-]. The elemental analysis, molar conductance measurements, magnetic susceptibility measurements, mass, IR, UV, NMR and EPR spectral studies of the compounds led to the conclusion that the ligand acts as a bidentate manner. The Schiff's base ligand forms hexacoordinated complexes having octahedral geometry for Mn(II) and tetragonal geometry for Cu(II) complexes. The thermal studies suggested that the complexes are more stable as compared to ligand. In molecular modelling the geometries of Schiff's base and metal complexes were fully optimized with respect to the energy using the 6-31g(d,p) basis set. The mycological studies of the compounds were examined against the plant pathogenic fungi i.e. Rhizoctonia bataticola, Macrophomina phaseolina, Fusarium odum.

  9. Mn(II) and Cu(II) complexes of a bidentate Schiff's base ligand: spectral, thermal, molecular modelling and mycological studies.

    Science.gov (United States)

    Tyagi, Monika; Chandra, Sulekh; Tyagi, Prateek

    2014-01-03

    Complexes of manganese(II) and copper(II) of general composition M(L)2X2 have been synthesized [L=2-acetyl thiophene thiosemicarbazone and X=Cl(-) and NO3(-)]. The elemental analysis, molar conductance measurements, magnetic susceptibility measurements, mass, IR, UV, NMR and EPR spectral studies of the compounds led to the conclusion that the ligand acts as a bidentate manner. The Schiff's base ligand forms hexacoordinated complexes having octahedral geometry for Mn(II) and tetragonal geometry for Cu(II) complexes. The thermal studies suggested that the complexes are more stable as compared to ligand. In molecular modelling the geometries of Schiff's base and metal complexes were fully optimized with respect to the energy using the 6-31g(d,p) basis set. The mycological studies of the compounds were examined against the plant pathogenic fungi i.e. Rhizoctonia bataticola, Macrophomina phaseolina, Fusarium odum. Copyright © 2013 Elsevier B.V. All rights reserved.

  10. BaFe12O19-chitosan Schiff-base Ag (I) complexes embedded in carbon nanotube networks for high-performance electromagnetic materials

    Science.gov (United States)

    Zhao, Jie; Xie, Yu; Guan, Dongsheng; Hua, Helin; Zhong, Rong; Qin, Yuancheng; Fang, Jing; Liu, Huilong; Chen, Junhong

    2015-01-01

    The multiwalled carbon nanotubes/BaFe12O19-chitosan (MCNTs/BF-CS) Schiff base Ag (I) complex composites were synthesized successfully by a chemical bonding method. The morphology and structures of the composites were characterized with electron microscopy, Fourier transform infrared spectroscopy and X-ray diffraction techniques. Their conductive properties were measured using a four-probe conductivity tester at room temperature, and their magnetic properties were tested by a vibrating sample magnetometer. The results show that the BF-CS Schiff base Ag (I) complexes are embedded into MCNT networks. When the mass ratio of MCNTs and BF-CS Schiff base is 0.95:1, the conductivity, Ms (saturation magnetization), Mr (residual magnetization), and Hc (coercivity) of the BF-CS Schiff base composites reach 1.908 S cm−1, 28.20 emu g−1, 16.66 emu g−1 and 3604.79 Oe, respectively. Finally, a possible magnetic mechanism of the composites has also been proposed. PMID:26218269

  11. Antimicrobial Activity and Spectral, Magnetic and Thermal Studies of Some Transition Metal Complexes of a Schiff Base Hydrazone Containing a Quinoline Moiety

    Directory of Open Access Journals (Sweden)

    Nora H Al-Sha’alan

    2007-05-01

    Full Text Available A series of new copper(II, cobalt(II, nickel(II, manganese(II, iron(III, and uranyl(VI complexes of the Schiff base hydrazone 7-chloro-4-(benzylidene-hydrazoquinoline (HL were prepared and characterized. The Schiff base behaves as a monobasic bidentate ligand. Mononuclear complexes with the general composition [ML2(Clm(H2O2(OEtn]·xEtOH (M = Cu(II, Co(II, Ni(II, Mn(II, Fe(III or UO2(VI; m and n = 0-1; x = 1-3 were obtained in the presence of Li(OH as a deprotonating agent. The nature of bonding and the stereochemistry of the complexes have been deduced from elemental analyses, infrared, electronic spectra, magnetic susceptibility and conductivity measurements. An octahedral geometry was suggested for all the complexes except the Cu(II and UO2(VI ones. The Cu(II complex has a square-planar geometry distorted towards tetrahedral, while the UO2(VI complex displays its favored heptacoordination. The Schiff base ligand, HL, and its complexes were tested against one strain Gram +ve bacteria (Staphylococcus aureus, Gram -ve bacteria (Escherichia coli, and Fungi (Candida albicans. The prepared metal complexes exhibited higher antibacterial activities than the parent ligand and their biopotency is discussed.

  12. Synthesis, characterization and anti-tumour activity of iron(III Schiff base complexes with unsymmetric tetradentate ligands

    Directory of Open Access Journals (Sweden)

    Fahmideh Shabani

    2010-08-01

    Full Text Available The synthesis and characterization of two new iron(III complexes, [Fe(pythsalI]Cl2 and [Fe(pythsalBr]Cl2 with the NSNO-donor tetradentate Schiff base ligands pythsalHX [(5–X-N-(2pyridylethylsulfanylethyl salicylideneimine] (X = I, Br obtained from the inserted condensation of 1-(2-pyridyl-3-thia-5-aminopentane with the respective derivative salicylaldehyde in a 1:1 molar ratio is reported. The iron(III complexes were characterized by several techniques using elemental analysis (C, H, N, FT-IR, electronic spectra and molar conductance measurements. The elemental analysis data suggest the stoichiometry to be 1:2 [M:L] ratio formation. The molar conductance measurements reveal the presence of 1:2 electrolytic nature complexes. Infrared spectral data agreed with the coordination to the central metal ion through deprotonated phenolic oxygen, imine and pyridine type nitrogens and the thioether sulfur atoms. From ligand field spectral data an octahedral geometry is assigned to the iron(III ion in all these complexes. These new compounds have showed anti-tumour activity against two kinds of cancer cells that are K562 (human chronic myeloid leukemia and Jurkat (human T lymphocyte carcinoma.

  13. Synthesis, Characterization of La(III, Nd(III, and Er(III Complexes with Schiff Bases Derived from Benzopyran-4-one and Thier Fluorescence Study

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    Aida L. El-Ansary

    2012-01-01

    Full Text Available The Schiff bases, L1, L2, and L3, are synthesized from the condensation of 5,7-dihydroxy-6-formyl-2-methylbenzopyran-4-one (L with 2-aminopyridine (1, p-phenylenediamine (2, and o-phenylenediamine (3. The prepared Schiff bases react with lanthanum (III, neodymium (III, and erbium (III nitrate to give complexes with stoichiometric ratio (1 : 1 (ligand : metal. The binuclear complexes of Er(III with L3 and the three metal ions with L2 are separated. The complexes have been characterized by elemental analysis, molar conductance, electronic absorption, and infrared, 1H-NMR spectral studies. The presence of hydrated and coordinated water molecules is inferred from thermogravimetric analysis. Thermal degradation studies show that the final product is the metal oxide. The luminescence properties of the Nd(III and Er(III complexes in dimethylformamide (DMF solutions were investigated.

  14. Design, spectral characterization, DFT and biological studies of transition metal complexes of Schiff base derived from 2-aminobenzamide, pyrrole and furan aldehyde.

    Science.gov (United States)

    Tyagi, Prateek; Chandra, Sulekh; Saraswat, B S; Sharma, Deepansh

    2015-05-15

    A series of two biologically active Schiff base ligands L(1), L(2) have been synthesized in equimolar reaction of 2-aminobenzamide with pyrrol-2-carboxaldehyde and furan-2-carboxaldehyde. The synthesized Schiff bases were used for complexation with different metal ions like Co(II), Ni(II) and Cu(II) by using a molar ratio of ligand: metal as 2:1. The characterization of newly formed complexes was done by (1)H NMR, UV-Vis, TGA, IR, mass spectrophotometry, EPR and molar conductivity studies. The thermal studies suggested that the complexes are more stable as compared to ligand. In DFT studies the geometries of Schiff bases and metal complexes were fully optimized with respect to the energy using the 6-31+g(d,p) basis set. On the basis of the spectral studies an octahedral geometry has been assigned for Co(II) and Ni(II) complexes and distorted octahedral geometry for Cu(II) complexes. All the synthesized compounds, were studied for their in vitro antimicrobial activities, against four bacterial strains and two fungal strains by using serial dilution method. The data also revealed that the metal complexes showed better activity than the ligands due to chelation/coordination. Copyright © 2015 Elsevier B.V. All rights reserved.

  15. Synthesis, structure characterization and biological activity of selected metal complexes of sulfonamide Schiff base as a primary ligand and some mixed ligand complexes with glycine as a secondary ligand

    Science.gov (United States)

    Sharaby, Carmen M.; Amine, Mona F.; Hamed, Asmaa A.

    2017-04-01

    The current work reports synthesis of metal complexes and mixed ligand complexes of a novel sulfonamide Schiff base ligand (HL) resulted from the condensation of sulfametrole [N‧-(4-methoxy-1,2,5-thiadiazol-3-yl]sulfanilamide and acetyl-acetone as a primary ligand and glycine as a secondary ligand. The metal complexes and mixed ligand complexes of HL Schiff base ligand were synthesized and characterized using different physicochemical studies as elemental analyses, mass spectra, conductivity measurement, IR spectra, 1H NMR spectra, UV-vis Spectra, solid reflectance, magnetic susceptibility, thermal analyses (TGA and DTA) and their microbial and anticancer activities. The spectroscopic data of the complexes suggest their 1:2(L1:M) complex structures and 1:2:2(L1:L2:M) mixed ligand complex structures, where L1 = HL and L2 = glycine. Also, the spectroscopic studies suggested the octahedral structure for all complexes. The synthesized Schiff base, its metal and mixed ligand complexes were screened for their bacterial, antifungal and anticancer activity. The activity data show that the metal complexes and mixed ligand complexes exhibited promising microbial and anticancer activities than their parent HL Schiff base ligand, also the data show that the mixed ligand complexes more effective than the metal complexes.

  16. Synthesis, spectroscopic studies and inhibitory activity against bacteria and fungi of acyclic and macrocyclic transition metal complexes containing a triamine coumarine Schiff base ligand.

    Science.gov (United States)

    Abou-Hussein, A A; Linert, Wolfgang

    2015-04-15

    Two series of new mono and binuclear complexes with a Schiff base ligand derived from the condensation of 3-acetylcoumarine and diethylenetriamine, in the molar ratio 2:1 have been prepared. The ligand was characterized by elemental analysis, IR, UV-visible, (1)H-NMR and mass spectra. The reaction of the Schiff base ligand with cobalt(II), nickel(II), copper(II), zinc(II) and oxovanadium(IV) lead to mono or binuclear species of cyclic or macrocyclic complexes, depending on the mole ratio of metal to ligand and as well as on the method of preparation. The Schiff base ligand behaves as a cyclic bidentate, tetradendate or pentaentadentae ligand. The formation of macrocyclic complexes depends significantly on the dimension of the internal cavity, the rigidity of the macrocycles, the nature of its donor atoms and on the complexing properties of the anion involved in the coordination. Electronic spectra and magnetic moments of the complexes indicate that the geometries of the metal centers are either square pyramidal or octahedral for acyclic or macro-cyclic complexes. The structures are consistent with the IR, UV-visible, ESR, (1)H-NMR, mass spectra as well as conductivity and magnetic moment measurements. The Schiff base ligand and its metal complexes were tested against two pathogenic bacteria as Gram-positive and Gram-negative bacteria as well as one kind of fungi. Most of the complexes exhibit mild antibacterial and antifungal activities against these organisms. Copyright © 2015 Elsevier B.V. All rights reserved.

  17. Synthesis, characterization and catecholase-like activity of new Schiff base metal complexes derived from visnagin: Theoretical and experimental study

    Science.gov (United States)

    Beyazit, Neslihan; Çatıkkaş, Berna; Bayraktar, Şahin; Demetgül, Cahit

    2016-09-01

    A new tetradentate, unsymmetrical Schiff base ligand (H2L) containing a donor set of N2O2 and its mononuclear Cu(II) and Fe(II) complexes ([CuL] and [FeL]), were synthesized and characterized on the basis of their elemental analysis, FT-IR, Raman, 1H and 13C NMR spectra, electronic and mass spectra, molar conductivity and magnetic susceptibility measurements. Density functional theory (DFT) calculations were performed in order to clarify molecular structures, 1H NMR and 13C NMR chemical shift values, frontier molecular orbitals (FMOs), nonlinear optical properties and map of molecular electrostatic potential (MEP) of the title molecules. In agreement with trials, the results provide a full explanation of the highest efficiency observed for the compounds in relation to the electronic and the structural characteristics. The catecholase-like activity of the complexes toward the oxidation of 3,5-di-tert-butylcatechol (3,5-DTBC) to the corresponding quinone showed that both complexes have moderate catalytic activity. [FeL] shows higher activity (kcat = 26.4 h-1) than that of [CuL] (kcat = 23.4 h-1).

  18. Synthesis, characterization, fluorescence and biological studies of Mn(II, Fe(III and Zn(II complexes of Schiff bases derived from Isatin and 3-substituted-4-amino-5-mercapto-1,2,4-triazoles

    Directory of Open Access Journals (Sweden)

    Sangamesh A. Patil

    2014-12-01

    Full Text Available A series of Mn(II, Fe(III and Zn(II complexes have been synthesized with Schiff bases derived from isatin and 3-substituted-4-amino-5-mercapto-1,2,4-triazole. The elemental, spectroscopic (Infrared, nuclear magnetic resonance, ultraviolet-visible, fast atom bombardment-mass, fluorescence and electrochemistry and magnetic studies suggested that the metal complexes possess octahedral geometry. The Schiff bases and their metal complexes exhibit fluorescent properties. The antimicrobial studies of Schiff bases and their metal complexes against various bacterial (Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa and Bacillus subtilis and fungal (Aspergillus niger, and Penicillium chrysogenum species by the minimum inhibitory concentration method revealed that the metal complexes possess more healing antibacterial activities than the Schiff bases. DNA cleavage property of Mn(II, Fe(III and Zn(II complexes revealed the important role of metal ion in the biological system.

  19. Newer mixed ligand Schiff base complexes from aquo-N-(2‧-hydroxy acetophenone) glycinatocopper(II) as synthon: DFT, antimicrobial activity and molecular docking study

    Science.gov (United States)

    Pramanik, Harun A. R.; Das, Dharitri; Paul, Pradip C.; Mondal, Paritosh; Bhattacharjee, Chira R.

    2014-02-01

    Synthesis of a series of newer mixed ligand copper(II) complexes of aminoacid Schiff base of the type [CuL(X)] (L = N-(2‧-hydroxy acetophenone) glycinate, X = imidazole (im) 2, benzimidazole (benz) 3, pyridine (py) 4, hydrazine (hz) 5,8-hydroxyquinoline (8-hq) 6, pyrrolidine (pyrr) 7, piperidine (pip) 8, and nicotinamide (nic) 9) have been accomplished from the interaction of an aquated Schiff base complex, [CuL(H2O)]·H2O, 1 with some selected neutral nitrogen-donor ligands. The copper(II) Schiff base complex, [CuL(H2O)]·H2O, L = N-(2‧-hydroxy acetophenone) glycinate was synthesized from the reaction of glycine and 2‧ hydroxy acetophenone and copper(II) acetate. The compounds were characterised by elemental analysis, spectral, magnetic and thermal studies. The density functional theory calculations were performed using LANL2DZ and 6-311 G(d, p) basis sets with B3LYP correlation functional to ascertain the stable electronic structure, HOMO-LUMO energy gap, chemical hardness and dipole moment of the mixed ligand complexes. A distorted square planar geometry has been conjectured for the complexes. Antibacterial activities of the ligand and its metal complexes have been tested against selected gram-positive and gram-negative strains and correlated with computational docking scores.

  20. Synthesis, Characterization, Antimicrobial, DNA Cleavage, and In Vitro Cytotoxic Studies of Some Metal Complexes of Schiff Base Ligand Derived from Thiazole and Quinoline Moiety

    Science.gov (United States)

    Yernale, Nagesh Gunvanthrao; Bennikallu Hire Mathada, Mruthyunjayaswamy

    2014-01-01

    A novel Schiff base ligand N-(4-phenylthiazol-2yl)-2-((2-thiaxo-1,2-dihydroquinolin-3-yl)methylene)hydrazinecarboxamide (L) obtained by the condensation of N-(4-phenylthiazol-2-yl)hydrazinecarboxamide with 2-thioxo-1,2-dihydroquinoline-3-carbaldehyde and its newly synthesized Cu(II), Co(II), Ni(II), and Zn(II) complexes have been characterized by elemental analysis and various spectral studies like FT-IR, 1H NMR, ESI mass, UV-Visible, ESR, TGA/DTA, and powder X-ray diffraction studies. The Schiff base ligand (L) behaves as tridentate ONS donor and forms the complexes of type [ML(Cl)2] with square pyramidal geometry. The Schiff base ligand (L) and its metal complexes have been screened in vitro for their antibacterial and antifungal activities by minimum inhibitory concentration (MIC) method. The DNA cleavage activity of ligand and its metal complexes were studied using plasmid DNA pBR322 as a target molecule by gel electrophoresis method. The brine shrimp bioassay was also carried out to study the in vitro cytotoxicity properties for the ligand and its metal complexes against Artemia salina. The results showed that the biological activities of the ligand were found to be increased on complexation. PMID:24729778

  1. Synthesis and investigation of thermal properties of vanadyl complexes with azo-containing Schiff-base dyes

    Directory of Open Access Journals (Sweden)

    Abbas Ali Salih Al-Hamdani

    2016-09-01

    Full Text Available Azo-Schiff base compounds (L1 and L2 have been synthesized from the reaction of m-hydroxy benzoic acid with 1,5-dimethyl-3-[2-(5-methyl-1H-indol-3-yl-ethylimino]-2-phenyl-2,3-dihydro-1H-pyrazol-4-ylamine and with 3-[2-(1H-indol-3-yl-ethylimino]-1,5-dimethyl-2-phenyl-2,3-dihydro-1H-pyrazol-4-ylamine. The free ligands and their complexes were characterized based on elemental analysis, determination of metal, molar conductivity, (1H, 13C NMR, UV–vis, FT-IR, mass spectra and thermal analysis (TGA. The molar conductance data revealed that all the complexes are non-electrolytes. The study of complex formation via molar ratio in DMF solution has been investigated and results were consistent to those found in the solid complexes with a ratio of (M:L as (1:1. Moreover, the thermodynamic activation parameters, such as ΔE∗, ΔH∗, ΔS∗, ΔG∗and K are calculated from the TGA curves using Coats–Redfern method. Hyper Chem-6 program has been used to predict the structural geometries of compounds in gas phase. The heat of formation (ΔHf° and binding energy (ΔEb at 298 K for the free ligands and their vanadyl complexes were calculated by PM3 method. The synthesized ligands and their metal complexes were screened for their biological activity against bacterial species, two Gram positive bacteria (Bacillus subtilis and Staphylococcus aureus and two Gram negative bacteria (Escherichia coli and Pseudomonas aeruginosa.

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

    Directory of Open Access Journals (Sweden)

    Hossein Naeimi

    2013-01-01

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

  3. Synthesis and Characterization of New Lead(II and Organotin(IV Complexes of Schiff Bases Derived from Histidine and Methionine

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    Har Lal Singh

    2012-01-01

    Full Text Available New Schiff base (HL ligand is prepared via condensation of isatins and amino acids in 1:1 molar ratio. Metal complexes are prepared and characterized by elemental analysis, molar conductance, electronic, infrared, and multinuclear magnetic resonance (1H NMR, 13C NMR, and 119Sn NMR. The analytical data showed that the ligand acts as bidentate toward metal ions via azomethine nitrogen and carboxylate oxygen by a stoichiometric reaction of metal : ligand (1 : 2 to from metal complexes (Pb(II(L2 and Bu2Sn(L2, where L is the Schiff base ligands of histidine and methionine. The conductivity values between 15 and 25 Ω−1cm2 mol−1 in DMF imply the presence of nonelectrolyte species. On the basis of the above spectral studies, distorted octahedral and tetrahedral geometry have been proposed for the resulting organotin(IV and lead(II complexes.

  4. Structural, theoretical investigations and biological evaluation of Cu(II), Ni(II) and Co(II) complexes of mercapto-pyrimidine schiff bases

    Science.gov (United States)

    Jone Kirubavathy, S.; Chitra, S.

    2017-11-01

    A new series of transition metal complexes of mercapto pyrimidine Schiff base complexes has been studied and characterized using various spectral techniques like single crystal XRD, FT-IR, electronic, EDX and TGA. The molecular properties of the ligand and the complexes have been derived from HOMO-LUMO calculations using Gaussian software. The biological evaluation of the ligands and the complexes has been studied and compared. The DNA binding studies of the complexes has been carried out and the binding constants are in the order of 104 M-1. The DNA cleavage activity of the complexes proves the mechanism of cleavage is through non-hydrolytic pathway.

  5. Synthesis, spectral characterization, catalytic and antibacterial studies of new Ru(III) Schiff base complexes containing chloride/bromide and triphenylphosphine/arsine as co-ligands

    Science.gov (United States)

    Arunachalam, S.; Padma Priya, N.; Jayabalakrishnan, C.; Chinnusamy, V.

    2009-10-01

    A new Ru(III) Schiff base complexes of the type [RuX(EPh 3)L] (X = Cl/Br; E = P/As; L = dianion of the Schiff bases were derived by the condensation of 1,4-diformylbenzene with o-aminobenzoic acid/ o-aminophenol/ o-aminothiophenol in the 1:2 stoichiometric ratio) have been synthesized from the reactions of [RuX 3(EPh 3) 3] with appropriate Schiff base ligands in benzene in the 2:1 stoichiometric ratio. The new complexes have been characterized by analytical, spectral (IR, electronic, 1H, 13C NMR and ESR), magnetic moment and electrochemical studies. An octahedral structure has been tentatively proposed for all these new complexes. All the new complexes have been found to be better catalyst for the oxidation of alcohols using molecular oxygen as co-oxidant at ambient temperature and aryl-aryl coupling reactions. These complexes were also subjected to antibacterial activity studies against Escherichia coli, Aeromonas hydrophilla and Salmonella typhi.

  6. Effect of the Schiff base complex diaqua-(N-salicylidene-l-glutamato)copper(II) monohydrate on human tumor cells.

    Science.gov (United States)

    Konarikova, Katarina; Andrezalova, Lucia; Rapta, Peter; Slovakova, Marianna; Durackova, Zdenka; Laubertova, Lucia; Gbelcova, Helena; Danisovic, Lubomir; Bohmer, Daniel; Ruml, Tomas; Sveda, Martin; Zitnanova, Ingrid

    2013-12-05

    The aim of our study was to estimate cytostatic/cytotoxic activity of the copper(II) Schiff base complex of the composition [Cu(N-salicylidene-l-glutamato)(H2O)2]·H2O, further Cu(SG-L)H2O, against human colon carcinoma cell line HT-29, as well as to determine type of cell death and to find out the molecular mechanism of apoptosis induced by this complex. Two highest concentrations (50, 100 µmol/l) of the complex showed a strong cytotoxic activity against human colon carcinoma cells HT-29 after 72 h of influence. Other concentrations had a cytostatic activity. Unchelated copper(II) ions and free ligands had no effect on the cell growth. Cu(SG-L)H2O preferentially reduced cancer cell viability compared to healthy cells (NIH-3T3). Cu(SG-L)H2O induced apoptosis of cells HT-29 at all concentrations used (1-100 µmol/l) after 48 h of influence. Apoptosis was carried out by the mitochondrial pathway with active caspases 3 and 9. By the spin-trapping technique combined with electron paramagnetic resonance we found that our complex is photochemically stable in aqueous systems and does not exhibit radical-scavenging activity when 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonate) cation radical was used as an oxidant. The complex exhibits a strong prooxidant property in the initial stages of thermal decomposition of K2S2O8 in water solutions leading to the massive production of (·)OH radicals. Therefore, this complex could strongly participate in anticancer action via a free radical mechanism. © 2013 Elsevier B.V. All rights reserved.

  7. Synthesis, electrochemical and photophysical properties of heterodinuclear Ru-Mn and Ru-Zn complexes bearing ambident Schiff base ligand.

    Science.gov (United States)

    Guillo, Pascal; Hamelin, Olivier; Loiseau, Frédérique; Pécaut, Jacques; Ménage, Stéphane

    2010-06-28

    While ruthenium tris(diimine) complexes have been extensively studied, this is not the case with ruthenium bis(diimine)X(2) complexes where X represents a pyridinyl-based ligand. The synthesis of a new complex ([2][PF(6)](2)) bearing two ambident Schiff base ligands (HL) constituted by the assembly of phenol and pyridinyl moieties is reported. Thanks to the heteroditopic property of HL, compound [2](2+) was used as an original metalloligand for the coordination of a redox-active (Mn(III)) and redox-inactive (Zn(II)) second metal cation affording three heterodinuclear complexes, namely, [(bpy)(2)Ru(2)Mn(acac)][PF(6)](2) ([3][PF(6)](2); acac = acetylacetonate), [(bpy)(2)Ru(2)Mn(OAc)][PF(6)](2) ([4][PF(6)](2), OAc = acetate), and [(bpy)(2)Ru(2)Zn][PF(6)](2) ([5][PF(6)](2)). The influence of the second metal with regard to the photophysical and electrochemical properties of the ruthenium bis(diimine)X(2) subunit was then investigated. In the case of Ru(II)-Mn(III) heterodinuclear complexes, a partial quenching of the luminescence was observed as a consequence of an efficient electron transfer process from the ruthenium to the manganese. EPR and spectrophotometric analyses of the oxidized species resulting from the one-electron oxidation of compounds [3](2+) and [4](2+) showed the formation of a Mn(IV) species for [3](2+) and an organic free radical for [4](2+).

  8. Solution combustion synthesis using Schiff-base aluminum complex without fuel and optical property investigations of alumina nanoparticles

    Science.gov (United States)

    Salehi, Mehdi; Arabsarhangi, Ehsan

    2015-05-01

    Synthesis of alumina nanomaterials via a solution combustion technique using Schiff base aluminum (III) complex at 820 and 950 °C for 4 h was performed successfully. The synthesis procedure was performed using the complex in the absence and presence of urea and glycine as fuel for comparison. The obtained data showed that the procedure without using fuel resulted in a better phase and morphology. To investigate the phase formation, powder X-ray diffraction technique was used. Also, SEM micrographs were used to investigate the morphology of the obtained materials. The optical properties of the obtained materials were studied by FTIR spectra. According to the PXRD data, it was found that with annealing at 950 °C, the phase formation of the obtained materials showed cubic crystal structure with cell parameter a = 3.14 Å for gamma phase. Also, by annealing at 820 °C using fuels for 4 h, the main phase was found to be in gamma.

  9. Synthesis, Characterization and Antibacterial Activity of Schiff Bases and their Metal Complexes Derived from 4-Acyl-1-phenyl-3-methyl-2-pyrazolin-5-ones and 2-Amino-4(4'-methylphenyl-thiazole

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    A. S. Thakar

    2010-01-01

    Full Text Available 4-Acyl-1-phenyl-3-methyl-2-pyrazolin-5-ones condensed with 2-amino-4(4'-methylphenyl-thiazole to form Schiff base. These Schiff bases from complexes of type ML22H2O (M=Mn, Fe, Co, Ni and Cu. Elemental analysis, magnetic susceptibility, electrical conductance, electronic and Infrared spectral data suggested octahedral structure for the complexes. All the compounds were tested for their antibacterial activity. The result indicates that the growth of the tested organism was inhibited by most of the compounds. These Schiff bases are characterized by elemental analysis, mass spectra, 1H-NMR spectra, 13C NMR spectra and FT IR spectra.

  10. (E)3-2-(1-(2,4-Dihydroxyphenyl)ethyldeneamino)phenyl)-2-methylquinazoline-4(3H)-one Schiff Base and Its Metal Complexes: A New Drug of Choice against Methicillin-Resistant Staphylococcus aureus

    Science.gov (United States)

    Siddappa, K.; Mane, Sunilkumar B.; Manikprabhu, Deene

    2014-01-01

    The 3-(2-aminophenyl) quinazolin-2-methyl-4(3H)-one and 2,4-dihydroxyacetophenone undergo condensation to afford (E)3-2-(1-(2,4-dihydroxyphenyl)ethyldeneamino)phenyl)-2-methylquinazoline-4(3H)-one Schiff base (DHPEAPMQ). The newly synthesized Schiff base (DHPEAPMQ) and its metal complexes were evaluated for their antimicrobial activity against methicillin-resistant Staphylococcus aureus isolated from the Gulbarga region in India. The Cu(II), Ni(II), and Zn(II) complexes of Schiff base (DHPEAPMQ) showed good antimicrobial activity. So, this could be a new drug of choice. PMID:24733996

  11. Synthesis, characterization, crystal structure and antibacterial activities of transition metal(II) complexes of the schiff base 2-[(4-methylphenylimino)methyl]-6-methoxyphenol.

    Science.gov (United States)

    Yu, Yu-Ye; Xian, Hui-Duo; Liu, Jian-Feng; Zhao, Guo-Liang

    2009-05-07

    Five transition metal(II) complexes, [ML(2)Cl(2)] 1 approximately 5, were synthesized from the reaction of MCl(2) x nH(2)O (M = Mn, Co, Ni, Cu, Cd) and the Schiff base ligand 2-[(4-methylphenylimino)methyl]-6-methoxyphenol (C(15)H(15)NO(2), L), obtained by condensation of o-vanillin (2-hydroxy-3-methoxybenzaldehyde) with p-toluidine. They were characterized by elemental analysis, molar conductance, FT-IR spectra, thermal analysis. The structure of complex 1 was determined by single-crystal X-ray diffraction. Its crystal structure is of monoclinic system, space group P2(1)/c with a = 9.0111(18) A, b = 11.222(2) A, c =28.130 (6) A, alpha = 90 masculine, beta = 92.29(3) masculine, gamma = 90 masculine, V = 2867.6(10) A(3), Z = 4. The Mn atom is six-coordinate and displays distorted octahedral geometry.The Schiff base ligand and its complexes have been tested in vitro to evaluate their antibacterial activity against bacteria, viz., Escherichia coli, Staphylococcus aureus and Bacillus subtilis. It has been found that the complexes have higher activity than the corresponding free Schiff base ligand against the same bacteria.

  12. Synthesis, Characterization, Crystal Structure and Antibacterial Activities of Transition Metal(II Complexes of the Schiff Base 2-[(4-Methylphenyliminomethyl]-6-methoxyphenol

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    Guo-Liang Zhao

    2009-05-01

    Full Text Available Five transition metal(II complexes, [ML2Cl2] 1~5, were synthesized from the reaction of MCl2·nH2O (M = Mn, Co, Ni, Cu, Cd and the Schiff base ligand 2-[(4-methylphenyliminomethyl]-6-methoxyphenol (C15H15NO2, L, obtained by condensation of o-vanillin (2-hydroxy-3-methoxybenzaldehyde with p-toluidine. They were characterized by elemental analysis, molar conductance, FT-IR spectra, thermal analysis. The structure of complex 1 was determined by single-crystal X-ray diffraction. Its crystal structure is of monoclinic system, space group P21/c with a = 9.0111(18 Å, b = 11.222(2 Å, c =28.130 (6 Å, α = 90 º, β = 92.29(3 º, γ = 90 º, V = 2867.6(10 Å3, Z = 4. The Mn atom is six-coordinate and displays distorted octahedral geometry.The Schiff base ligand and its complexes have been tested in vitro to evaluate their antibacterial activity against bacteria, viz., Escherichia coli, Staphylococcus aureus and Bacillus subtilis. It has been found that the complexes have higher activity than the corresponding free Schiff base ligand against the same bacteria.

  13. Synthesis, spectral characterization and DNA binding of Schiff-base metal complexes derived from 2-amino-3-hydroxyprobanoic acid and acetylacetone.

    Science.gov (United States)

    Hosny, Nasser Mohammed; Hussien, Mostafa A; Radwan, Fatima M; Nawar, Nagwa

    2014-11-11

    Four new metal complexes derived from the reaction of Cu(II), Co(II), Ni(II) and Zn(II) acetates with the Schiff-base ligand (H3L) resulted from the condensation of the amino acid 2-amino-3-hydroxyprobanoic acid (serine) and acetylacetone have been synthesized and characterized by, elemental analyses, ES-MS, IR, UV-Vis., 1H NMR, 13C NMR, ESR, thermal analyses (TGA and DTG) and magnetic measurements. The results showed that the Schiff-base ligand acts as bi-negative tridentate through the azomethine nitrogen, the deprotonated carboxylate oxygen and the enolic carbonyl oxygen. The optical band gaps measurements indicated the semi-conducting nature of these complexes. Molecular docking was used to predict the binding between the Schiff base ligand with the receptor of prostate cancer mutant H874Y. The interactions between the Cu(II) complex and calf thymus DNA (CT-DNA) have been studied by UV spectra. The results confirm that the Cu(II) complex binds to CT-DNA in an intercalative mode. Copyright © 2014 Elsevier B.V. All rights reserved.

  14. Zn(II), Ni(II), Cu(II) and Pb(II) complexes of tridentate asymmetrical Schiff base ligands: Synthesis, characterization, properties and biological activity

    Science.gov (United States)

    Şahin, Mustafa; Koçak, Nuriye; Erdenay, Damla; Arslan, Uğur

    2013-02-01

    New asymmetrical tridentate Schiff base ligands were synthesized using 1,2-phenylenediamine, 4-methyl-1,2-phenylenediamine, 2-hydroxy-1-napthaldehyde, 9-anthracenecarboxaldehyde. Schiff base ligands and their metal complexes were synthesised and characterized by using FT-IR, 1H NMR, 13C NMR, UV-Vis, XRD, ESR, elemental analysis and fluorescence studies. The antimicrobial activity of the ligands and their metal complexes were studied against Staphylococcus aureus ATCC 29213, S. aureus ATCC 25923, Streptococcus mutans RSHM 676, Enterococcus faecalis ATCC 29212, Escherichia coli ATCC 25922, Pseudomonas aeruginosa ATCC 27853. The determination of the antibacterial activity was done using the broth microdilution methods. In general, it has been determined that the studied compounds have MIC values similar to Gram-positive and Gram-negative bacteria. It has been found that Ni, Pb, Zn derivatives of HL1A and ZnL2A has lower MIC values than ampicillin for P. aeruginosa ATCC 27853 strain.

  15. Synthesis, Spectral Characterization, Molecular Modeling, and Antimicrobial Studies of Cu(II), Ni(II), Co(II), Mn(II), and Zn(II) Complexes of ONO Schiff Base

    National Research Council Canada - National Science Library

    Mendu, Padmaja; Pragathi, J; Anupama, B; Kumari, C. Gyana

    2012-01-01

    .... The nature of bonding and geometry of the transition metal complexes as well as schiff base ligand L have been deduced from elemental analysis, FT-IR, UV-Vis, 1HNMR, ESR spectral studies, mass, thermal (TGA and DTA...

  16. Chemopreventive evaluation of a Schiff base derived copper (II) complex against azoxymethane-induced colorectal cancer in rats.

    Science.gov (United States)

    Hajrezaie, Maryam; Hassandarvish, Pouya; Moghadamtousi, Soheil Zorofchian; Gwaram, Nura Suleiman; Golbabapour, Shahram; Najihussien, Abdrabuh; Almagrami, Amel Abdullah; Zahedifard, Maryam; Rouhollahi, Elham; Karimian, Hamed; Fani, Somaye; Kamalidehghan, Behnam; Majid, Nazia Abdul; Ali, Hapipah Mohd; Abdulla, Mahmood Ameen

    2014-01-01

    Based on the potential of Schiff base compounds to act as sources for the development of cancer chemotherapeutic agents, this in vivo study was performed to investigate the inhibitory properties of the synthetic Schiff base compound Cu(BrHAP)2 on colonic aberrant crypt foci (ACF). This study involved five groups of male rats. The negative control group was injected with normal saline once a week for 2 weeks and fed 10% Tween 20 for 10 weeks, the cancer control group was subcutaneously injected with 15 mg/kg azoxymethane once per week for two consecutive weeks, the positive control group was injected with 15 mg/kg azoxymethane once per week for two consecutive weeks and 35 mg/kg 5-fluorouracil (injected intra-peritoneally) for 4 weeks, and the experimental groups were first injected with 15 mg/kg azoxymethane once per week for two consecutive weeks and then fed 2.5 or 5 mg/kg of the Schiff base compound once a day for 10 weeks. Application of the Schiff base compound suppressed total colonic ACF formation by up to 72% to 74% (PSchiff base compound decreased the mean crypt scores in azoxymethane-treated rats. Significant elevations of superoxide dismutase, glutathione peroxidase and catalase activities and a reduction in the level of malondialdehyde were also observed. Histologically, all treatment groups exhibited significant decreases in dysplasia compared to the cancer control group (P<0.05). Immunohistochemical staining demonstrated down-regulation of the PCNA protein. Comparative western blot analysis revealed that COX-2 and Bcl2 were up-regulated and Bax was down-regulated compared with the AOM control group. The current study demonstrated that the Cu(BrHAP)2 compound has promising chemoprotective activities that are evidenced by significant decreases in the numbers of ACFs in azoxymethane-induced colon cancer.

  17. Comments on "Synthesis aspects, structural, spectroscopic, antimicrobial and room temperature ferromagnetism of zinc iodide complex with Schiff based ligand" by K. Shakila and S. Kalainathan, Spectrochim. Acta 135 A (2015) 1059-1065.

    Science.gov (United States)

    Srinivasan, Bikshandarkoil R; Nadkarni, V S

    2016-06-15

    Shakila and Kalainathan report on the synthetic and structural aspects of a zinc iodide complex with Schiff based ligand, which exhibits room temperature ferromagnetism. In this comment, many points of criticism, concerning the characterization of this so called zinc iodide complex of Schiff based ligand are highlighted to prove that the title paper is completely erroneous. Copyright © 2016 Elsevier B.V. All rights reserved.

  18. Synthesis of novel p-tert-butylcalix[4]arene Schiff bases and their complexes with C60, potential HIV-Protease inhibitors

    Science.gov (United States)

    Khadra, Khalid Abu; Mizyed, Shehadeh; Marji, Deeb; Haddad, Salim F.; Ashram, Muhammad; Foudeh, Ayat

    2015-02-01

    Some p-tert-butylcalix[4]arene Schiff base crown ethers were synthesized, characterized using 1H, 13C-NMR, DEPT 135 and Mass spectrometry. Their complexes with C60 were isolated and characterized. The inhibition effect of these complexes on HIVP was studied and found that complexes of 9 and 10 have comparable Ki values to Pepstatine which is known as HIVP inhibitor and used as a control. The synthesis of the ligands, complexes and the inhibition behavior are discussed in this article.

  19. Carbazole-based N4-donor Schiff base macrocycles: obtained metal free and as Cu(ii) and Ni(ii) complexes.

    Science.gov (United States)

    Malthus, Stuart J; Wilson, Rajni K; Vikas Aggarwal, A; Cameron, Scott A; Larsen, David S; Brooker, Sally

    2017-03-07

    The very different multi-step routes to the closely related pair of diformyl-carbazole head units, 1,8-diformyl-3,6-di-tert-butyl-9H-carbazole (1tBu) and 1,8-diformyl-9H-carbazole (1H), are detailed and compared. The first examples of Schiff base macrocycles derived from diformyl-carbazole head units are reported. Specifically, the direct cyclisation of 1tBu or 1H with diethylenetriamine gives the two metal-free [1 + 1] Schiff base macrocycles HLH and HLtBu in high yields. Four carbazole-based macrocyclic complexes, [Cu(II)L(OH2)]OAc and [Ni(II)L]OAc, where L = LH or LtBu, were accessed either by metallation of these macrocycles, or by metal templated reaction of the macrocycle components. [Cu(II)LtBu(OH2)]OAc·0.5(Ether) and [NiLH]OAc·EtOH, were structurally characterised, confirming the nickel(ii) complexes are square planar (both show diamagnetic NMR spectra) and that the copper(ii) complexes are square pyramidal with a water molecule bound in the axial site. Like porphyrins, both of these N4-donor macrocycles, which differ only in the R group present at the 3 and 6 positions (H or tBu), impose a strong ligand field.

  20. Synthesis and Crystal Structure of Binuclear and Pentanuclear Nickel(II Complexes Containing 4-(salicylaldiminatoantipyrine Schiff base

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    Mohamed N. EL-Kaheli

    2015-11-01

    Full Text Available The new title binuclear Ni (II compound  (1 and the novel pentanuclear Ni (II cluster {[   } (2 are formed from the reaction of an asymmetric Schiff base ligand L (L = 4-(salicylaldiminatoantipyrine with Ni .4  in the former or Ni(ClO42.6H2O in presence of malonate in the later.  Complex (1 consists of ( ]+ cation and one uncoordinated tetraphenylborate anion.  The cation adopts a distorted octahedral arrangement around each metal center.  In the binuclear unit both Ni(II ions are linked through two phenolate (µ2-O oxygen atoms of L, and two oxygen atoms of a  bridging carboxylate group. Each Ni (II coordinates to four oxygen atoms at the basal plane, two oxygen atoms from two bridging phenolate groups, one from pyrazolone ring and the last of an aqua molecule, and at the axial positions to a bridging carboxylate-O atom and an azomethine nitrogen atom.  In the pentanuclear cluster (2 consisting of [ ]+2 cation and two tetraphenylborate anions, the core of the cation is assembled by four [Ni( ] units, linked to the central Ni-ion by two bridging water molecules. The resulting coordination sphere for the external symmetry related nickel ions is a pseudo octahedron.  The central Ni-atom unusually adopts dodecahedron geometry through its coordination to eight bridging water molecules. In complex (1 each Ni-atom is coordinated to one tridentate L ligand and in complex (2 each [Ni ( ] unit is coordinated to two bidentate L ligands.  Inter-and intramolecular hydrogen bonds are present in both crystal structures.

  1. Pd(II and Zn(II Based Complexes with Schiff Base Ligands: Synthesis, Characterization, Luminescence, and Antibacterial and Catalytic Activities

    Directory of Open Access Journals (Sweden)

    Zhi-Qiang Feng

    2013-01-01

    Full Text Available Two new metal complexes involving Schiff base ligands, namely, [Pd(L12] (1 and [Zn(L22] (2, [HL1: 2,4-dibromo-6-((E-(mesityliminomethylphenol and HL2: 2-((E-(2,6-diisopropylphenyliminomethyl-4,6-dibromophenol], have been solvothermally synthesized and characterized by elemental analysis, IR-spectroscopy, thermogravimetric analysis, powder X-ray diffraction, and single-crystal X-ray diffraction. Both 1 and 2 are mononuclear cyclometalated complexes with square planar and tetrahedral coordination geometry, respectively. 1 and 2 display photoluminescence in the solid state at 298 K (fluorescence lifetimes τ = 5.521 μs at 508 nm for 1; τ = 3.697 μs at 506 nm for 2. These Schiff base ligands and their metal complexes have been screened for antibacterial activity against several bacteria strains, and the results are compared with the activity of penicillin. Moreover, the Suzuki reaction of 4-bromoanisole with phenylboronic acid by 1 has also been studied.

  2. DNA interaction, antimicrobial studies of newly synthesized copper (II) complexes with 2-amino-6-(trifluoromethoxy)benzothiazole Schiff base ligands.

    Science.gov (United States)

    Rambabu, Aveli; Pradeep Kumar, Marri; Tejaswi, Somapangu; Vamsikrishna, Narendrula; Shivaraj

    2016-12-01

    Four novel Schiff base ligands, L 1 (1-((E)-(6-(trifluoromethoxy)benzo[d]thiazol-2-ylimino)methyl)naphthalen-2-ol, C 19 H 11 F 3 N 2 O 2 S), L 2 (3-((E)-(6-(trifluoromethoxy)benzo[d]thiazol-2-ylimino)methyl)benzene-1,2-diol, C 15 H 9 F 3 N 2 O 3 S), L 3 (2-((E)-(6-(trifluoromethoxy)benzo[d]thiazol-2-ylimino)methyl)-5-methoxyphenol, C 16 H 11 F 3 N 2 O 3 S) and L 4 (2-((E)-(6-(trifluoromethoxy)benzo[d]thiazol-2-ylimino)methyl)-4-bromophenol, C 15 H 8 BrF 3 N 2 O 2 S) and their binary copper(II) complexes 1 [Cu(L 1 ) 2 ], 2 [Cu(L 2 ) 2 ], 3 [Cu(L 3 ) 2 ] and 4 [Cu(L 4 ) 2 ] have been synthesized and characterized by elemental analysis, 1 H NMR, 13 C NMR, ESI mass, FT-IR, ESR, UV-Visible, magnetic susceptibility, TGA, SEM and powder XRD studies. Based on spectral and analytical data, a square planar geometry is assigned for all Cu(II) complexes. The ligands and their Cu(II) complexes have been screened for antimicrobial activity against bacterial species E. coli, P. aeruginosa, B. amyloliquefaciens and S. aureus and fungal species S. rolfsii and M. phaseolina and it is observed that all Cu(II) complexes are more potent than corresponding ligands. DNA binding (UV absorption, fluorescence and viscosity titrations) and cleavage (oxidative and photo cleavage) studies of Cu(II) complexes have also been investigated against calf thymus DNA (CT-DNA) and supercoiled pBR322 DNA respectively. From the experimental results, it is found that the complexes bound effectively to CT-DNA through an intercalative mode and also cleaved pBR322 DNA in an efficient manner. The DNA binding and cleavage affinities of newly synthesized Cu(II) complexes are in the order of 2>1>3>4. Copyright © 2016 Elsevier B.V. All rights reserved.

  3. Substituent effects on spin state in a series of mononuclear manganese(III) complexes with hexadentate Schiff-Base ligands.

    Science.gov (United States)

    Gildea, Brendan; Harris, Michelle M; Gavin, Laurence C; Murray, Caroline A; Ortin, Yannick; Müller-Bunz, Helge; Harding, Charles J; Lan, Yanhua; Powell, Annie K; Morgan, Grace G

    2014-06-16

    Eleven new mononuclear manganese(III) complexes prepared from two hexadentate ligands, L1 and L2, with different degrees of steric bulk in the substituents are reported. L1 and L2 are Schiff bases resulting from condensation of N,N'-bis(3-aminopropyl)ethylenediamine with 3-methoxy-2-hydroxybenzaldehyde and 3-ethoxy-2-hydroxybenzaldehyde respectively, and are members of a ligand series we have abbreviated as R-Sal2323 to indicate the 323 alkyl connectivity in the starting tetraamine and the substitution (R) on the phenolate ring. L1 hosts a methoxy substituent on both phenolate rings, while L2 bears a larger ethoxy group in the same position. Structural and magnetic properties are reported in comparison with those of a previously reported analogue with L1, namely, [MnL1]NO3, (1e). The BPh4(-) and PF6(-) complexes [MnL1]BPh4, (1a), [MnL2]BPh4, (2a), [MnL1]PF6, (1b'), and [MnL2]PF6, (2b), with both ligands L1 and L2, remain high-spin (HS) over the measured temperature range. However, the monohydrate of (1b') [MnL1]PF6·H2O, (1b), shows gradual spin-crossover (SCO), as do the ClO4(-), BF4(-), and NO3(-) complexes [MnL1]ClO4·H2O, (1c), [MnL2]ClO4, (2c), [MnL1]BF4·H2O, (1d), [MnL2]BF4·0.4H2O, (2d), [MnL1]NO3, (1e), and [MnL2]NO3·EtOH, (2e). The three complexes formed with ethoxy-substituted ligand L2 all show a higher T1/2 than the analogous complexes with methoxy-substituted ligand L1. Analysis of distortion parameters shows that complexes formed with the bulkier ligand L2 exhibit more deformation from perfect octahedral geometry, leading to a higher T1/2 in the SCO examples, where T1/2 is the temperature where the spin state is 50% high spin and 50% low spin. Spin state assignment in the solid state is shown to be solvate-dependent for complexes (1b) and (2e), and room temperature UV-visible and NMR spectra indicate a solution-state spin assignment intermediate between fully HS and fully low spin in 10 complexes, (1a)-(1e) and (2a)-(2e).

  4. Metal complexes of Schiff base derived from sulphametrole and o-vanilin . Synthesis, spectral, thermal characterization and biological activity

    Science.gov (United States)

    Mohamed, Gehad G.; Sharaby, Carmen M.

    2007-04-01

    Metal complexes of Schiff base derived from condensation of o-vanilin (3-methoxysalicylaldehyde) and sulfametrole [ N1-(4-methoxy-1,2,5-thiadiazole-3-yl)sulfanilamide] (H 2L) are reported and characterized based on elemental analyses, IR, 1H NMR, solid reflectance, magnetic moment, molar conductance, mass spectra, UV-vis and thermal analysis (TGA). From the elemental analyses data, the complexes were proposed to have the general formulae [M 2X 3(HL)(H 2O) 5]· yH 2O (where M = Mn(II), Co(II), Ni(II), Cu(II), Zn(II) and Cd(II), X = Cl, y = 0-3); [Fe 2Cl 5(HL)(H 2O) 3]·2H 2O; [(FeSO 4) 2(H 2L)(H 2O) 4] and [(UO 2) 2(NO 3) 3(HL)(H 2O)]·2H 2O. The molar conductance data reveal that all the metal chelates were non-electrolytes. The IR spectra show that, H 2L is coordinated to the metal ions in a tetradentate manner with ON and NO donor sites of the azomethine-N, phenolic-OH, enolic sulphonamide-OH and thiadiazole-N. From the magnetic and solid reflectance spectra, it is found that the geometrical structures of these complexes are octahedral. The thermal behaviour of these chelates shows that the hydrated complexes losses water molecules of hydration in the first step followed immediately by decomposition of the anions and ligand molecules in the subsequent steps. The activation thermodynamic parameters, such as, E*, Δ H*, Δ S* and Δ G* are calculated from the DrTG curves using Coats-Redfern method. The synthesized ligand, in comparison to their metal complexes also were screened for their antibacterial activity against bacterial species, Escherichia coli, Salmonella typhi, Bacillus subtillus, Staphylococcus aureus and Fungi ( Aspergillus terreus and Aspergillus flavus). The activity data show that the metal complexes to be more potent/antimicrobial than the parent Shciff base ligand against one or more microbial species.

  5. DNA incision evaluation, binding investigation and biocidal screening of Cu(II), Ni(II) and Co(II) complexes with isoxazole Schiff bases.

    Science.gov (United States)

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

    2017-10-01

    Two new series of binary metal complexes [M(L 1 ) 2 ] and [M(L 2 ) 2 ] where, M=Cu(II), Ni(II) & Co(II) and L 1 =4-((3,4-dimethylisoxazol-5-ylimino)methyl)benzene-1,3-diol; L 2 =2-((3,4-dimethylisoxazol-5-ylimino)methyl)-5-methoxyphenol were synthesized and characterized by elemental analysis, 1 H NMR, 13 C NMR, FT-IR, ESI mass, UV-Visible, magnetic moment, ESR, SEM and powder XRD studies. Based on these results, a square planar geometry is assigned for all the metal complexes where the Schiff base acts as uninegatively charged bidentate chelating agent via the hydroxyl oxygen and azomethine nitrogen atoms. DNA binding studies of all the complexes with calf thymus DNA have been comprehensively investigated using electronic absorption spectroscopy, fluorescence quenching and viscosity studies. The oxidative and photo cleavage affinity of metal complexes towards supercoiled pBR322 DNA has been ascertained by agarose gel electrophoresis assay. From the results, it is observed that all the metal complexes bind effectively to CT-DNA via an intercalative mode of binding and also cleave pBR322 DNA in a promising manner. Further the Cu(II) complexes have shown better binding and cleavage properties towards DNA. The antimicrobial activities of the Schiff bases and their metal complexes were studied on bacterial and fungal strains and the results denoted that the complexes are more potent than their Schiff base ligands. Copyright © 2017 Elsevier B.V. All rights reserved.

  6. Synthesis, characterization, single crystal X-ray determination, fluorescence and electrochemical studies of new dinuclear nickel(II) and oxovanadium(IV) complexes containing double Schiff base ligands.

    Science.gov (United States)

    Shafaatian, Bita; Ozbakzaei, Zahra; Notash, Behrouz; Rezvani, S Ahmad

    2015-04-05

    A series of new bimetallic complexes of nickel(II) and vanadium(IV) have been synthesized by the reaction of the new double bidentate Schiff base ligands with nickel acetate and vanadyl acetylacetonate in 1:1 M ratio. In nickel and also vanadyl complexes the ligands were coordinated to the metals via the imine N and enolic O atoms. The complexes have been found to possess 1:1 metals to ligands stoichiometry and the molar conductance data revealed that the metal complexes were non-electrolytes. The nickel and vanadyl complexes exhibited distorted square planar and square pyramidal coordination geometries, respectively. The emission spectra of the ligands and their complexes were studied in methanol. Electrochemical properties of the ligands and their metal complexes were also investigated in DMSO solvent at 150 mV s(-1) scan rate. The ligands and metal complexes showed both quasi-reversible and irreversible processes at this scan rate. The Schiff bases and their complexes have been characterized by FT-IR, 1H NMR, UV/Vis spectroscopies, elemental analysis and conductometry. The crystal structure of the nickel complex has been determined by single crystal X-ray diffraction. Copyright © 2014 Elsevier B.V. All rights reserved.

  7. Non-enolisable Knoevenagel condensate appended Schiff bases-metal (II) complexes: Spectral characteristics, DNA-binding and nuclease activities

    Science.gov (United States)

    Gubendran, Ammavasi; Kesavan, Mookkandi Palsamy; Ayyanaar, Srinivasan; Mitu, Liviu; Athappan, Periyakaruppan; Rajesh, Jegathalaprathaban

    2017-06-01

    New Schiff base complexes [Cu(L1)Cl] (1), [Ni(L1)Cl] (2), [Zn(L1)Cl] (3), and [Fe(L2)H2OCl] (4) {L1 = (4E)-3-(2-hydroxybenzylidene)-4-(2-hydroxyphenylimino)pentan-2-one, L2 = 2,2‧-(1E,1‧E)-(3-(2-hydroxybenzylidene)-pentane-2,4-diylidene)bis(azan-1-yl-1 idene)diphenol} have been synthesized and characterized by elemental analysis, UV-Vis, IR, FAB-mass, EPR, spectral studies and electrochemical studies, the ligands L1 &L2 were characterized by 1H and 13C NMR spectra. Complex 1 show a visible spectral d-d band near 600 nm and display cyclic voltammetric quasireversible response for the Cu(II)/Cu(I) couple vs Ag/AgCl in DMSO. The EPR spectrum of 1 show g‖ > g⊥ suggesting a square planar geometry around copper with dx2 - y2 as the ground state. The mass spectral results have confirmed the proposed structure for complexes 1-4. DNA binding properties of these complexes 1-4 have been investigated by absorption titrations, cyclic voltammetric studies and circular dichroism studies. On titration with DNA, the complexes 1-4 show hypochromism at the MLCT band (13-31%) with a red shift of 1-8 nm in the electronic spectrum and positive shift of voltammetric E1/2 in the CV studies are in favour of intercalative binding. CD spectra of 1 showed an increase in molar ellipticity (θ278) of the positive band with a minor red shift indicating the transition of B-form of DNA to A like form. DNA cleavage studies of complexes 1 and 4 with pUC18 DNA were studied by gel electrophoresis and complex 4 cleaves supercoiled pUC18 DNA in an oxidative manner in the presence of H2O2 and on photo irradiation at 312 nm.

  8. New insights into the coordination chemistry of Schiff bases derived from amino acids: Planar [Ni4] complexes with tyrosine side-chains

    Science.gov (United States)

    Muche, Simon; Hołyńska, Małgorzata

    2017-08-01

    Structure and properties of a rare metal complex of the chiral Schiff base ligand derived from ortho-vanillin and L-tyrosine are presented. This study is a continuation of research on ligands containing biologically compatible moieties. The ligand is also fully characterized in form of a sodium salt, in particular in solution, for the first time. The metal complex contains a unique bowl-shaped [Ni4] core. Its structure is investigated both in solution (ESI-MS, NMR) and in solid state (X-ray diffraction studies). Under certain conditions the complex can be isolated as crystalline DMF solvate which is studied in solid state.

  9. Synthesis of samarium complexes with the derivative binder of Schiff Quinolinic base. Characterization and photophysical study; Sintesis de complejos de samario con el ligante derivado de base de Schiff Quinolinica. Caracterizacion y estudio fotofisico

    Energy Technology Data Exchange (ETDEWEB)

    Lucas H, J.

    2016-07-01

    In this work we determined the metal: binder stoichiometry of the species formed during the UV/Vis spectrophotometric titration of the derivative binder of Schiff quinolinic base, L1 with the samarium nitrate pentahydrate in methanol. Statistical analysis of the data allowed proposing the metal: binder stoichiometry for the synthesis of the complexes which was one mole of samarium salt by 2.5 moles of binder and thus favor the formation of complexes with 1M: 1L and 1M: 2L stoichiometries. They were synthesized in aqueous-organic medium (water-ethanol), isolated and purified two complexes with stoichiometry 1 Sm: 1 L1, complex 1 and 1 Sm: 2 L1, complex 2. The overall yield of the reaction was 76%. The characterization of the formed complexes was performed by visible ultraviolet spectrometry (UV/Vis), nuclear magnetic resonance, X-ray photoelectron spectroscopy (XP S), thermal gravimetric analysis with differential scanning calorimetry (TGA/DSC), and radial distribution function. These complexes were studied by fluorescence and emission phosphorescence at variable temperature. Spectroscopic techniques used in both solution and solid demonstrated the formation and stability of these complexes. In addition XP S indicated that in both complexes the samarium retains its oxidation state 3+. Luminescence studies indicated that there is intra-binding charge transfer which decreases the transfer of light energy from the binder to the samarium. Based on the experimental results, L1 binder molecules and complexes 1 and 2 were modeled that demonstrated the proposed Nc for each complex, as well as allowed to visualize the structural arrangement of the molecules, complexes and binder. (Author)

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

    National Research Council Canada - National Science Library

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

    2014-01-01

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

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

    Directory of Open Access Journals (Sweden)

    N. RAMAN

    2007-10-01

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

  12. Studies of Mn (II) and Ni (II) complexes with Schiff base derived from ...

    African Journals Online (AJOL)

    However, manganese(II) complex is insoluble in most organic solvents but soluble in dimethylsulphoxide (DMSO). The molar conductance of the complexes measured are low, indicating their non-electrolytic nature. The potentiometric and spectrophotometric studies of the complex compounds revealed 1:1 metal to ligand ...

  13. Studies of mn (ii) and ni (ii) complexes with schiff base derived from ...

    African Journals Online (AJOL)

    However, manganese(II) complex is insoluble in most organic solvents but soluble in dimethylsulphoxide (DMSO). The molar conductance of the complexes measured are, indicating their non-electrolytic nature. The potentiometric and spectrophotometric studies of the complex compounds revealed 1:1 metal to ligand ratio.

  14. Tetranuclear copper(ii)-Schiff-base complexes as active catalysts for oxidation of cyclohexane and toluene.

    Science.gov (United States)

    Roy, Partha; Manassero, Mario

    2010-02-14

    Three new Cu(ii) complexes, [Cu(4)(O)(L(n))(2)(CH(3)COO)(4)] where HL(1) = 4-methyl-2,6-bis(2-fluoroethyliminomethyl) phenol for complex , HL(2) = 4-methyl-2,6-bis(2-chloroethyliminomethyl) phenol for complex .0.25CH(3)CN and HL(3) = 4-methyl-2,6-bis(2-bromoethyliminomethyl) phenol for complex have been synthesized and characterized by elemental analysis, FTIR, UV-vis spectroscopy, and electrospray ionization mass spectroscopy. The structure of complex .0.25CH(3)CN has also been confirmed by single crystal X-ray diffraction analysis. These complexes have been found to be active catalysts for the oxidation of cyclohexane and toluene in the presence of hydrogen peroxide as the oxidant under mild conditions. Cyclohexane is oxidized to yield cyclohexanol and cyclohexanone, whereas toluene is oxidized to benzyl alcohol and benzaldehyde.

  15. Cu(II complexes of an ionic liquid-based Schiff base [1-{2-(2-hydroxy benzylidene amino ethyl}-3-methyl­imidazolium]Pf6: Synthesis, characterization and biological activities

    Directory of Open Access Journals (Sweden)

    Saha Sanjoy

    2015-01-01

    Full Text Available Two Cu(II complexes of an ionic liquid based Schiff base 1-{2-(2-hydroxybenzylideneamino ethyl}-3-methylimidazolium hexaflurophosphate, were prepared and characterized by different analytical and spectroscopic methods such as elemental analysis, magnetic susceptibility, UV-Vis, IR, NMR and mass spectroscopy. The Schiff base ligand was found to act as a potential bidentate chelating ligand with N, O donor sites and formed 1:2 metal chelates with Cu(II salts. The synthesized Cu(II complexes were tested for biological activity.

  16. Synthesis and Characterization of Some Novel Schiff Base Complexes of Oxovanadium(IV Cation

    Directory of Open Access Journals (Sweden)

    A. K. Yadava

    2013-01-01

    Full Text Available A series of oxovanadium(IV complexes of the type [VO(mac]SO4 (where mac = tetraazamacrocyclic ligands derived from condensation of 4,4,4-trifluro-1-(2-furyl-1,3-butanedione or 4,4,4-trifluro-1-(2-thenyl-1,3-butanedione with p-phenylenediamine and their reaction with β-diketones have been prepared using oxometal ion of vanadium as kinetic template. These complexes have been ascertained by electrical conductance, magnetic moment, elemental analyses, infrared, e.s.r. and electronic spectral data. All the oxovanadium(IV complexes are five-coordinate ones.

  17. Synthesis and Antimicrobial Studies of Tridentate Schiff Base Ligands with Pyrazolone Moiety and Their Metal Complexes

    Directory of Open Access Journals (Sweden)

    Ramasamy Jayarajan

    2010-01-01

    Full Text Available Synthesis, characterization, and antimicrobial activity of tridentate Schiffbase ligands containing pyrazolone moiety (3a and 3b and their transition metal complexes of VO(II, Cu(II, Fe(III, and Co(II 4a–h have been investigated. The complexes show enhanced antibacterial activity against S. aureus, E. coli, and S. typhi and antifungal activity against C. albicans, Rhizopus sp., and A. niger compared to the ligands.

  18. Silver(I)-pyridinyl Schiff base complexes: Synthesis, characterisation and antimicrobial studies

    Science.gov (United States)

    Njogu, Eric M.; Omondi, Bernard; Nyamori, Vincent O.

    2017-05-01

    Fifteen new silver(I)-pyridinyl complexes of the general formula [AgL2]X, where X = ClO4-, OTf or NO3-, were synthesised by reacting (E)-N-(pyridinylmethylene)aniline ligands and the respective silver(I) salts namely AgClO4, AgOTf, or AgNO3. The ligands were obtained by neat grinding of 2- or 4-pyridincarboaxaldehyde together with aniline, 2,6-dimethylaniline or 2,6-diisopropylaniline. The obtained (E)-N-(pyridinylmethylene)aniline ligands were further reacted with respective silver(I) salts in a 2:1 ratio in anhydrous ethanol at room temperature under inert atmosphere using the Schlenk techniques. Chemical structures of complexes were identified by nuclear magnetic resonance, electrospray ionization mass spectrometry, elemental analysis, infrared spectroscopy and some by single-crystal X-ray diffraction analysis. Reactions involving the 2-pyridinyl derivatives resulted in cationic complexes in which two ligands chelate silver(I) centres through the pyridinyl N and imine N atoms, with the counter anion out of the coordination sphere. The 4-pyridinyl derivatives conversely gave complexes in which two ligands coordinate to the silver(I) centre through their pyridinyl N atoms only, most likely a linear fashion. The newly synthesised silver(I) complexes and the free ligands were evaluated for their in vitro antimicrobial activity against Escherichia coli, Salmonella typhimirium, Staphylococcus aureus and Candida albicans. The complexes showed varied growth inhibitory activity against the test organisms.

  19. Synthesis, characterization, in silico ADMET prediction, and protein binding analysis of a novel zinc(II) Schiff-base complex: Application of multi-spectroscopic and computational techniques.

    Science.gov (United States)

    Shahraki, Somaye; Shiri, Fereshteh; Saeidifar, Maryam

    2017-06-22

    By reaction of 1,2-diaminocyclohexane with the 2,3-butanedione monoxime in the presence of ZnCl2, a new Schiff base complex was obtained. This complex was characterized by elemental analyses, FT-IR, (1)H NMR, UV-Vis, and conductivity measurements. The reactivity of this complex to human serum albumin (HSA) under simulative physiological conditions was studied by spectroscopic and molecular docking analysis. Experimental results at various temperatures indicated that the intrinsic fluorescence of protein was quenched through a static quenching mechanism. The negative value of enthalpy change and positive value of entropy change indicated that both hydrogen bonding and hydrophobic forces played a major role in the binding of Zn(II) complex to HSA. FT-IR, three-dimensional fluorescence, and UV-Vis absorption results showed that the secondary structure of HSA changed after Zn(II) complex bound to protein. The binding distance was calculated to be 4.96 nm, according to fluorescence resonance energy transfer. Molecular docking results confirmed the spectroscopic results and showed that above complex is embedded into subdomain IIA of protein. All these experimental and computational results clarified that Zn(II) complex could bind with HSA effectively, which could be a useful guideline for efficient Schiff-base drug design.

  20. Synthesis, Characterization, Antimicrobial, DNA Cleavage, and Antioxidant Studies of Some Metal Complexes Derived from Schiff Base Containing Indole and Quinoline Moieties

    Science.gov (United States)

    Karekal, Mahendra Raj; Biradar, Vivekanand; Bennikallu Hire Mathada, Mruthyunjayaswamy

    2013-01-01

    A new Schiff base of 5-chloro-3-phenyl-1H-indole-2-carboxyhydrazide and 3-formyl-2-hydroxy-1H-quinoline (HL), and its Cu(II), Co(II), Ni(II), Zn(II), Cd(II), and Hg(II) complexes have been synthesized and characterized in the light of microanalytical, IR, H1 NMR, UV-Vis, FAB-mass, ESR, XRD, and TGA spectral studies. The magnetic susceptibility measurements and low conductivity data provide evidence for monomeric and neutral nature of the complexes. On the basis of spectral studies and analytical data, it is evident that the Schiff base acts as tridentate ligand. The Cu(II), Co(II), and Ni(II) complexes were octahedral, whereas Zn(II), Cd(II), and Hg(II) complexes were tetrahedral in nature. The redox behavior of the Cu(II) complex was investigated by electrochemical method using cyclic voltammetry. In order to evaluate the effect of metal ions upon chelation, both the ligand and its metal complexes were screened for their antibacterial and antifungal activities by minimum inhibitory concentration (MIC) method. The DNA cleavage experiment performed using agarose gel electrophoresis method showed the cleavage of DNA by all the metal complexes. The free radical scavenging activity of newly synthesized compounds has been determined at a different concentration range by means of their interaction with the stable free radical 1,1-diphenyl-2-picrylhydrazyl (DPPH). PMID:24194692

  1. Synthesis, Electrochemical, Spectroscopic, Antimicrobial, and Superoxide Dismutase Activity of Nickel (II Complexes with Bidentate Schiff Bases

    Directory of Open Access Journals (Sweden)

    R. N. Patel

    2013-01-01

    Full Text Available Five new nickel (II complexes, namely, [Ni(L12](ClO42(1; [Ni(L22](ClO42(2; [Ni(L32](ClO42(3; [Ni(L42](ClO42(4; [Ni(L52](ClO42(5, where L1 = benzoylhydrazide; L2 = N-[(1-1-(2-methylphenylethylidene]benzohydrazide; L3=N-[(1-1-(4-methylphenylethylidene]benzohydrazide; L4=N-[(1-1-(2-methoxyphenylethylidene]benzohydrazide; L5 = N-[(1-1-(4-methoxy-phenylethylidene]benzohydrazide, have been synthesized and characterized by various physicochemical and spectroscopic techniques. The synthesized complexes are stable powders, insoluble in common organic solvents such as ethanol, benzene, carbon tetrachloride, chloroform, and diethyl ether, and are nonelectrolytes. The magnetic and spectroscopic data indicate a distorted square planar geometry for all complexes. The superoxide dismutase activity of these complexes has been measured and discussed. Antibacterial and antifungal properties of these complexes were also tested.

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

    Science.gov (United States)

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

    2010-09-15

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

  3. Synthesis and characterization of tin(II) complexes of fluorinated Schiff bases derived from amino acids.

    Science.gov (United States)

    Singh, Har Lal

    2010-07-01

    New tin(II) complexes of general formula Sn(L)(2) (L=monoanion of 3-methyl-4-fluoro-acetophenone phenylalanine L(1)H, 3-methyl-4-fluoro-acetophenone alanine L(2)H, 3-methyl-4-fluoro acetophenone tryptophan L(3)H, 3-methyl-4-fluoro-acetophenone valine L(4)H, 3-methyl-4-fluoro-acetophenone isoleucine L(5)H and 3-methyl-4-fluoro-acetophenone glycine L(6)H) have been prepared. It is characterized by elemental analyses, molar conductance measurements and molecular weight determinations. Bonding of these complexes is discussed in terms of their UV-visible, infrared, and nuclear magnetic resonance ((1)H, (13)C, (19)F and (119)Sn NMR) spectral studies. The ligands act as bidentate towards metal ions, via the azomethine nitrogen and deprotonated oxygen of the respective amino acid. Elemental analyses and NMR spectral data of the ligands with their tin(II) complexes agree with their proposed square pyramidal structures. A few representative ligands and their tin complexes have been screened for their antibacterial activities and found to be quite active in this respect. Copyright 2010 Elsevier B.V. All rights reserved.

  4. A new Co (III) complex of Schiff base derivative for electrochemical ...

    Indian Academy of Sciences (India)

    The complex has been combined with polyvinyl chloride (PVC) membrane of various compositions and tested as an electrochemical electrode towards recognition of several anions. The electrode exhibits exceptional electrochemical recognition for the nitrite (NO⁻ ₂ ) anion in aqueous media. The electrode exhibited a ...

  5. Dioxygen affinities and catalytic oxidation activities of cobalt complexes with Schiff bases containing crown ether

    NARCIS (Netherlands)

    Sun, B.; Chen, J.R.; Hu, J.Y.; Li, X.J.

    2006-01-01

    The stoichiometry of dioxygen uptake of Co complexes with 4',5'-bis-(5-chloro-2-hydroxyphenylmethylideneimino)benzo-12-crown-4 (la), 4',5'-bis(2-hydroxyphenylmethylideneimino)benzo-12-crown-4(1b), 4',5'-bis-(5-methoxy-2-hydroxyphenylmethylideneimino)benzo-12-crown-4 (1c),

  6. Synthesis, characterization and electrochemical behaviour of cobalt(II) and cobalt(III):O 2- complexes, respectively, with linear and tripodal tetradentate ligands derived from Schiff bases

    Science.gov (United States)

    Djebbar-Sid, S.; Benali-Baitich, O.; Deloume, J. P.

    2001-07-01

    New octahedral cobalt complexes with linear and tripodal tetradentate ligands derived from Schiff bases have been synthesized and characterized using elemental analysis, molar conductance, IR spectra, magnetic measurements, electronic and ESR spectra. The experimental results support the binding of linear ligands with two N and two O donor sites to cobalt ion. They show a square planar geometry and tripodal ligands coordinated to the metal ion by only one nitrogen atom, giving an arrangement of NO 3 donor groups, the other axial sites being occupied by the molecular oxygen and/or the aquo molecules. From the results of cyclic voltammetry it is shown that chelate structure and ligand geometry and electron donating effect of the ligand substituents are among the factors influencing the redox potentials of the complexes. Linear ligands lead to high-spin cobalt(II) complexes. They do not interact with dioxygen and stabilize the Co(II) state counter to their related Schiff-base complexes. The low-spin complexes with tripodal ligands are O 2 adducts and the configuration in these complexes is best formulated as [Co IIIO 2-].

  7. Synthesis, crystal structure and interaction of L-valine Schiff base divanadium(V) complex containing a V2O3 core with DNA and BSA

    Science.gov (United States)

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

    2013-04-01

    A divanadium(V) complex, [V2O3(o-van-val)2] (o-van-val = Schiff base derived from o-vanillin and L-valine), has been synthesized and structurally characterized. The crystal structure shows that both of the vanadium centers in the complex have a distorted octahedral coordination environment composed of tridentate Schiff base ligand. A V2O3 core in molecular structure adopts intermediate between cis and trans configuration with the O1dbnd V1⋯V1Adbnd O1A torsion angle 115.22 (28)° and the V1⋯V1A distance 3.455 Å. The binding properties of the complex with calf thymus DNA (CT-DNA) have been investigated by UV-vis absorption, fluorescence, CD spectra and viscosity measurement. The results indicate that the complex binds to CT-DNA in non-classical intercalative mode. Meanwhile, the interaction of the complex with bovine serum albumin (BSA) has been studied by UV-vis absorption, fluorescence and CD spectra. Results indicated that the complex can markedly quench the intrinsic fluorescence of BSA via a static quenching process, and cause its conformational change. The calculated apparent binding constant Kb was 1.05 × 106 M-1 and the binding site number n was 1.18.

  8. Synthesis, spectral, thermal and biological studies of mixed ligand complexes with newly prepared Schiff base and 1,10-phenanthroline ligands

    Science.gov (United States)

    Abd El-Halim, Hanan F.; Mohamed, Gehad G.; Khalil, Eman A. M.

    2017-10-01

    A series of mixed ligand complexes were prepared from the Schiff base (L1) as a primary ligand, prepared by condensation of oxamide and furan-2-carbaldehyde, and 1,10-phenanthroline (1,10-phen) as a secondary ligand. The Schiff base ligand and its mixed ligand chelates were characterized based on elemental analysis, IR, 1H NMR, thermal analysis, UV-Visible, mass, molar conductance, magnetic moment. X-ray diffraction, solid reflectance and ESR also have been studied. The mixed ligand complexes were found to have the formulae of [M(L1) (1,10-phen)]Clm.nH2O (M = Cr(III) and Fe(III) (m = 3) (n = 0); M = Mn(II), Cu(II) and Cd(II) (m = 2) (n = 0); and M = Co(II) (m = 2) (n = 1), Ni(II) (m = 2) (n = 2) and Zn(II) (m = 2) (n = 3)) and that the geometrical structure of the complexes were octahedral. The parameters of thermodynamic using Coats-Redfern and Horowitz-Metzger equations were calculated. The synthesized Schiff base ligand, 1,10-phenanthroline ligand and Their mixed ligand complexes were also investigated for their antibacterial and antifungal activity against bacterial species (Gram-Ve bacteria: Pseudomonas aeruginosa and Escherichia coli) and (Gram + Ve bacteria: Bacillus subtilis and Streptococcus pneumonia) and fungi (Aspergillus fumigates and Candida albicans). The anticancer activity of the new compounds had been tested against breast (MFC7) and colon (HCT-116) cell lines. The results showed high activity for the synthesized compounds.

  9. Spectral characterization, optical band gap calculations and DNA binding of some binuclear Schiff-base metal complexes derived from 2-amino-ethanoic acid and acetylacetone

    Science.gov (United States)

    Hussien, Mostafa A.; Nawar, Nagwa; Radwan, Fatima M.; Hosny, Nasser Mohammed

    2015-01-01

    Bi-nuclear metal complexes derived from the reaction of Cu(II), Co(II), Ni(II) and Zn(II) acetates with the Schiff-base ligand (H2L) resulted from the condensation of 2-amino-ethanoic acid (glycine) and acetylacetone have been synthesized and characterized by elemental analyses, Raman spectra, FT-IR, ES-MS, UV-Vis., 1H NMR, ESR, thermal analyses (TG, DTG and DTA) and magnetic measurements. The results showed that, the Schiff base ligand can bind two metal ions in the same time. It coordinates to the first metal ion as mono-negative bi-dentate through azomethine nitrogen and enolic carbonyl after deprotonation. At the same time, it binds to the second metal ion via carboxylate oxygen after deprotonation. The thermodynamic parameters E∗, ΔH∗, ΔG∗ and ΔS∗ have been calculated by Coats-Redfern (CR) and Horowitz-Metzger (HM) methods. The optical band gaps of the isolated complexes have been calculated from absorption spectra and the results indicated semi-conducting nature of the investigated complexes. The interactions between the copper (II) complex and calf thymus DNA (CT-DNA) have been studied by UV spectra. The results confirm that the Cu(II) complex binds to CT-DNA.

  10. Structural, spectral and biological studies of binuclear tetradentate metal complexes of N 3O Schiff base ligand synthesized from 4,6-diacetylresorcinol and diethylenetriamine

    Science.gov (United States)

    Emara, Adel A. A.

    2010-09-01

    The binuclear Schiff base, H 2L, ligand was synthesized by reaction of 4,6-diacetylresorcinol with diethylenetriamine in the molar ratio 1:2. The coordination behavior of the H 2L towards Cu(II), Ni(II), Co(II), Zn(II), Fe(III), Cr(III), VO(IV) and UO 2(VI) ions has been investigated. The elemental analyses, magnetic moments, thermal studies and IR, electronic, 1H NMR, ESR and mass spectra were used to characterize the isolated ligand and its metal complexes. The ligand acts as dibasic with two N 3O-tetradentate sites and can coordinate with two metal ions to form binuclear complexes. The bonding sites are the nitrogen atoms of the azomethine and amine groups and the oxygen atoms of the phenolic groups. The metal complexes exhibit either square planar, tetrahedral, square pyramid or octahedral structures. The Schiff base ligand and its metal complexes were tested against four pathogenic bacteria ( Staphylococcus aureus and Streptococcus pyogenes) as Gram-positive bacteria, and ( Pseudomonas fluorescens and Pseudomonas phaseolicola) as Gram-negative bacteria and two pathogenic fungi ( Fusarium oxysporum and Aspergillus fumigatus) to assess their antimicrobial properties. Most of the complexes exhibit mild antibacterial and antifungal activities against these organisms.

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

    Directory of Open Access Journals (Sweden)

    Elena Pahonțu

    2015-04-01

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

  12. Synthesis, spectral, thermal and optical properties of Schiff-base complexes derived from 2(E)-2-((z)-4-hydroxypent-3-en-2-ylideneamino)-5-guanidinopentanoic acid and acetylacetone

    Science.gov (United States)

    Hosny, Nasser Mohammed; Hussien, Mostafa A.; Radwan, Fatima M.; Nawar, Nagwa

    2017-09-01

    New metal complexes derived from the in situ reaction of Cu(II), Co(II), Ni(II) and Zn(II) acetates with the Schiff-base ligand (H2L) resulted from the condensation of 2-amino-5-guanidinopentanoic acid (arginine) and acetylacetone have been synthesized. The resulting complexes have been characterized by, elemental analyses, ES-MS, IR, Raman spectra, UV-Vis., 1HNMR, ESR, thermal analyses (TGA and DTG) and magnetic measurements. The results showed that, The Schiff-base ligand acts as bi-negative tridentate coordinating via azomethine nitrogen, enolic carbonyl oxygen and carboxylate oxygen after displacement of hydrogen. The thermodynamic parameters E∗, ΔH, ΔG and ΔS of the isolated complexes have been calculated. The optical band gap (Eg) values of Cu, Co, Ni and Zn were found to be 3.3, 3.4, 3.7 and 4.3 eV, respectively, arising from direct transitions. Optical band gap measurements indicate the semi-conductivity nature of these complexes.

  13. Self assembly of dialkoxo bridged dinuclear Fe(III) complex of pyridoxal Schiff base with C-C bond formation - structure, spectral and magnetic properties

    Czech Academy of Sciences Publication Activity Database

    Murašková, V.; Szabó, N.; Pižl, M.; Hoskovcová, I.; Dušek, Michal; Huber, Š.; Sedmidubský, D.

    2017-01-01

    Roč. 461, May (2017), s. 111-119 ISSN 0020-1693 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 : iron (III) dinuclear complex * dialkoxo bridged pyridoxal Schiff base * C-C bond * crystal structure * magnetic properties Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 2.002, year: 2016

  14. Synthesis of Schiff bases of naphtha[1,2-d]thiazol-2-amine and metal complexes of 2-(2′-hydroxy)benzylideneaminonaphthothiazole as potential antimicrobial agents

    Science.gov (United States)

    Azam, Faizul; Singh, Satendra; Khokhra, Sukhbir Lal; Prakash, Om

    2007-01-01

    Objective: A series of 2-benzylideneaminonaphthothiazoles were designed and synthesized incorporating the lipophilic naphthalene ring to render them more capable of penetrating various biomembranes. Methods: Schiff bases were synthesized by the reaction of naphtha[1,2-d]thiazol-2-amine with various substituted aromatic aldehydes. 2-(2′-Hydroxy)benzylideneaminonaphthothiazole was converted to its Co(II), Ni(II) and Cu(II) metal complexes upon treatment with metal salts in ethanol. All the compounds were evaluated for their antibacterial activities by paper disc diffusion method with Gram positive Staphylococcus aureus and Staphylococcus epidermidis and Gram negative Escherichia coli and Pseudomonas aeruginosa bacteria. The minimum inhibitory concentrations of all the Schiff bases and metal complexes were determined by agar streak dilution method. Results: All the compounds moderately inhibited the growth of Gram positive and Gram negative bacteria. In the present study among all Schiff bases 2-(2′-hydroxy)benzylideneaminonaphthothiazole showed maximum inhibitory activity and among metal complexes Cu(II) metal complex was found to be most potent. Conclusion: The results obtained validate the hypothesis that Schiff bases having substitution with halogens, hydroxyl group and nitro group at phenyl ring are required for the antibacterial activity while methoxy group at different positions in the aromatic ring has minimal role in the inhibitory activity. The results also indicated that the metal complexes are better antibacterial agents as compared to the Schiff bases. PMID:17565517

  15. Synthesis in aqueous medium and organic praseodymium complexes with ligands derived from Schiff base quinolinic. Characterization and physicochemical study; Sintesis en medio acuoso y organico de complejos de praseodimio con ligantes derivados de base de Schiff quinolicos. Caracterizacion y estudio fisicoquimico

    Energy Technology Data Exchange (ETDEWEB)

    Garcia G, A.

    2015-07-01

    It was investigated the coordination ability of the quinolinic Schiff base organic tetradentate quinolinic ligand (Q Schiff-(OH){sub 2}) towards the trivalent praseodymium by UV/Vis spectrophotometric titration (St). By St, was studied the formed species between the Q Schiff-(OH){sub 2} ligand and the praseodymium nitrate salt in equimolar concentrations (5.86 x 10{sup -4} M: 5.22 x 10{sup -4} M) in methanol. The statistical analysis of the experimental results suggested three complexed species with 1Pr:3L, 1Pr:2L y 1Pr:1L stoichiometries. The predominant stoichiometries were the second and the latter. Based on these results and data from the scientific literature, the methodology for the syntheses of the complexes Q Schiff-(OH){sub 2}-Pr in aqueous-organic and organic media was established and a molar ratio M:L= 1:2 of praseodymium nitrate and the ligand was used. The new complexes were characterized by UV/Vis, Infrared, X-ray Photoelectron Spectroscopy (XP S), Diffuse Reflectance (Dr) and Thermogravimetric Analysis/Differential Scanning Calorimetry (TGA/DSC). Elemental analysis of C, N, O and Pr by XP S suggested 1Pr:2L:1Na (PrC{sub 32}H{sub 20}N{sub 4}O{sub 4}Na) stoichiometry of the complex synthesized by the aqueous-organic medium while for the complex synthesized by the organic medium it was 1Pr:3L (PrC{sub 48}H{sub 33}N{sub 6}O{sub 6}). In the first case, the praseodymium ion charge was neutralized by the anionic ligands whose remaining charge was compensated by the sodium ion. In the second case, the ion charge was neutralized by the ligands. The minimum formula was Pr(Q Schiff){sub 2}Na for the pure coordination compound from the aqueous-organic medium and the minimum formula Pr(Q Schiff){sub 3} for that from the organic medium. XP S also indicated that the oxidation state of praseodymium ion was maintained. Both complexes were stable in methanol, ethanol and acetonitrile at least for 5 days. The photophysical properties of the studied complexes were

  16. Spectroscopic, electrochemical, docking and molecular dynamics studies on the interaction of three oxovanadium (IV) Schiff base complexes with bovine serum albumin and their cytotoxicity against cancer.

    Science.gov (United States)

    Amiri, Majid; Ajloo, Davood; Fazli, Mostafa; Mokhtarieh, Amir; Grivani, Gholamhossein; Saboury, A A

    2017-11-07

    This study was designed to investigate the interaction of three oxovanadium (IV) Schiff base complexes with bovine serum albumin (BSA) by means of various spectroscopic and electrochemical methods along with molecular docking study and molecular dynamics (MD) simulations. Binding constants were estimated by fluorescence and UV-Vis spectroscopy. The results indicated a good affinity of the complexes for BSA in which furyl derivative had more activity. Molecular docking study showed that these complexes have the similar binding modes and located within subdomain IB in site III of BSA. The supporting of molecular docking and molecular dynamics results by experimental data, confirms the validity of the interactions data obtained by these methods. Biological activity against cancer cell showed that furyl derivative has higher activity than other complexes. Pharmaceutical analysis also showed that, these complexes potentially can be used as cancer daisies.

  17. Synthesis, characterization and antimicrobial activities of mixed ligand transition metal complexes with isatin monohydrazone Schiff base ligands and heterocyclic nitrogen base

    Science.gov (United States)

    Devi, Jai; Batra, Nisha

    2015-01-01

    Mixed ligand complexes of Co(II), Ni(II), Cu(II) and Zn(II) with various uninegative tridentate ligands derived from isatin monohydrazone with 2-hydroxynapthaldehyde/substituted salicylaldehyde and heterocyclic nitrogen base 8-hydroxyquinoline have been synthesized and characterized by elemental analysis, conductometric studies, magnetic susceptibility and spectroscopic techniques (IR, UV-VIS, NMR, mass and ESR). On the basis of these characterizations, it was revealed that Schiff base ligands existed as monobasic tridentate ONO bonded to metal ion through oxygen of carbonyl group, azomethine nitrogen and deprotonated hydroxyl oxygen and heterocyclic nitrogen base 8-hydroxyquinoline existed as monobasic bidentate ON bonded through oxygen of hydroxyl group and nitrogen of quinoline ring with octahedral or distorted octahedral geometry around metal ion. All the compounds have been tested in vitro against various pathogenic Gram positive bacteria, Gram negative bacteria and fungi using different concentrations (25, 50, 100, 200 μg/mL) of ligands and their complexes. Comparative study of antimicrobial activity of ligands, and their mixed complexes indicated that complexes exhibit enhanced activity as compared to free ligands and copper(II) Cu(LIV)(Q)ṡH2O complex was found to be most potent antimicrobial agent.

  18. Cu(II), Ni(II) complexes derived from chiral Schiff-base ligands: Synthesis, characterization, cytotoxicity, protein and DNA-binding properties.

    Science.gov (United States)

    Li, Zhen; Yan, Hui; Chang, Guoliang; Hong, Min; Dou, Jianmin; Niu, Meiju

    2016-10-01

    A series of novel copper (II) and nickel (II) complexes derived from chiral Schiff-base ligands [(R)/(S)-H2L(1)=(R)/(S)-2-[(1-Hydroxymethyl-propylimino)-methyl]-5-methoxy-phenol and (R)/(S)-H2L(2)=(R)/(S)-2-[(1-Hydroxymethyl-2-phenyl-ethylimino)-methyl]-5-methoxy-phenol], were synthesized and characterized by elemental analyses, (1)H NMR spectra, FT-IR spectrum. The crystal structures of complexes 1-5 were determined through single crystal X-ray diffraction (SXRD). The structures showed the ligands coordinated to the Cu/Ni (II) ion in a neutral manner via ONO donor atoms, and oxygen atoms of solvent molecules occupy the axial positions in Ni (II) complexes 3 and 4. The complexes interactions with BSA and CT-DNA were investigated by various spectroscopic methods (UV-Visible, circular dichroism spectrum, fluorescence spectroscopic and synchronous fluorescence spectra). Interactions of chiral copper (II) complexes are stronger than nickel (II) complexes. Further, the cytotoxicities of the complexes 1-6 towards three kinds of cancerous cell lines, were human lung adenocarcinoma (A549), human cervical carcinoma cell (HeLa) and human breast cancer cell (MCF-7) respectively, were evaluated by MTT assay. All complexes exhibited good cytotoxic activity. Furthermore, Cu (II) complex 5 derived from (R)-Schiff-base ligand was found to be more effective towards HeLa cancerous cell. The results showed that chirality and metal ion have important influence on their anticancer activities and interactions with DNA/BSA. Copyright © 2016 Elsevier B.V. All rights reserved.

  19. 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.

  20. A novel Schiff base derived from the gabapentin drug and copper (II) complex: Synthesis, characterization, interaction with DNA/protein and cytotoxic activity.

    Science.gov (United States)

    Shokohi-Pour, Zahra; Chiniforoshan, Hossein; Momtazi-Borojeni, Amir Abbas; Notash, Behrouz

    2016-09-01

    A novel Schiff base [C20H23NO3], has been prepared and characterized using FT-IR, UV-vis, (1)H NMR spectroscopy, elemental analysis and X-ray crystallography. A copper (II) complex [Cu(C20H22NO3)2]·H2O has also been synthesized and characterized. The new ligand and complex thus obtained were investigated by their interaction with calf thymus DNA and BSA using electronic absorption spectroscopy, fluorescence spectroscopy, and thermal denaturation. The intrinsic binding constants Kb of the ligand and Cu (II) complex, with CT-DNA obtained from UV-vis absorption studies were 1.53×10(4)M(-1) and 3.71×10(5)M(-1), respectively. Moreover the addition of the two compounds to CT-DNA (1:2) led to an increase of the melting temperature of DNA up to around 2.61°C for the ligand and 3.99°C for the Cu (II) complex. The ligand and Cu (II) complex bind to CT-DNA via a partial intercalative, as shown by the experimental data. In addition, the albumin interactions of the two compounds were studied by fluorescence quenching spectra, the results indicating that the binding mechanism is a static quenching process. The in vitro cytotoxicity of the two compounds on three different cancer cell lines was evaluated by MTT assay. The results showed that the copper complex exerted enhanced cytotoxicity compared with the Schiff base ligand; thereby, this complex clearly implies a positive synergistic effect. Furthermore, the copper complex showed a high, selective, and dose-dependent cytotoxicity against cancer cell lines. Copyright © 2016. Published by Elsevier B.V.

  1. Novel photoluminescent mesogenic Schiff-base ligands bearing [N{sub 4}O{sub 4}] donors and their bimetallic Zn(II) complexes

    Energy Technology Data Exchange (ETDEWEB)

    Bhattacharjee, Chira R., E-mail: crbhattacharjee@rediffmail.com; Datta, Chitraniva; Das, Gobinda; Mondal, Paritosh

    2012-05-01

    Novel photoluminescent salicylaldimine ligands condensed from 3{sup /}, 3{sup /}, 4{sup /}, 4{sup /}-tetraminobiphenyl and 4-substituted long alkoxy salicylaldehyde possessing two sets of tetradentate [N{sub 2}O{sub 2}] donor site and their binuclear zinc(II) complexes have been synthesized. The mesogenic and photophysical properties were investigated. The compounds were characterized by FT-IR, {sup 1}H and {sup 13}C NMR, UV-vis, elemental analyses, solution electrical conductivity measurements and FAB mass spectrometry. The mesomorphic behavior of these compounds was probed by differential scanning calorimetry and polarized optical microscopy. The ligand with six carbon chain length showed monotropic nematic mesomorphism at 128 Degree-Sign C. However, the ligand with alkoxy tail of carbon length 12 showed enantiotropic SmC phase. The complexes are devoid of any mesomorphism. The low molar conductance values in CH{sub 2}Cl{sub 2} indicate that the complexes are non-electrolytes. At 330 nm excitation, the ligand emits green light at {approx} 516 nm ({Phi} = 30%) and {approx} 549 nm ({Phi} = 16%) in solution and solid state, respectively. At similar excitation wavelength, the complexes exhibit blue light in solution at {approx} 452 nm ({Phi} = 20%) and green light in solid state {approx} 555 nm ({Phi} = 11%). The DFT calculations were performed using DMol3 program at BLYP/DNP level to ascertain the stable electronic structure of the complex. - Graphical abstract: Green emissive mesogenic compartmental salen type Schiff base compound with four terminal chains and their binuclear Zn(II) complex are described. The ligand exhibits nematic/SmC mesomorphism however complexes did not exhibit mesogenicity. Highlights: Black-Right-Pointing-Pointer New photoluminescent compartmental Schiff-base. Black-Right-Pointing-Pointer Nematic and SmC mesomorphism. Black-Right-Pointing-Pointer Green emissive ligand. Black-Right-Pointing-Pointer Distorted square planner geometry. Black

  2. Copper complexes based on chiral Schiff-base ligands: DNA/BSA binding ability, DNA cleavage activity, cytotoxicity and mechanism of apoptosis.

    Science.gov (United States)

    Zhou, Xue-Quan; Li, Yang; Zhang, Dong-Yan; Nie, Yan; Li, Zong-Jin; Gu, Wen; Liu, Xin; Tian, Jin-Lei; Yan, Shi-Ping

    2016-05-23

    Four copper(II) complexes with chiral Schiff-base ligands, [Cu(R-L(1))2]·EtOAc (1) and [Cu(S-L(1))2]·EtOAc (2), [Cu(R-L(2))2]·EtOAc (3) and [Cu(S-L(2))2]·EtOAc (4), (R/S-HL(1) = (R/S)-(1-naththyl)-salicylaldimine, R/S-HL(2) = (R/S)-(1-naththyl)-3-methoxysalicylaldimine, EtOAc = ethyl acetate) were synthesized to serve as artificial nucleases and anticancer drugs. All complexes and R/S-HL(1) ligands were structurally characterized by X-ray crystallography. The interaction of these complexes with CT-DNA was researched via several spectroscopy methods, which indicates that complexes bind to CT-DNA by moderate intercalation binding mode. Moreover, DNA cleavage experiments revealed that the complexes exhibited remarkable DNA cleavage activities in the presence of H2O2via the generation of hydroxyl radical. Particularly, complex 4 also could nick DNA with the production of (1)O2. And all complexes exhibited excellent cytotoxicity to MDA-MB-231, A549 and Hela human cancer cells in micromole magnitude. Furthermore, complex 4 exhibited comparable cytotoxic effect to cisplatin against the proliferation of MDA-MB-231 and A549 cancer cells, as well as showed better anticancer ability to the three cancer cells than the other complexes. The results of cell cycle analysis indicated that complexes 3-4 could induce G2/M phase cell cycle arrest. Furthermore, MDA-MB-231 cells treated with 3 and 4 were subjected to apoptosis and death by generation of ROS and the activation of caspase-3. Interestingly, the chiral complexes 3 and 4 may induce cell apoptosis through extrinsic and mitochondrial intrinsic pathway, respectively. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

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

    Science.gov (United States)

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

    2014-07-01

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

  4. Immobilized molybdenum–thiosemicarbazide Schiff base complex on the surface of magnetite nanoparticles as a new nanocatalyst for the epoxidation of olefins

    Energy Technology Data Exchange (ETDEWEB)

    Mohammadikish, M., E-mail: mohammadikish@yahoo.com [Department of Chemistry, Faculty of Sciences, Kermanshah Branch, Islamic Azad University, Kermanshah (Iran, Islamic Republic of); Masteri-Farahani, M.; Mahdavi, S. [Faculty of Chemistry, Kharazmi University, Tehran (Iran, Islamic Republic of)

    2014-03-15

    In this work, a new magnetically recoverable nanocatalyst was developed by immobilization of thiosemicarbazide ligand on the surface of silica coated magnetite nanoparticles (SCMNPs) through Schiff base condensation and followed complexation with MoO{sub 2}(acac){sub 2}. Characterization of the prepared nanocatalyst was performed with different physicochemical methods such as Fourier transform infrared (FT-IR) and atomic absorption spectroscopies, X-ray diffraction (XRD), vibrating sample magnetometry (VSM), thermogravimetric analysis (TGA), field-emission scanning electron microscopy (FE-SEM), and transmission electron microscopy (TEM). The prepared catalyst catalyzed the epoxidation of olefins and allyl alcohols with tert-butyl hydroperoxide (TBHP) and cumene hydroperoxide (CHP) quantitatively with excellent selectivity toward the corresponding epoxides under mild reaction conditions. - Highlights: • Silica coated magnetite nanoparticles were modified with a thiosemicarbazide-Schiff base ligand. • Complexation of the supported ligand with molybdenum resulted in preparation of a new hybrid nanomaterial. • The prepared hybrid nanomaterial acted as an efficient and reusable catalyst in the epoxidation of olefins.

  5. Syntheses, structural properties and catecholase activity of copper(II) complexes with reduced Schiff base N-(2-hydroxybenzyl)-amino acids.

    Science.gov (United States)

    Yang, Chang-Tong; Vetrichelvan, Muthalagu; Yang, Xiandong; Moubaraki, Boujemaa; Murray, Keith S; Vittal, Jagadese J

    2004-01-07

    A number of dicopper(II) complexes of reduced Schiff base ligands, N-(2-hydroxybenzyl)-amino acids [Cu2L2(H2O)x].yH2O (L = Sgly (1), D-Sala (2), L-Sala (3), DL-Sala (4), Sab2 (5), Sbal (6), Sab4 (7), Sval (8), Shis (9), Styr (10) and Stryp (11), x= 0-2 & y= 0-2) have been synthesized, and the solid-state structures of, and have been determined. The compounds and are binuclear in which the Cu(II) centres have square-pyramidal geometry with apical sites occupied by aqua ligands. In and one axial site is occupied by water and the other by an oxygen atom of the carboxylate group from the adjacent dimer through oxygen atoms to form 1D helical polymer. Variable temperature magnetic measurements of the dimer and helical polymer showed that they are typical for moderately strong antiferromagnetic coupling. All the complexes show significant catalytic activity on the oxidation of 3,5-di-tert-butylcatechol. The activity measured in terms of Kcat in the range 199-3800 h(-1) has been found to follow the order: 7>6>8>3>5 approximately 2 approximately 1>4 >10 >9 >11. The catalytic activity is found to increase with increasing the length of the methylene side chain of the amino acid in the reduced Schiff base ligands.

  6. The effect of metal and substituent on DNA binding, cleavage activity, and cytotoxicity of new synthesized Schiff base ligands and Zn(II) complex

    Science.gov (United States)

    Asadi, Zahra; Nasrollahi, Neda

    2017-11-01

    New water soluble Schiff base ligands [N,Nʹ-bis{5-[(triphenylphosphonium percholorate)-methyl]salicylidine}-1,3-diamino-2-propanol] (L1) and [N,Nʹ-bis(salicylidine)-1,3-diamino-2-propanol] (L2) and zinc (II) complex of L1: [N,Nʹ-bis{5-[(triphenylphosphonium percholorate)-methyl]salicylidine}-1,3-diamino-2-propanol]Zn(II) were synthesized and characterized by elemental analysis, FT-IR, 1HNMR and UV-Vis spectroscopy. In vitro DNA binding of the compounds were investigated by UV-Vis absorption spectroscopy, viscosity measurement, cyclic voltammetry, fluorescence spectroscopy, and gel electrophoresis. The present study aimed to investigate the effect of metal and substituent on DNA binding, cleavage activity and cytotoxicity of new synthesized Schiff base ligands and Zn(II) complex. The order of DNA binding affinity (Kb) calculated from the absorption spectroscopy was: ZnL1 > L2 > L1. Molecular docking studies explore more details on the mode of binding and binding energies. Although the compounds revealed strong DNA binding affinity but electrophoresis studies don't show any effects on the DNA structure and single or double strand breaks. The cytotoxicity experiments against human Hepatoma (HepG2) showed the order: L1 > ZnL1 > L2.

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

    Science.gov (United States)

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

    2014-07-15

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

  8. Effect of the substitutional groups on the electrochemistry, kinetic of thermal decomposition and kinetic of substitution of some uranyl Schiff base complexes

    Energy Technology Data Exchange (ETDEWEB)

    Asadi, Zahra; Nasrollahi, Rahele; Ranjkeshshorkaei, Mohammad; Firuzabadi, Fahimeh Dehghani [Shiraz Univ. (Iran, Islamic Republic of). Chemistry Dept.; Dusek, Michal; Fejfarova, Karla [ASCR, Prague (Czech Republic). Inst. of Physics

    2016-05-15

    Uranyl(VI) complexes, [UO{sub 2}(X-saloph)(solvent)], where saloph denotes N,N{sup '}-bis(salicylidene)-1,2-phenylenediamine and X = NO{sub 2}, Cl, Me, H; were synthesized and characterized by 61H NMR, IR, UV-Vis spectroscopy, thermal gravimetry (TG), cyclic voltammetry, elemental analysis (C.H.N) and X-ray crystallography. X-ray crystallography of [UO{sub 2}(4-nitro-saloph)(DMF)] revealed coordination of the uranyl by the tetradentate Schiff base ligand and one solvent molecule, resulting in seven-coordinated uranium. The complex of [UO{sub 2}(4-nitro-saloph)(DMF)] was also synthesized in nano form. Transmission electron microscopy image showed nano-particles with sizes between 30 and 35 nm. The TG method and analysis of Coats-Redfern plots revealed that the kinetics of thermal decomposition of the complexes is of the first-order in all stages. The kinetics and mechanism of the exchange reaction of the coordinated solvent with tributylphosphine was investigated by spectrophotometric method. The second-order rate constants at four temperatures and the activation parameters showed an associative mechanism for all corresponding complexes with the following trend: 4-Nitro > 4-Cl > H > 4-Me. It was concluded that the steric and electronic properties of the complexes were important for the reaction rate. For analysis of anticancer properties of uranyl Schiff base complexes, cell culture and MTT assay was carried out. These results showed a reduction of jurkat cell line concentration across the complexes.

  9. Bio-important antipyrine derived Schiff bases and their transition metal complexes: Synthesis, spectroscopic characterization, antimicrobial, anthelmintic and DNA cleavage investigation

    Science.gov (United States)

    Manjunath, M.; Kulkarni, Ajaykumar D.; Bagihalli, Gangadhar B.; Malladi, Shridhar; Patil, Sangamesh A.

    2017-01-01

    Spectroscopic (IR, NMR, UV-vis, ESR, ESI-mass), magnetic and TGA studies suggests octahedral geometry for all the CoII, NiII and CuII complexes of the Schiff bases, derived from 4-aminoantipyrine and 8-formyl-7-Hydroxy-4-methylcoumarin/5-formyl-6-hydroxycoumarin, coordinated through ONO donor sites. Antibacterial (Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa and Salmonella typhi), antifungal (Aspergillus niger, Aspergillus flavus and Cladosporium) and DNA cleavage properties of the metal complexes are investigated. The results suggested that some of the synthesized compounds are potential antimicrobials. The synthesized compounds tested for their anthelmintic activities and it was found that CoII and NiII complexes exhibited good anthelmintic properties.

  10. Synthesis, spectroscopic characterization and antimicrobial studies of Co(II), Ni(II), Cu(II) and Zn(II) complexes with Schiff bases derived from 5-bromo-salicylaldehyde

    Science.gov (United States)

    Kursunlu, Ahmed Nuri; Guler, Ersin; Sevgi, Fatih; Ozkalp, Birol

    2013-09-01

    In this study, the new Schiff base ligands derived from condensation of amine and 5-bromo-salicylaldehyde were characterized. All compounds, the Schiff bases and the metal complexes, were characterized by elemental analyzes, FT-IR, 1H NMR, 13C NMR and magnetic susceptibility measurements. The synthesized ligands, along with their metal (II) complexes, were screened for their in vitro antibacterial activity against four Gram-negative (Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa and Salmonella enteritidis) and four Gram-positive (Streptococcus pyogones, Bacillus cereus, Staphylococcus aureus and Methicillin-resistant S. aureus) bacterial strains by using disc diffusion and broth microdilution techniques.

  11. 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

  12. Synthesis, Characterization, and Catalytic Studies of Mn(III-Schiff Base-Dicyanamide Complexes: Checking the Rhombicity Effect in Peroxidase Studies

    Directory of Open Access Journals (Sweden)

    Manuel R. Bermejo

    2017-01-01

    Full Text Available The condensation of 3-methoxy-2-hydroxybenzaldehyde and the diamines 1,2-diphenylendiamine, 1,2-diamine-2-methylpropane and 1,3-propanediamine yielded the dianionic tetradentate Schiff base ligands N,N′-bis(2-hydroxy-4-methoxybenzylidene-1,2-diphenylendiimine (H2L1, N,N′-bis(2-hydroxy-4-methoxybenzylidene-1,2-diamino-2-methylpropane (H2L2 and N,N′-bis(2-hydroxy-4-methoxybenzylidene-1,3-diaminopropane (H2L3 respectively. The organic compounds H2L1 and H2L2 have been characterized by elemental analysis, IR, 1H and 13C NMR spectroscopies and mass spectrometry electrospray (ES. The crystal structure of H2L2 in solid state, solved by X-ray crystallography, is highly conditioned in the solid state by two N-H•••N intramolecular interactions. The synthesis of three new manganese(III complexes 1–3, incorporating these ligands, H2L1–H2L3, and dicyanamide (DCA, is reported. The complexes 1–3 have been physicochemically characterized by elemental analysis, IR and paramagnetic 1H NMR spectroscopy, ESI mass spectrometry, magnetic moment at room temperature and conductivity measurements. Complex 1 has been crystallographically characterized. The X-ray structure shows the self-assembly of the Mn(III-Schiff base-DCA complex through µ-aquo bridges between neighbouring axial water molecules and also by π-π stacking interactions, establishing a dimeric structure. The manganese complexes were also tested as peroxidase mimics for the H2O2-mediated reaction with the water-soluble trap ABTS, showing complexes 1-2 relevant peroxidase activity in contrast with 3. The rhombicity around the metal ion can explain this catalytic behaviour.

  13. Synthesis, characterization of 1,2,4-triazole Schiff base derived 3d-metal complexes: Induces cytotoxicity in HepG2, MCF-7 cell line, BSA binding fluorescence and DFT study.

    Science.gov (United States)

    Tyagi, Prateek; Tyagi, Monika; Agrawal, Swati; Chandra, Sulekh; Ojha, Himanshu; Pathak, Mallika

    2017-01-15

    Two novel Schiff base ligands H2L1 and H2L2 have been synthesized by condensation reaction of amine derivative of 1,2,4-triazole moiety with 2-hydroxy-4-methoxybenzaldehyde. Co(II), Ni(II), Cu(II) and Zn(II) of the synthesized Schiff bases were prepared by using a molar ratio of ligand:metal as 1:1. The structure of the Schiff bases and synthesized metal complexes were established by 1H NMR, UV-Vis, IR, Mass spectrometry and molar conductivity. The thermal stability of the complexes was study by TGA. Fluorescence quenching mechanism of metal complexes 1-4 show that Zn(II) and Cu(II) complex binds more strongly to BSA. In DFT studies the geometries of Schiff bases and metal complexes were fully optimized with respect to the energy using the 6-31+g(d,p) basis set. The spectral data shows that the ligands behaves as binegative tridentate. On the basis of the spectral studies, TGA and DFT data an octahedral geometry has been assigned for Co(II), Ni(II), square planar for Cu(II) and tetrahedral for Zn(II) complexes. The anticancer activity were screened against human breast cancer cell line (MCF-7) and human hepatocellular liver carcinoma cell line (Hep-G2). Result indicates that metal complexes shows increase cytotoxicity in proliferation to cell lines as compared to free ligand. Copyright © 2016. Published by Elsevier B.V.

  14. Biological activity of palladium(II) and platinum(II) complexes of the acetone Schiff bases of S-methyl- and S-benzyldithiocarbazate and the X-ray crystal structure of the [Pd(asme)2] (asme=anionic form of the acetone Schiff base of S-methyldithiocarbazate) complex.

    Science.gov (United States)

    Akbar Ali, Mohammad; Mirza, Aminul Huq; Butcher, Raymond J; Tarafder, M T H; Keat, Tan Boon; Ali, A Manaf

    2002-11-25

    Palladium(II) and platinum(II) complexes of general empirical formula, [M(NS)(2)] (NS=uninegatively charged acetone Schiff bases of S-methyl- and S-benzyldithiocarbazate; M=Pt(II) and Pd(II)) have been prepared and characterized by a variety of physicochemical techniques. Based on conductance, IR and electronic spectral evidence, a square-planar structure is assigned to these complexes. The crystal and molecular structure of the [Pd(asme)(2)] complex (asme=anionic form of the acetone Schiff base of S-methyldithiocarbazate) has been determined by X-ray diffraction. The complex has a distorted cis-square planar structure with the ligands coordinated to the palladium(II) ions as uninegatively charged bidentate NS chelating agents via the azomethine nitrogen and the mercaptide sulfur atoms. The distortion from a regular square-planar geometry is attributed to the restricted bite angles of the ligands. Antimicrobial tests indicate that the Schiff bases exhibit strong activities against the pathogenic bacteria, Bacillus subtilis (mutant defective DNA repair), methicillin-resistant Staphylococcus aureus, B. subtilis (wild type) and Pseudomonas aeruginosa and the fungi, Candida albicans (CA), Candida lypotica (2075), Saccharomyces cerevisiae (20341) and Aspergillus ochraceous (398)-the activities exhibited by these compounds being greater than that of the standard antibacterial and antifungal drugs, streptomycin and nystatin, respectively. The palladium(II) and platinum(II) complexes are inactive against most of these organisms but, the microbe, Pseudomonas aeruginosa shows strong sensitivity to the platinum(II) complexes. Screening of the compounds for their cytotoxicities against T-lymphoblastic leukemia cancer cells has shown that the acetone Schiff base of S-methyldithiocarbazate (Hasme) exhibits a very weak activity, whereas the S-benzyl derivative (Hasbz) is inactive. However, the palladium(II) complexes exhibit strong cytotoxicities against this cancer; their

  15. Adherence to Bürgi–Dunitz stereochemical principles requires significant structural rearrangements in Schiff-base formation: insights from transaldolase complexes

    Science.gov (United States)

    Light, Samuel H.; Minasov, George; Duban, Mark-Eugene; Anderson, Wayne F.

    2014-01-01

    The Bürgi–Dunitz angle (αBD) describes the trajectory of approach of a nucleophile to an electrophile. The adoption of a stereoelectronically favorable αBD can necessitate significant reactive-group repositioning over the course of bond formation. In the context of enzyme catalysis, interactions with the protein constrain substrate rotation, which could necessitate structural transformations during bond formation. To probe this theoretical framework vis-à-vis biocatalysis, Schiff-base formation was analysed in Francisella tularensis trans­aldolase (TAL). Crystal structures of wild-type and Lys→Met mutant TAL in covalent and noncovalent complexes with fructose 6-­phosphate and sedoheptulose 7-phosphate clarify the mechanism of catalysis and reveal that substrate keto moieties undergo significant conformational changes during Schiff-base formation. Structural changes compelled by the trajectory considerations discussed here bear relevance to bond formation in a variety of constrained enzymic/engineered systems and can inform the design of covalent therapeutics. PMID:24531488

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

    Science.gov (United States)

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

    2017-10-01

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

  17. Antibacterial and antioxidant properties of macrocyclic Schiff bases ...

    African Journals Online (AJOL)

    CLEMENT O BEWAJI

    Also in-vitro antioxidant activity of all compounds was determined by nitric acid free radical scavanging assay. Keywords: Macrocyclic Schiff Bases; Vanadium complexes; Antibacterial; Antioxidant activities. 1. INTRODUCTION. The macrocyclic ligands are highly significant in bioinorganic chemistry, catalysis, extraction of ...

  18. Synthesis, spectral characterization of Schiff base transition metal ...

    Indian Academy of Sciences (India)

    TECS

    Studies of a new kind of chemotherapeutic Schiff bases are now attracting the attention of biochemists. 4,5. Earlier work reported that some drugs showed increased ac- tivity, when administered as metal complexes rather than as organic compounds. 6,7. Deoxyribonucleic acid (DNA) is the primary target molecule for most.

  19. Synthesis of Schiff bases derived from 2-hydroxy-1- naphth ...

    African Journals Online (AJOL)

    The current studies were designed to prepare tin(II) complexes of various Schiff base derivatives of 2-hydroxy-1-naphthaldehyde (HN) with L-histidine and sulfamethazine have been prepared and characterized by different physiochemical studies such as elemental analysis, atomic absorption, UV-Vis spectra, FTIR spectra, ...

  20. Characterization of Schiff base derived from 2-hydroxo-1 ...

    African Journals Online (AJOL)

    Synthesis of Copper (II) complex with a Schiff base derived from the reaction of 2 – hydroxyl-1- naphthaldehyde and ethylenediammine was carried out. Solubility, melting/decomposition temperature, molar conductance, potentiometric, elemental analysis as well as uv-visible spectrophotometric studies were carried out.

  1. synthesis of schiff bases derived from 2-hydroxy-1-naphth

    African Journals Online (AJOL)

    be involved in copper transport in blood [12]. .... complex. This shift suggests that tin ion is coordinated to the nitrogen atom of azomethine in the ligand. The bands for ν(SO2) are observed at 1344 cm-1 and 1384 cm-1 in ligand and are ..... biological activities and DNA cleaving studies of amino acid Schiff base metal(II).

  2. Antibacterial and antioxidant properties of macrocyclic Schiff bases ...

    African Journals Online (AJOL)

    Macrocyclic Schiff bases have been synthesized by the condensation of acetyl acetone with semicarbazide hydrochloride and thiosemicarbazide in presence of methanol. Further, their oxovanadium complexes have been synthesized by using vanadium acetylacetone. The structural assignment of these compounds has ...

  3. Another step toward DNA selective targeting: Ni(II) and Cu(II) complexes of a Schiff base ligand able to bind gene promoter G-quadruplexes.

    Science.gov (United States)

    Terenzi, Alessio; Lötsch, Daniela; van Schoonhoven, Sushilla; Roller, Alexander; Kowol, Christian R; Berger, Walter; Keppler, Bernhard K; Barone, Giampaolo

    2016-05-04

    DNA G-rich sequences are able to form four-stranded structures organized in stacked guanine tetrads. These structures, called G-quadruplexes, were found to have an important role in the regulation of oncogenes expression and became, for such a reason, appealing targets for anticancer drugs. Aiming at finding selective G-quadruplex binders, we have designed, synthesized and characterized a new water soluble Salen-like Schiff base ligand and its Ni(II) and Cu(II) metal complexes. UV-Vis, circular dichroism and FRET measurements indicated that the nickel complex can stabilize oncogene promoter G-quadruplexes with high selectivity, presenting no interactions with duplex DNA at all. The same compound exhibited dose-dependent cytotoxic activity in MCF-7 breast cancer cells when combined with lipofectamine as lipophilic carrier.

  4. Nucleophilic addition to an achiral dehydroalanine Schiff base Ni(II) complex as a route to amino acids. A case of stereodetermining asymmetric protonation in the presence of TADDOL

    NARCIS (Netherlands)

    Belokon, Yuri N.; Harutyunyan, Syuzanna; Vorontsov, Evgeni V.; Peregudov, Alexander S.; Chrustalev, Viktor N.; Kochetkov, Konstantin A.; Pripadchev, Dmitriy; Sagyan, Ashot S.; Beck, Albert K.; Seebach, Dieter

    2004-01-01

    We describe herein the elaboration of a new type of a substrate based on the Ni(II) complex of a Schiff base of dehydroalanine, 1, and Michael addition of nucleophiles to it, leading to the synthesis of racemic α-amino acids. We have also developed a catalytic method for the asymmetric 1,4 conjugate

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

    Science.gov (United States)

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

    2011-05-01

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

  6. Synthesis, Spectral Characterization, SEM, Antimicrobial, Antioxidative Activity Evaluation, DNA Binding and DNA Cleavage Investigation of Transition Metal(II) Complexes Derived from a tetradentate Schiff base bearing thiophene moiety.

    Science.gov (United States)

    Abdel Aziz, Ayman A; Seda, Sabry H

    2017-05-01

    A novel series of Co(II), Ni(II), Cu(II) and Zn(II) mononuclear complexes have been synthesized involving a potentially tetradentate Schiff base ligand, which was obtained by condensation of 2-aminophenol with 2,5-thiophene-dicarboxaldehyde. The complexes were synthesized via reflux reaction of methanolic solution of the appropriate Schiff base ligand with one equivalent of corresponding metal acetate salt. Based on different techniques including micro analysis, FT-IR, NMR, UV-Vis, ESR, ESI-mass and conductivity measurements, four-coordinated geometry was assigned for all complexes. Spectroscopic data have shown that, the reported Schiff base coordinated to metal ions as a dibasic tetradentate ligand through the phenolic oxygen and the azomethine nitrogen. The antimicrobial activities of the parent ligand and its complexes were investigated by using the agar disk diffusion method. Antioxidation properties of the novel complexes were investigated and it was found that all the complexes have good radical scavenging properties. The binding of complexes to calf thymus DNA (CT-DNA) was investigated by absorption, emission and viscosity measurements. Binding studies have shown that all the complexes interacted with CT-DNA via intercalation mode and the binding affinity varies with relative order as Cu(II) complex > Co(II) complex > Zn(II) complex > Ni(II) complex. Furthermore, DNA cleavage properties of the metal complexes were also investigated. The results suggested the possible utilization of novel complexes for pharmaceutical applications.

  7. Two novel Co(II complexes with two different Schiff bases: inhibiting growth of human skin cancer cells

    Directory of Open Access Journals (Sweden)

    Y.-J. Xiao

    Full Text Available Using two flexible Schiff bases, H2L1 and H2L2, two new cobalt II (Co(II-coordination compounds, namely, Py3CoL1 (1 and Py3CoL2 (2 (Py=pyridine, L1=3,5-ClC6H2(OC=NC6H3(O-4-NO2, L2=3,5-BrC6H2(OC=NC6H3(O-4-NO2 have been synthesized under solvothermal conditions. Single crystal X-ray structural analysis revealed that compounds 1 and 2 are both six-coordinate in a distorted octahedral geometry, and the 1D chain structure was formed by the π…π and C-H…O interactions or C-H…Cl interaction. The in vitro antitumor activities of 1, 2 and their corresponding organic ligands Py, L1, and L2 were studied and evaluated, in which three human skin cancer cell lines (A-431, HT-144 and SK-MEL-30 were used in the screening tests.

  8. Synthesis, characterization, crystal structure determination and computational study of a new Cu(II) complex of bis [2-{(E)-[2-chloroethyl)imino]methyl}phenolato)] copper(II) Schiff base complex

    Science.gov (United States)

    Grivani, Gholamhossein; Vakili, Mohammad; Khalaji, Aliakbar Dehno; Bruno, Giuseppe; Rudbari, Hadi Amiri; Taghavi, Maedeh

    2016-07-01

    The copper (II) Schiff base complex of [CuL2] (1), HL = 2-{(E)-[2-chloroethyl) imino]methyl}phenol, has been synthesized and characterized by elemental (CHN) analysis, UV-Vis and FT-IR spectroscopy. The molecular structure of 1 was determined by single crystal X-ray diffraction technique. The conformational analysis and molecular structures of CuL2 were investigated by means of density functional theory (DFT) calculations at B3LYP/6-311G* level. An excellent agreement was observed between theoretical and experimental results. The Schiff base ligand of HL acts as a chelating ligand and coordinates via one nitrogen atom and one oxygen atom to the metal center. The copper (II) center is coordinated by two nitrogen atoms and two oxygen atoms from two Schiff base ligands in an approximately square planar trans-[MN2O2] coordination geometry. Thermogravimetric analysis of CuL2 showed that it was decomposed in five stages. In addition, the CuL2 complex thermally decomposed in air at 660 °C and the XRD pattern of the obtained solid showed the formation of CuO nanoparticles with an average size of 34 nm.

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

    Science.gov (United States)

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

    2015-12-14

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

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

    Science.gov (United States)

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

    2017-09-01

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

  11. Synthesis and spectral characterization of Schiff base complexes of Cu(II), Co(II), Zn(II) and VO(IV) containing 4-(4-aminophenyl)morpholine derivatives: Antimicrobial evaluation and anticancer studies

    Science.gov (United States)

    Dhahagani, K.; Mathan Kumar, S.; Chakkaravarthi, G.; Anitha, K.; Rajesh, J.; Ramu, A.; Rajagopal, G.

    2014-01-01

    Metal(II) chelates of Schiff bases derived from the condensation of 4-morpholinoaniline with substituted salicylaldehyde have been prepared and characterized by 1H NMR, IR, electronic, EPR, and magnetic measurement studies. The complexes are of the type M(X-MPMP)2 [where M = Cu(II), Co(II)), Zn(II), or VO(IV); MPMP = 2-[(4 morpholinophenyl imino) methyl] 4-X-phenol, X = Cl, (L1H), X = Br (L2H)]. Single crystal X-ray crystallography studies confirm the structure of newly synthesized Schiff bases. The Schiff bases act as bidentate monobasic ligands, coordinating through deprotonated phenolic oxygen and azomethine nitrogen atoms. The free ligands and metal complexes are screened for their biopotency. Metal complexes exhibit better activity than ligands. Anticancer activity of ligands and their metal complexes are evaluated in human heptocarcinoma(HepG2) cells. The preliminary bioassay indicates that the Schiff base and its zinc complex exhibit inhibitory activity against the human gastric cancer cell lines.

  12. Synthesis, characterization, X-ray crystal structures and antibacterial activities of Schiff base ligands derived from allylamine and their vanadium(IV), cobalt(III), nickel(II), copper(II), zinc(II) and palladium(II) complexes

    Science.gov (United States)

    Amiri Rudbari, Hadi; Iravani, Mohammad Reza; Moazam, Vahid; Askari, Banafshe; Khorshidifard, Mahsa; Habibi, Neda; Bruno, Giuseppe

    2016-12-01

    A new Schiff base ligand, HL2, and four new Schiff base complexes, NiL12, PdL12, NiL22 and ZnL22, have been prepared and characterized by elemental analysis (CHN), FT-IR and UV-Vis spectroscopy. 1H and 13C NMR techniques were employed for characterization of the ligand (HL2) and the diamagnetic complexes (PdL12 and ZnL22). The molecular structures of PdL12, NiL22 and ZnL22 complexes were determined by the single crystal X-ray diffraction technique. The crystallographic data reveal that in these complexes the metal centers are four-coordinated by two phenolate oxygen and two imine nitrogen atoms of two Schiff base ligands. The geometry around the metal center in the PdL12 and NiL22 complexes is square-planar and for ZnL22 it is a distorted tetrahedral.In the end, five new (HL2, NiL12, PdL12, NiL22 and ZnL22) and six reported (HL1, VOL12, CoL13, CuL12, ZnL12 and Zn2L14) Schiff base compounds were tested for their in vitro antimicrobial activity against Staphylococcus aureus and Escherichia coli as examples of Gram-positive and Gram-negative bacterial strains, respectively, by disc diffusion method.

  13. Syntheses, crystallographic, mass-spectroscopic determination and antioxidant studies of Co(II), Ni(II) and Cu(II) complexes of a new imidazol based Schiff base.

    Science.gov (United States)

    Demir, Serkan; Güder, Aytaç; Yazıcılar, Turan K; Çağlar, Sema; Büyükgüngör, Orhan

    2015-01-01

    A new imidazole-based Schiff base, 2-((1H-imidazol-4-yl)methyleneamino)benzylalcohol (HL) and corresponding analogous bis(2-((1H-imidazol-4-yl)methyleneimino)benzylalcohol)metal(II) perchlorates (M: Co(1), Ni(2), Cu(3)) have prepared and characterized by elemental analyses, ESI-MS, IR, UV-Vis spectroscopies and conductivity measurements. X-ray single crystal structures of 1 and 2 have been also determined. Elemental analyses, spectroscopic and conductance data of 3 demonstrated similar structural features with these of crystallographically characterized complexes and based upon this relevances, HL ligands are neutrally coordinated to metal(II) ions in tridentate mode and all complexes are isostructural, dicathionic, contain perchlorate anions as complementary ions and, are in octahedral geometry with the formulae of [M(HL)2](ClO4)2 (for 3) and [M(HL)2](ClO4)2·H2O (for 1 and 2). Radical scavenging activities of the complexes have been evaluated by using DPPH, DMPD(+), and ABTS(+) assays. SC50 values (μg/mL) of the complexes and standards on DPPH, DMPD(+), ABTS(+) follow the sequences, BHA (9.06±0.33)>CMPD3 (15.62±0.52)>CMPD2 (17.43±0.29)>Rutin (21.65±0.60)>CMPD1 (25.67±0.51)>Trolox (28.57±0.37), Rutin>BHA>CMPD3>CMPD2>Trolox>CMPD1, and Trolox>BHA>CMPD3>CMPD2>Rutin>CMPD1 respectively. Copyright © 2015 Elsevier B.V. All rights reserved.

  14. Synthesis, spectroscopic characterization, solid state d.c. electrical conductivity and biological studies of some lanthanide(III chloride complexes with a heterocyclic Schiff base ligand

    Directory of Open Access Journals (Sweden)

    K. Mohanan

    2016-07-01

    Full Text Available Condensation of 2-hydroxy-1-naphthaldehyde with 2-amino-3-carboxyethyl-4,5-dimethylthiophene in 1:1 molar ratio, yielded a potentially tridentate Schiff base viz. 2-[N-(2′-hydroxy-1-naphthylideneamino]-3-carboxyethyl-4,5-dimethylthiophene (HNAT. This ligand formed complexes with lanthanum(III, cerium(III, praseodymium(III, neodymium(III, samarium(III, europium(III and gadolinium(III chloride under well defined conditions. These complexes were characterized through elemental analysis, molar conductance, magnetic moment measurements, IR, UV–Vis, FAB mass and 1H NMR spectral studies. Analytical data showed that all the metal complexes exhibited 1:1 metal–ligand ratio. Molar conductance values adequately confirmed the non-electrolytic nature of the metal complexes. The proton NMR spectral observations supplement the IR spectral assignments. The spectral data revealed that the ligand acted as neutral tridentate, coordinating to the metal ion through azomethine nitrogen, ester carbonyl and naphtholate oxygen without deprotonation. The ligand and its lanthanum(III chloride complex were subjected to XRD studies. The lanthanum(III chloride complex has undergone a facile transesterification reaction. The solid state d.c. electrical conductivity of some selected complexes were measured as a function of temperature, indicating the semiconducting nature of the metal complexes. The antimicrobial activities were examined by disk diffusion method against some pathogenic bacterial and fungal species.

  15. Synthesis, characterization, DFT calculations and biological studies of Mn(II), Fe(II), Co(II) and Cd(II) complexes based on a tetradentate ONNO donor Schiff base ligand

    Science.gov (United States)

    Abdel-Rahman, Laila H.; Ismail, Nabawia M.; Ismael, Mohamed; Abu-Dief, Ahmed M.; Ahmed, Ebtehal Abdel-Hameed

    2017-04-01

    This study highlights synthesis and characterization of a tetradentate ONNO Schiff base ligand namely (1, 1‧- (pyridine-2, 3-dimethyliminomethyl) naphthalene-2, 2‧-diol) and hereafter denotes as "HNDAP″ and selected metal complexes including Mn(II), Fe(II), Co(II) and Cd(II) as a central metal. HNDAP was synthesized from 1:2 M ratio condensation of 2, 3-diaminopyridine and 2- hydroxy-1-naphthaldhyde, respectively. The stoichiometric ratios of the prepared complexes were estimated using complementary techniques such as; elemental analyses (-C, H, N), FT-IR, magnetic measurements and molar conductivity. Furthermore, their physicochemical studies were carried out using thermal TGA, DTA and kinetic-thermodynamic studies along with DFT calculations. The results of elemental analyses showed that these complexes are present in a 1:1 metal-to- ligand molar ratio. Moreover, the magnetic susceptibilities values at room temperature revealed that Mn(II), Fe(II) and Co(II) complexes are paramagnetic in nature and have an octahedral (Oh) geometry. In contrast, Cd(II) is diamagnetic and stabilizes in square planar sites. The molar conductivity measurements indicated that all complexes are nonelectrolytes in dimethyl formamide. Spectral data suggested that the ligand is as tetradentate and coordinated with Co(II) ion through two phenolic OH and two azomethine nitrogen. However, for Mn(II), Fe(II) and Cd(II) complexes, the coordination occurred through two phenolic oxygen and two azomethine nitrogen with deprotonation of OH groups. The proposed chemical structures have been validated by quantum mechanics calculations. Antimicrobial activities of both the HNDAP Schiff base ligand and its metal complexes were tested against strains of Gram (-ve) E. coli and Gram (+ve) B. subtilis and S. aureus bacteria and C. albicans, A. flavus and T. rubrum fungi. All the prepared compounds showed good results of inhibition against the selected pathogenic microorganisms. The investigated

  16. Five coordinate M(II)-diphenolate [M = Zn(II), Ni(II), and Cu(II)] Schiff base complexes exhibiting metal- and ligand-based redox chemistry.

    Science.gov (United States)

    Franks, Mark; Gadzhieva, Anastasia; Ghandhi, Laura; Murrell, David; Blake, Alexander J; Davies, E Stephen; Lewis, William; Moro, Fabrizio; McMaster, Jonathan; Schröder, Martin

    2013-01-18

    Five-coordinate Zn(II), Ni(II), and Cu(II) complexes containing pentadentate N(3)O(2) Schiff base ligands [1A](2-) and [1B](2-) have been synthesized and characterized. X-ray crystallographic studies reveal five coordinate structures in which each metal ion is bound by two imine N-donors, two phenolate O-donors, and a single amine N-donor. Electron paramagnetic resonance (EPR) spectroscopic studies suggest that the N(3)O(2) coordination spheres of [Cu(1A)] and [Cu(1B)] are retained in CH(2)Cl(2) solution and solid-state superconducting quantum interference device (SQUID) magnetometric studies confirm that [Ni(1A)] and [Ni(1B)] adopt high spin (S = 1) configurations. Each complex exhibits two reversible oxidation processes between +0.05 and +0.64 V vs [Fc](+)/[Fc]. The products of one- and two-electron oxidations have been studied by UV/vis spectroelectrochemistry and by EPR spectroscopy which confirm that each oxidation process for the Zn(II) and Cu(II) complexes is ligand-based with sequential formation of mono- and bis-phenoxyl radical species. In contrast, the one-electron oxidation of the Ni(II) complexes generates Ni(III) products. This assignment is supported by spectroelectrochemical and EPR spectroscopic studies, density functional theory (DFT) calculations, and the single crystal X-ray structure of [Ni(1A)][BF(4)] which contains Ni in a five-coordinate distorted trigonal bipyramidal geometry.

  17. Characterization of Ni(II) complexes of Schiff bases of amino acids and (S)-N-(2-benzoylphenyl)-1-benzylpyrrolidine-2-carboxamide using ion trap and QqTOF electrospray ionization tandem mass spectrometry

    NARCIS (Netherlands)

    Jirasko, Robert; Holcapek, Michal; Kolarova, Lenka; Nadvornik, Milan; Popkov, Alexander

    This work demonstrates the application of electrospray ionization mass spectrometry (ESI-MS) using two different mass analyzers, ion trap and hybrid quadrupole time-of-flight (QqTOF) mass analyzer, for the structural characterization of Ni(II) complexes of Schiff bases of

  18. A new synthesis of enantiomerically pure syn-(S)-β-hydroxy-α-amino acids via asymmetric aldol reactions of aldehydes with a homochiral Ni(II)-glycine/(S)-BPB Schiff base complex

    NARCIS (Netherlands)

    Belokon, Yuri N.; Kochetkov, Konstantin A.; Ikonnikov, Nikolai S.; Strelkova, Tatiana V.; Harutyunyan, Syuzanna R.; Saghiyan, Ashot S.

    2001-01-01

    syn-(S)-β-Hydroxy-α-amino acids were synthesised stereoselectively via elaboration of the asymmetric aldol reactions of aldehydes with a chiral Ni(II)-(S)-BPB/glycine Schiff base complex in the presence of equimolar NaH in THF. The stereoselectivity of the reaction was studied as a function of time,

  19. Tetradentate-arm Schiff base derived from the condensation reaction of 3,3′-dihydroxybenzidine, glyoxal/diacetyl and 2-aminophenol: Designing, structural elucidation and properties of their binuclear metal(II complexes

    Directory of Open Access Journals (Sweden)

    E. Akila

    2017-05-01

    Full Text Available The novel binuclear Schiff base complexes were prepared by the reaction of 3,3′-dihydroxybenzidine, glyoxal/diacetyl and 2-aminophenol in 1:2:2 M ratio. The binucleating Schiff base ligand and its complexes of Cu(II, Ni(II and VO(II ions were characterized by elemental analysis, molar conductance, 1H NMR, infrared, electronic spectra, cyclic voltammetry, thermal, magnetic and EPR studies. The low molar conductance values of the complexes support the non-electrolytic in nature. In IR spectra, the comparison of shift in frequency of the complexes with the ligand reveals the coordination of donor atom to the metal atom. The binuclear nature of the complexes is assessed from their magnetic susceptibility values. The electronic and EPR spectra of the metal complexes provide information about the geometry of the complexes and are in good agreement with the proposed square planar geometry for Cu(II, Ni(II and square pyramidal for VO(II complexes. Molecular modeling has been used to suggest the structure of the complexes. The DNA cleavage ability of the complexes was monitored by gel electrophoresis using supercoiled pUC18 DNA. The metal complexes were screened for their antibacterial activities against pathogenic bacteria like Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae and Bacillus subtilis. The activity data show that the metal complexes are more potent activity than the parent Schiff base ligand against microorganisms.

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

    Science.gov (United States)

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

    2017-03-01

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

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

    Science.gov (United States)

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

    2014-03-25

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

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

    Science.gov (United States)

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

    2014-03-01

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

  3. Binding affinities of Schiff base Fe(II) complex with BSA and calf-thymus DNA: Spectroscopic investigations and molecular docking analysis

    Science.gov (United States)

    Rudra, Suparna; Dasmandal, Somnath; Patra, Chiranjit; Kundu, Arjama; Mahapatra, Ambikesh

    2016-09-01

    The binding interaction of a synthesized Schiff base Fe(II) complex with biological macromolecules viz., bovine serum albumin (BSA) and calf thymus(ct)-DNA have been investigated using different spectroscopic techniques coupled with viscosity measurements at physiological pH and 298 K. Regular amendments in emission intensities of BSA upon the action of the complex indicate significant interaction between them, and the binding interaction have been characterized by Stern Volmer plots and thermodynamic binding parameters. On the basis of this quenching technique one binding site with binding constant (Kb = (7.6 ± 0.21) × 105) between complex and protein have been obtained at 298 K. Time-resolved fluorescence studies have also been encountered to understand the mechanism of quenching induced by the complex. Binding affinities of the complex to the fluorophores of BSA namely tryptophan (Trp) and tyrosine (Tyr) have been judged by synchronous fluorescence studies. Secondary structural changes of BSA rooted by the complex has been revealed by CD spectra. On the other hand, hypochromicity of absorption spectra of the complex with the addition of ct-DNA and the gradual reduction in emission intensities of ethidium bromide bound ct-DNA in presence of the complex indicate noticeable interaction between ct-DNA and the complex with the binding constant (4.2 ± 0.11) × 106 M- 1. Life-time measurements have been studied to determine the relative amplitude of binding of the complex to ct-DNA base pairs. Mode of binding interaction of the complex with ct-DNA has been deciphered by viscosity measurements. CD spectra have also been used to understand the changes in ct-DNA structure upon binding with the metal complex. Density functional theory (DFT) and molecular docking analysis have been employed in highlighting the interactive phenomenon and binding location of the complex with the macromolecules.

  4. Binding affinities of Schiff base Fe(II) complex with BSA and calf-thymus DNA: Spectroscopic investigations and molecular docking analysis.

    Science.gov (United States)

    Rudra, Suparna; Dasmandal, Somnath; Patra, Chiranjit; Kundu, Arjama; Mahapatra, Ambikesh

    2016-09-05

    The binding interaction of a synthesized Schiff base Fe(II) complex with biological macromolecules viz., bovine serum albumin (BSA) and calf thymus(ct)-DNA have been investigated using different spectroscopic techniques coupled with viscosity measurements at physiological pH and 298K. Regular amendments in emission intensities of BSA upon the action of the complex indicate significant interaction between them, and the binding interaction have been characterized by Stern Volmer plots and thermodynamic binding parameters. On the basis of this quenching technique one binding site with binding constant (Kb=(7.6±0.21)×10(5)) between complex and protein have been obtained at 298K. Time-resolved fluorescence studies have also been encountered to understand the mechanism of quenching induced by the complex. Binding affinities of the complex to the fluorophores of BSA namely tryptophan (Trp) and tyrosine (Tyr) have been judged by synchronous fluorescence studies. Secondary structural changes of BSA rooted by the complex has been revealed by CD spectra. On the other hand, hypochromicity of absorption spectra of the complex with the addition of ct-DNA and the gradual reduction in emission intensities of ethidium bromide bound ct-DNA in presence of the complex indicate noticeable interaction between ct-DNA and the complex with the binding constant (4.2±0.11)×10(6)M(-1). Life-time measurements have been studied to determine the relative amplitude of binding of the complex to ct-DNA base pairs. Mode of binding interaction of the complex with ct-DNA has been deciphered by viscosity measurements. CD spectra have also been used to understand the changes in ct-DNA structure upon binding with the metal complex. Density functional theory (DFT) and molecular docking analysis have been employed in highlighting the interactive phenomenon and binding location of the complex with the macromolecules. Copyright © 2016 Elsevier B.V. All rights reserved.

  5. Oxovanadium(IV complexes of bioinorganic and medicinal relevance: Synthesis, characterization and 3D molecular modeling of some oxovanadium(IV complexes involving O, N-donor environment of salicylaldehyde-based sulfa drug Schiff bases

    Directory of Open Access Journals (Sweden)

    R.C. Maurya

    2016-11-01

    Full Text Available The present paper reports the synthesis and characterization of some new sulfa drug based Schiff base oxovanadium(IV complexes of composition, [VO(sal-sdz2(H2O]·H2O, [VO(sal-sgn2(H2O]·H2O, [VO(sal-snm(H2O]·H2O, [VO(sal-smr2(H2O]·H2O and [VO(dadps(H2O]2·2H2O, where sal-sdzH = N-(salicylidenesulfadizine, sal-sgnH = N-(salicylidenesulfaguanidine, sal-snmH = N-(salicylidenesulfanilamide, sal-smrH = N-(salicylidenesulfamerizine, sal-dadpsH2 = N,N′-bis(salicylidene-4,4′-diaminodiphenylsulfone, respectively. Complexes, (1–(4 were prepared by the reaction of VOSO4·5H2O with the Schiff bases in 1:2 metal-ligand ratio while complex (5 in 2:2 metal-ligand ratio in DMF-ethanol medium. The compounds so obtained were characterized by different physico-chemical studies, such as, elemental analysis, molar conductance and magnetic measurements, infrared, ESR, thermogravimetric studies, mass and electronic spectral studies. The overall IR studies conclude that the ligand in complex (1–(4 behave as monobasic bidentate ON donor, while the ligand in the complex (5 behaves as dibasic tetradentate O2N2 donor. The 3D-molecular modeling and analysis for bond lengths and bond angles have also been carried out for two representative compounds, [VO(sal-snm2(H2O]·H2O (3 and [VO(dadps(H2O]2·2H2O (5 to substantiate the proposed structures. Based on these studies suitable octahedral structures have been proposed for these complexes.

  6. New cobalt(II) and nickel(II) complexes of benzyl carbazate Schiff bases: Syntheses, crystal structures, in vitro DNA and HSA binding studies.

    Science.gov (United States)

    Nithya, Palanivelu; Helena, Sannasi; Simpson, Jim; Ilanchelian, Malaichamy; Muthusankar, Aathi; Govindarajan, Subbiah

    2016-12-01

    In the present study, new Schiff base complexes with the composition [M(NCS)2(L1)2]·nH2O, where M=Co (n=0) (1) and Ni (n=2) (2); [M(NCS)2(L2)2], M=Co (3) and Ni (4) as well as [M(NCS)2(L3)2], M=Co (5) and Ni (6); (L1=benzyl 2-(propan-2-ylidene)hydrazinecarboxylate, L2=benzyl 2-(butan-2-ylidene)hydrazinecarboxylate and L3=benzyl 2-(pentan-3-ylidene)hydrazinecarboxylate) have been synthesized by a template method. The complexes were characterised by analytical methods, spectroscopic studies, thermal and X-ray diffraction techniques. The structures of all the complexes explore that the metal(II) cation has a trans-planar coordination environment, the monomeric units containing a six-coordinated metal center in octahedral geometry with N-bound isothiocyanate anions coordinated as terminal ligands. Furthermore, the binding of the two Schiff base ligands to the metal centers involves the azomethine nitrogen and the carbonyl oxygen in mutually trans configuration. The binding interactions of all the complexes with Calf thymus-deoxyribonucleic acid (CT-DNA) and human serum albumin (HSA) have been investigated using absorption and emission spectral techniques. The CT-DNA binding properties of these complexes reveal that they bind to CT-DNA through a partial intercalation mode and the binding constant values were calculated using the absorption and emission spectral data. The binding constant values (~10×10(6)moldm(-3)) indicate strong binding of metal complexes with CT-DNA. HSA binding interaction studies showed that the cobalt and nickel complexes can quench the intrinsic fluorescence of HSA through static quenching process. Also, molecular docking studies were supported out to apprehend the binding interactions of these complexes with DNA and HSA which offer new understandings into the experimental model observations. Copyright © 2016 Elsevier B.V. All rights reserved.

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

    Directory of Open Access Journals (Sweden)

    Zafer Uyar

    2017-09-01

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

  8. Synthesis, structural and biochemical activity studies of a new hexadentate Schiff base ligand and its Cu(II), Ni(II), and Co(II) complexes

    Science.gov (United States)

    Ekmekcioglu, Pinar; Karabocek, Nevin; Karabocek, Serdar; Emirik, Mustafa

    2015-11-01

    A new Schiff base ligand (H2L) and its metal complexes have been prepared and characterized by elemental analysis, magnetic moment and spectral studies. The comparative in-vitro antimicrobial activities against various pathogens with reference to known antibiotics activity under the standard control of different concentrations revealed that the metal complexes (6-8) showed enhanced antimicrobial activities in general as compared to free ligand. As an exception, the free ligand showed better activity against Trichoderma. The antifungal activity experiments were performed in triplicate. The order of biochemical activity for metal complexes were observed as in the following. CuL > CoL > NiL, which is exactly same as the order of stability constants of these complexes. Additionally, we performed DFT and TD-DFT calculation for free ligand and Cu(II) complex to support the experimental data. The geometries of the Cu(II) complex have been optimized using the B3LYP level of theory. The theoretical calculations confirm that the copper (II) center exhibits a distorted square pyramidal geometry which is favored by experimental results.

  9. Asymmetric synthesis of α-amino acids via homologation of Ni(II) complexes of glycine Schiff bases; Part 1: alkyl halide alkylations.

    Science.gov (United States)

    Sorochinsky, Alexander E; Aceña, José Luis; Moriwaki, Hiroki; Sato, Tatsunori; Soloshonok, Vadim A

    2013-10-01

    Alkylations of chiral or achiral Ni(II) complexes of glycine Schiff bases constitute a landmark in the development of practical methodology for asymmetric synthesis of α-amino acids. Straightforward, easy preparation as well as high reactivity of these Ni(II) complexes render them ready available and inexpensive glycine equivalents for preparing a wide variety of α-amino acids, in particular on a relatively large scale. In the case of Ni(II) complexes containing benzylproline moiety as a chiral auxiliary, their alkylation proceeds with high thermodynamically controlled diastereoselectivity. Similar type of Ni(II) complexes derived from alanine can also be used for alkylation providing convenient access to quaternary, α,α-disubstituted α-amino acids. Achiral type of Ni(II) complexes can be prepared from picolinic acid or via recently developed modular approach using simple secondary or primary amines. These Ni(II) complexes can be easily mono/bis-alkylated under homogeneous or phase-transfer catalysis conditions. Origin of diastereo-/enantioselectivity in the alkylations reactions, aspects of practicality, generality and limitations of this methodology is critically discussed.

  10. Synthesis, spectral studies and in vitro antimicrobial activity of some new di/tri-organotin (IV complexes of Schiff bases derived from 2-benzoylpyridine

    Directory of Open Access Journals (Sweden)

    Khatkar Priyanka

    2017-01-01

    Full Text Available In the present work, a series of twenty-four organotin (IV complexes of the type [R2SnLCl, R3SnL] have been synthesized by the condensation of 2-benzoylpyridine Schiff bases with R2SnCl2, R3SnCl (R= Me, n-Bu, Ph in 1:1 molar ratio. These complexes were well characterized by IR, 1H, and 13C, 119Sn NMR, XRD and mass spectral techniques. In the search for biologically more effective antimicrobial agents, all the synthesized ligands and organotin complexes were evaluated for their in vitro antimicrobial activities against two Gram positive and two Gram negative bacteria, and two fungal strains by serial dilution method. The results of spectral data revealed that the complexes formed were hexacoordinated with tridentate ligands which coordinated through azomethine N, pyridine N and carboxylate O ligation sites. The ligands on co-ordination with tin metal showed a discernible augmentation in biocidal activity, however, the Ph and Bu complexes were found to be more intoxicating. The results revealed that the synthesized complexes were more noxious towards Gram positive strains as compared to Gram negative strains which may be attributed to the presence of an outer lipid membrane of lipopolysaccharides.

  11. Synthesis and characterization of bioactive zinc(II) and cadmium(II) complexes with new Schiff bases derived from 4-nitrobenzaldehyde and acetophenone with ethylenediamine.

    Science.gov (United States)

    Prakash, Anant; Singh, Bibhesh K; Bhojak, Narendar; Adhikari, Devjani

    2010-08-01

    The new Schiff bases N,N'-bis (4-nitro benzaldehyde) ethylenediamine (L(1)) and N,N'-bis (acetophenone) ethylenediamine (L(2)) and its Zn(II), Cd(II) complexes were synthesized and characterized by different physicochemical studies. Vibrational spectra indicate coordination of metal ion through azomethine nitrogen and acetate/nitrate ions. The presence of water molecule in all the complexes has been supported by TG/DTA studies. Mass spectrum explains the successive degradation of the molecular species in solution and justifies ML complexes. Kinetic and thermodynamic parameters were computed from the thermal data using Coats and Redfern method, which confirm first order kinetics. The bioefficacy of the ligands and their complexes have been examined against the growth of bacteria in vitro to evaluate their antimicrobial potential. The results indicate that the ligand and their metal complexes possess notable antimicrobial properties. X-ray powder diffraction determines the cell parameters of the complexes. Copyright 2010 Elsevier B.V. All rights reserved.

  12. Platinum(II Complexes with Tetradentate Schiff Bases as Ligands: Synthesis, Characterization and Detection of DNA Interaction by Differential Pulse Voltammetry

    Directory of Open Access Journals (Sweden)

    Lijun Li

    2012-01-01

    Full Text Available Five sterically hindered platinum(II complexes with tetradentate schiff bases as ligands, [Pt(L] (L= N,N′-bisalicylidene-1,2-ethylenediamine (L1, N,N′-bisalicylidene-1,2-cyclohexanediamine (L2, N,N′-bis(5-hydroxyl-salicylidene-1,2-cyclohexanediamine (L3, N,N′-bisalicylidene-1,2-diphenyl-ethylenediamine (L4 and N,N′-bis(3-tert-butyl-5-methyl-salicylidene-1,2-diphenylethylenediamine (L5 have been synthesized and characterized by IR spectroscopy and elemental analysis. The sterical hindrance of antitumor drug candidates potentially makes them less susceptible to deactivation by sulphur containing proteins and helping to overcome resistance mechanisms. The interaction of these metal complexes with fish sperm single-stranded DNA (ssDNA was studied electrochemically based on the oxidation signals of guanine and adenine. Differential pulse voltammetry was employed to monitor the DNA interaction in solution by using renewable pencil graphite electrode. The results indicate that ligands with different groups can strongly affect the interaction between [Pt(L] complexes and ssDNA due to sterical hindrances and complex [Pt(L1] has the best interaction with DNA among the five complexes.

  13. Stabilization of G-quadruplex DNA with platinum(II) Schiff base complexes: luminescent probe and down-regulation of c-myc oncogene expression.

    Science.gov (United States)

    Wu, Peng; Ma, Dik-Lung; Leung, Chung-Hang; Yan, Siu-Cheong; Zhu, Nianyong; Abagyan, R; Che, Chi-Ming

    2009-12-07

    The interactions of a series of platinum(II) Schiff base complexes with c-myc G-quadruplex DNA were studied. Complex [PtL(1a)] (1 a; H(2)L(1a)=N,N'-bis(salicylidene)-4,5-methoxy-1,2-phenylenediamine) can moderately inhibit c-myc gene promoter activity in a cell-free system through stabilizing the G-quadruplex structure and can inhibit c-myc oncogene expression in cultured cells. The interaction between 1 a and G-quadruplex DNA has been examined by (1)H NMR spectroscopy. By using computer-aided structure-based drug design for hit-to-lead optimization, an in silico G-quadruplex DNA model has been constructed for docking-based virtual screening to develop new platinum(II) Schiff base complexes with improved inhibitory activities. Complex [PtL(3)] (3; H(2)L(3)=N,N'-bis{4-[1-(2-propylpiperidine)oxy]salicylidene}-4,5-methoxy-1,2-phenylenediamine) has been identified with a top score in the virtual screening. This complex was subsequently prepared and experimentally tested in vitro for its ability to stabilize or induce the formation of the c-myc G-quadruplex. The inhibitory activity of 3 (IC(50)=4.4 muM) is tenfold more than that of 1 a. The interaction between 1 a or 3 with c-myc G-quadruplex DNA has been examined by absorption titration, emission titration, molecular modeling, and NMR titration experiments, thus revealing that both 1 a and 3 bind c-myc G-quadruplex DNA through an external end-stacking mode at the 3' terminal face of the G-quadruplex. Such binding of G-quadruplex DNA with 3 is accompanied by up to an eightfold increase in the intensity of photoluminescence at lambda(max)=652 nm. Complex 3 also effectively down-regulated the expression of c-myc in human hepatocarcinoma cells.

  14. Synthesis, spectroscopic characterisation, DNA cleavage, superoxidase dismutase activity and antibacterial properties of some transition metal complexes of a novel bidentate Schiff base derived from isatin and 2-aminopyrimidine

    Science.gov (United States)

    Nitha, L. P.; Aswathy, R.; Mathews, Niecy Elsa; Sindhu kumari, B.; Mohanan, K.

    2014-01-01

    Complexes of manganese(II), cobalt(II), nickel(II), copper(II) and zinc(II) with a Schiff base, formed by the condensation of isatin with 2-aminopyrimidine have been synthesised and characterised through elemental analysis, molar conductance measurements, magnetic susceptibility, IR, UV-Vis, 1HNMR, FAB mass and EPR spectral studies. The spectral data revealed that the ligand acts as neutral bidentate, coordinating to the metal ion through the carbonyl oxygen and azomethine nitrogen. Molar conductance values adequately support the electrolytic nature of the complexes. On the basis of the above observations the complexes have been formulated as [M(ISAP)2]X2, where M = Mn(II), Co(II), Ni(II), Cu(II) and Zn(II); X = Cl, OAc; ISAP = 2-[N-indole-2-one]aminopyrimidine. The ligand and copper(II) complex were subjected to X-ray diffraction studies. The DNA cleavage study was monitored by gel electrophoresis method. The superoxide dismutase (SOD) mimetic activities of the ligand and the metal complexes were checked using NBT assay. The in vitro antibacterial activity of the synthesized compounds has been tested against gram negative and gram positive bacteria.

  15. Crystal structures, DFT calculations and Hirshfeld surface analyses of three new cobalt(III) Schiff base complexes derived from meso-1,2-diphenyl-1,2-ethylenediamine

    Science.gov (United States)

    Masoudi, Mohaddeseh; Behzad, Mahdi; Arab, Ali; Tarahhomi, Atekeh; Rudbari, Hadi Amiri; Bruno, Giuseppe

    2016-10-01

    Three new Cobalt(III) Schiff base complexes were synthesized and characterized by spectroscopic methods and x-ray crystallography. The DFT optimized structures of the complexes agreed well with the corresponding x-ray structures. According to the calculated vibrational normal modes, the observed signals in the IR spectra of the complexes were assigned. The experimental UV-Vis spectra of the complexes were also discussed considering the calculated excited states and molecular orbitals. Hirshfeld surface analysis was carried out to study the inter-contact interactions in these complexes. These studies provided comprehensive description of such inter-contact interactions by means of an appealing graphical approach using 3D Hirshfeld surfaces and 2D fingerprint plots derived from the surfaces. It indicated the dominant role of various hydrogen intermolecular interactions such as H⋯H (above 60%), C⋯H/H⋯C (near 15%-20%), O⋯H/H⋯O (about 16% or 17% for structures with counter ion ClO4-) and H⋯F (17% for structure with counter ion PF6-) contacts into the crystal packing which are discussed in details.

  16. Cooperative influence of pseudohalides and ligand backbone of Schiff-bases on nuclearity and stereochemistry of cobalt(iii) complexes: experimental and theoretical investigation.

    Science.gov (United States)

    Mandal, Arnab; Dasgupta, Sanchari; Ganguly, Sumi; Bauzá, Antonio; Frontera, Antonio; Das, Debasis

    2017-10-25

    Four cobalt(iii) complexes, [Co(HL(1))(NCS)2(EtOH)] (1), [Co2(L(1))2(N3)2] (2) and [Co(HL(2))(NCS)2(EtOH)] (3), [Co(HL(2))(N3)2] (4) were synthesized from two Schiff-base ligands namely, (E)-2-((2-(2-hydroxyethylamino)ethylimino)methyl)phenol (H2L1) and (E)-2-((3-(2-hydroxyethylamino)propylimino)methyl)phenol (H2L2), respectively. All the four complexes have been thoroughly characterised by using various physicochemical studies such as UV-Vis, FT-IR, ESI-MS, EPR and single crystal X-ray diffraction. Depending on flexibility of the ligand backbone subtle structural differences are observed in the synthesized complexes. In complex 1 the two thiocyanate ligands are trans to each other whereas in complex 3 they are cis to each other with addition of one additional methylene (-CH2-) group to the ligand system. Complex 2 is dinuclear while complex 4 is mononuclear in the presence of the azide co-anionic ligand. Theoretical studies are carried out in order to rationalize the structural differences observed in the complexes. Catecholase like activity of all the four complexes were performed in N,N-dimethylformamide (DMF) using 3,5-di-tert-butylcatechol (3,5-DTBC) as a model substrate. Complex 2 was found to exhibit the highest activity. Mechanistic investigation of the catecholase like activity revealed the formation of the imine radical during catalytic reactions of complexes 2 and 4 which are further corroborated by the EPR study.

  17. Near-infrared luminescence and RNA cleavage ability of lanthanide Schiff base complexes derived from N,N'-bis(3-methoxysalicylidene)ethylene-1,2-diamine ligands.

    Science.gov (United States)

    Kaczmarek, Anna M; Porebski, Piotr W Alvarez; Mortier, Tineke; Lynen, Frederic; Van Deun, Rik; Van Hecke, Kristof

    2016-10-01

    A complete series of lanthanide Schiff base salen-type complexes were prepared with trivalent lanthanide ions (Ln3+) and the N,N'-bis-(3-methoxysalicylidene)ethylene-1,2-diamine ligand (Ln3+=La3+, Ce3+, Pr3+, Nd3+, Sm3+, Eu3+, Gd3+, Tb3+, Dy3+, Ho3+, Er3+, Tm3+, Yb3+, Lu3+). Three unique crystal structures of La3+ and Pr3+N,N'-bis-(3-methoxysalicylidene)ethylene-1,2-diamine complexes, with the La3+ complex prepared in two different synthetic approaches, are reported, namely a dimeric [La(H2L)(NO3)3]2 (H2L=N,N'-bis-(3-methoxysalicylidene)ethylene-1,2-diamine) complex, an asymmetric two-centered [La2(H2L)2(NO3)6] complex and a discrete mononuclear [Pr(H2L)(NO3)2(H2O)2] complex. For Nd3+ and Sm3+, an isotypic mononuclear [Nd(H2L)(NO3)3] and 1D polymeric [Sm(H2L)(NO3)3(MeOH)]n structure was obtained, respectively. The whole series of complexes was tested for their ability to cleave the 20-mer RNA oligonucleotide 5'-AGC-GAU-AAG-AUU-CAU-AUA-UC-3'. Additionally three complexes (Ln3+=Nd3+, Sm3+, Ho3+) were tested for the cleavage of the 12-mer RNA oligonucleotide 5'-GCA-CCC-UGU-CAG-3'. A detailed luminescence study was additionally carried out and revealed that the Eu3+ complex emitted bright red light upon excitation at both 285.8nm and 394.4nm. The Nd3+, Er3+, and Yb3+ complexes showed strong emission in the near-infrared region after excitation at 380nm. Copyright © 2016 Elsevier Inc. All rights reserved.

  18. 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.

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

    Science.gov (United States)

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

    2013-08-05

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

  20. Synthesis, structural characterization and antioxidant activity of some vanadium(IV), Mo(VI)/(IV) and Ru(II) complexes of pyridoxal Schiff base derivatives

    Science.gov (United States)

    Elsayed, Shadia A.; Noufal, Aya M.; El-Hendawy, Ahmed M.

    2017-09-01

    New complexes containing vanadium(IV), Mo(VI)/(IV) and Ru(II) derived from Schiff base of pyridoxal and S-benzyldithiocarbazate (H2pysb) or p-toluidine (Hpytol) have been prepared. The structures of the described compounds were elucidated by elemental analyses, spectroscopic techniques (IR, 1H NMR, UV-Vis and EPR) magnetism, molar conductivity and thermal analysis measurements. Their redox behaviors were also studied by cyclic voltammetry. The ligand H2pysb showed coordination to the metal ions in a dibasic tridenate manner through deprotonated phenolate oxygen, azomethine nitrogen and thiolate sulfur, while Hpytol behaved as monobasic bidentate through phenolate oxygen and azomethine nitrogen. The complexes were tested for their antioxidant activity by 2,2-diphenyl-1-picrylhydrazyl radical (DPPH) and the data obtained revealed that the scavenging activity of the complexes towards DPPH is high for the oxovanadium(IV) complexes with lower IC50 values which are comparable to ascorbic acid as a standard antioxidant. The EC50 concentration ratio together with other antioxidant parameters are also reported.

  1. Structurally diverse copper complexes bearing NNO-tridentate Schiff-base derivatives as efficient catalysts for copolymerization of carbon dioxide and cyclohexene oxide.

    Science.gov (United States)

    Tsai, Chen-Yen; Huang, Bor-Hunn; Hsiao, Mon-Wei; Lin, Chu-Chieh; Ko, Bao-Tsan

    2014-05-19

    Structurally diverse copper acetate complexes based on NNO-tridentate Schiff-base ligands were synthesized and characterized as mono-, di-, and trinuclear complexes with respect to varied ancillary ligands. Treatment of the ligand precursors (L(1)-H = 2-(1-((2-(dimethylamino)ethyl)imino)ethyl)-4-methylphenol, L(2)-H = 4-chloro-2-(1-((2-(dimethylamino)ethyl)imino)ethyl)phenol, and L(3)-H = 2-(1-((2-(dimethylamino)ethyl)imino)ethyl)-5-methylphenol) with Cu(OAc)2·H2O (1 equiv) in refluxing ethanol afforded five-coordinate mono- or bimetallic copper complexes ([(L(1))Cu(OAc)(H2O)] (1); [(L(2))Cu(OAc)(H2O)] (2); [(L(3))2Cu2(OAc)2] (3)) in high yields. Dinuclear copper acetate analogue [(L(1))2Cu2(OAc)2] (4) resulted from treatment of L(1)-H as the ligand precursor in refluxing anhydrous MeOH with equimolar proportions of metal acetate salt under a dry nitrogen atmosphere. However, a trinuclear complex, [(L(4))2Cu3(OAc)4] (5), was obtained on utilizing 2-(1-((2-(dimethylamino)ethyl)imino)ethyl)-5-methoxyphenol (L(4)-H) as the proligand under the same synthetic route of 1-3; this complex was also synthesized in the reaction of L(4)-H and copper(II) acetate monohydrate in the ratio of 2:3, giving a quantitative yield. All complexes are active catalysts for copolymerization of cyclohexene oxide (CHO) and CO2 without cocatalysts. In particular, dinuclear Cu complex 3 performed satisfactorily to produce polycarbonates with controllable molecular weights and high carbonate linkages. These copper complexes are the first examples that are effective for both CO2/CHO copolymerization and formation of polymers in a controlled fashion.

  2. Synthesis of .alpha.-Amino Acids via Asymmetric Phase Transfer-Catalyzed Alkylation of Achiral Niclkel(II) Complexes of Glycine-Derived Schiff bases

    Czech Academy of Sciences Publication Activity Database

    Belokon, Y. N.; Bespalova, N. B.; Churkina, T. D.; Císařová, I.; Ezernitskaya, M. G.; Harutyunyan, S. R.; Hrdina, R.; Kagan, H. B.; Kočovský, P.; Kochetkov, K. A.; Larionov, O. G.; Lysenko, K. A.; North, M.; Polášek, Miroslav; Peregudov, A. S.; Prisyazhnyuk, V. V.; Vyskočil, Š.

    2003-01-01

    Roč. 125, - (2003), s. 12860-12870 ISSN 0002-7863 R&D Projects: GA ČR GP203/01/D051 Institutional research plan: CEZ:AV0Z4040901 Keywords : .alpha.amino acids * achiral nickel(II) * glycine-derived schiff bases Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 6.516, year: 2003

  3. Some new nano-sized Fe(II), Cd(II) and Zn(II) Schiff base complexes as precursor for metal oxides: Sonochemical synthesis, characterization, DNA interaction, in vitro antimicrobial and anticancer activities.

    Science.gov (United States)

    Abdel-Rahman, Laila H; Abu-Dief, Ahmed M; El-Khatib, Rafat M; Abdel-Fatah, Shimaa Mahdy

    2016-12-01

    The complexes of Fe(II), Cd(II) and Zn(II) with Schiff base derived from 2-amino-3-hydroxypyridine and 3-methoxysalicylaldehyde have been prepared. Melting points, decomposition temperatures, Elemental analyses, TGA, conductance measurements, infrared (IR) and UV-Visible spectrophotometric studies were utilized in characterizing the compounds. The UV-Visible spectrophotometric analysis revealed 1:1 (metal-ligand) stoichiometry for the three complexes. In addition to, the prepared complexes have been used as precursors for preparing their corresponding metal oxides nanoparticles via thermal decomposition. The structures of the nano-sized complexes and their metal oxides were characterized by X-ray powder diffraction and transmittance electron microscopy. Moreover, the prepared Schiff base ligand, its complexes and their corresponding nano-sized metal oxides have been screened in vitro for their antibacterial activity against three bacteria, gram-positive (Microccus luteus) and gram-negative (Escherichia coli, Serratia marcescence) and three strains of fungus. The metal chelates were shown to possess more antimicrobial activity than the free Schiff-base chelate and their nano-sized metal oxides have the highest activity. The binding behaviors of the complexes to calf thymus DNA have been investigated by absorption spectra, viscosity mensuration and gel electrophoresis. The DNA binding constants reveal that all these complexes interact with DNA through intercalative binding mode. Furthermore, the cytotoxic activity of the prepared Schiff base complexes on human colon carcinoma cells, (HCT-116 cell line) and hepatic cellular carcinoma cells, (HepG-2) showed potent cytotoxicity effect against growth of carcinoma cells compared to the clinically used Vinblastine standard. Copyright © 2016 Elsevier Inc. All rights reserved.

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

    Science.gov (United States)

    Nagaraj, Karuppiah; Sakthinathan, Subramanian; Arunachalam, Sankaralingam

    2014-03-01

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

  5. Studies on some VO(IV, Ni(II and Cu(II complexes of non-symmetrical tetradentate Schiff-bases

    Directory of Open Access Journals (Sweden)

    Aderoju A. Osowole

    2008-08-01

    Full Text Available The coordination chemistry of VO(IV, Ni(II and Cu(II with unsymmetrical Schiff base ligands, [HO(OCH3C6H3C(CH3:N(CH2CH2N:C(CH3CH:C(C6H5OH], H2L and [HO(OCH3C6H3C(CH3:N(CH2CH2N:C(CH3CH:C(CH3OH], H2L1 (derived from condensation of 1-phenyl-1,3-butanedione/2,4-pentanedione, ethylenediamine and 5-methoxy-2-hydroxy acetophenone is discussed. The metal complexes were characterized by elemental analysis, molar conductance, magnetic susceptibility, infrared and electronic spectral measurements. They are magnetically dilute, non-electrolytes in nitromethane. The ligands are tetradentately coordinating via the imine N and enolic O atoms, resulting in 5-coordinate square-pyramidal geometry for the VO(IV complexes and 4-coordinate square-planar geometry for the Ni(II and Cu(II complexes. The assignment of geometry is supported by magnetic and spectral measurements.

  6. Synthesis, characterization, electrochemical behavior and antibacterial/antifungal activities of [Cd(lX2] complexes with a Schiff base ligand

    Directory of Open Access Journals (Sweden)

    Montazerozohori Morteza

    2014-01-01

    Full Text Available A new symmetrical bidentate Schiff base ligand (L was applied for the synthesis of some new cadmium coordination compounds with general formula of [Cd(LX2] in which X is halide and pseudo-halide. The ligand and all cadmium complexes were characterized by some techniques such as elemental analysis, FT-IR, 1H, 13C NMR, UV-Visible and molar conductance. Electrochemical behavior of ligand and Cd(II complexes were investigated by cyclic voltammetry method. Morphology and shape of [Cd(LCl2] particles were depicted by SEM. Antimicrobial properties such as antibacterial and antifungal activities of the complexes as compared with ligand were checked against three Gram-negative bacteria; Escherichia coli (ATCC 25922, Pseudomunase aeroginosa (ATCC 9027 and Salmonella Spp. and two Gram-positive bacteria; Staphylococcus aureus (ATCC 6538 and Corynebacterium renale and three fungal strains including Aspergillus Niger, Penicillium chrysogenum and Candida albicans. The results revealed appropriate antibacterial and antifungal activities for all compounds, and it was also found that the coordination of ligand to Cd (II lead to an increase in the antimicrobial activities in most of cases.

  7. Microwave-assisted Decomposition of two Simple Zinc(II Schiff Base Complexes: A Facile and Fast Route to Synthesize ZnO Nanostructures

    Directory of Open Access Journals (Sweden)

    S. Farhadi

    2013-06-01

    Full Text Available ZnO nanorods and nanoparticles have been easily prepared via the decomposition of two simple Schiff base zinc (II complexes, namely (N,N'–disalicylalethylenediaminezince(II and (N,N'–disalicylalphenylenediaminezince(II under microwave irradiation. The decomposition products of the complexes were characterized by FT-IR, XRD, SEM, EDX and UV-visible spectroscopy.  FT-IR, XRD and EDX results confirmed that as-prepared products are pure and single-phase ZnO. SEM images show that the product of each complex was made up of ZnO nanoparticles average diameter size of 50 nm and ZnO nanorods with diameter of 70–100 nm and length up to 3.5 μm .ZnO nanostructures prepared by present method could be appropriate photocatalytic materials due to a red shift in their band gaps (2.80 and 2.95 eV compared with the bulk sample (3.37 eV. This method is simple, fast, safe, low-cost and also it is suitable for large-scale preparation of high purity ZnO nanostructures for applied purposes.

  8. HOMO- AND HETERONUCLEAR COMPLEXES OF COPPER (II WITH SCHIFF BASE OBTAINED ON THE BASE OF 2-HYDROXY-3-CARBOXYNAPHTALDEHYDE

    Directory of Open Access Journals (Sweden)

    A.G. Lazarescu

    2006-06-01

    Full Text Available The complexes of general formula Cu(H2L (II; [CuLn(L(NO3(H2On] (where H4L=N,NI-bis[2- hydroxy(3-carboxynaphtalidene]ethylenediamine; Ln: Nd, n=6 (III; Eu, n=4 (IV; Gd, n=6 (V have been synthesized and investigated by different methods (IR spectroscopy, TG analysis and magnetochemistry. The coordination set of complex generators are Cu(N2O2 and Ln(O8-9. The effective magnetic moment values, μeff, at 300 K are: 1.78 (II, 3.22 (III, 6.44 (V B.M. The temperature dependence (300-2 K of magnetic susceptibility of [CuNd(L(NO3(H2O6] indicates the antiferromagnetic interaction between metal ions.

  9. HOMO- AND HETERONUCLEAR COMPLEXES OF COPPER (II) WITH SCHIFF BASE OBTAINED ON THE BASE OF 2-HYDROXY-3-CARBOXYNAPHTALDEHYDE

    OpenAIRE

    A.G. Lazarescu; T.C. Popa

    2006-01-01

    The complexes of general formula Cu(H2L) (II); [CuLn(L)(NO3)(H2O)n] (where H4L=N,NI-bis[2- hydroxy(3-carboxynaphtalidene)]ethylenediamine; Ln: Nd, n=6 (III); Eu, n=4 (IV); Gd, n=6 (V) have been synthesized and investigated by different methods (IR spectroscopy, TG analysis and magnetochemistry). The coordination set of complex generators are Cu(N2O2) and Ln(O8-9). The effective magnetic moment values, μeff, at 300 K are: 1.78 (II), 3.22 (III), 6.44 (V) B.M. The temperature dependence (300-2 K...

  10. Synthesis and DNA binding studies of Ni(II), Co(II), Cu(II) and Zn(II) metal complexes of N 1,N 5-bis[pyridine-2-methylene]-thiocarbohydrazone Schiff-base ligand

    Science.gov (United States)

    Tiwari, A. D.; Mishra, A. K.; Mishra, S. B.; Mamba, B. B.; Maji, B.; Bhattacharya, S.

    2011-09-01

    The thiocarbohydrazone Schiff-base ligand with a nitrogen and sulphur donor was synthesized through condensation of pyridine-2-carbaldehyde and thiocarbohydrazide. Schiff-base ligands have the ability to conjugate with metal salts. A series of metal complexes with a general formula [MCl 2(H 2L)]· nH 2O (M dbnd Ni, Co, Cu and Zn) were synthesized by forming complexes of the N 1,N 5-bis[pyridine-2-methylene]-thiocarbohydrazone (H 2L) Schiff-base ligand. These metal complexes and ligand were characterized by using ultraviolet-visible (UV-Vis), Fourier Transform Infrared (FT-IR), 1H and 13C NMR spectroscopy and mass spectroscopy, physicochemical characterization, CHNS and conductivity. The biological activity of the synthesized ligand was investigated by using Escherichia coli DNA as target. The DNA interaction of the synthesized ligand and complexes on E. coli plasmid DNA was investigated in the aqueous medium by UV-Vis spectroscopy and the binding constant ( Kb) was calculated. The DNA binding studies showed that the metal complexes had an improved interaction due to trans-geometrical isomers of the complexes than ligand isomers in cis-positions.

  11. Structure and Heme-Independent Peroxidase Activity of a Fully-Coordinated Mononuclear Mn(II) Complex with a Schiff-Base Tripodal Ligand Containing Three Imidazole Groups

    Energy Technology Data Exchange (ETDEWEB)

    Sarkar, Shuranjan; Lee, Hong In [Kyungpook National University, Daegu (Korea, Republic of); Moon, Do Hyun [Pohang Accelerator Laboratory, Pohang (Korea, Republic of); Lah, Myoung Soo [Ulsan National Institute of Science and Technology, Ulsan (Korea, Republic of)

    2010-11-15

    New complex [Mn(II)H{sub 1.5}L]{sub 2}[Mn(II)H{sub 3}L]{sub 2}(ClO{sub 4}){sub 5}·3H{sub 2}O, where H{sub 3}L is tris{2-(4-imidazolyl)methyliminoethyl} amine (imtren), has been prepared by reacting manganese(II) perchlorate hexahydrate with the imtren ligand in methanol. X-ray crystallographic study revealed that the imtren ligand hexadentately binds to Mn(II) ion through the three Schiff-base imine N atoms and three imidazole N atoms with a distorted octahedral geometry, and the apical tertiary amine N atom of the ligand pseudo-coordinates to Mn(II), forming overall a pseudo-seven coordination environment. The hydrogen-bonds between imidazole and imidazolate of [Mn(II)H{sub 1.5}L]{sup 0.5+} complex ions are extended to build a 2D puckered network with trigonal voids. [Mn(II)H{sub 3}L]{sup 2+} complex ions constitutes another extended 2D puckered layer without hydrogen bonds. Two layers are wedged each other to constitute overall stack of the crystal. Peroxidase activity of complex 1 was examined by observing the oxidation of 2,2'-azinobis(3-ethylbenzothiazoline)- 6-sulfonic acid (ABTS) with hydrogen peroxide in the presence of complex 1. Generation of ABTS{sup +·} was observed by UV-vis and EPR spectroscopies, indicating that the complex 1, a fully-coordinated mononuclear Mn(II) complex with nitrogen-only ligand, has a heme-independent peroxidase activity.

  12. Schiff base oligopyrrolic macrocycles as ligands for lanthanides and actinides

    Energy Technology Data Exchange (ETDEWEB)

    Sessler, Jonathan L. [Department of Chemistry and Biochemistry, Institute for Cellular and Molecular Biology, 1 University Station A5300, University of Texas at Austin, Austin, TX 78712-0165 (United States)]. E-mail: sessler@mail.utexas.edu; Melfi, Patricia J. [Department of Chemistry and Biochemistry, Institute for Cellular and Molecular Biology, 1 University Station A5300, University of Texas at Austin, Austin, TX 78712-0165 (United States); Tomat, Elisa [Department of Chemistry and Biochemistry, Institute for Cellular and Molecular Biology, 1 University Station A5300, University of Texas at Austin, Austin, TX 78712-0165 (United States); Callaway, Wyeth [Department of Chemistry and Biochemistry, Institute for Cellular and Molecular Biology, 1 University Station A5300, University of Texas at Austin, Austin, TX 78712-0165 (United States); Huggins, Michael T. [Department of Chemistry and Biochemistry, Institute for Cellular and Molecular Biology, 1 University Station A5300, University of Texas at Austin, Austin, TX 78712-0165 (United States); Gordon, Pamela L. [C-Chemistry and NMT-Nuclear Materials Technology Divisions, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Webster Keogh, D. [C-Chemistry and NMT-Nuclear Materials Technology Divisions, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Date, Richard W. [Department of Chemistry, University of Exeter, Stocker Road, Exeter EX4 4QD (United Kingdom); Bruce, Duncan W. [Department of Chemistry, University of Exeter, Stocker Road, Exeter EX4 4QD (United Kingdom); Department of Chemistry, University of York, Heslington, YORK YO10 5DD (United Kingdom); Donnio, Bertrand [Institut de Physique et Chimie des Materiaux de Strasbourg (IPCMS), Groupe des Materiaux Organiques (GMO), CNRS-ULP - UMR 7504, 23 rue du Loess BP 43, F-67034 Strasbourg Cedex 2 (France)

    2006-07-20

    The coordination of f-block cations with Schiff base oligopyrrolic macrocycles is discussed. Analysis of the mesophase of a uranyl 2,5-diformylpyrrole-derived expanded porphyrin complex through temperature-dependent X-ray diffraction (XRD) methods has provided evidence for liquid-crystalline properties, and for molecular stacking into columns, arranged in a 2D hexagonal lattice. In separate studies, UV-vis spectral analysis has indicated the formation of three new f-block oligopyrrolic complexes. Addition of neptunyl ([NpO{sub 2}]{sup 2+}) or plutonyl ([PuO{sub 2}]{sup 2+}) chloride salts to the free base of a dipyrromethane-derived Schiff base macrocycle induces an immediate spectral change, namely the growth of a Q-like band at 630 nm. Such changes in the absorption spectra cause a dramatic color change from pale yellow to blue. It is postulated that oxidation of this macrocycle, stimulated by reduction of the metal center, leads to the observed spectral changes. An immediate visible and spectral change is also observed with the reaction of lutetium silylamide (Lu[N(Si(CH{sub 3}){sub 3}){sub 2}]{sub 3}), with a different, tetrapyrrole-containing Schiff base macrocycle. In this case, the formation of a complex with 1:1 metal-to-ligand binding stoichiometry is further supported by MALDI-TOF mass spectrometry.

  13. Characterization of Schiff base derived from 2-hydroxo-1 ...

    African Journals Online (AJOL)

    MBI

    2014-03-04

    Mar 4, 2014 ... each aliquot (0.50cm3) addition, the corresponding. pH meter reading was recorded (Angelici, 1971). Determination of Stability Constant of the Schiff. Base Copper (II) Complex. 0.4moldm-3 Sodium-liganate was added to a stirred mixture of 90cm3 distilled water, 10cm3. 0.1moldm-3 nitric acid, 100cm3.

  14. Synthesis and crystal structure of the dinuclear copper(II) Schiff base complex μ-hydroxido-μ-chlorido-bis{[bis(trans-2-nitrocinnamaldehyde)ethylenediamine]chloridocopper(II)} dichloromethane sesquisolvate.

    Science.gov (United States)

    Barati, Kazem; Clegg, William; Habibi, Mohammad Hossein; Harrington, Ross W; Lalegani, Arash; Montazerozohori, Morteza

    2016-03-01

    Transition metal complexes of Schiff base ligands have been shown to have particular application in catalysis and magnetism. The chemistry of copper complexes is of interest owing to their importance in biological and industrial processes. The reaction of copper(I) chloride with the bidentate Schiff base N,N'-bis(trans-2-nitrocinnamaldehyde)ethylenediamine {Nca2en, systematic name: (1E,1'E,2E,2'E)-N,N'-(ethane-1,2-diyl)bis[3-(2-nitrophenyl)prop-2-en-1-imine]} in a 1:1 molar ratio in dichloromethane without exclusion of air or moisture resulted in the formation of the title complex μ-chlorido-μ-hydroxido-bis(chlorido{(1E,1'E,2E,2'E)-N,N'-(ethane-1,2-diyl)bis[3-(2-nitrophenyl)prop-2-en-1-imine]-κ(2)N,N'}copper(II)) dichloromethane sesquisolvate, [Cu2Cl3(OH)(C20H18N4O4)2]·1.5CH2Cl2. The dinuclear complex has a folded four-membered ring in an unsymmetrical Cu2OCl3 core in which the approximate trigonal bipyramidal coordination displays different angular distortions in the equatorial planes of the two Cu(II) atoms; the chloride bridge is asymmetric, but the hydroxide bridge is symmetric. The chelate rings of the two Nca2en ligands have different conformations, leading to a more marked bowing of one of the ligands compared with the other. This is the first reported dinuclear complex, and the first five-coordinate complex, of the Nca2en Schiff base ligand. Molecules of the dimer are associated in pairs by ring-stacking interactions supported by C-H...Cl interactions with solvent molecules; a further ring-stacking interaction exists between the two Schiff base ligands of each molecule.

  15. Synthesis, spectroscopic, antimicrobial and DNA cleavage studies of new Co(II), Ni(II), Cu(II), Cd(II), Zn(II) and Hg(II) complexes with naphthofuran-2-carbohydrazide Schiff base

    Science.gov (United States)

    Halli, Madappa B.; Sumathi, R. B.

    2012-08-01

    A series of Co(II), Ni(II), Cu(II), Cd(II), Zn(II) and Hg(II) complexes have been synthesized with newly synthesized Schiff base derived from naphthofuran-2-carbohydrazide and cinnamaldehyde. The elemental analyses of the complexes are confined to the stoichiometry of the type MLCl2 [M = Co(II) and Cu(II)], ML2Cl2 [M = Ni(II), Cd(II), Zn(II) and Hg(II)] respectively, where L is Schiff base ligand. Structures have been proposed from elemental analyses, IR, electronic, mass, 1H NMR, ESR spectral data, magnetic, and thermal studies. The measured low molar conductance values in DMF indicate that the complexes are non-electrolytes. Spectroscopic studies suggest coordination occurs through azomethine nitrogen and carbonyl oxygen of the ligand with the metal ions. The Schiff base and its complexes have been screened for their antibacterial (Escherichia coli, Staphylococcus aureus, Bacillus subtilis and Salmonella typhi) and antifungal (Aspergillus niger, Aspergillus flavus, Cladosporium and Candida albicans) activities by minimum inhibitory concentration (MIC) method. The DNA cleavage studies by agarose gel electrophoresis method was studied for all the complexes.

  16. Phenoxo bridged dinuclear Zn(II) Schiff base complex as new precursor for preparation zinc oxide nanoparticles: Synthesis, characterization, crystal structures and photoluminescence studies

    Energy Technology Data Exchange (ETDEWEB)

    Saeednia, S., E-mail: sami_saeednia@yahoo.com [Department of Chemistry, Faculty of Science, Vali-e-Asr University of Rafsanjan, Rafsanjan 77188-97111 (Iran, Islamic Republic of); Iranmanesh, P. [Department of physics, Faculty of Science, Vali-e-Asr University of Rafsanjan, Rafsanjan 77188-97111 (Iran, Islamic Republic of); Ardakani, M. Hatefi; Mohammadi, M.; Norouzi, Gh. [Department of Chemistry, Faculty of Science, Vali-e-Asr University of Rafsanjan, Rafsanjan 77188-97111 (Iran, Islamic Republic of)

    2016-06-15

    Highlights: • A novel nano-scale Zn(II) complex was synthesized by solvothermal method. • Chemical structure of the nanostructures was characterized as well as bulk complex. • The photoluminescence property of the complex was investigated at room temperature. • The thermogravimetry and differential thermal analysis were carried out. • Thermal decomposition of the nanostructures was prepared zinc oxide nanoparticles. - Abstract: Nanoparticles of a novel Zn(II) Schiff base complex, [Zn(HL)NO{sub 3}]{sub 2} (1), (H{sub 2}L = 2-[(2-hydroxy-propylimino) methyl] phenol), was synthesized by using solvothermal method. Shape, morphology and chemical structure of the synthesized nanoparticles were characterized by scanning electron microscopy (SEM), X-ray powder diffraction (XRD), Fourier Transform Infrared Spectoscopy (FT-IR) and UV–vis spectroscopy. Structural determination of compound 1 was determined by single-crystal X-ray diffraction. The results were revealed that the zinc complex is a centrosymmetric dimer in which deprotonated phenolates bridge the two five-coordinate metal atoms and link the two halves of the dimer. The thermal stability of compound 1 was analyzed by thermal gravimetric analysis (TGA) and differential scanning calorimetry (DSC). The effect of the initial substrates concentration and reaction time on size and morphology of compound 1 nanostructure was investigated as well. Furthermore, the luminescent properties of the complex 1 were examined. ZnO nanoparticles with diameter between 15 and 20 nm were simply synthesized by solid-state transformation of compound 1 at 700 °C.

  17. Metal-free and dicopper(II) complexes of Schiff base [2 + 2] macrocycles derived from 2,2'-iminobisbenzaldehyde: syntheses, structures, and electrochemistry.

    Science.gov (United States)

    Cameron, Scott A; Brooker, Sally

    2011-04-18

    Three new bis-terdentate Schiff base [2 + 2] macrocycles (H(2)L(Et), H(2)L(Pr), and H(2)L(Bu)) have been prepared in high yields by 1:1 condensation of 2,2'-iminobisbenzaldehyde with 1,2-diaminoethane, 1,3-diaminopropane, and 1,4-diaminobutane, respectively. Metalation of these macrocycles yields the corresponding dicopper(II) acetate (1, 2, and 3) and tetrafluoroborate (4, 5, and 6) complexes. The structures of H(2)L(Et), H(2)L(Pr), H(2)L(Bu), [Cu(II)(2)L(i)(OAc)(2)]·solvents (where i is Et, Pr or Bu) and [Cu(II)(2)L(Pr)(DMF)(4)] (BF(4))(2)·0.5H(2)O are reported. Intramolecular hydrogen bonding is a feature of the metal-free macrocycles. The copper(II) centers in [Cu(II)(2)L(i)(OAc)(2)]·solvents are four coordinate, and the macrocycles have U-shaped (Et, Bu) or stepped (Pr) conformations. Complex 5 crystallizes with two dimethylformamide (DMF) molecules bound per five coordinate copper(II) center. Electrochemical studies revealed ligand based oxidations for all of the macrocycles and complexes. Complexes 1 and 2 undergo two quasi-reversible oxidations in DCM which are associated with the deposition of a visible film on the electrode after multiple scans in this oxidative region, suggestive of electropolymerization. Complexes 4-6, studied in MeCN, have Cu(II) → Cu(I) redox potentials at more positive potentials than for 1-3.

  18. Ruthenium(III Complexes of Heterocyclic Tridentate (ONN Schiff Base: Synthesis, Characterization and its Biological Properties as an Antiradical and Antiproliferative Agent

    Directory of Open Access Journals (Sweden)

    Ikechukwu P. Ejidike

    2016-01-01

    Full Text Available The current work reports the synthesis, spectroscopic studies, antiradical and antiproliferative properties of four ruthenium(III complexes of heterocyclic tridentate Schiff base bearing a simple 2′,4′-dihydroxyacetophenone functionality and ethylenediamine as the bridging ligand with RCHO moiety. The reaction of the tridentate ligands with RuCl3·3H2O lead to the formation of neutral complexes of the type [Ru(LCl2(H2O] (where L = tridentate NNO ligands. The compounds were characterized by elemental analysis, UV-vis, conductivity measurements, FTIR spectroscopy and confirmed the proposed octahedral geometry around the Ru ion. The Ru(III compounds showed antiradical potentials against 2,2-Diphenyl-1-Picrylhydrazyl (DPPH and 2,2′-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid (ABTS radicals, with DPPH scavenging capability in the order: [(PAEBODRuCl2] > [(BZEBODRuCl2] > [(MOABODRuCl2] > [Vit. C] > [rutin] > [(METBODRuCl2], and ABTS radical in the order: [(PAEBODRuCl2] < [(MOABODRuCl2] < [(BZEBODRuCl2] < [(METBODRuCl2]. Furthermore, in vitro anti-proliferative activity was investigated against three human cancer cell lines: renal cancer cell (TK-10, melanoma cancer cell (UACC-62 and breast cancer cell (MCF-7 by SRB assay.

  19. Tetrameric Self-Assembly of a Cu(II) Complex Containing Schiff-Base Ligand and Its Unusually High Catecholase-like Activity

    Energy Technology Data Exchange (ETDEWEB)

    Sarkar, Shuranjan; Lee, Hongin [Kyungpook National Univ., Daegu (Korea, Republic of); Lee, Woo Ram; Hong, Chang Seop [Korea Univ., Seoul (Korea, Republic of)

    2013-09-15

    We report a new tetrameric supramolecular Cu(II) complex (Cu{sub 4}L{sub 4} = tetrakis(N,N'-bis(salicylidene)-2,2'-ethylenedianiline) Copper(II)) with a Schiff-base ligand (H{sub 2}L = N,N'-bis (salicylaldimine)-1,2-ethylenediamine) containing two N,O-bidentate chelate groups. Though the copper sites of Cu{sub 4}L{sub 4} are non-coupled, the complex exhibits a unusually high catecholase-like activity (k{sub cat} = 935 h{sup -1}) when the Cu{sub 4}L{sub 4} solution is treated with 3,5-di-tert-butylcatechol (3,5-DTBC) at basic condition in the presence of air. Combined information obtained from UV-VIS and EPR measurements could lead the suggestion of the reaction pathway in which the substrate may bind to Cu(II) ions by anti-anti didentate bridging mode.

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

    Science.gov (United States)

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

    2014-03-07

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

  1. Synthesis, characterization and biological relevance of some metal (II) complexes with oxygen, nitrogen and oxygen (ONO) donor Schiff base ligand derived from thiazole and 2-hydroxy-1-naphthaldehyde

    Science.gov (United States)

    Nagesh, G. Y.; Mruthyunjayaswamy, B. H. M.

    2015-04-01

    The novel Schiff base ligand 2-((2-hydroxynaphthalen-1-yl)methylene)-N-(4-phenylthiazol-2-yl)hydrazinecarboxamide (L) obtained by the condensation of N-(4-phenylthiazol-2-yl)hydrazinecarboxamide with 2-hydroxy-1-naphthaldehyde and its newly synthesized Cu(II), Co(II), Ni(II), Zn(II) and Cd(II) complexes have been characterized by microanalysis, molar conductance, IR, 1H NMR, ESI-mass, UV-Visible, TGA/DTA, ESR and powder X-ray diffraction data to explicate their structures. The IR results confirmed the tridentate binding of the ligand involving oxygen atom of amide carbonyl, azomethine nitrogen and naphthol oxygen. 1H NMR spectral data of the ligand (L) and its Zn(II) complex agreed well with the proposed structures. Thermogravimetric studies for Cu(II) and Ni(II) complexes indicated the presence of coordinated water molecules and the final product is the metal oxide. In order to appraise the effect of antimicrobial activity of metal ions upon chelation, the newly synthesized ligand and its metal complexes were screened for their antimicrobial activity by minimum inhibitory concentration (MIC) method. The DNA cleavage activities were studied using plasmid DNA pBR322 (Bangal re Genei, Bengaluru, Cat. No 105850) as a target molecule by agarose gel electrophoresis method. The brine shrimp bioassay was also carried out to study the in vitro cytotoxicity properties against Artemia salina. Furthermore, the antioxidant activity were determined in vitro by reduction of 1,1-diphenyl-2-picryl hydrazyl (DPPH). The ligand exhibited better in vitro-antioxidant activity than its metal complexes.

  2. Synthesis and characterization of novel Cu (II) complexes with 3-substituted-4-amino-5-mercapto-1,2,4-triazole Schiff bases: A new route to CuO nanoparticles

    Science.gov (United States)

    Aly, Hisham M.; Moustafa, Moustafa E.; Nassar, Moustafa Y.; Abdelrahman, Ehab A.

    2015-04-01

    Cu (II) complexes, were synthesized with newly derived biologically active 1,2,4-triazole Schiff bases. The Schiff bases were synthesized by condensation of 3-substituted-4-amino-5-mercapto-1,2,4-triazole with dibenzoylmethane. The synthesized compounds were characterized using elemental analysis, magnetic moment, thermal analysis and spectral tools (FT-IR, 1HNMR, ESR, and UV-Vis spectroscopy). All the synthesized complexes are nonelectrolytes in N,N-dimethylformamide. The synthesized Schiff bases and their Cu (II) complexes have been screened for antibacterial (Escherichia coli &Staphylococcus aureus) and antifungal (Aspergillus flavus &Candida albicans) activity using a modified Bauer-Kirby method. Interestingly, the synthesized Cu (II) complexes were used as precursors for CuO nanoparticles which were characterized using XRD, HR-TEM, FT-IR and UV-Vis spectroscopy. The photocatalytic activity of the prepared CuO nanoparticles was studied by performing the degradation of methylene blue dye under UV illumination in the presence of H2O2 and the results showed that the maximum percent of the degradation of methylene blue dye (MB) was found 96.18% after 360 min.

  3. Sonochemical synthesis and DFT studies of nano novel Schiff base cadmium complexes: Green, efficient, recyclable catalysts and precursors of Cd NPs

    Science.gov (United States)

    Parsaee, Zohreh

    2017-10-01

    Novel asymmetric (N4) Schiff bases (Ln, n = 1-3) and their nanosized cadmium complexes derived of 4,4'-(pentylazanediyl) dibenzaldehyde and aminobenzaldehyde are synthesized by sonochemical method and characterized based on physicochemical analysis including 1H NMR, 13C NMR, SEM, TGA, Mass, FT-IR, UV-Vis spectroscopy, elemental analysis, magnetic moment and molar conductance measurements. According to the analytic results of the NMR, UV-Vis and magnetic moment studies, it is found that the geometrical structures of these complexes [CdII2LnCl4], (L = C45H40N5X, X = CH3, Cl, OH) are square planer. The synthesized complexes were so effective as nanocatalyst on the oxidation of primary and secondary alcohols. The oxidation reactions were carried out in ethyl-methyl-imidazolium ionic liquid in presence of NaOCl. In addition Cd NPs were synthesized through the thermal decomposition of mentioned complexes and characterized by using FT-IR, SEM, TEM, EDX and XRD methods, which indicated close accordance to the standard pattern of CdO nanoparticles and an acceptable size at the nanorange (22-27 nm). Furthermore geometrical optimization of the Cd2LnCl4 calculated using DFT/B3LYP with LanL2DZ/6-311+G (d,p) level. The electronic parameter including HOMO-LUMO orbitals, bond gap, chemical hardness-softness, electronegativity, electrophilicity, NMR chemical shifts and IR frequencies were calculated. The calculated NMR shifts and vibrational frequencies showed excellent agreement with experimental data.

  4. A Schiff base complex of Zn(II) as a neutral carrier for highly selective PVC membrane sensors for the sulfate ion.

    Science.gov (United States)

    Shamsipur, M; Yousefi, M; Hosseini, M; Ganjali, M R; Sharghi, H; Naeimi, H

    2001-07-01

    Novel polymeric membrane (PME) and coated graphite (CGE) sulfate-selective electrodes based on a recently synthesized Schiff base complex of Zn(II) were prepared. The electrodes reveal a Nernstian behavior over wide SO4(2-) ion concentration ranges (5.0 x 10(-5)-1.0 x 10(-1) M for PME and 1.0 x 10(-7)-1.0 x 10(-1) M for CGE) and very low detection limits (2.8 x 10(-5) M for PME and 8.5 x 10(-8) M for CGE). The potentiometric response is independent of the pH of the solution in the pH range 3.0-7.0. The electrodes manifest advantages of low resistance, very fast response, and, most importantly, good selectivities relative to a wide variety of other anions. In fact, the selectivity behavior of the proposed SO4(2) ion-selective electrodes shows a great improvement compared to the previously reported electrodes for sulfate ion. The electrodes can be used for at least 3 months without any appreciable divergence in potentials. The electrodes were used as an indicator electrode in the potentiometric titration of sulfate and barium ions and in the determination of iron in ferrous sulfate tablets.

  5. Asymmetric synthesis of α-amino acids via homologation of Ni(II) complexes of glycine Schiff bases. Part 2: aldol, Mannich addition reactions, deracemization and (S) to (R) interconversion of α-amino acids.

    Science.gov (United States)

    Sorochinsky, Alexander E; Aceña, José Luis; Moriwaki, Hiroki; Sato, Tatsunori; Soloshonok, Vadim

    2013-11-01

    This review provides a comprehensive treatment of literature data dealing with asymmetric synthesis of α-amino-β-hydroxy and α,β-diamino acids via homologation of chiral Ni(II) complexes of glycine Schiff bases using aldol and Mannich-type reactions. These reactions proceed with synthetically useful chemical yields and thermodynamically controlled stereoselectivity and allow direct introduction of two stereogenic centers in a single operation with predictable stereochemical outcome. Furthermore, new application of Ni(II) complexes of α-amino acids Schiff bases for deracemization of racemic α-amino acids and (S) to (R) interconversion providing additional synthetic opportunities for preparation of enantiomerically pure α-amino acids, is also reviewed. Origin of observed diastereo-/enantioselectivity in the aldol, Mannich-type and deracemization reactions, generality and limitations of these methodologies are critically discussed.

  6. Metal complexes of triazine - Schiff bases: Spectroscopic and thermodynamic studies of complexation of some divalent metal ions with 3-(a-acetylethylidenehydrazino-5,6-diphenyl-1,2,4-triazine

    Directory of Open Access Journals (Sweden)

    A. TAHA

    1999-10-01

    Full Text Available Metal complexes of some divalent metal ions (Co, Ni, Cu and Zn with 3-(a-acetylethylidenehydrazino-5,6-diphenyl-1,2,4-triazine (AHDT as a Schiff-base have been investigated potentiometrically and spectrophotometrically and found to have the stoichiometric formulae 1:1 and 1:2 (M:L. The formation constants of the proton-ligand and metal-ligand complexes have been determined potentiometrically at different temperatures (10, 20, 30, 40 and 50°C at an ionic strength of 0.1 M KNO3 in 75% (v/v dioxane-water solution. The standard thermodynamic parameters, viz. DG°, DH°, and DS°, for the proton-ligand and the stepwise metal-ligand complexes have been evaluated.

  7. Charge and Spin States in Schiff Base Metal Complexes with a Disiloxane Unit Exhibiting a Strong Noninnocent Ligand Character: Synthesis, Structure, Spectroelectrochemistry, and Theoretical Calculations.

    Science.gov (United States)

    Cazacu, Maria; Shova, Sergiu; Soroceanu, Alina; Machata, Peter; Bucinsky, Lukas; Breza, Martin; Rapta, Peter; Telser, Joshua; Krzystek, J; Arion, Vladimir B

    2015-06-15

    Mononuclear nickel(II), copper(II), and manganese(III) complexes with a noninnocent tetradentate Schiff base ligand containing a disiloxane unit were prepared in situ by reaction of 3,5-di-tert-butyl-2-hydroxybenzaldehyde with 1,3-bis(3-aminopropyl)tetramethyldisiloxane followed by addition of the appropriate metal(II) salt. The ligand H2L resulting from these reactions is a 2:1 condensation product of 3,5-di-tert-butyl-2-hydroxybenzaldehyde with 1,3-bis(3-aminopropyl)tetramethyldisiloxane. The resulting metal complexes, NiL·0.5CH2Cl2, CuL·1.5H2O, and MnL(OAc)·0.15H2O, were characterized by elemental analysis, spectroscopic methods (IR, UV-vis, X-band EPR, HFEPR, (1)H NMR), ESI mass spectrometry, and single crystal X-ray diffraction. Taking into account the well-known strong stabilizing effects of tert-butyl groups in positions 3 and 5 of the aromatic ring on phenoxyl radicals, we studied the one-electron and two-electron oxidation of the compounds using both experimental (chiefly spectroelectrochemistry) and computational (DFT) techniques. The calculated spin-density distribution and localized orbitals analysis revealed the oxidation locus and the effect of the electrochemical electron transfer on the molecular structure of the complexes, while time-dependent DFT calculations helped to explain the absorption spectra of the electrochemically generated species. Hyperfine coupling constants, g-tensors, and zero-field splitting parameters have been calculated at the DFT level of theory. Finally, the CASSCF approach has been employed to theoretically explore the zero-field splitting of the S = 2 MnL(OAc) complex for comparison purposes with the DFT and experimental HFEPR results. It is found that the D parameter sign strongly depends on the metal coordination geometry.

  8. Synthesis of alpha-amino acids via asymmetric phase transfer-catalyzed alkylation of achiral nickel(II) complexes of glycine-derived Schiff bases.

    Science.gov (United States)

    Belokon, Yuri N; Bespalova, Natalia B; Churkina, Tatiana D; Císarová, Ivana; Ezernitskaya, Marina G; Harutyunyan, Syuzanna R; Hrdina, Radim; Kagan, Henri B; Kocovský, Pavel; Kochetkov, Konstantin A; Larionov, Oleg V; Lyssenko, Konstantin A; North, Michael; Polásek, Miroslav; Peregudov, Alexander S; Prisyazhnyuk, Vladimir V; Vyskocil, Stepán

    2003-10-22

    Achiral, diamagnetic Ni(II) complexes 1 and 3 have been synthesized from Ni(II) salts and the Schiff bases, generated from glycine and PBP (7) and PBA (11), respectively, in MeONa/MeOH solutions. The requisite carbonyl-derivatizing agents pyridine-2-carboxylic acid(2-benzoyl-phenyl)-amide 7 (PBP) and pyridine-2-carboxylic acid(2-formyl-phenyl)-amide 11 (PBA) were readily prepared from picolinic acid and o-aminobenzophenone or picolinic acid and methyl o-anthranilate, respectively. The structure of 1 was established by X-ray crystallography. Complexes 1 and 3 were found to undergo C-alkylation with alkyl halides under PTC conditions in the presence of beta-naphthol or benzyltriethylammonium bromide as catalysts to give mono- and bis-alkylated products, respectively. Decomposition of the complexes with aqueous HCl under mild conditions gave the required amino acids, and PBP and PBA were recovered. Alkylation of 1 with highly reactive alkyl halides, carried out under the PTC conditions in the presence of 10% mol of (S)- or (R)-2-hydroxy-2'-amino-1,1'-binaphthyl 31a (NOBIN) and/or its N-acyl derivatives and by (S)- or (R)-2-hydroxy-8'-amino-1,1'-binaphthyl 32a (iso-NOBIN) and its N-acyl derivatives, respectively, gave rise to alpha-amino acids with high enantioselectivities (90-98.5% ee) in good-to-excellent chemical yields at room temperature within several minutes. An unusually large positive nonlinear effect was observed in these reactions. The Michael addition of acrylic derivatives 37 to 1 was conducted under similar conditions with up to 96% ee. The (1)H NMR and IR spectra of a mixture of the sodium salt of NOBIN and 1 indicated formation of a complex between the two components. Implications of the association and self-association of NOBIN for the observed sense of asymmetric induction and nonlinear effects are discussed.

  9. Synthesis, crystal structure, catecholase and phenoxazinone synthase activities of a mononuclear cobalt(III) complex containing in situ formed tridentate N-donor Schiff base

    Science.gov (United States)

    Maji, Ashis Kumar; Chatterjee, Arnab; Khan, Sumitava; Ghosh, Barindra Kumar; Ghosh, Rajarshi

    2017-10-01

    Synthesis and structural characterization of a mononuclear cobalt(III) Schiff base complex is reported. It crystallizes with monoclinic crystal system with P21/n space group with a = 9.9793(4) Å, b = 28.2907(12) Å and c = 13.1233(6) Å, and β = 97.532(3)°. The compound is active to catecholase and phenoxazinone synthase activities in MeOH, and MeOH and MeCN solvents, respectively at room temperature. Each of the reactions was found to be of first order with reaction rate 8.08 × 10-3 min-1 (MeOH) for the catecholase activity and 1.05 × 10-3 min-1 (MeOH) and 3.82 × 10-3 min-1 (MeCN) for the phenoxazinone synthase activity. The turn over numbers for the catecholase activity is 5.02 × 103 h-1 (MeOH) and for the phenoxazinone synthase activity is 4.59 × 103 h-1 (MeOH) and 5.12 × 103 h-1 (MeCN). Substrate-catalyst adduct was tried to be trapped in each case using mass spectrometry.

  10. Influence of the geometry around the manganese ion on the peroxidase and catalase activities of Mn(III)-Schiff base complexes.

    Science.gov (United States)

    Vázquez-Fernández, M Ángeles; Bermejo, Manuel R; Fernández-García, M Isabel; González-Riopedre, Gustavo; Rodríguez-Doutón, M Jesús; Maneiro, Marcelino

    2011-12-01

    The peroxidase and catalase activities of eighteen manganese-Schiff base complexes have been studied. A correlation between the structure of the complexes and their catalytic activity is discussed on the basis of the variety of systems studied. Complexes 1-18 have the general formulae [MnL(n)(D)(2)](X)(H(2)O/CH(3)OH)(m), where L(n)=L(1)-L(13); D=H(2)O, CH(3)OH or Cl; m=0-2.5 and X=NO(3)(-), Cl(-), ClO(4)(-), CH(3)COO(-), C(2)H(5)COO(-) or C(5)H(11)COO(-). The dianionic tetradentate Schiff base ligands H(2)L(n) are the result of the condensation of different substituted (OMe-, OEt-, Br-, Cl-) hydroxybenzaldehyde with diverse diamines (1,2-diaminoethane for H(2)L(1)-H(2)L(2); 1,2-diamino-2-methylethane for H(2)L(3)-H(2)L(4); 1,2-diamino-2,2-dimethylethane for H(2)L(5); 1,2-diphenylenediamine for H(2)L(6)-H(2)L(7); 1,3-diaminopropane for H(2)L(8)-H(2)L(11); 1,3-diamino-2,2-dimethylpropane for H(2)L(12)-H(2)L(13)). The new Mn(III) complexes [MnL(1)(H(2)O)Cl](H(2)O)(2.5) (2), [MnL(2)(H(2)O)(2)](NO(3))(H(2)O) (4), [MnL(6)(H(2)O)(2)][MnL(6)(CH(3)OH)(H(2)O)](NO(3))(2)(CH(3)OH) (8), [MnL(6)(H(2)O)(OAc)](H(2)O) (9) and [MnL(7)(H(2)O)(2)](NO(3))(CH(3)OH)(2) (12) were isolated and characterised by elemental analysis, magnetic susceptibility and conductivity measurements, redox studies, ESI spectrometry and UV, IR, paramagnetic (1)H NMR, and EPR spectroscopies. X-ray crystallographic studies of these complexes and of the ligand H(2)L(6) are also reported. The crystal structures of the rest of the complexes have been previously published and herein we have only revised their study by those techniques still not reported (EPR and (1)H NMR for some of these compounds) and which help to establish their structures in solution. Complexes 1-12 behave as more efficient mimics of peroxidase or catalase in contrast with 13-18. The analysis between the catalytic activity and the structure of the compounds emphasises the significance of the existence of a vacant or a labile position in the

  11. Synthesis and characterization of some metal complexes of a Schiff ...

    African Journals Online (AJOL)

    amino acid. III. Scheme 1. The reaction of ninhydrin with α-amino acids [22]. Schiff bases are good ligands for metal ions [23, 24]. The ketimine, IV, is, therefore, a .... cultures of each bacterium were then diluted further with sterile nutrient broth. ... were dissolved in DMSO to make a solution of 25 mg/mL concentration.

  12. Synthesis, spectroscopic, antimicrobial, XRD, fluorescence of new Ni(II), Cd(II), Hg(II) and U(VI) complexes with 1-(2-furylmethylene)-N-(3-phenylallylidene)methanamine Schiff base

    Science.gov (United States)

    El-Wahab, Zeinab H. Abd; Ali, Omyma A. M.; Ismail, Basma A.

    2017-09-01

    The 1:1 condensation of 2-furfurylamine and cinnamaldehyde under template condition gives the Schiff base ligand 1-(2-furylmethylene)-N-(3-phenylallylidene)methanamine (L). The reaction of the ligand with Ni(II), Cd(II), Hg(II) and U(VI) ions gives a series of novel complexes formulated as [NiLCl(H2O)]Cl·1½H2O, [CdL2(H2O)2]·2NO3·½H2O, [HgL2Cl2] and [UO2L3]·2NO3·H2O. The stoichiometry of the complexes was 1:1 for Ni(II), 1:2 for both Cd(II) and Hg(II) and 1:3 (M:L) for U(VI) complexes. The molar conductance of the complexes lies in the range of 135-250 Ω-1mol-1cm2 indicating their electrolytic behavior except Hg(II) complex. Electronic spectra and magnetic moments suggested varieties of geometries around the central metal atoms. The emission spectra of these complexes indicate the luminescence characteristics of the complexes. The X-ray diffraction (XRD) patterns of Schiff base and its complexes were investigated in powder forms. Thermodynamic parameters were computed from the thermal data using Coats and Redfern method. Structural optimization of the ligand and its Ni(II), Cd(II) and Hg(II) complexes was computed using the density functional theory (DFT), where the B3LYP functional was employed. The synthesized complexes exhibited higher antimicrobial activity than its free Schiff base ligand.

  13. A tetranuclear cubane-like nickel(II complex with a tridentate salicylideneimine Schiff base ligand: tetrakis[μ3-4-methyl-N-(2-oxidophenylsalicylideneiminato]tetrakis[methanolnickel(II] methanol 0.8-solvate

    Directory of Open Access Journals (Sweden)

    Gordana Pavlović

    2016-12-01

    Full Text Available The tetranuclear title complex, [Ni4(C14H11NO24(CH3OH4]·0.8CH3OH, has a distorted cubane topology shaped by four Schiff base ligands. The cubane [Ni4(μ3-O4] core is formed via the O atoms from the Schiff base ligands. The octahedrally coordinated NiII ions occupy alternating vertices of the cube. Each NiII ion is coordinated by one O,N,O′-tridentate dianionic ligand, two O atoms of oxidophenyl groups from adjacent ligands and the O atom of a coordinating methanol molecule. The cubane core is stabilized via an intramolecular O—H...O hydrogen bond between the hydroxy group of the coordinating methanol molecules and the phenolate O atom of the aldehyde Schiff base fragment. Additional stabilization is obtained via intramolecular C—H...O hydrogen bonds involving aromatic C—H groups and the oxygen atoms of adjacent methanol molecules. In the crystal, complex molecules are linked into chains parallel to the c axis via weak C—H...O hydrogen bonds. The partial-occupancy disordered methanol solvent molecule has a site occupancy of 0.8 and is linked to the tetranuclear unit via an intermolecular C—H...O hydrogen bond involving a phenolate O atom.

  14. benzoic acid Schiff base and evaluation as corrosion

    African Journals Online (AJOL)

    user

    ABSTRACT: The synthesis of 4-[(E)-(-2,5- dimethoxybenzylidene)amino] benzoic acid. Schiff base, SBDAB was carried out inorder to determine its inhibitory efficiency at higher temperature using weight loss and gasometric techniques. The results showed that the inhibition efficiency of the studied Schiff base increased with ...

  15. Synthesis and Spectroscopic Analysis of Schiff Bases of Imesatin ...

    African Journals Online (AJOL)

    ADOWIE PERE

    reaction pathway that is efficient and operational simplicity for the synthesis of Schiff bases derivatives. ... chromic acids. The synthetic versatility of Isatin has led to the wide applications of this compound in organic synthesis with medical and pharmacological properties of ... In organic synthesis, Schiff base reactions are.

  16. Intramolecular hydrogen bonding and tautomerism in Schiff bases ...

    Indian Academy of Sciences (India)

    Administrator

    2-Hydroxy Schiff bases; hydrogen bonding and tautomerism; crystal structure; heteronu- clear correlation techniques. 1. Introduction. 2-Hydroxy Schiff bases formed by condensation reactions of salicylaldehyde and 2-hydroxy-1- naphthaldehyde with various amines have been extensively studied. 1–7. This originated from ...

  17. Schiff bases of N-(2-aminoethyl)-3-aminopropyltrimethoxysilane and ...

    Indian Academy of Sciences (India)

    and leads to the synthesis of corresponding silatranes 1–5 bearing Schiff base functionalized long chain in the axial position. All the synthesized compounds are characterized by spectroscopic methods, elemental analy- sis and mass spectrometry. The authentication of Schiff base modified silatranes is scrutinized by single ...

  18. Synthesis, spectral characterisation, morphology, biological activity and DNA cleavage studies of metal complexes with chromone Schiff base

    Directory of Open Access Journals (Sweden)

    P. Kavitha

    2016-07-01

    Full Text Available Cu(II, Co(II, Ni(II and Zn(II complexes have been synthesized using 3-((pyridine-2-yliminomethyl-4H-chromen-4-one as a ligand derived from 3-formyl chromone and 2-amino pyridine. All the complexes were characterised by analytical, conductivity, IR, electronic, magnetic, ESR, thermal, powder XRD and SEM studies. The analytical data revealed that the metal to ligand molar ratio is 1:2 in all the complexes. Molar conductivity data indicates that all the complexes are neutral in nature. On the basis of magnetic and electronic spectral data, octahedral geometry is proposed for all the complexes. Thermal behaviour of the synthesized complexes indicates the coordinated and lattice water molecules are present in the complexes. The X-ray diffraction data suggest a triclinic system for all compounds. Different surface morphologies were identified from SEM micrographs. All metal complexes exhibit fluorescence. The antimicrobial and nematicidal activity data show that metal complexes are more potent than the parent ligand. The DNA cleavage activity of the ligand and its metal complexes were observed in the presence of H2O2.

  19. Novel mixed ligand complexes of bioactive Schiff base (E)-4-(phenyl (phenylimino) methyl) benzene-1,3-diol and 2-aminophenol/2-aminobenzoic acid: synthesis, spectral characterization, antimicrobial and nuclease studies.

    Science.gov (United States)

    Subbaraj, P; Ramu, A; Raman, N; Dharmaraja, J

    2014-01-03

    A novel bidentate Schiff base ligand has been synthesized using 2,4-dihydroxybenzophenone and aniline. Its mixed ligand complexes of MAB type [M=Mn(II), Co(II), Ni(II), Cu(II) and Zn(II); HA=Schiff base and B=2-aminophenol/2-aminobenzoic acid] have been synthesized and characterized on the basis of spectral data UV-Vis, IR, (1)H NMR, FAB-Mass, EPR, SEM and magnetic studies. All the complexes were soluble in DMF and DMSO. Elemental analysis and molar conductance values indicate that the complexes are non-electrolytes. HA binds with M(II) ions through azomethine and deprotonated phenolic group and B binds through the primary amine group and deprotonated phenolic/carboxylic groups. Using FAB-Mass the cleavage pattern of the ligand (HA) has been established. All the complexes adopt octahedral geometry around the metal ions. It has been confirmed with the help of UV-Vis, IR, (1)H NMR and FAB-Mass spectral data. DNA binding activities of the complexes 1d and 2d are studied by UV-Vis spectroscopy and cleavage studies of Schiff base ligand and its complexes 1d and 2d have been by agarose gel electrophoresis method. In vitro biological activities of the free ligand (HA) and their metal complexes (1a-1e and 2a-2e) were screened against few bacteria, Escherichia coli, Staphylococcus saphyphiticus, Staphylococcus aureus, Pseudomonas aeruginosa and fungi Aspergillus niger, Enterobacter species, Candida albicans by well diffusion technique. Copyright © 2013 Elsevier B.V. All rights reserved.

  20. Spectral, thermal and magnetic properties of Cu(II and Ni(II complexes with Schiff base ligands

    Directory of Open Access Journals (Sweden)

    Cristóvão Beata

    2011-01-01

    Full Text Available Mononuclear copper(II and nickel(II complexes of the formulae [Cu(L1] (1, [Ni(L1] (2, [Cu(L2] (3 and [Cu(L3H2O] (4 (where L1 = N,N’-ethylenebis(4,6-dimethoxysalicylidenaminato, L2 = N,N’-ethylenebis(5-bromosalicylidenaminato and L3 = N,N’-ethylenebis(5-bromo-3-methoxysalicylidenaminato were synthesized as microcrystalline powders and characterized by IR spectroscopy, thermal analysis and magnetic measurements. The magnetic susceptibility of the Cu(II complexes changed with temperature according to the Curie-Weiss law. The complexes 1, 3 and 4 exhibit magnetic moments of 2.29, 2.20 and 1.88 µB, respectively, at 303 K. These values practically do not change with lowering the temperature to 77 K. The nickel(II complex 2 is diamagnetic.

  1. Studies in stability constants of schiff base hydrazone complexes with transition metal ions. Effect of ligand on seed germination

    Science.gov (United States)

    Meshram, U. P.; Pethe, G. B.; Yaul, A. R.; Khobragade, B. G.; Narwade, M. L.

    2017-10-01

    Spectrophotometric investigation of Cu (II), Ni(II), Co(II), and Fe(III) complexes with 2,4-dihydroxyacetophonone 2,4-dichlorobenzoylhydrazone (H2L1) and 2,4-didydroxy-5-nitroacetophenone 2,4-dichlorobenzoylhydrazone (H2L2) shows 1: 1 and 1: 2 complex formation between the pH range of 3.0 to 6.0 and also studied by jobs variation method at 0.1 M ionic strength at 30 ± 1°C specrtophotometrically. The conditional stability constants are determined for 1: 1 complexes. Effect of H2L1 and H2L2 ligand and its complexes on seed germination is studied.

  2. Directed synthesis of a heterobimetallic complex based on a novel unsymmetric double-Schiff-base ligand: preparation, characterization, reactivity and structures of hetero- and homobimetallic nickel(II) and zinc(II) complexes.

    Science.gov (United States)

    Roth, Arne; Buchholz, Axel; Rudolph, Manfred; Schütze, Eileen; Kothe, Erika; Plass, Winfried

    2008-01-01

    A series of bimetallic zinc(II) and nickel(II) complexes based on the novel dinucleating unsymmetric double-Schiff-base ligand benzoic acid [1-(3-{[2-(bispyridin-2-ylmethylamino)ethylimino]methyl}-2-hydroxy-5-methylphenyl)methylidene]hydrazide (H(2)bpampbh) has been synthesized and structurally characterized. The metal centers reside in two entirely different binding pockets provided by the ligand H(2)bpampbh, a planar tridentate [ONO] and a pentadentate [ON(4)] compartment. The utilized ligand H(2)bpampbh has been synthesized by condensation of the single-Schiff-base proligand Hbpahmb with benzoic acid hydrazide. The reaction of H(2)bpampbh with two equivalents of either zinc(II) or nickel(II) acetate yields the homobimetallic complexes [Zn(2)(bpampbh)(mu,eta(1)-OAc)(eta(1)-OAc)] (ZnZn) and [Ni(2)(bpampbh)(mu-H(2)O)(eta(1)-OAc)(H(2)O)](OAc) (NiNi), respectively. Simultaneous presence of one equivalent zinc(II) and one equivalent nickel(II) acetate results in the directed formation of the heterobimetallic complex [NiZn(bpampbh)(mu,eta(1)-OAc)(eta(1)-OAc)] (NiZn) with a selective binding of the nickel ions in the pentadentate ligand compartment. In addition, two homobimetallic azide-bridged complexes [Ni(2)(bpampbh)(mu,eta(1)-N(3))]ClO(4) (NiNi(N(3))) and [Ni(2)(bpampbh)(mu,eta(1)-N(3))(MeOH)(2)](ClO(4))(0.5)(N(3))(0.5) (NiNi(N(3))(MeOH)(2)) were synthesized. In all complexes, the metal ions residing in the pentadentate compartment adopt a distorted octahedral coordination geometry, whereas the metal centers placed in the tridentate compartment vary in coordination number and geometry from square-planar (NiNi(N(3))) and square-pyramidal (ZnZn and NiZn), to octahedral (NiNi and NiNi(N(3))(MeOH)(2)). In the case of complex NiNi(N(3)) this leads to a mixed-spin homodinuclear nickel(II) complex. All compounds have been characterized by means of mass spectrometry as well as IR and UV/Vis spectroscopies. Magnetic susceptibility measurements show significant zero

  3. Gastroprotection studies of Schiff base zinc (II derivative complex against acute superficial hemorrhagic mucosal lesions in rats.

    Directory of Open Access Journals (Sweden)

    Shahram Golbabapour

    Full Text Available BACKGROUND: The study was carried out to assess the gastroprotective effect of the zinc (II complex against ethanol-induced acute hemorrhagic lesions in rats. METHODOLOGY/PRINCIPAL FINDING: The animals received their respective pre-treatments dissolved in tween 20 (5% v/v, orally. Ethanol (95% v/v was orally administrated to induce superficial hemorrhagic mucosal lesions. Omeprazole (5.790×10(-5 M/kg was used as a reference medicine. The pre-treatment with the zinc (II complex (2.181×10(-5 and 4.362×10(-5 M/kg protected the gastric mucosa similar to the reference control. They significantly increased the activity levels of nitric oxide, catalase, superoxide dismutase, glutathione and prostaglandin E2, and decreased the level of malondialdehyde. The histology assessments confirmed the protection through remarkable reduction of mucosal lesions and increased the production of gastric mucosa. Immunohistochemistry and western blot analysis indicated that the complex might induced Hsp70 up-regulation and Bax down-regulation. The complex moderately increased the gastroprotectiveness in fine fettle. The acute toxicity approved the non-toxic characteristic of the complex (<87.241×10(-5 M/kg. CONCLUSION/SIGNIFICANCE: The gastroprotective effect of the zinc (II complex was mainly through its antioxidant activity, enzymatic stimulation of prostaglandins E2, and up-regulation of Hsp70. The gastric wall mucus was also a remarkable protective mechanism.

  4. Synthesis, spectroscopic characterization and biological activity of the metal complexes of the Schiff base derived from phenylaminoacetohydrazide and dibenzoylmethane.

    Science.gov (United States)

    El-Tabl, Abdou Saad; El-Saied, Fathey A; Plass, Winfried; Al-Hakimi, Ahmed Noman

    2008-11-01

    A new series of mono and binuclear Mn(II), Fe(III), Co(II), Ni(II), Cu(II), Zn(II), La(III), Ru(III), Hf(IV), ZrO(II) and UO2(II) complexes of phenylaminodibenzoylhydrazone have been synthesized and characterized by elementals analyses, IR UV-vis spectra, magnetic moments, conductances, thermal analyses (DTA and TGA) and electron spin resonance (ESR) measurements. The IR spectral data show that, the ligand behaves as a neutral bidentate type (15 and 16), monobasic bidentate type (6), or monobasic tridentate type (5, 7, 8, 10, 11, 13, 14, 17-21) or dibasic tridentate type 2-4, 9 and 12 towards the metal ion. Molar conductances in DMF solution indicate that, the complexes are non-electrolytes. The ESR spectra of solid complexes (9 and 10) show axial and non-axial types indicating a d(x2-y2) ground state with significant covalent bond character. However, complexes (11 and 12), show isotropic type, indicating manganese(II) octahedral geometry. Antibacterial and antifungal tests of the ligand and its metal complexes are also carried out and it has been observed that the complexes are more potent bactericides and fungicides than the ligand.

  5. Synthesis, spectroscopic characterization and biological activity of the metal complexes of the Schiff base derived from phenylaminoacetohydrazide and dibenzoylmethane

    Science.gov (United States)

    El-Tabl, Abdou Saad; El-Saied, Fathey A.; Plass, Winfried; Al-Hakimi, Ahmed Noman

    2008-11-01

    A new series of mono and binuclear Mn(II), Fe(III), Co(II), Ni(II), Cu(II), Zn(II), La(III), Ru(III), Hf(IV), ZrO(II) and UO 2(II) complexes of phenylaminodibenzoylhydrazone have been synthesized and characterized by elementals analyses, IR UV-vis spectra, magnetic moments, conductances, thermal analyses (DTA and TGA) and electron spin resonance (ESR) measurements. The IR spectral data show that, the ligand behaves as a neutral bidentate type ( 15 and 16), monobasic bidentate type ( 6), or monobasic tridentate type ( 5, 7, 8, 10, 11, 13, 14, 17- 21) or dibasic tridentate type 2- 4, 9 and 12 towards the metal ion. Molar conductances in DMF solution indicate that, the complexes are non-electrolytes. The ESR spectra of solid complexes ( 9 and 10) show axial and non-axial types indicating a d ground state with significant covalent bond character. However, complexes ( 11 and 12), show isotropic type, indicating manganese(II) octahedral geometry. Antibacterial and antifungal tests of the ligand and its metal complexes are also carried out and it has been observed that the complexes are more potent bactericides and fungicides than the ligand.

  6. Complexation of Oxovanadium(IV and Dioxouranium(VI with Synthesized 1,2-(Diimino-4′-antipyrinyl-1,2-diphenylethane Schiff Base: A Thermodynamic, Kinetic, and Bioactivity Investigation

    Directory of Open Access Journals (Sweden)

    Shabnum Bashir

    2014-01-01

    Full Text Available We report the comparative synthetic methodologies and characterization of a tetradentate Schiff base ligand 1,2-(diimino-4′-antipyrinyl-1,2-diphenylethane (DE. The target synthesis of oxovanadium(IV and dioxouranium(VI complexes (vanadyl and uranyl with the (DE ligand was also attempted to envisage the effect of metal ion steric factor on complexation process through solution phase thermodynamic and kinetic studies. The thermodynamic stabilities of synthesized vanadyl and uranyl (DE complexes are discussed in light of their solution phase thermodynamic stability constants obtained by electroanalytical method. A comparative kinetic profile of vanadyl and uranyl complexation with DE is also reported. The complexation reaction proceeds with an overall 2nd order kinetics with both metal ions. Temperature dependent studies of rate constants present an activation energy barrier of ca. 40.913 and 48.661 KJ mol−1, for vanadyl and uranyl complexation, respectively, highlighting the metal ion steric and ligand preorganization effects. The synthesized Schiff base ligand and its vanadyl and uranyl complexes were screened for biocidal potential as antibacterial, antifungal, and anthelmintic agents with the results compared to corresponding reference drugs.

  7. Synthesis, structure, fluorescent property, and antibacterial activity of new Cd(II) metal complex based on multidentate Schiff base ligand N,N‧-Bis(3-methoxysalicylidenimino)-1,3-diaminopropane

    Science.gov (United States)

    Majumdar, Dhrubajyoti; Das, Sourav; Biswas, Jayanta Kumar; Mondal, Monojit

    2017-04-01

    The sequential reaction of a multisite coordinating compartmental ligand N,N‧-Bis(3-methoxysalicylidenimino)-1,3-diaminopropane (H2L1) with Cd(OAc)2 followed by the addition of NaCl in a 2:3:2 stoichiometric ratio affords homometallic trinuclear Cd(II) coordination compound [Cd3(L1)2(Cl)2] (1). The complex 1 has been thoroughly characterized by common elemental analysis (CHN), FT-IR and UV-Vis spectroscopy. Single crystal X-ray diffraction was also performed to determine the complete structure of complex 1. X-ray diffraction studies reveal that the molecular complex comprises a linear tri-nuclear ensemble of cadmium metal ions, which is further supported by the concerted coordination action of two dianionic [L1]2- ligands along with two monodentate Cl- ligands. The central Cd(II) ion is attached to the terminal Cd(II) ions through two phenoxide bridging groups of the fully deprotonated ligands [L1]2-. This arrangement leads to two neighbouring four membered Cd2O2 rings. The terminal Cd(II) ions are penta-coordinated (2 N, 2O, Cl) in a distorted square pyramidal geometry and central Cd(II) ion attained distorted trigonal prismatic geometry through six oxygen atoms coordination from ligands. Tri-nuclear Cd(II) complex 1 display intraligand (π-π∗) fluorescence in DMSO solution at room temperature. The fluorescence properties of complex 1 as well as the respective di-compartmental Schiff base ligand (H2L1) have been investigated in DMSO solvent at room temperature with a comparative approach. Result confirmed that complex 1 is highly fluorescence active mediated due to "chelation enhanced fluorescence" [CHEF] but Schiff base ligand (H2L1) is fluorescence silent. The antibacterial efficacy of complex 1 was further investigated against some important Gram-positive and Gram-negative bacteria.

  8. A Turn-on and Reversible Fluorescence Sensor for Zinc Ion Based on 4,5-Diazafluorene Schiff Base.

    Science.gov (United States)

    Li, Hui; Zhang, ShuJiang; Gong, ChenLiang; Wang, JianZhi; Wang, Feng

    2016-09-01

    A new 4,5-diazafluorene-based fluorescent chemosensor has been synthesized by Schiff base condensation of 9,9-bis(3,5-dimethyl-4-aminophenyl)-4,5-diazafluorene with salicylaldehyde. The interaction of Schiff base with different metal ions has been studied over photofluorescent spectra. The results showed that Schiff base exhibited 194-fold enhancements in fluorescence at 465 nm after Zn(2+) ions. Such fluorescent responses could be detected by naked eye under UV-lamp. The complex solution (L-Zn(2+)) exhibited reversibility with EDTA.

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

    Science.gov (United States)

    Gökçe, Cansu; Gup, Ramazan

    2013-05-05

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

  10. Ni(II Complexes with Schiff Base Ligands: Preparation, Characterization, DNA/Protein Interaction and Cytotoxicity Studies

    Directory of Open Access Journals (Sweden)

    Hui Yu

    2017-10-01

    Full Text Available In this study, two Ni(II complexes, namely [Ni(HL12(OAc2] (1 and [Ni(L22] (2 (where HL1 and HL2 are (E-1-((1-(2-hydroxyethyl-1H-pyrazol-5-yliminomethyl-naphthalen-2-ol and (E-ethyl-5-((2-hydroxynaphthalen-1-ylmethyleneamino-1-methyl-1H-pyrazole-4-carboxylate, respectively, were synthesized and characterized by X-ray crystallography, Electrospray Ionization Mass Spectrometry (ESI-MS, elemental analysis, and IR. Their uptake in biological macromolecules and cancer cells were preliminarily investigated through electronic absorption (UV-Vis, circular dichroism (CD and fluorescence quenching measurements. Bovine serum albumin (BSA interaction experiments were investigated by spectroscopy which showed that the complexes and ligands could quench the intrinsic fluorescence of BSA through an obvious static quenching process. The spectroscopic studies indicated that these complexes could bind to DNA via groove, non-covalent, and electrostatic interactions. Furthermore, in vitro methyl thiazolyl tetrazolium (MTT assays and Annexin V/PI flow cytometry experiments were performed to assess the antitumor capacity of the complexes against eight cell lines. The results show that both of the complexes possess reasonable cytotoxicities.

  11. Cu(II Complexes of Isoniazid Schiff Bases: DNA/BSA Binding and Cytotoxicity Studies on A549 Cell Line

    Directory of Open Access Journals (Sweden)

    Pulipaka Ramadevi

    2014-01-01

    Full Text Available A series of isonicotinoyl hydrazones have been synthesized via template method and were complexed to Cu(II. The ligands are coordinated to Cu(II ion through the enolic oxygen and azomethine nitrogen resulting in a square planar geometry. The CT-DNA and bovine serum albumin binding propensities of the compounds were determined spectrophotometrically, the results of which indicate good binding propensity of complexes to DNA and BSA with high binding constant values. Furthermore, the compounds have been investigated for their cytotoxicities on A549 human lung cancer cell. Also the mode of cell death was examined employing various staining techniques and was found to be apoptotic.

  12. Synthesis, characterization, and biological activity of some novel Schiff bases and their Co(II) and Ni(II) complexes: A new route for Co3O4 and NiO nanoparticles for photocatalytic degradation of methylene blue dye

    Science.gov (United States)

    Nassar, Mostafa Y.; Aly, Hisham M.; Abdelrahman, Ehab A.; Moustafa, Moustafa E.

    2017-09-01

    Six novel Co(II) and Ni(II)-triazole Schiff base complexes have been successfully synthesized by refluxing the prepared triazole Schiff bases with CoCl2·6H2O or NiCl2·6H2O. The Schiff base ligands were prepared through condensation of 3-R-4-amino-5-hydrazino-1,2,4-triazole with dibenzoylmethane [Rdbnd H, CH3, and CH2CH3; namely, L1, L2, and L3, respectively]. The prepared Co(II) and Ni(II) complexes have been identified using elemental analysis, FT-IR, UV-Vis, magnetic moment, conductivity, and thermal analysis. On the basis of the conductance results, it was concluded that all the prepared complexes are nonelectrolytes. Interestingly, the prepared Co(II) and Ni(II) complexes were employed as precursors for producing of Co3O4 and NiO nanoparticles, respectively. The produced nanostructures have been identified by XRD, HR-TEM, FT-IR and UV-Vis spectra. The produced nanoparticles revealed good photocatalytic activity for the degradation of methylene blue dye under UV illumination in presence of hydrogen peroxide. The percent of degradation was estimated to be 55.71% in 420.0 min and 90.43% in 360.0 min for Co3O4 and NiO, respectively. Moreover, the synthesized complexes, nano-sized Co3O4, and NiO products have been examined, employing modified Bauer- Kirby method, for antifungal (Candida albicans and Aspergillus flavus) and antibacterial (Staphylococcus aureus and Escherichia coli) activities.

  13. Potentiometric and Thermodynamic Studies of Some Schiff-Base Derivatives of 4-Aminoantipyrine and Their Metal Complexes

    Directory of Open Access Journals (Sweden)

    A. A. El-Bindary

    2013-01-01

    Full Text Available The proton-ligand dissociation constant of 4-(4-amino-1,5-dimethyl-2-phenyl-1,2-dihydro-pyrazol-3-ylideneamino-phenol ( and 4-(4-amino-1,5-dimethyl-2-phenyl-1,2-dihydro-pyrazol-3-ylideneamino-benzoic acid ( and metal-ligand stability constants of their complexes with metal ions (Mn2+, Co2+, Ni2+, and Cu2+ have been determined potentiometrically in 0.1 mol·dm−3 KCl and 10% (by volume ethanol-water mixture and at 298, 308, and 318 K. The stability constants of the formed complexes increase in the order Mn2+, Co2+, Ni2+, and Cu2+. The effect of temperature was studied, and the corresponding thermodynamic parameters (, , and were derived and discussed. The dissociation process is nonspontaneous, endothermic, and entropically unfavourable. The formation of the metal complexes has been found to be spontaneous, endothermic, and entropically favourable.

  14. Trinuclear Mixed-valent Manganese Complex with Non-schiff-base Tetradentate Ligand Showing a Ferromagnetic Coupling

    Directory of Open Access Journals (Sweden)

    Masahiro Mikuriya

    2017-12-01

    Full Text Available Mixed-valent trinuclear manganese complex with N,N’-bis(2-hydroxy-3,5-dimethylbenzyl-N,N’-dimethyl-1,2-ethanediamine (H2hdde, [Mn3(hdde2(CH3CO22(CH3O2], was synthesized. The X-ray crystal structure analysis revealed a linearly arrangement of MnIII-MnII-MnIIIcore, where a ferromagnetic coupling (J = 2.62 cm–1 between the MnIII and MnII ions.

  15. Aggregate manganese Schiff base moieties by terephthalate or acetate: dinuclear manganese and trinuclear mixed metal Mn2/Na complexes.

    Science.gov (United States)

    Chen, Changneng; Huang, Deguang; Zhang, Xiaofeng; Chen, Feng; Zhu, Hongping; Liu, Qiutian; Zhang, Cunxi; Liao, Daizheng; Li, Licun; Sun, Licheng

    2003-06-02

    A reaction system consisting of terephthalic acid, NaOH, inorganic Mn(II) or Mn(III) salt, and salicylidene alkylimine resulted in dinuclear manganese complexes (salpn)(2)Mn(2)(mu-phth)(CH(3)OH)(2) (1, salpn = N,N'-1,3-propylene-bis(salicylideneiminato); phth = terephthalate dianion), (salen)(2)Mn(2)(mu-phth)(CH(3)OH)(2) (2, salen = N,N'-ethylene-bis(salicylideneiminato)), (salen)(2)Mn(2)(mu-phth)(CH(3)OH)(H(2)O) (3), and (salen)(2)Mn(2)(mu-phth) (4), while the absence of NaOH in the reaction led to a mononuclear Mn complex (salph)Mn(CH(3)OH)(NO(3)) (5, salph = N,N'-1,2-phenylene-bis(salicylideneiminato)). In addition, a trinuclear mixed metal complex H[Mn(2)Na(salpn)(2)(mu-OAc)(2)(H(2)O)(2)](OAc)(2) (6) was obtained from the reaction system by using maleic acid instead of terephthalic acid. Five-coordinate Mn ions were found in 4 giving rise to an intermolecular interaction and constructing a one-dimensional linear structure. Antiferromagnetic exchange interactions were observed for 1-3, and a total ferromagnetic exchange of 4 was considered to stem from intermolecular magnetic coupling. (1)H NMR signals of phenolate ring and alkylene (or phenylene) backbone of the diamine are similar to those reported in the literature, and the phth protons are at -2.3 to -10.1 ppm. Studies on structure, bond valence sum analysis, and magnetic properties indicate the oxidation states of the Mn ions in 6 to be +3, which are also indicated by ESR spectra in dual mode. Ferromagnetic exchange interaction between the Mn(III) sites was observed with J = 1.74 cm(-1). A quasireversible redox pair at -0.29V/-0.12V has been assigned to the redox of Mn(2)(III)/Mn(III)Mn(II), implying the intactness of the complex backbone in solution.

  16. Sonochemical synthesis, in vitro evaluation and DFT study of novel phenothiazine base Schiff bases and their nano copper complexes as the precursors for new shaped CuO-NPs.

    Science.gov (United States)

    Parsaee, Zohreh; Joukar Bahaderani, Ehsan; Afandak, Azam

    2018-01-01

    The current work reports the ultrasound-assisted synthesis of two nano binuclear copper complexes derived from novel tetradentate (N2O2) phenothiazine based Schiff bases. The synthesized compounds were characterized using the physicochemical methods, including 1H NMR, 13C NMR, FE-SEM, Mass, FT-IR, UV-Vis, elemental analysis, magnetic moment and molar conductance measurements. It is found that the geometrical structure of CuII2LnCl4 is distorted tetrahedral around the copper atoms using the results of 1H NMR, UV-Vis and magnetic moment studies. In addition, CuO nano particles were produced in the nano range (14.3-12.1nm) by the thermal decomposition of the copper complexes CuO NPs were characterized using FT-IR, FE-SEM, XRD, UV-Vis and photoluminescence methods and indicated a close accordance with the standard pattern. Also, the antioxidant studies revealed that the copper complexes exhibit comparable scavenging effects (against O2 and OH) with the standard antioxidants, such as vitamin C, while, they show more antioxidant activity than ligands. Similarly, the complexes show more antibacterial activity against four gram positive and gram negative bacteria in comparison to their Schiff base ligands. furthermore, The optimized structure, Molecular orbital (M.O.), Mulliken population analysis (MPA), contour of Electrostatic Potential (ESP) and Molecular Electrostatic Potential (MEP) map of the titled compounds were calculated base on DFT calculations that were carried out at the B3LYP levels of theory with a double basis set LANL2DZ for copper, and 6-311+G(d,p) basis set for the other atoms. Copyright © 2017 Elsevier B.V. All rights reserved.

  17. A new synthesis of enantiomerically pure syn-(S)-β-hydroxy-α-amino acids via asymmetric aldol reactions of aldehydes with a homochiral Ni(II)-glycine/(S)-BPB Schiff base complex

    OpenAIRE

    Belokon, Yuri N.; Kochetkov, Konstantin A.; Ikonnikov, Nikolai S.; Strelkova, Tatiana V.; Harutyunyan, Syuzanna R.; Saghiyan, Ashot S.

    2001-01-01

    syn-(S)-β-Hydroxy-α-amino acids were synthesised stereoselectively via elaboration of the asymmetric aldol reactions of aldehydes with a chiral Ni(II)-(S)-BPB/glycine Schiff base complex in the presence of equimolar NaH in THF. The stereoselectivity of the reaction was studied as a function of time, the reaction conditions, the nature of the carbonyl compounds and the base used. The synthetic potential of this asymmetric method was demonstrated in the preparation of syn-(S)-β-hydroxyleucine o...

  18. Preparation and Characterization of a Molybdenum(VI Schiff Base Complex as Magnetic Nanocatalyst for Synthesis of 2-Amino-4H-benzo[h]chromenes

    Directory of Open Access Journals (Sweden)

    Naghmeh Divsalar

    2016-10-01

    Full Text Available A new recoverable molybdenum nanocatalyst was prepared by immobilization  of a Schiff base ligand on the surface of silica coated magnetite nanoparticles (Fe3O4@SiO2 through condensation reaction between 3-aminopropyl triethoxysilane and 2-hydroxy1-naphthaldehyde and succeeding reaction with dioxomolybdenum(VI acetylacetonate (MoO2(acac2. The synthesized catalyst was characterized by inductively coupled plasma, thermogravimetric analysis, scanning electron microscopy, vibrating sample magnetometry, Energy-dispersive X-ray, Fourier transform infrared and X-raydiffraction spectroscopy. Catalytic performance of the synthesized nanocatalyst was investigated for the preparation of 2-amino-4H-benzo[h]chromenes. The compounds were prepared high yield through one-pot, three-component reaction of 1-naphthol, various of aldehydes and malonitrile in the presence of nanocatalyst, Fe3O4@SiO2@Mo-Schiff base, under solvent-free conditions. The benefits of this protocol are short reaction time, simple work-up procedure, high yields and use of the concept of green chemistry. The magnetic nanocatalyst could be separated easily from the reaction media using an external magnetic field and reused in subsequent catalytic runs without significant deterioration of its activity.

  19. Synthesis, spectral characterization, in vitro antibacterial, antifungal and cytotoxic activities of Co(II), Ni(II) and Cu(II) complexes with 1,2,4-triazole Schiff bases.

    Science.gov (United States)

    Bagihalli, Gangadhar B; Avaji, Prakash Gouda; Patil, Sangamesh A; Badami, Prema S

    2008-12-01

    A series of metal complexes of cobalt(II), nickel(II) and copper(II) have been synthesized with newly synthesized biologically active 1,2,4-triazole Schiff bases derived from the condensation of 3-substituted-4-amino-5-mercapto-1,2,4-triazole and 8-formyl-7-hydroxy-4-methylcoumarin, which have been characterized by elemental analyses, spectroscopic measurements (IR, UV-vis, fluorescence, ESR), magnetic measurements and thermal studies. Electrochemical study of the complexes is also reported. All the complexes are soluble to limited extent in common organic solvents but soluble to larger extent in DMF and DMSO and are non-electrolytes in DMF and DMSO. All these Schiff bases and their complexes have also been screened for their antibacterial (Escherichia coli, Staphylococcus aureus, Streptococcus pyogenes, Pseudomonas aeruginosa and Salmonella typhi) and antifungal activities (Aspergillus niger, Aspergillus flavus and Cladosporium) by MIC method. The brine shrimp bioassay was also carried out to study their in vitro cytotoxic properties.

  20. Synthesis, spectral characterization, solution equilibria, in vitro antibacterial and cytotoxic activities of Cu(II), Ni(II), Mn(II), Co(II) and Zn(II) complexes with Schiff base derived from 5-bromosalicylaldehyde and 2-aminomethylthiophene

    Science.gov (United States)

    El-Sherif, Ahmed A.; Eldebss, Taha M. A.

    2011-09-01

    Schiff base namely 2-aminomethylthiophenyl-4-bromosalicylaldehyde (ATS)(4-bromo-2-(thiophen-2-yl-imino)methylphenol) and its metal complexes have been synthesized and characterized by elemental analyses, IR, 1H NMR, solid reflectance, magnetic moment, molar conductance, mass spectra, ESR and thermal analysis (TGA). The analytical data of the complexes show the formation of 1:2 [M:L] ratio of the formula [ML 2], where M represents Ni(II), Zn(II) and Cu(II) ions, while L represents the deprotonated Schiff base. IR spectra show that ATS is coordinated to the metal ions in a bidentate manner through azomethine-N and phenolic-oxygen groups. The ligand and their metal chelates have been screened for their antimicrobial activities using the disc diffusion method against the selected bacteria. A cytotoxicity of the compounds against colon (HCT116) and larynx (HEP2) cancer cells have been studied. Protonation constants of (ATS) ligand and stability constants of its Cu 2+, Co 2+, Mn 2+, Zn 2+ and Ni 2+ complexes were determined by potentiometric titration method in 50% (v/v) DMSO-water solution at ionic strength of 0.1 M NaNO 3.

  1. Electronic structure and spectroscopic properties of mononuclear manganese(III) Schiff base complexes: a systematic study on [Mn(acen)X] complexes by EPR, UV/vis, and MCD spectroscopy (X = Hal, NCS).

    Science.gov (United States)

    Westphal, Anne; Klinkebiel, Arne; Berends, Hans-Martin; Broda, Henning; Kurz, Philipp; Tuczek, Felix

    2013-03-04

    The manganese(III) Schiff base complexes [Mn(acen)X] (H2acen: N,N'-ethylenebis(acetylacetone)imine, X: I(-), Br(-), Cl(-), NCS(-)) are considered as model systems for a combined study of the electronic structure using vibrational, UV/vis absorption, parallel-mode electron paramagnetic resonance (EPR) and low-temperature magnetic circular dichroism (MCD) spectroscopy. By variation of the co-ligand X, the influence of the axial ligand field within a given square-pyramidal coordination geometry on the UV/vis, EPR, and MCD spectra of the title compounds is investigated. Between 25000 and 35000 cm(-1), the low-temperature MCD spectra are dominated by two very intense, oppositely signed pseudo-A terms, referred to as "double pseudo-A terms", which change their signs within the [Mn(acen)X] series dependent on the axial ligand X. Based on molecular orbital (MO) and symmetry considerations, these features are assigned to π(n.b.)(s, a) → yz, z(2) ligand-to-metal charge transfer transitions. The individual MCD signs are directly determined from the calculated MOs of the [Mn(acen)X] complexes. The observed sign change is explained by an inversion of symmetry among the π(n.b.)(s, a) donor orbitals which leads to an interchange of the positive and negative pseudo-A terms constituting the "double pseudo-A term".

  2. Schiff Base Metal Derivatives Enhance the Expression of HSP70 and Suppress BAX Proteins in Prevention of Acute Gastric Lesion

    Directory of Open Access Journals (Sweden)

    Shahram Golbabapour

    2013-01-01

    Full Text Available Schiff base complexes have appeared to be promising in the treatment of different diseases and disorders and have drawn a lot of attention to their biological activities. This study was conducted to evaluate the regulatory effect of Schiff base metal derivatives on the expression of heat shock proteins (HSP 70 and BAX in protection against acute haemorrhagic gastric ulcer in rats. Rats were assigned to 6 groups of 6 rats: the normal control (Tween 20 5% v/v, 5 mL/kg, the positive control (Tween 20 5% v/v, 5 mL/kg, and four Schiff base derivative groups named Schiff_1, Schiff_2, Schiff_3, and Schiff_4 (25 mg/kg. After 1 h, all of the groups received ethanol 95% (5 mL/kg but the normal control received Tween 20 (Tween 20 5% v/v, 5 mL/kg. The animals were euthanized after 60 min and the stomachs were dissected for histology (H&E, immunohistochemistry, and western blot analysis against HSP70 and BAX proteins. The results showed that the Schiff base metal derivatives enhanced the expression of HSP70 and suppressed the expression of BAX proteins during their gastroprotection against ethanol-induced gastric lesion in rats.

  3. Schiff Base Metal Derivatives Enhance the Expression of HSP70 and Suppress BAX Proteins in Prevention of Acute Gastric Lesion

    Science.gov (United States)

    Gwaram, Nura Suleiman; Al-Obaidi, Mazen M. Jamil; Soleimani, A. F.; Ali, Hapipah Mohd; Abdul Majid, Nazia

    2013-01-01

    Schiff base complexes have appeared to be promising in the treatment of different diseases and disorders and have drawn a lot of attention to their biological activities. This study was conducted to evaluate the regulatory effect of Schiff base metal derivatives on the expression of heat shock proteins (HSP) 70 and BAX in protection against acute haemorrhagic gastric ulcer in rats. Rats were assigned to 6 groups of 6 rats: the normal control (Tween 20 5% v/v, 5 mL/kg), the positive control (Tween 20 5% v/v, 5 mL/kg), and four Schiff base derivative groups named Schiff_1, Schiff_2, Schiff_3, and Schiff_4 (25 mg/kg). After 1 h, all of the groups received ethanol 95% (5 mL/kg) but the normal control received Tween 20 (Tween 20 5% v/v, 5 mL/kg). The animals were euthanized after 60 min and the stomachs were dissected for histology (H&E), immunohistochemistry, and western blot analysis against HSP70 and BAX proteins. The results showed that the Schiff base metal derivatives enhanced the expression of HSP70 and suppressed the expression of BAX proteins during their gastroprotection against ethanol-induced gastric lesion in rats. PMID:24298554

  4. Spectrophotometric and spectrofluorimetric investigation of different equilibria of a recently synthesized Schiff base with the aid of chemometric methods

    Energy Technology Data Exchange (ETDEWEB)

    Afkhami, Abbas, E-mail: afkhami@basu.ac.i [Faculty of Chemistry, Bu-Ali Sina University, Hamedan 65174 (Iran, Islamic Republic of); Keypour, Hasan; Khajavi, Farzad [Faculty of Chemistry, Bu-Ali Sina University, Hamedan 65174 (Iran, Islamic Republic of); Rezaeivala, Majid [Department of Chemical Engineering, Hamedan University of Technology, Hamedan 65155 (Iran, Islamic Republic of)

    2011-07-15

    In this study ground and excited states acidic dissociation constants of a recently synthesized Schiff base was obtained in a DMF:water mixture of 30:70 (v/v) using absorption and fluorescent spectra of the Schiff base in different pH values with the aid of chemometric methods. In addition, the fluorescent of the two kinds of tautomers of this Schiff base was investigated and the rate of tautomerization was obtained using rank annihilation factor analysis (RAFA). The effect of different kinds of surfactants such as sodium dodecyl sulfate (SDS), cetyltrimethylammonium bromide (CTAB) and Triton X-100 on fluorescence spectrum of the Schiff base in a DMF:water mixture of 2:98 (v/v) was investigated. CTAB increased the fluorescence intensity of the Schiff base while SDS and Triton X-100 had no significant effect on it. {beta}-Cyclodextrin increased the fluorescence intensity of the Schiff base. Also the sensing behavior of this Schiff base toward metal ions was studied in DMF and ethanol by fluorescence spectroscopy. The Schiff base showed prominent fluorescent signal in the presence of Zn{sup 2+}, whereas other metal ions failed to induce response and ground-state dissociation constant of the complex was determined by direct fluorimetric titration as a function of Zn{sup 2+} concentration. - Highlights: {yields} Acidity and rate of the tautomerization of a recently synthesized Schiff base were studied. {yields} Ground and excited states acidity constants and tautomerization rate constant were obtained. {yields} These parameters were obtained with the aid of hard model and Rank annihilation factor analysis. {yields} The effect of some factors on the fluorescence intensity of the Schiff base was studied.

  5. Phenoxyacetohydrazide Schiff Bases: β-Glucuronidase Inhibitors

    Directory of Open Access Journals (Sweden)

    Waqas Jamil

    2014-06-01

    Full Text Available Phenoxyacetohydrazide Schiff base analogs 1–28 have been synthesized and their in vitro β-glucouoronidase inhibition potential studied. Compounds 1 (IC50 = 9.20 ± 0.32 µM, 5 (IC50 = 9.47 ± 0.16 µM, 7 (IC50 = 14.7 ± 0.19 µM, 8 (IC50 = 15.4 ± 1.56 µM, 11 (IC50 = 19.6 ± 0.62 µM, 12 (IC50 = 30.7 ± 1.49 µM, 15 (IC50 = 12.0 ± 0.16 µM, 21 (IC50 = 13.7 ± 0.40 µM and 22 (IC50 = 22.0 ± 0.14 µM showed promising β-glucuronidase inhibition activity, better than the standard (D-saccharic acid-1,4-lactone, IC50 = 48.4 ± 1.25 µM.

  6. Synthesis and Characterization of New Schiff Bases Derived from N (1)-Substituted Isatin with Dithiooxamide and Their Co(II), Ni(II), Cu(II), Pd(II), and Pt(IV) Complexes

    OpenAIRE

    Abdul-Ghani, Ahlam J.; Asmaa M. N. Khaleel

    2009-01-01

    Three new Schiff bases of N-substituted isatin LI, LII, and LIII = Schiff base of N-acetylisatin, N-benzylisatin, and N-benzoylisatin, respectively, and their metal complexes C1a,b=[Co2(LI)2Cl3]Cl, C2=[Ni(LI)2Cl2]0.4BuOH, C3=[CuLICl(H2O)]Cl⋅0.5BuOH, C4=[Pd(LI)2Cl]Cl, C5=[Pt(L1)2Cl2]Cl2⋅1.8EtOH.H2O, C6a=[CoLIICl]Cl⋅0.4H2O⋅0.3DMSO, C6b=[CoLIICl]Cl⋅0.3H2O⋅0.1BuOH,C7=[NiLIICl2], C8=[CuLII]Cl2⋅H2O00000, C9=[Pd(LII)2]Cl2, C10=[Pt(LII)2.5Cl]Cl3, C11a=[Co(LIII)]C12⋅H2O, C11b=[Co(LIII)]Cl2...

  7. Electrically conducting polymers from phenylacetylene substituted Schiff`s base momomers

    Energy Technology Data Exchange (ETDEWEB)

    Kim, I. [Dept. of Chemical Engineering, Univ. of Ulsan (Korea, Republic of); Lee, D.J. [R and D Center, Kumho and Co., Kwangju (Korea, Republic of)

    1995-03-01

    Electrically conducting polymers have been synthesized from novel mono- or difunctional phenylacetylene-substituted Schiff`s base monomers. These monomers melt to a viscous liquid state, and on continued heating above about 300 C, thermally polymerize to form an electrically insulating thermoset polymers. On further postcure heat treatment, the polymers become electroconductive showing a bulk conductivity of approximately 10{sup -2}S/cm. Because the monomers remain in a liquid stage for 1-2h, depending on the cure conditions, moldings, castings, and pre-pregs can be fabricated using conventional processing techniques. In addition, since reactive dopants are not used, the resulting polymers and conductivity are stable in ambient as well as more aggressive environments, allowing them to function at 300 C and above. The monomers are well characterized, but the structure of the cured and postcured polymers are not yet well defined because of their high stability and intractability in the cured state. (orig.)

  8. Spectroscopic, DNA binding ability, biological activity, DFT calculations and non linear optical properties (NLO) of novel Co(II), Cu(II), Zn(II), Cd(II) and Hg(II) complexes with ONS Schiff base

    Science.gov (United States)

    Abdel Aziz, Ayman A.; Elantabli, Fatma M.; Moustafa, H.; El-Medani, Samir M.

    2017-08-01

    The reaction of Co(II), Cu(II), Zn(II), Cd(II) and Hg(II) with the synthesized N-(2-hydroxy-1-naphthylidene)-2-aminothiophenol Schiff base ligand (H2L) at room temperature resulted in the formation of the five complexes; [Co(HL)2]H2O, 1; [M(HL)2] (M = Cu, Zn and Cd), (2-4) and [Hg(HL)Cl], 5. The ligand and its complexes were characterized based on elemental analyses, IR, 1H NMR, magnetic measurement, molar conductance, and thermal analysis. Coats and Redfern method was used to compute the kinetic and thermodynamic parameters. Antimicrobial activities of H2L and its complexes have been studied. The binding of Co(II), Cu(II) and Zn(II) complexes to calf thymus DNA (CT-DNA) has been investigated using UV-Vis and fluorescence absorption spectra. The results indicated that the ligand and its complexes may bind to DNA by intercalation modes, with a much higher binding affinity of the complexes than that of the ligand. The equilibrium geometries of the studied complexes are investigated theoretically at the B3LYP/LANL2DZ level of theory, and it was found that these geometries are non-linear. The calculated EHOMO and ELUMO energies of the studied complexes can be used to calculate the global properties. The calculated nonlinear optical parameters (NLO); first order hyperpolarizibility (β) of the studied complexes show promising optical properties.

  9. A new oxovanadium(IV) complex containing an O,N-bidentate Schiff base ligand: Synthesis at ambient temperature, characterization, crystal structure and catalytic performance in selective oxidation of sulfides to sulfones using H2O2 under solvent-free conditions

    Science.gov (United States)

    Menati, Saeid; Rudbari, Hadi Amiri; Khorshidifard, Mahsa; Jalilian, Fariba

    2016-01-01

    A new bidentate ON Schiff base ligand, HL, was synthesized by simple condensation reaction of isopropylamine and salicylaldehyde. Then by reaction of HL and VO(acac)2 in the ratio of 2:1 at ambient temperature, a new oxovanadium(IV) Schiff base complex, VOL2, was synthesized. The Schiff base ligand and its oxovanadium(IV) complex were characterized by elemental analyses, FT-IR, 1H NMR, 13C NMR and UV-visible spectroscopies. The crystal structure of oxovanadium(IV) complex, VOL2, was also determined by single crystal X-ray analysis. The vanadium center in this structure is coordinated to two bidentate Schiff base ligands with the two nitrogen and two phenolate oxygen atoms in equatorial positions and one oxo oxygen in the axial position to complete the distorted trigonal bipyramidal N2O3 coordination sphere. Catalytic performance of the VOL2 complex was studied in the selective oxidation of thioanisole with the green oxidant 35% aqueous H2O2 under solvent-free conditions and under organic solvents (EtOH, CHCl3, CH2Cl2, DMF, CH3CN, EtOAc) as a model. Due to better catalytic performance of the VOL2 complex under solvent-free conditions, this complex used for the oxidation of the different sulfides to the corresponding sulfones under solvent-free conditions. The use of hydrogen peroxide as oxidant and the absence of solvent makes these reactions interesting from environmental and economic points of view.

  10. Synthesis and X-ray structure analysis of a new binuclear Schiff base Co(II) complex with the ligand N,N'-bis(3-methoxysalicylidene)-1,4-butanediamine

    Energy Technology Data Exchange (ETDEWEB)

    Nasr-Esfahani, M., E-mail: m-nasresfahani@iaun.ac.ir [Islamic Azad University, Najafabad Branch, Department of Materials Science and Engineering (Iran, Islamic Republic of)

    2009-12-15

    The title binuclear complex, tris[N,N-bis(3-methoxysalicylidene)-1,4-diaminobutane] dicobalt(II), C{sub 60}H{sub 70}Co{sub 2}N{sub 6}O{sub 15}, was prepared by the reaction of the tetradentate Schiff base ligand bis(3-methoxysalicylidene)-1,4-diaminobutane and Co(CH{sub 3}COO){sub 2} . 4H{sub 2}O in a ethanol solution and structurally characterized by single-crystal X-ray diffraction. This complex has a dinuclear structure where two Co(II) ions are bridged by one N{sup 0},N'-bis(3-methoxysalicylidene)-1,4-diaminobutane. The two Co(II) ions, have two distorted octahedral coordination involving two O and two N atoms.

  11. 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.

  12. Olefin Metathesis Mediated By: - Schiff Base Ru-Alkylidenes -Ru-Alkylidenes Bearing Unsymmetrical NH Ligands

    Science.gov (United States)

    Monsaert, Stijn; Voort, Pascal Van Der; Ledoux, Nele; Allaert, Bart; Drozdzak, Renata; Verpoort, Francis

    The classic Grubbs second-generation complex 2 was modified through 1. The introduction of a bidentate Schiff base ligand 2. Changes in the amino side groups of the NHC ligand Representative olefin metathesis test reactions show the effects induced by the ligand modifications and demonstrate some interesting new properties of the described catalysts. catalysts.

  13. Synthesis and characterization of iron (ii) and nickel (ii) schiff base ...

    African Journals Online (AJOL)

    The complexes of iron (II) and nickel (II) with schiff base derived from benzoin and 2-amino benzoic acid have been prepared. Solubility, melting point, decomposition temperature, conductance measurement, infrared (IR) and UV – Visible spectrophotometric studies were used in characterizing the compounds. The melting ...

  14. Half-sandwich (η6-arene) ruthenium (II) chiral Schiff base ...

    Indian Academy of Sciences (India)

    sandwich (6-arene)ruthenium(II) chiral Schiff base complexes: Analysis of the diastereomeric mixtures in solution by 2D-NMR spectroscopy. Rakesh K Rath G A Nagana Gowda Akhil R Chakravarty. Inorganic and Analytical Volume 114 Issue 5 ...

  15. Anion recognition by simple chromogenic and chromo-fluorogenic salicylidene Schiff base or reduced-Schiff base receptors.

    Science.gov (United States)

    Dalapati, Sasanka; Jana, Sankar; Guchhait, Nikhil

    2014-08-14

    This review contains extensive application of anion sensing ability of salicylidene type Schiff bases and their reduced forms having various substituents with respect to phenolic OH group. Some of these molecular systems behave as receptor for recognition or sensing of various anions in organic or aqueous-organic binary solvent mixture as well as in the solid supported test kits. Development of Schiff base or reduced Schiff base receptors for anion recognition event is commonly based on the theory of hydrogen bonding interaction or deprotonation of phenolic -OH group. The process of charge transfer (CT) or inhibition of excited proton transfer (ESIPT) or followed by photo-induced electron transfer (PET) lead to naked-eye color change, UV-vis spectral change, chemical shift in the NMR spectra and fluorescence spectral modifications. In this review we have tried to discuss about the anion sensing properties of Schiff base or reduced Schiff base receptors. Copyright © 2014 Elsevier B.V. All rights reserved.

  16. Synthesis, crystal structures, and biological evaluation of Cu(II) and Zn(II) complexes of 2-benzoylpyridine Schiff bases derived from S-methyl- and S-phenyldithiocarbazates.

    Science.gov (United States)

    Li, Ming Xue; Zhang, Li Zhi; Chen, Chun Ling; Niu, Jing Yang; Ji, Bian Sheng

    2012-01-01

    Two NNS tridentate Schiff base ligands of 2-benzoylpyridine S-methyldithiocarbazate (HL(1)) and 2-benzoylpyridine S-phenyldithiocarbazate (HL(2)) and their transition metal complexes [Cu(2)(L(1))(2)(CH(3)COO)](ClO(4)) (1), [Zn(2)(L(1))(2)(ClO(4))(2)] (2), [Zn(L(2))(2)](3) have been prepared and characterized by elemental analysis, IR, MS, NMR and single-crystal X-ray diffraction studies. In the solid state, each of two Schiff bases remains in its thione tautomeric form with the thione sulfur atom trans to the azomethine nitrogen atom. Under similar prepared conditions, three new complexes showed distinctly different coordination modes depending on their coordinating preferences. Each copper atom in S-bridged dinuclear complex [Cu(2)(L(1))(2)(CH(3)COO)](ClO(4)) (1) is surrounded by five donor atoms in a square-pyramidal fashion (4+1). [Zn(2)(L(1))(2)(ClO(4))(2)] (2) is a dimer in which each zinc atom adopts a seven-coordinate distorted pentagonal bipyramidal geometry, while mononuclear [Zn(L(2))(2)] (3) has octahedral coordination geometry. Biological studies, carried out in vitro against selected bacteria, fungi, and K562 leukaemia cell line, respectively, have shown that different substituted groups attached at the dithiocarbazate moieties and metals showed distinctive differences in the biological property. Zinc(II) complexes 2 and 3 could distinguish K562 leukaemia cell line from normal hepatocyte QSG7701 cell line. Effect of the title compounds on Mitochondria membrane potential (MMP) and PI-associated fluorescence intensity in K562 leukaemia cell line are also studied. The title compounds may exert their cytotoxicity activity via induced loss of MMP. Copyright © 2011 Elsevier Inc. All rights reserved.

  17. Synthesis and characterization of the polyaniline dopant Schiff base

    Directory of Open Access Journals (Sweden)

    Mirian Y. Matsumoto

    2012-06-01

    Full Text Available The Schiff base, N-salicilidenoanilina was used as dopant to induce polymerization of aniline and thus preparing polyaniline (PAni. The different conditions of preparation, including Schiff base structure, and the dosage of acidity reaction medium, were investigated to discuss the influence of these conditions relative conductivity of the resulting samples. The products were also characterized by Fourier transform infrared (FTIR, ultraviolet-visible (UV-Vis, electrochemical impedance spectroscopy (EIE. The results showed the synthesis conditions play an important in the formation and the final properties of the polyaniline

  18. Structure dependent selective efficacy of pyridine and pyrrole based Cu(II) Schiff base complexes towards in vitro cytotoxicity, apoptosis and DNA-bases binding in ground and excited state.

    Science.gov (United States)

    Koley Seth, Banabithi; Saha, Arpita; Haldar, Srijan; Chakraborty, Partha Pratim; Saha, Partha; Basu, Samita

    2016-09-01

    This work highlights a systematic and comparative study of the structure-dependent influence of a series of biologically active Cu(II) Schiff base complexes (CSCs) on their in vitro cytotoxicity, apoptosis and binding with polymeric DNA-bases in ground and photo-excited states. The structure-activity relationship of the closely resembled CSCs towards in vitro cytotoxicity and apoptosis against cervical cancerous HeLa and normal human diploid WI-38 cell lines has been investigated by MTT assay and FACS techniques respectively. The steady-state and time-resolved spectroscopic studies have also been carried out to explore the selective binding affinities of the potential complexes towards different polymeric nucleic acid bases (poly d(A), poly d(T), poly d(G), poly d(C), Poly d(G)-Poly d(C)), which enlighten the knowledge regarding their ability in controlling the structure and medium dependent interactions in 'ground' and 'excited' states. The pyridine containing water soluble complexes (CuL(1) and CuL(3)) are much more cytotoxic than the corresponding pyrrole counterparts (CuL(2) and CuL(4)). Moreover the acidic hydrogens in CuL(1) increase its cytotoxicity much more than methyl substitution as in CuL(3). The results of MTT assay and double staining FACS experiments indicate selective inhibition of cell growth (cell viability 39% (HeLa) versus 85% (WI-38)) and occurrence of apoptosis rather than necrosis. The ground state binding of CuL(1) with polymeric DNA bases, especially with guanine rich DNA (Kb=6.41±0.122×10(5)), that enhances its cytotoxic activity, is further confirmed from its binding isotherms. On the other hand the pyrrole substituted CuL(4) complex exhibits the structure and medium dependent selective electron-transfer in triplet state as observed in laser flash photolysis studies followed by magnetic field (MF) effect. Copyright © 2016 Elsevier B.V. All rights reserved.

  19. Synthesis and Spectroscopic Analysis of Schiff Bases of Imesatin ...

    African Journals Online (AJOL)

    ADOWIE PERE

    Synthesis and Biological Evaluation of some Novel. Mannich Bases of Isatin, Journal of Pharmaceutical. Research, 5(2):61-64. Kaura, AK; Kaura, M (2012) Synthesis, Spectral and. Comparative Antimicrobial Study of Schiff bases,. International Journal of Chemical and Pharmaceutical. Sciences, 3(4):24-29. Kumar, V ...

  20. Synthesis and characterization of a heptadentate (N4O3 Schiff base ligand and associated La(III, Sm(III and Gd(III complexes, and a theoretical study

    Directory of Open Access Journals (Sweden)

    Sadegh Salehzadeh

    2010-04-01

    Full Text Available A new symmetrical potentially heptadentate (N4O3 Schiff base ligand {N[CH2CH2CH2N=CH(2-OH-5-BrC6H3]3} (H3L6 and associated neutral Gd(III, La(III and Sm(III complexes, were synthesized. The new compounds were characterized by IR spectroscopy, elemental analysis and mass spectrometry in all cases and in the case of ligand also with NMR spectroscopy. The relative capability of H3L6 to encapsulate a lanthanide ion, herein La(III, has been theoretically studied by ab initio restricted Hartree-Fock (RHF and DFT (B3LYP methods. The calculation confirmed that the H3L6 ligand can effectively encapsulate a lanthanide ion and enforce a seven-coordinate geometry.

  1. Structural and molecular docking studies of biologically active mercaptopyrimidine Schiff bases

    Science.gov (United States)

    Kirubavathy, S. Jone; Velmurugan, R.; Karvembu, R.; Bhuvanesh, N. S. P.; Enoch, Israel V. M. V.; Selvakumar, P. Mosae; Premnath, D.; Chitra, S.

    2017-01-01

    Novel Schiff bases derived from the treatment of mercapto-diamino pyrimidine with two different aldehydes are characterized using elemental analysis, single crystal X-ray diffraction and 1H NMR spectroscopy. The pharmacological action of the synthesized compounds viz., antimicrobial, anticancer and antitubercular activities is studied. The Schiff bases show a very good activity against various test pathogens. DNA and β-CD binding interactions of the compounds are studied using UV-Visible absorption and fluorescence spectral measurements. The binding constants of the compounds towards β-CD are in the order of 103 to 104. Molecular docking is done using MOE program on the 3D structure of the enzymes, viz., human thymidylate synthase complexed with dump and raltitrex, candida albicans N-myristoyltransferasepeptidic inhibitor, catalytic domain of protein kinase pKnb from mycobacterium tuberculosis in complex with mitoxantrone, pare, topoisomerase atpase inhibitor, E. coli and lactobacillus casdihydrofolatereductase. The MIC/IC50 values of the Schiff bases are compared with the glide scores from the molecular docking studies. The number of hydrogen bonding interactions between the Schiff bases and amino acid residues are also reported.

  2. Synthesis, characterization, spectroscopic and catalytic oxidation studies of Fe(III), Ni(II), Co(III), V(IV) and U(VI) Schiff base complexes with N, O donor ligands derived from 2,3-diaminopyridine

    Energy Technology Data Exchange (ETDEWEB)

    Zabardasti, Abedien; Shangaie, Sayed Asad [Lorestan Univ., Khorramabad (Iran, Islamic Republic of). Dept. of Chemistry

    2016-10-15

    Fifteen new complexes of transition metals were designed using three Schiff base ligands and aldol condensation of 2,3-diaminopyridine with 5-R-2-hydroxybenzaldehyde (R = F, Cl, Br) in the 1:2 molar ratio. The tetradentate ligands N,N{sup '}-bis(5-R-2-hydroxybenzaldehyde) pyridine were acquired with the common formula H{sub 2}[(5-R-sal){sub 2}py] and characterized by IR, UV-Vis spectra, {sup 1}H-NMR and elemental analysis. These ligands produce 1:1 complexes M[(5-R-sal){sub 2}py] with Fe(III), Ni(II), Co(III), V(IV) and U(VI) metal ions. The electronic property and nature of complexes were identified by IR, UV-Vis spectra, elemental analysis, X-ray crystallography and cyclic voltammetric methods. The catalytic activity of complexes for epoxidation of styrene with UHP as primary oxidant at minimal temperature (10 C) has been planned. The spectral data of the ligands and their complexes are deliberate in connection with the structural changes which happen due to complex preparation. The electrochemical outcome has good conformability with what suggested for electronic interaction among metal center and ligand by the UV-Vis and IR measurements.

  3. Coordination of Tridentate Schiff Base Derivatives of 4 ...

    African Journals Online (AJOL)

    NICO

    The potentially tridentate Schiff base derivatives H2nap and Hoap were synthesized by the condensation reaction of .... determined, and the molecular positional parameters of the atoms in the 'inner core' are well defined. In 3 the hydrogen atoms in the water molecule have not .... The weak absorption at lowest energy is.

  4. Schiff bases of N-(2-aminoethyl)-3-aminopropyltrimethoxysilane and ...

    Indian Academy of Sciences (India)

    All the synthesized compounds are characterized by spectroscopic methods, elemental analysis and mass spectrometry. The authentication of Schiff base modified silatranes is scrutinized by single X-ray crystal structure of silatrane 1. The thermal stability of the five silatranes is studied by thermo-gravimetric analysis (TGA).

  5. Intramolecular hydrogen bonding and tautomerism in Schiff bases ...

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Chemical Sciences; Volume 121; Issue 6. Intramolecular hydrogen bonding and tautomerism in Schiff bases: Part VI. Syntheses and structural investigation of salicylaldimine and naphthaldimine derivatives. Selen Bi̇lge Zeynel Kiliç Zeli̇ha Hayvali Tuncer Hökelek Serap Safran. Volume 121 ...

  6. Synthesis of Novel Bisindolylmethane Schiff bases and Their Antibacterial Activity

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    Syahrul Imran

    2014-08-01

    Full Text Available In an effort to develop new antibacterial drugs, some novel bisindolylmethane derivatives containing Schiff base moieties were prepared and screened for their antibacterial activity. The synthesis of the bisindolylmethane Schiff base derivatives 3–26 was carried out in three steps. First, the nitro group of 3,3'-((4-nitrophenyl-methylenebis(1H-indole (1 was reduced to give the amino substituted bisindolylmethane 2 without affecting the unsaturation of the bisindolylmethane moiety using nickel boride in situ generated. Reduction of compound 1 using various catalysts showed that combination of sodium borohydride and nickel acetate provides the highest yield for compound 2. Bisindolylmethane Schiff base derivatives were synthesized by coupling various benzaldehydes with amino substituted bisindolylmethane 2. All synthesized compounds were characterized by various spectroscopic methods. The bisindolylmethane Schiff base derivatives were evaluated against selected Gram-positive and Gram-negative bacterial strains. Derivatives having halogen and nitro substituent display weak to moderate antibacterial activity against Salmonella typhi, S. paratyphi A and S. paratyphi B.

  7. Synthesis, Characterization and Biological Activities of Cu(II, Co(II, Mn(II, Fe(II, and UO2(VI Complexes with a New Schiff Base Hydrazone: O-Hydroxyacetophenone-7-chloro-4-quinoline Hydrazone

    Directory of Open Access Journals (Sweden)

    Nora H. Al-Shaalan

    2011-10-01

    Full Text Available The Schiff base hydrazone ligand HL was prepared by the condensation reaction of 7-chloro-4-quinoline with o-hydroxyacetophenone. The ligand behaves either as monobasic bidentate or dibasic tridentate and contain ONN coordination sites. This was accounted for be the presence in the ligand of a phenolic azomethine and imine groups. It reacts with Cu(II, Ni(II, Co(II, Mn(II, UO2 (VI and Fe(II to form either mono- or binuclear complexes. The ligand and its metal complexes were characterized by elemental analyses, IR, NMR, Mass, and UV-Visible spectra. The magnetic moments and electrical conductance of the complexes were also determined. The Co(II, Ni(II and UO2 (VI complexes are mononuclear and coordinated to NO sites of two ligand molecules. The Cu(II complex has a square-planar geometry distorted towards tetrahedral, the Ni(II complex is octahedral while the UO2 (VI complex has its favoured heptacoordination. The Co(II, Mn(II complexes and also other Ni(II and Fe(III complexes, which were obtained in the presence of Li(OH as deprotonating agent, are binuclear and coordinated via the NNNO sites of two ligand molecules. All the binuclear complexes have octahedral geometries and their magnetic moments are quite low compared to the calculated value for two metal ions complexes and thus antiferromagnetic interactions between the two adjacent metal ions. The ligand HL and metal complexes were tested against a strain of Gram +ve bacteria (Staphylococcus aureus, Gram −ve bacteria (Escherichia coli, and fungi (Candida albicans. The tested compounds exhibited high antibacterial activities.

  8. Synthesis, characterization, thermal study and biological evaluation of Cu(II), Co(II), Ni(II) and Zn(II) complexes of Schiff base ligand containing thiazole moiety

    Science.gov (United States)

    Nagesh, G. Y.; Mahendra Raj, K.; Mruthyunjayaswamy, B. H. M.

    2015-01-01

    The novel Schiff base ligand 2-(4-(dimethylamino)benzylidene)-N-(4-phenylthiazol-2-yl)hydrazinecarboxamide (L) obtained by the condensation of N-(4-phenylthiazol-2-yl)hydrazinecarboxamide with 4-dimethylaminobenzaldehyde and its newly synthesized Cu(II), Co(II), Ni(II) and Zn(II) complexes have been characterized by microanalysis, magnetic susceptibility, molar conductance, thermal analysis, FT-IR, 1H NMR, ESI mass, UV-Visible, ESR spectroscopy and powder X-ray diffraction data. The newly synthesized ligand behaves as a bidentate ON donor. The IR results confirmed the bidentate binding of the ligand involving oxygen atom of amide carbonyl and azomethine nitrogen. 1H NMR spectral data of the ligand (L) and its Zn(II) complex agreed well with the proposed structures. In order to evaluate the effect of antimicrobial activity of metal ions upon chelation, the newly synthesized ligand and its metal complexes were screened for their antibacterial and antifungal activities by minimum inhibitory concentration (MIC) method. The DNA cleavage activities were studied using plasmid DNA pBR322 as a target molecule by agarose gel electrophoresis method. The brine shrimp bioassay was also carried out to study the in vitro cytotoxicity properties of all the compounds against Artemia salina. Furthermore, the antioxidant activity of the ligand (L) and its metal complexes were determined in vitro by reduction of 1,1-diphenyl-2-picryl hydrazyl (DPPH), the ligand exhibited potent in vitro - antioxidant activity than its metal complexes.

  9. Acute Toxicity and Gastroprotective Effect of the Schiff Base Ligand 1H-Indole-3-ethylene-5-nitrosalicylaldimine and Its Nickel (II Complex on Ethanol Induced Gastric Lesions in Rats

    Directory of Open Access Journals (Sweden)

    Pouya Hassandarvish

    2012-10-01

    Full Text Available The present study was performed to evaluate the gastroprotective activity of Schiff base ligand derived from the condensation reaction of tryptamine (an indole derivative and 5-nitrosalicylaldehyde (TNS and its nickel (II complex against ethanol-induced gastric ulcer in rats. The compounds were orally administered with low (30 mg/kg and high (60 mg/kg doses to ulcer-induced Sprague-Dawley rats. Macroscopically, the ulcer control group exhibited severe mucosal injury, whereas pre-treatment with either cimetidine or TNS and its nickel (II complex each resulted in significant protection against gastric mucosal injury. Flattening of gastric mucosal folds was also observed in rats pretreated with TNS and its nickel complex. Histological studies of the gastric wall of ulcer control group revealed severe damage of gastric mucosa, along with edema and leucocytes infiltration of the submucosal layer compared to rats pre-treated with either cimetidine or TNS and its nickel (II compound, where there was marked gastric protection along with reduction of edema and leucocytes infiltration of the submucosal layer. Acute toxicity study done on mice with a higher dose of 5 g/kg of TNS and its nickel (II complex did not manifest any toxicological signs. Research finding suggest that TNS and its nickel (II complex could be considered as effective gastroprotective compounds.

  10. Synthesis, spectroscopic, thermal and molecular modeling studies of Zn2+, Cd2+ and UO22+ complexes of Schiff bases containing triazole moiety. Antimicrobial, anticancer, antioxidant and DNA binding studies.

    Science.gov (United States)

    Gaber, Mohamed; El-Ghamry, Hoda A; Fathalla, Shaimaa K; Mansour, Mohammed A

    2018-02-01

    A novel series of Zn2+, Cd2+ and UO22+ complexes of ligands namely 1-[(5-mercapto-1H-1,2,4-triazole-3-ylimino) methyl]naphthalene-2-ol (HL1) and [(1H-1,2,4-triazole-3-ylimino) methyl] naphthalene-2-ol (HL2) have been prepared and characterized by different analytical and spectral techniques. The stoichiometry, stereochemistry, conductivity measurements and mode of bonding of the complexes have been elucidated. Accurate comparison of the IR spectra of the ligands with their metal chelates proved the involvement of nitrogen atoms of the azomethine group and/or triazole ring in chelation in addition to the deprotonated hydroxyl oxygen. The UV-Vis and molar conductance data supported the octahedral geometry for the metal complexes. TGA technique has been used to study the thermal decomposition way of the metal complexes and the thermo kinetic parameters were estimated. Valuable information is obtained from calculations of molecular parameters using the molecular modeling techniques. The interaction between the metal complexes and CT-DNA has been studied from which the binding constants (kb) were calculated. The Schiff bases and their metal chelates have shown potent antimicrobial, antioxidant and antitumor activities. The antitumor activities of the compounds have been tested in vitro against HEPG2 cell line and in silico by the molecular docking analysis with the VEGFR-2 receptor responsible for angiogenesis. Copyright © 2017 Elsevier B.V. All rights reserved.

  11. Schiff base-Poloxamer P85 combination demonstrates chemotherapeutic effect on prostate cancer cells in vitro.

    Science.gov (United States)

    Demirci, Selami; Doğan, Ayşegül; Türkmen, Neşe Başak; Telci, Dilek; Rizvanov, Albert A; Şahin, Fikrettin

    2017-02-01

    Prostate cancer is a multistep and complicated cancer type that is regulated by androgens at the cellular level and remains the second commonest cause of death among men. Discovery and development of novel chemotherapeutic agents enabling rapid tumor cell death with minimal toxic effects to healthy tissues might greatly improve the safety of chemotherapy. The present study evaluates the anti-cancer activity of a novel heterodinuclear copper(II)Mn(II) complex (Schiff base) in combination with poly(ethylene oxide) and poly(propylene oxide) block copolymer (Pluronic) P85. We used assays for cell proliferation, apoptosis, cell migration and invasion, DNA binding and cleavage to elucidate the molecular mechanisms of action, in addition to the anti-inflammatory potency of the new combination. The combined treatment of Schiff base and P85 lead to a remarkable anti-cancer effect on prostate cancer cell lines. Cell proliferation was inhibited in Schiff base-P85 treatment. The activity of this formulation is on DNA binding and cleavage and prevents inflammation in in vitro conditions. This is the first study presenting the anti-cancer activity of the present Schiff base derivative and its combination with P85 to treat prostate cancer in vitro. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  12. Synthesis, spectroscopic characterization and in vitro antimicrobial studies of Schiff base ligand, H2L derived from glyoxalic acid and 1,8-diaminonaphthalene and its Co(II, Ni(II, Cu(II and Zn(II complexes

    Directory of Open Access Journals (Sweden)

    Saud I. Al-Resayes

    2016-05-01

    Full Text Available A novel Schiff base ligand, N,N′-bis (glyoxalicacidcarboxaldiimine-1,8-diaminonaphthalene [H2L] obtained by the condensation of glyoxalic acid and 1,8-diaminonaphthalene and its mononuclear complexes of type, [ML] [M = Co(II, Ni(II, Cu(II, Zn(II] have been synthesized and characterized on the basis of elemental analysis, molar conductance, magnetic susceptibility measurements and spectroscopic studies viz., FT-IR, EPR, 1H NMR, FAB-Mass, UV–vis and magnetic moment data. A square planar geometry has been assigned on the basis of UV–vis and magnetic susceptibility around Co(II, Ni(II and Cu(II ions while conductivity data showed non electrolytic nature of all the complexes. The synthesized ligand, H2L and its complexes have been tested against Streptococcus mutans, Staphylococcus pyogenes, MRSA (Gram positive bacteria, Pseudomonas aeruginosa, Salmonella typhimurium, Escherichia coli (Gram negative bacteria, Candida albicans, Candida krusei, Candida parapsilosis and Candida neroformans and results suggested that Cu(II complex has significant antimicrobial activity.

  13. Synthesis, spectral characterization and antimicrobial studies of nano-sized oxovanadium(IV) complexes with Schiff bases derived from 5-(phenyl/substituted phenyl)-2-hydrazino-1,3,4-thiadiazole and indoline-2,3-dione

    Science.gov (United States)

    Sahani, M. K.; Yadava, U.; Pandey, O. P.; Sengupta, S. K.

    A new class of oxovanadium(IV) complexes with Schiff bases derived by the condensation of 5-(phenyl/substituted phenyl)-2-hydrazino-1,3,4-thiadiazoles and indoline-2,3-dione have been prepared in ethanol in the presence of sodium acetate. Micro-analytical data, magnetic susceptibility, UV-Vis, IR, EPR and XRD spectral techniques were used to confirm the structures. Electronic absorption spectra of the complexes suggest a square-pyramidal geometry. The oxovanadium(IV) complexes have monoclinic crystal system and particle sizes were found to be in the range 18.0 nm to 24.0 nm (nano-size). In vitro antifungal activity of synthesized compounds was determined against fungi Aspergillus niger, Colletotrichum falcatum and Colletotrichum pallescence and in vitro antibacterial activity was determined by screening the compounds against Gram-negative (Escherichia coli and Salmonella typhi) and Gram-positive (Staphylococcus aureus and Bacillus subtilis) bacterial strains. The oxovanadium(IV) complexes have higher antimicrobial effect than free ligands.

  14. Synthesis, spectroscopic, molecular structure, antioxidant, antimicrobial and antitumor behavior of Mn(II), Co(II), Ni(II), Cu(II) and Zn(II) complexes of O2N type tridentate chromone-2-carboxaldehyde Schiff's base ligand

    Science.gov (United States)

    Ammar, Reda A.; Alaghaz, Abdel-Nasser M. A.; Zayed, Mohamed E.; Al-Bedair, Lamia A.

    2017-08-01

    Tridentate Schiff's base (HL) ligand was synthesized via condensation of salicylaldehyde and 3-hydroxypyridin-2-yliminomethyl-4H-chromen-4-one and their corresponding Mn(II), Co(II), Ni(II), Cu(II) and Zn(II) complexes have been synthesized. The isolated solid complexes were characterized by elemental analyses, molar conductance, spectral (IR, UV-Vis, 1H NMR), magnetic moment, EPR, and thermal measurements. The IR spectra showed that HL was coordinated to the metal ions in tridentate manner with O2N donor sites of the azomethine N, deprotonated phenolic-OH and carbonyl-O. The activation of thermodynamic parameters are calculated using Coast-Redfern and Horowitz-Metzger (HM). The octahedral geometry of the complexes is confirmed using DFT method from DMOL3 calculations, UV-Vis and magnetic moment measurements, ESR and ligand field parameters. Antioxidant activities have also been performed for all the compounds. The investigated ligand and metal complexes were screened for their in-vitro antimicrobial activities against different types of fungal and bacterial strains. The resulting data assert on the inspected compounds as a highly promising bactericides and fungicides. The antitumor activities of all inspected compounds were evaluated towards human liver Carcinoma (HepG2) cell line.

  15. DNA and HSA interaction of Vanadium (IV), Copper (II), and Zinc (II) complexes derived from an asymmetric bidentate Schiff-base ligand: multi spectroscopic, viscosity measurements, molecular docking, and ONIOM studies.

    Science.gov (United States)

    Dehkhodaei, Monireh; Sahihi, Mehdi; Amiri Rudbari, Hadi; Momenbeik, Fariborz

    2018-03-01

    The interaction of three complexes [Zn(II), Cu(II), and V(IV)] derived from an asymmetric bidentate Schiff-base ligand with DNA and HSA was studied using fluorescence quenching, UV-Vis spectroscopy, viscosity measurements, and computational methods [molecular docking and our Own N-layered Integrated molecular Orbital and molecular Mechanics (ONIOM)]. The obtained results revealed that the DNA and HSA affinities for binding of the synthesized compounds follow as V(IV) > Zn(II) > Cu(II) and Zn(II) > V(IV) > Cu(II), respectively. The distance between these compounds and HSA was obtained based on the Förster's theory of non-radiative energy transfer. Furthermore, computational molecular docking was carried out to investigate the DNA- and HSA-binding pose of the compounds. Molecular docking calculations showed that H-bond, hydrophobic, and π-cation interactions have dominant role in stability of the compound-HSA complexes. ONIOM method was utilized to investigate the HSA binding of the compounds more precisely in which molecular-mechanics method (UFF) and semi-empirical method (PM6) were selected for the low layer and the high layer, respectively. The results show that the structural parameters of the compounds changed along with binding, indicating the strong interaction between the compounds with HSA and DNA. Viscosity measurements as well as computational docking data suggest that all metal complexes interact with DNA, presumably by groove-binding mechanism.

  16. Design of cinnamaldehyde amino acid Schiff base compounds based on the quantitative structure–activity relationship

    Science.gov (United States)

    Hui Wang; Mingyue Jiang; Shujun Li; Chung-Yun Hse; Chunde Jin; Fangli Sun; Zhuo Li

    2017-01-01

    Cinnamaldehyde amino acid Schiff base (CAAS) is a new class of safe, bioactive compounds which could be developed as potential antifungal agents for fungal infections. To design new cinnamaldehyde amino acid Schiff base compounds with high bioactivity, the quantitative structure–activity relationships (QSARs) for CAAS compounds against Aspergillus niger (A. niger) and...

  17. Synthesis, structure and stability of a chiral imine-based Schiff-based ligand derived from L-glutamic acid and its [Cu4] complex

    Science.gov (United States)

    Muche, Simon; Levacheva, Irina; Samsonova, Olga; Biernasiuk, Anna; Malm, Anna; Lonsdale, Richard; Popiołek, Łukasz; Bakowsky, Udo; Hołyńska, Małgorzata

    2017-01-01

    Studies of the stability of a ligand derived from L-glutamic acid and ortho-vanillin and its new [Cu4] complex are presented. The [Cu4] complex contains a heterocubane [CuII4O4] core and pendant carboxylic groups increasing its solubility in water, also under basic conditions. The stability of the complex in different solvents is confirmed with ESI-MS studies and such experiments as successful recrystallization. The complex is stable also under physiological conditions whereas the ligand is partly decomposed to L-glutamic acid and ortho-vanillin.

  18. A selective naked-eye chemosensor derived from 2-methoxybenzylamine and 2,3-dihydroxybenzaldehyde - synthesis, spectral characterization and electrochemistry of its bis-bidentates Schiff bases metal complexes

    Science.gov (United States)

    Djouhra, Aggoun; Ali, Ourari; Ramiro, Ruiz-Rosas; Emilia, Morallon

    2017-09-01

    A new colorimetric receptor HL, acting as a bidentate Schiff base ligand, has been synthesized by condensation of 2-methoxybenzylamine on 2,3-dihydroxybenzaldehyde in a methanolic solution. Interestingly, this chelating agent can selectively detect Cu2 +, Co2 +, Fe2 + and Fe3 + ions with a simple and an easy-to-make, well defined naked-eye visible color changes in two different solvents like acetonitrile and methanol. This bidentate ligand coordinates three metal ions of Co(II), Cu(II) and Fe(II) via nitrogen and oxygen atoms. The molecular structures of the synthesized compounds were elucidated by various physicochemical properties such as the elemental analysis, FT-IR, HNMR, UV-Vis and the Mass spectrometry. The resulting general formulae [M(L)2·H2O] (M(II) = Cu, Fe, Co) are proposed as mononuclear complexes. The solvatochromism properties of these compounds were studied with their absorption spectra using different solvents as methanol (MeOH), acetonitrile (AN), tetrahydrofuran (THF), dimethylformamid (DMF), dimethylsulfoxid (DMSO) and dichloromethane (DC). The Electrochemical behavior of copper complex was explored in DMF solutions by cyclic voltammetry (CV) with two working electrodes: glassy carbon (GC) and platinum electrode (Pt). This study reveals that copper complex shows successively two redox systems as CuIII/II and CuII/I. The FeIII/II and CoII/I redox systems have also been studied in DMF and DMSO media.

  19. Primordial transport of sugars and amino acids via Schiff bases

    Science.gov (United States)

    Stillwell, William; Rau, Aruna

    1981-09-01

    Experimental support is given for a model concerning the origin of a primordial transport system. The model is based on the facilitated diffusion of amino acids stimulated by aliphatic aldehyde carriers and sugars stimulated by aliphatic amine carriers. The lipid-soluble diffusing species is the Schiff base. The possible role of this simple transport system in the origin of an early protocell is discussed.

  20. New platinum (II) and palladium (II) complexes of coumarin-thiazole Schiff base with a fluorescent chemosensor properties: Synthesis, spectroscopic characterization, X-ray structure determination, in vitro anticancer activity on various human carcinoma cell lines and computational studies.

    Science.gov (United States)

    Şahin, Ömer; Özdemir, Ümmühan Özmen; Seferoğlu, Nurgül; Genc, Zuhal Karagöz; Kaya, Kerem; Aydıner, Burcu; Tekin, Suat; Seferoğlu, Zeynel

    2018-01-01

    A new coumarin-thiazole based Schiff base (Ligand, L) and its Pd(II), Pt(II) complexes; ([Pd(L) 2 ] and [Pt(L) 2 ]), were synthesized and characterized using spectrophotometric techniques (NMR, IR, UV-vis, LC-MS), magnetic moment, and conductivity measurements. A single crystal X-ray analysis for only L was done. The crystals of L have monoclinic crystal system and P21/c space group. To gain insight into the structure of L and its complexes, we used density functional theory (DFT) method to optimize the molecules. The photophysical properties changes were observed after deprotonation of L with CN - via intermolecular charge transfer (ICT). Additionally, as the sensor is a colorimetric and fluorimetric cyanide probe containing active sites such as coumarin-thiazole and imine (CH=N), it showed fast color change from yellow to deep red in the visible region, and yellow fluorescence after CN - addition to the imine bond, in DMSO. The reaction mechanisms of L with CN - , F - and AcO - ions were evaluated using 1 H NMR shifts. The results showed that, the reaction of L with CN - ion was due to the deprotonation and addition mechanisms at the same time. The anti-cancer activity of L and its Pd(II) and Pt(II) complexes were evaluated in vitro using MTT assay on the human cancer lines MCF-7 (human breast adenocarcinoma), LS174T (human colon carcinoma), and LNCAP (human prostate adenocarcinoma). The anti-cancer effects of L and its complexes, on human cells, were determined by comparing the half maximal inhibitory concentration (IC 50 ) values. The activity results showed that, the Pd(II) complex of L has higher anti-tumor effect than L and its Pt(II) complex against the tested human breast adenocarcinoma (MCF-7), human prostate adenocarcinoma (LNCAP), and human colon carcinoma (LS174T) cell lines. Copyright © 2017 Elsevier B.V. All rights reserved.

  1. Isoskeletal Schiff base polynuclear coordination clusters: synthetic and theoretical aspects

    OpenAIRE

    Griffiths, Kieran; Dokorou, Vassiliki N; Spencer, John; Abdul-Sada, Alaa; Vargas, Alfredo; Kostakis, George E.

    2016-01-01

    This work addresses and enlightens synthetic aspects derived from our effort to systematically construct isoskeletal tetranuclear coordination clusters (CCs) of the general formula [TR2Ln2(LX)4(NO3)2(solv)2] possessing a specific defected dicubane topology, utilizing various substituted Schiff base organic ligands (H2LX) and NiII/CoII and Dy(OTf)3 salts. Our synthetic work is further supported by DFT studies.

  2. Synthesis, spectroscopic, thermal and antimicrobial studies of some novel metal complexes of Schiff base derived from [ N1-(4-methoxy-1,2,5-thiadiazol-3-yl)sulfanilamide] and 2-thiophene carboxaldehyde

    Science.gov (United States)

    Sharaby, Carmen M.

    2007-04-01

    Keeping in view the chemotherapeutic of the sulfa-drugs, Schiff base namely 2-thiophene carboxaldehyde-sulfametrole (HL) and its tri-positive and di-positive metal complexes have been synthesized and characterized by elemental analyses, IR, 1H NMR, solid reflectance, magnetic moment, molar conductance, mass spectra, UV-vis and thermal analysis (TGA and DrTG). The low molar conductance values suggest the non-electrolytic nature of these complexes. IR spectra show that HL is coordinated to the metal ions in a tetradentate manner through hetero five-membered ring-S and azomethine-N, enolic sulfonamide-OH and thiadiazole-N, respectively. Zn(II), Cd(II) and UO 2(II) complexes are found to be diamagnetic (as expected). The proposed general formulae of the prepared complexes are [M 2X 4(HL)(H 2O) 4] (where M = Mn(II), Co(II), Ni(II), Cu(II), Zn(II) and Cd(II), X = Cl, [Fe 2Cl 6(HL)(H 2O) 2], [(FeSO 4) 2(HL)(H 2O) 4] and [(UO 2) 2(HL) (NO 3) 4]·H 2O. The thermal behaviour of these chelates shows that the hydrated complexes loss water of hydration in first step in case of uranium complexes followed loss coordinated water followed immediately by decomposition of the anions and ligand molecules in the subsequent steps. The activation thermodynamic parameters, such as Δ E*, Δ H*, Δ S*, and Δ G* are calculated from the DrTG curves using Coats-Redfern method. The antimicrobial activity of the obtained products was performed using Chloramphenicol and Grisofluvine as standards, indicate that in some cases metallation increase activity than the ligand.

  3. Three Co(II) complexes with a sexidentate N2O4-donor bis-Schiff base ligand: Synthesis, crystal structures, DFT studies, urease inhibition and molecular docking studies

    Science.gov (United States)

    Wang, Hu; Zhang, Xia; Zhao, Yu; Zhang, Dongmei; Jin, Fan; Fan, Yuhua

    2017-11-01

    Three new N2O4-donor bis-Schiff base Co(II) complexes, Co(C36H34N2O8)·2CH3OH (1), Co(C28H34N2O8S2)·H2O (2) and Co(C40H36N4O8)·3CH3OH (3) with distorted octahedral six-coordinate Co(II) centers were synthesized and determined by single crystal X-ray analysis. The X-ray crystallography shows that the metal atoms of three complexes are all six-coordinate with two nitrogen atoms from Cdbnd N groups, two oxygen atoms from ether groups and two carboxylic oxygen atoms in the mono-ligand, forming a distorted octahedral geometry. Theoretical studies of the three complexes were carried out by density functional theory (DFT) Becke's three-parameter hybrid (B3LYP) method employing the 6-31G basis set. The DFT studies indicate that the calculation is in accordance with the experimental results. Moreover, inhibition of jack bean urease by Co(II) complexes 1-3 have also been investigated. At the same time, a docking analysis using a DOCK program was conducted to determine the probable binding mode by inserting the complexes into the active site of jack bean urease. The experimental values and docking simulation exhibited that the complex 3 showed strong inhibitory activity (IC50 = 16.43 ± 2.35 μM) and the structure-activity relationships were further discussed.

  4. Schiff bases as corrosion inhibitor for aluminium in HCl solution

    Energy Technology Data Exchange (ETDEWEB)

    Safak, Serpil [Eskisehir Osmangazi University, Faculty of Science and Letters, Department of Chemistry, 26480 Eskisehir (Turkey); Duran, Berrin, E-mail: bduran@ogu.edu.tr [Eskisehir Osmangazi University, Faculty of Science and Letters, Department of Chemistry, 26480 Eskisehir (Turkey); Yurt, Aysel [Eskisehir Osmangazi University, Faculty of Science and Letters, Department of Chemistry, 26480 Eskisehir (Turkey); Tuerkoglu, Guelsen [Anadolu University, Faculty of Science, Department of Chemistry, 26470 Eskisehir (Turkey)

    2012-01-15

    Highlights: Black-Right-Pointing-Pointer Three Schiff bases have been tested as possible corrosion inhibitors for aluminium. Black-Right-Pointing-Pointer Corrosion tests have been performed via EIS and Tafel polarisation methods. Black-Right-Pointing-Pointer Experimental inhibition efficiencies were correlated with quantum chemical parameters. - Abstract: Three Schiff bases named 1,5-bis[2-(2-hydroxybenzylideneamino)phenoxy]-3-oxopentane (D1), 1,5-bis[2-(5-chloro-2-hydroxybenzylideneamino)phenoxy]-3-oxopentane (D2) and 1,5-bis[2-(5-bromo-2-hydroxybenzylideneamino)phenoxy]-3-oxopentane (D3) were synthesized and their inhibitive capabilities on the aluminium corrosion in 0.1 M HCl were investigated by means of electrochemical impedance spectroscopy, Tafel polarisation and scanning electron microscopy techniques. Results showed that, compounds under study exhibit inhibitor properties and adsorption of these compounds was found to accord with Temkin adsorption isotherm. Polarisation curves indicated that the studied Schiff bases were cathodic inhibitor and the effectiveness of these inhibitors decreased in the order of D3 > D2 > D1. Quantum chemical calculations were performed to provide further insight into the inhibition efficiencies determined experimentally.

  5. Asymmetric synthesis of α-amino acids via homologation of Ni(II) complexes of glycine Schiff bases. Part 3: Michael addition reactions and miscellaneous transformations.

    Science.gov (United States)

    Aceña, José Luis; Sorochinsky, Alexander E; Soloshonok, Vadim

    2014-09-01

    The major goal of this review is a critical discussion of the literature data on asymmetric synthesis of α-amino acids via Michael addition reactions involving Ni(II)-complexes of amino acids. The material covered is divided into two conceptually different groups dealing with applications of: (a) Ni(II)-complexes of glycine as C-nucleophiles and (b) Ni(II)-complexes of dehydroalanine as Michael acceptors. The first group is significantly larger and consequently subdivided into four chapters based on the source of stereocontrolling element. Thus, a chiral auxiliary can be used as a part of nucleophilic glycine Ni(II) complex, Michael acceptor or both, leading to the conditions of matching vs. mismatching stereochemical preferences. The particular focus of the review is made on the practical aspects of the methodology under discussion and mechanistic considerations.

  6. pKa of the protonated Schiff base of bovine rhodopsin. A study with artificial pigments.

    OpenAIRE

    Steinberg, G; Ottolenghi, M; Sheves, M

    1993-01-01

    Artificial bovine rhodopsin pigments derived from synthetic retinal analogues carrying electron-withdrawing substituents (fluorine and chlorine) were prepared. The effects of the electron withdrawing substituents on the pKa values of the pigments and on the corresponding Schiff bases in solution were analyzed. The data suggest that the apparent pKa of the protonated Schiff base is above 16. However, the alternative possibility that the retinal Schiff base linkage in bovine rhodopsin is not ac...

  7. The pKa of the protonated Schiff bases of gecko cone and octopus visual pigments.

    OpenAIRE

    Liang, J; Steinberg, G; Livnah, N; Sheves, M; Ebrey, T G; Tsuda, M

    1994-01-01

    A visual pigment is composed of retinal bound to its apoprotein by a protonated Schiff base linkage. Light isomerizes the chromophore and eventually causes the deprotonation of this Schiff base linkage at the meta II stage of the bleaching cycle. The meta II intermediate of the visual pigment is the active form of the pigment that binds to and activates the G protein transducin, starting the visual cascade. The deprotonation of the Schiff base is mandatory for the formation of meta II interme...

  8. Synthesis, crystal structures, magnetic properties and catecholase activity of double phenoxido-bridged penta-coordinated dinuclear nickel(II) complexes derived from reduced Schiff-base ligands: mechanistic inference of catecholase activity.

    Science.gov (United States)

    Biswas, Apurba; Das, Lakshmi Kanta; Drew, Michael G B; Aromí, Guillem; Gamez, Patrick; Ghosh, Ashutosh

    2012-08-06

    Three double phenoxido-bridged dinuclear nickel(II) complexes, namely [Ni(2)(L(1))(2)(NCS)(2)] (1), [Ni(2)(L(2))(2)(NCS)(2)] (2), and [Ni(2)(L(3))(2)(NCS)(2)] (3) have been synthesized using the reduced tridentate Schiff-base ligands 2-[1-(3-methylamino-propylamino)-ethyl]-phenol (HL(1)), 2-[1-(2-dimethylamino-ethylamino)-ethyl]-phenol (HL(2)), and 2-[1-(3-dimethylamino-propylamino)-ethyl]-phenol (HL(3)), respectively. The coordination compounds have been characterized by X-ray structural analyses, magnetic-susceptibility measurements, and various spectroscopic methods. In all complexes, the nickel(II) ions are penta-coordinated in a square-pyramidal environment, which is severely distorted in the case of 1 (Addison parameter τ = 0.47) and 3 (τ = 0.29), while it is almost perfect for 2 (τ = 0.03). This arrangement leads to relatively strong antiferromagnetic interactions between the Ni(II) (S = 1) metal centers as mediated by double phenoxido bridges (with J values of -23.32 (1), -35.45 (2), and -34.02 (3) cm(3) K mol(-1), in the convention H = -2JS(1)S(2)). The catalytic activity of these Ni compounds has been investigated for the aerial oxidation of 3,5-di-tert-butylcatechol. Kinetic data analysis following Michaelis-Menten treatment reveals that the catecholase activity of the complexes is influenced by the flexibility of the ligand and also by the geometry around the metal ion. Electrospray ionization mass spectroscopy (ESI-MS) studies (in the positive mode) have been performed for all the coordination compounds in the presence of 3,5-DTBC to characterize potential complex-substrate intermediates. The mass-spectrometry data, corroborated by electron paramagnetic resonance (EPR) measurements, suggest that the metal centers are involved in the catecholase activity exhibited by the complexes.

  9. Different conjugated system Zn(ii) Schiff base complexes: supramolecular structure, luminescent properties, and applications in the PMMA-doped hybrid materials.

    Science.gov (United States)

    Dong, Yu-Wei; Fan, Rui-Qing; Chen, Wei; Zhang, Hui-Jie; Song, Yang; Du, Xi; Wang, Ping; Wei, Li-Guo; Yang, Yu-Lin

    2017-01-24

    A series of Zn(ii) complexes with different conjugated systems, [ZnL1Cl2]2 (Zn1), [ZnL2Cl2] (Zn2), [Zn(L3)2]·(ClO4)2 (Zn3), [Zn2L4Cl4] (Zn4), and [ZnL5Cl2] (Zn5), were synthesized and subsequently characterized via single crystal X-ray diffraction, (1)H and (13)C NMR, FT-IR, elemental analyses, melting point, and PXRD. The X-ray diffraction analyses revealed that the supramolecular frameworks of complexes Zn1-Zn5 are constructed by C-HO/Cl hydrogen bonds and ππ interactions. Complexes Zn1-Zn3 feature 3D 6-connected {4(12)·6(3)} topological structures, whereas complex Zn4 exhibits a 3D 7-connected supramolecular framework with a {4(17)·6(4)} topological structure. However, complex Zn5 shows one-dimensional "wave-like" chains. Based on these varied structures, the emission maximum wavelengths of complexes Zn1-Zn5 can be tuned in a wide range of 461-592 nm due to the red shift direction of λem caused by different conjugated systems and their electron donating abilities. Complex Zn3 shows a strong luminescence in the solid state and in the acetonitrile solution. Therefore, a series of Zn3-poly(methylmethacrylate) (Zn3-PMMA) hybrid materials were obtained by controlling the concentration of complex Zn3 in poly(methylmethacrylate) (PMMA). At an optimal concentration of 4%, the doped polymer film of Zn3-PMMA displays strong green luminescence emissions that are 19-fold in the luminescence intensities and 98 °C higher in the thermal stability temperature compared to the Zn3 film.

  10. Synthesis of palladium(II) complex with NNS donor Schiff base ligand via Csbnd S bond cleavage: X-ray structure, electrochemistry and DFT computation

    Science.gov (United States)

    Biswas, Sujan; Roy, Puspendu; Mondal, Tapan Kumar

    2017-08-01

    Reaction of ligand, L-Ch2Ph with Na2PdCl4 in acetonitrile yielded palladium(II) complex, [Pd(L)Cl] via Csbnd S bond cleavage. It is characterized by several spectroscopic techniques and the structure is confirmed by single crystal X-ray study. The complex exhibits quasi-reversible oxidation couple at 0.86 V corresponds to ligand based thiophenolato to thiyl radical oxidation. Electronic structure, solution spectrum and redox properties are interpreted by DFT and TDDFT calculations.

  11. Photostabilizing Efficiency of PVC in the Presence of Schiff Bases as Photostabilizers

    Directory of Open Access Journals (Sweden)

    Emad Yousif

    2015-11-01

    Full Text Available The photostabilization of polyvinyl chloride (PVC films by Schiff bases was investigated. Polyvinyl chloride films containing 0.5 wt % Schiff bases were produced using the same casting method as that used for additive-free PVC films from tetrahydrofuran (THF solvent. The photostabilization activities of these compounds were determined by monitoring the carbonyl, polyene and hydroxyl indices with irradiation time. The changes in viscosity average molecular weight of PVC with irradiation time were also monitored using THF as a solvent. The quantum yield of chain scission (Φcs for the studied complexes in PVC was estimated to range between 4.72 and 8.99 × 10−8. According to the experimental results, several mechanisms were suggested, depending on the structure of the additive. Ultra violet (UV absorption, peroxide decomposition and radical scavenging were suggested as the photostabilizing mechanisms.

  12. A novel schiff base zinc coordination compound inhibits proliferation and induces apoptosis of human osteosarcoma cells.

    Science.gov (United States)

    Yan, Ming; Pang, Li; Ma, Tan-tan; Zhao, Cheng-liang; Zhang, Nan; Yu, Bing-xin; Xia, Yan

    2015-10-01

    Various kinds of schiff base metal complexes have been proven to induce apoptosis of tumor cells. However, it remains largely unknown whether schiff base zinc complexes induce apoptosis in human cancer cells. Here, we synthesized a novel schiff base zinc coordination compound (SBZCC) and investigated its effects on the growth, proliferation and apoptosis of human osteosarcoma MG-63 cells. A novel SBZCC was synthesized by chemical processes and used to treat MG-63 cells. The cell viability was determined by CCK-8 assay. The cell cycle progression, mitochondrial membrane potential and apoptotic cells were analyzed by flow cytometry. The apoptosis-related proteins levels were determined by immunoblotting. Treatment of MG-63 cells with SBZCC resulted in inhibition of cell proliferation and cell cycle arrest at G1 phase. Moreover, SBZCC significantly reduced the mitochondrial membrane potential and induced apoptosis, accompanied with increased Bax/Bcl-2 and FlasL/Fas expression as well as caspase-3/8/9 cleavage. Our results demonstrated that the synthesized novel SBZCC could inhibit the proliferation and induce apoptosis of MG-63 cells via activating both the mitochondrial and cell death receptor apoptosis pathways, suggesting that SBZCC is a promising agent for the development as anticancer drugs.

  13. Sulfadiazine Salicylaldehyde-Based Schiff Bases: Synthesis, Antimicrobial Activity and Cytotoxicity

    National Research Council Canada - National Science Library

    Martin Kratký; Magdalena Dzurkova; Jiří Janoušek; Klara Konečna; František Trejtnar; Jiřina Stolaříkova; Jarmila Vinšova

    2017-01-01

    The resistance among microbes has brought an urgent need for new drugs. Thus, we synthesized a series of Schiff bases derived from the sulfa drug sulfadiazine and various salicylaldehydes. The resulting 4...

  14. Synthesis of cytotoxic and antioxidant Schiff's base analogs of aloin.

    Science.gov (United States)

    Kumar, S; Matharasi, D Priya; Gopi, Sreeraj; Sivakumar, S; Narasimhan, S

    2010-05-01

    Aloin (10-glucopyranosyl-1,8-dihydroxy-3-hydroxymethyl-9(10H)-anthracenone), a bioactive compound in Aloe vera, although known to have an anticancer effect, has not been used in current drug research. Optimization of the lead structure could enhance the utility of this compound. Hence, aloin was modified using natural amino acids to produce Schiff's base, a potential pharmacophore, and its corresponding aglycones. The synthetic derivatives exhibited significant enhancement in their efficacy toward antioxidant (DPPH radical scavenging) and cytotoxic activities than those of the parent compound, aloin showing promise for application in cancer treatment.

  15. Synthesis, Characterization and Use of Schiff Bases as Fluorimetric Analytical Reagents (Part II

    Directory of Open Access Journals (Sweden)

    Mohamed N. Ibrahim

    2011-01-01

    Full Text Available Many Schiff bases were prepared by condensation reaction of certain aromatic amines with aromatic aldehydes derivatives and then the fluorescence properties of these Schiff bases were examined in acidic and basic media. It is shown that these compounds can be used for fluorimetric monitoring of small pH changes.

  16. (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.

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

    Science.gov (United States)

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

    2014-09-01

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

  18. Subtle Structural Changes in (Cu(II)L)2Mn(II) Complexes To Induce Heterometallic Cooperative Catalytic Oxidase Activities on Phenolic Substrates (H2L = Salen Type Unsymmetrical Schiff Base).

    Science.gov (United States)

    Mahapatra, Prithwish; Ghosh, Soumavo; Giri, Sanjib; Rane, Vinayak; Kadam, Ramakant; Drew, Michael G B; Ghosh, Ashutosh

    2017-05-01

    A new Cu(II) complex of an asymmetrically dicondensed Schiff base (H2L = N-(2-hydroxyacetophenylidene)-N'-salicylidene-1,3-propanediamine) derived from 1,3-propanediamine, salicylaldehyde, and o-hydroxyacetophenone has been synthesized. Using this complex, [CuL] (1), as a metalloligand, two new trinuclear Cu-Mn complexes, [(CuL)2Mn(N3)(H2O)](ClO4)·H2O (2) and [(CuL)2Mn(NCS)2] (3), have been prepared. Single-crystal structural analyses reveal that complexes 2 and 3 both have the same bent trinuclear {(CuL)2Mn}(2+) structural unit in which two terminal bidentate square-planar (CuL) units are chelated to the central octahedral Mn(II) ion. This structural similarity is also evident from the variable-temperature magnetic susceptibility measurements, which suggest that compounds 2 and 3 are both antiferromagnetically coupled with comparable exchange coupling constants (-21.8 and -22.3 cm(-1), respectively). The only difference between 2 and 3 lies in the coordination around the central Mn(II) ion; in 3, two SCN(-) groups are coordinated to the Mn(II), leaving a neutral complex, but in 2, one N3(-) group and one H2O molecule are coordinated to give a positively charged species. The presence of such a labile H2O coligand makes 2 catalytically active in mimicking two well-known polynuclear copper proteins, catecholase and phenoxazinone synthase. The turnover numbers (kcat) for the aerial oxidation of 3,5-di-tert-butylcatechol and o-aminophenol are 1118 and 6581 h(-1), respectively, values which reflect the facility of the heterometallic catalyst in terms of both efficiency and catalytic promiscuity for aerial dioxygen activation. The mechanisms of these biomimetic oxidase reactions are proposed for the first time involving any heterometallic catalyst on the basis of mass spectral analysis, EPR spectroscopy, and cyclic voltammetry. The evidence of the intermediates indicates possible heterometallic cooperative activity where the substrates bind to a Mn(II) center and Cu

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

    Science.gov (United States)

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

    2013-04-01

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

  20. Spectroscopic and structural studies of the Schiff base 3-methoxy-N-salicylidene-o-amino phenol complexes with some transition metal ions and their antibacterial, antifungal activities

    Science.gov (United States)

    Abo-Aly, M. M.; Salem, A. M.; Sayed, M. A.; Abdel Aziz, A. A.

    2015-02-01

    Spectroscopic (IR, Raman, NMR, UV-visible, and ESR), and structural studies of the ligand 3-methoxy-N-salicylidene-o-amino phenol (H2L) and its synthesized complexes with some transition metal ions (Mn(II), Co(II), Ni(II)), Cu(II) and Zn(II)) were recorded and analyzed. The magnetic properties and thermal gravimetric analysis (TGA and DTA) were also measured for the complexes. The metal complexes were found to have The structural formula MLṡH2O and the metal ions Mn(II), Co(II), Ni(II)) and Zn(II) were found to form tetrahedral complexes with the ligand whereas Cu(II) formed a square planar one. Antimicrobial activity of the ligand and its complexes were also investigated and discussed.

  1. Copper (II), cobalt (II), nickel (II) and zinc (II) complexes of Schiff ...

    Indian Academy of Sciences (India)

    Abstract. New Schiff base chelates of Cu(II), Co(II), Ni(II) and Zn(II) derived from benzil-2,4-dinitrophenylhydrazone with aniline have been synthesised. Microanalytical data, molar conductance, and magnetic susceptibility values have been obtained, and IR, 1H NMR, 13C NMR, UV-Vis, CV and EPR spectral studies have ...

  2. Electrochemical studies of DNA interaction and antimicrobial activities of MnII, FeIII, CoII and NiII Schiff base tetraazamacrocyclic complexes

    Science.gov (United States)

    Kumar, Anuj; Vashistha, Vinod Kumar; Tevatia, Prashant; Singh, Randhir

    2017-04-01

    Tetraazamacrocyclic complexes of MnII, FeIII, CoII and NiII have been synthesized by template method. These tetraazamacrocycles have been analyzed with various techniques like molar conductance, IR, UV-vis, mass spectral and cyclic voltammetric studies. On the basis of all these studies, octahedral geometry has been assigned to these tetraazamacrocyclic complexes. The DNA binding properties of these macrocyclic complexes have been investigated by electronic absorption spectra, fluorescence spectra, cyclic voltammetric and differential pulse voltammetric studies. The cyclic voltammetric data showed that ipc and ipa were effectively decreased in the presence of calf thymus DNA, which is a strong evidence for the interaction of these macrocyclic complexes with the calf thymus DNA (ct-DNA). The heterogeneous electron transfer rate constant found in the order: KCoII > KNiII > KMnII which indicates that CoII macrocyclic complex has formed a strong intercalated intermediate. The Stern-Volmer quenching constant (KSV) and voltammetric binding constant were found in the order KSV(CoII) > KSV(NiII) > KSV(MnII) and K+(CoII) > K+(NiII) > K+(MnII) which shows that CoII macrocyclic complex exhibits the high interaction affinity towards ct-DNA by the intercalation binding. Biological studies of the macrocyclic complexes compared with the standard drug like Gentamycin, have shown antibacterial activities against E. coli, P. aeruginosa, B. cereus, S. aureus and antifungal activity against C. albicans.

  3. Synthesis, Spectral Characterization, DNA/ Protein Binding, DNA Cleavage, Cytotoxicity, Antioxidative and Molecular Docking Studies of Cu(II)Complexes Containing Schiff Base-bpy/Phen Ligands.

    Science.gov (United States)

    Anupama, Berelli; Aruna, Airva; Manga, Vijjulatha; Sivan, Sreekanth; Sagar, Madamsetty Vijay; Chandrashekar, Ravula

    2017-05-01

    Ternary Cu(II) complexes [Cu(II)(L)(bpy)Cl] 1, [Cu(II)(L)(Phen)Cl] 2 [L = 2,3-dimethyl-1-phenyl-4(2 hydroxy-5-methyl benzylideneamino)-pyrazol-5-one, bpy = 2,2' bipyridine, phen =1,10 phenanthroline) were synthesized and characterized by elemental analyses, UV-Visible, FT-IR, ESR, Mass, thermogravimetric and SEM EDAX techniques. The complexes exhibit octahedral geometry. The interaction of the Cu(II) with cailf thymus DNA (CT-DNA) was explored by using absorption and fluorescence spectroscopic methods. The results revealed that the complexes have an affinity constant for DNA in the order of 104 M-1 and mode of interaction is intercalative mode. The DNA cleavage study showed that the complexes cleaved DNA without any external agent. The interaction of Cu(II) complexes with bovine serum albumin (BSA) was also studied using absorption and fluorescence techniques. The cytotoxic activity of the Cu(II) complexes was probed in HeLa (human breast adenocarcinoma cell line), B16F10 (Murine melanoma cell line) and HEPA1-6 celllines, complex 1 has good cytotoxic activity which is comparable with the doxarubicin drug, with IC50 values ranging from 3 to 12.6 μM. A further molecular docking technique was employed to understand the binding of the complexes towards the molecular target DNA. Investigation of the antioxidative properties showed that the metal complexes have significant radical scavenging activity potency against DPPH radical.

  4. Synthesis, spectral characterization, electrochemical, anti-microbial, DNA binding and cleavage studies of new binuclear Schiff base metal(II complexes derived from o-hydroxyacetophenone

    Directory of Open Access Journals (Sweden)

    P. Jayaseelan

    2016-11-01

    Full Text Available A new tetradentate binucleating ligand [H2L] has been synthesized by condensation between 3, 3′-diaminobenzidine and o-hydroxyacetophenone in the molar ratio 1:4. The reaction of the ligand with metal chelation leads to bimolecular complexes of the general formula [M2(L]. The ligand and metal complexes have been characterized by elemental analysis, UV, IR,…1H NMR, 13C NMR, conductivity measurements and magnetic studies. In conductivity experiments, all metal chelates showed to be non-electrolytic in nature. The bonding sites are the nitrogen atoms of the azomethine and the oxygen atoms of the phenolic groups. The anti-microbial activities were screened against one Gram-positive bacterium (Streptococcus pyogenes and one Gram-negative bacterium (Klebsella pneumoniae. The anti-fungal activity was screened against Asperigillus flavus. All complexes showed significant anti-bacterial and anti-fungal activities. The DNA binding studies were performed by electronic spectroscopy, cyclic voltammetry studies and viscosity measurements. The cleavage studies of these complexes are investigated by gel electrophoresis method in the presence of peroxide. All complexes cleaved efficiently and the complex interacts with DNA through an intercalating way.

  5. Ligational behavior of Schiff bases towards transition metal ion and metalation effect on their antibacterial activity

    Science.gov (United States)

    Devi, Jai; Batra, Nisha; Malhotra, Rajesh

    2012-11-01

    New Schiff bases pyrazine-2-carboxylicacid (phenyl-pyridin-2-yl-methylene)-hydrazide (Hpch-bp) HL1 and pyrazine-2-carboxylicacid (pyridin-2-ylmethylene)-hydrazide (Hpch-pc) HL2 derived from condensation of pyrazine carboxylic hydrazide (Hpch) with 2-benzoyl pyridine (bp) or pyridine 2-carbaldehyde (pc) and their transition metal complexes of type ML(1-2)2 have been synthesized, where M = Mn(II), Co(II), Ni(II), Cu(II) and Zn(II). Characterization of ligands and their metal complexes was carried out by elemental analysis, conductimetric studies, magnetic susceptibility, spectroscopic techniques (IR, UV-VIS, NMR, ESR, Mass) and thermogravimetric analysis. The physico-chemical studies revealed octahedral geometry or distorted octahedral geometry around metal ion. These azomethine Schiff base ligands acted as tridentate ? coordinating through carbonyl, azomethine and pyridine nitrogen present in the ligand. The thermodynamic and thermal properties of the complexes have been investigated and it was observed on the basis of these studies that thermal stability of complexes follows the order Mn activity at different concentrations against bacteria viz. Gram positive Bacillus subtilis, Micrococcus luteus and Gram negative Pseudomonas aeruginosa, Pseudomonas mendocina. A marked enhancement in biocidal activity of the ligands under similar experimental conditions was observed as a consequence of coordination with metal ions. The trend of growth inhibition in the complexes was found to be in the order: Cu > Mn > Ni > Co > Zn.

  6. Synthesis, spectral characterization, structural investigation and antimicrobial studies of mononuclear Cu(II), Ni(II), Co(II), Zn(II) and Cd(II) complexes of a new potentially hexadentate N2O4 Schiff base ligand derived from salicylaldehyde

    Science.gov (United States)

    Keypour, Hassan; Shayesteh, Maryam; Rezaeivala, Majid; Chalabian, Firoozeh; Elerman, Yalcin; Buyukgungor, Orhan

    2013-01-01

    A new potentially hexadentate N2O4 Schiff base ligand, H2L derived from condensation reaction of an aromatic diamine and salicylaldehyde, and its metal complexes were characterized by elemental analyses, IR, UV-Vis, EI-MS, 1H and 13C NMR spectra, as well as conductance measurements. It has been originated that the Schiff base ligand with Cu(II), Ni(II), Co(II), Cd(II) and Zn(II) ions form mononuclear complexes on 1:1 (metal:ligand) stoichiometry. The conductivity data confirm the non-electrolytic nature of the complexes. Also the crystal structures of the complexes [ZnL] and [CoL] have also been determined by using X-ray crystallographic technique. The Zn(II) and Co(II) complexes show a tetrahedral configuration. Electronic absorption spectra of the Cu(II) and Ni(II) complexes suggest a square-planar geometry around the central metal ion. The synthesized compounds have antibacterial activity against the three Gram-positive bacteria: Bacillus cereus, Enterococcus faecalis and Listeria monocytogenes and also against the three Gram-negative bacteria: Salmonella paraB, Citrobacter freundii and Enterobacter aerogenes. The results showed that in some cases the antibacterial activity of complexes were more than nalidixic acid and amoxicillin as standards.

  7. Unique mononuclear Mn(II) complexes of an end-off compartmental Schiff base ligand: experimental and theoretical studies on their bio-relevant catalytic promiscuity.

    Science.gov (United States)

    Adhikary, Jaydeep; Chakraborty, Aratrika; Dasgupta, Sanchari; Chattopadhyay, Shyamal Kumar; Kruszynski, Rafał; Trzesowska-Kruszynska, Agata; Stepanović, Stepan; Gruden-Pavlović, Maja; Swart, Marcel; Das, Debasis

    2016-08-02

    Three new mononuclear manganese(ii) complexes, namely [Mn(HL)2]·2ClO4 (1), [Mn(HL)(N(CN)2)(H2O)2]·ClO4 (2) and [Mn(HL)(SCN)2] (3) [LH = 4-tert-butyl-2,6-bis-[(2-pyridin-2-yl-ethylimino)-methyl]-phenol], have been synthesized and structurally characterized. An "end-off" compartmental ligand (LH) possesses two symmetrical compartments with N2O binding sites but accommodates only one manganese atom instead of two due to the protonation of the imine nitrogen of one compartment. Although all three complexes are mononuclear, complex 1 is unique as it has a 1 : 2 metal to ligand stoichiometry. The catalytic promiscuity of complexes 1-3 in terms of two different bio-relevant catalytic activities namely catecholase and phenoxazinone synthase has been thoroughly investigated. EPR and cyclic voltametric studies reveal that radical formation rather than metal centered redox participation is responsible for their catecholase-like and phenoxazinone synthase-like catalytic activity. A computational approach suggests that imine bond bound radical generation rather than phenoxo radical formation is most likely responsible for the oxidizing properties of the complexes.

  8. Characterization of Complexes Synthesized Using Schiff Base Ligands and Their Screening for Toxicity Two Fungal and One Bacterial Species on Rice Pathogens

    Directory of Open Access Journals (Sweden)

    T. Mangamamba

    2014-01-01

    Full Text Available Coordination complexes with metal ions Cu(II, Ni(II, Co(II, Fe(III, Mn(II, Cr(III, and VO(II with six ligands formed by condensation products using azides and aldehydes or ketones are characterized. Both the ligands and the complexes synthesized are characterized by C, H, N, Cl and metal analyses, IR, UV-Vis, TGA, and magnetic susceptibility for tentative structure proposal. Several of them are screened for their toxicity (i.e., physiological activity against fungal species Rhizoctonia solani and Acrocylindrium oryzae and a bacterium, Xanthomonas oryzae on rice pathogens. The study shows that the observed physiological activity is enhanced for the metal complexes as compared to the simple metal salts or ligands, except in the case of L3 or HAEP ligand, where the free –OH and –NH2 groups on the ligand seemed to have inhibited the activity. It is also observed that the order of activity has a dependence on the increased atomic weight of the metal ion in use. In some cases, especially the VO(II complexes, they are found to be better than the standards in use, both for the fungicides and for the bactericide.

  9. Lead(II) complexes with some SNO and ONO tridentate Schiff base ligands and their evaluation as lead(II) sensors

    Energy Technology Data Exchange (ETDEWEB)

    Saadeh, Salman M., E-mail: hazemona1@yahoo.co.uk [Chemistry Department, College of Sciences, Islamic University of Gaza, Gaza (Palestinian Territory, Occupied); Abu Shawish, Hazem M., E-mail: hazemona1@yahoo.co.uk [Chemistry Department, College of Sciences, Al-Aqsa University, Gaza (Palestinian Territory, Occupied); Dalloul, Hany M. [Chemistry Department, College of Sciences, Al-Aqsa University, Gaza (Palestinian Territory, Occupied); EL-Halabi, Nabil M.; Kh. Daher, Baha [Chemistry Department, College of Sciences, Islamic University of Gaza, Gaza (Palestinian Territory, Occupied)

    2012-04-01

    New Pb(II) complexes of the general formula PbL{sub 2} where HL 2-acetylthiophene benzoylhydrazone, 2-acetylfuran benzoylhydrazone, 2-carboxaldehydethiophene benzoylhydrazone and 2-carboxaldehydefuran benzoylhydrazone were synthesized by reaction of lead(II) acetate with the ligands in methanol in lead to ligand ratio of 1: 2. The complexes are insoluble in common organic solvents but soluble in DMF and DMSO. The measured molar conductance values in DMF indicate that, the complexes are non-electrolytes in nature. In view of analytical and spectral (IR, UV-vis and NMR) studies, it has been concluded that, all the metal complexes possess octahedral geometry in which the ligand is coordinated to lead(II) through azomethine nitrogen, benzoyl oxygen and thiophene sulfur or furan oxygen atom via deprotonation. These complexes were tested as ionophores for lead(II) determination. Pb(ATBH){sub 2} gave the best response with two plasticizers Doph and DOS were fully characterized. Their detection limit were 3.9 Multiplication-Sign 10{sup -7} mol L{sup -1}, 7.9 Multiplication-Sign 10{sup -7} mol L{sup -1}, concentration range 5.9 Multiplication-Sign 10{sup -7} -1.0 Multiplication-Sign 10{sup -2} mol L{sup -1}, 9.1 Multiplication-Sign 10{sup -7}-1.0 Multiplication-Sign 10{sup -2} mol L{sup -1} response time {approx} 8-10 sec and pH range 6.2-7.8. The proposed sensors show a reasonable discrimination ability towards Pb(II) in comparison to some alkali, alkaline earth, transition heavy metal ions. The modified electrodes were applied as an indicator electrode and successfully used to determine Pb(II) in synthesized polluted water samples giving satisfactory results. - Highlights: Black-Right-Pointing-Pointer Preparation and characterization of lead complexes of some SNO and NNO tridentate ligands. Black-Right-Pointing-Pointer New chemically modified carbon paste electrodes (CMCPEs) for lead(II) were designed. Black-Right-Pointing-Pointer Lead complexes were used as sensing

  10. Synthesis of salicylaldehyde Schiff base modified Cu nanocrystals by thermal treatment in liquid paraffin

    Science.gov (United States)

    Wen, Yueli; Huang, Wei; Wang, Bin; Fan, Jinchuan; Gao, Zhihua; Yin, Lihua

    2011-11-01

    Cuboid copper nanocrystals were synthesized by thermal treatment in liquid paraffin without any inert gas protection with salicylaldehyde Schiff base copper (II) (Cu (II)-Salen) complex as precursor. Liquid paraffin was used as solvent and reductant. The obtained copper nanocrystals are morphology-controlled and stable when exposed to air for one year. The nanocrystals were characterized by X-ray diffraction measurements (XRD), UV-visible spectroscopy (UV-vis), transmission electron microscope (TEM), and Fourier transform infrared spectroscopy (FT-IR). The results showed that the stable cuboid copper nanocrystals are synthesized by using Salen as capping agents.

  11. Controlling the pKa of the bacteriorhodopsin Schiff base by use of artificial retinal analogues.

    OpenAIRE

    Sheves, M; Albeck, A; Friedman, N; Ottolenghi, M

    1986-01-01

    Artificial bacteriorhodopsin pigments based on synthetic retinal analogues carrying an electron-withdrawing CF3 substituent group were prepared. The effects of CF3 on the spectra, photocycles, and Schiff base pKa values of the pigments were analyzed. A reduction of 5 units in the pKa of the Schiff base is observed when the CF3 substituent is located at the C-13 polyene position, in the vicinity of the protonated Schiff base nitrogen. The results lead to the unambiguous characterization of the...

  12. Zeolite encapsulated Ni(II)-Schiff-base complex: a novel size-selective electro-catalyst for the determination of the purity of stevioside.

    Science.gov (United States)

    Avei, Mehdi Rashvand; Jafarian, Majid; Etezadi, Sedigheh; Gobal, Fereydoon; Khakali, Maryam; Rayati, Saeed; Mahjani, Mohammad Ghasem

    2013-04-15

    Ship-in-a-bottle complex of nickel(II) containing the ligand N,N'-bis(2,4-dihydroxyacetophenone)-2,2-dimethylpropandiimine (H2{salnptn(4-OH)2}) has been synthesized in zeolite Y. The characteristics of the encapsulated complex are identified by the methods of EDX, SEM, XRD, FT-IR and cyclic voltammetry. A catalytic effect in the electrochemical oxidation of glucose, fructose and sucrose, and a blocking effect in stevioside oxidation are demonstrated on the Ni(II){salnptn(4-OH)2}-Y/CPE. The effects of some parameters, such as potential scan rate and concentration of carbohydrates are investigated. The rate constants for the catalytic reaction (k') of carbohydrates are also obtained. The size-selective electro-catalyst shows a good linear dependency on carbohydrates' concentration in the range of 0.01-0.06 M with the detection limit of 6.4mM at the signal-to-noise ratio of 3. Furthermore, the modified electrode exhibits no interference with the simultaneous presence of stevioside. In brief, these results demonstrate that Ni(II){salnptn(4-OH)2}-Y composites have a great potential for synthesizing size-selective electrocatalysts for determining the purity of stevioside. Copyright © 2013 Elsevier B.V. All rights reserved.

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

    Science.gov (United States)

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

    2016-01-01

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

  14. Design, synthesis, and biological activities of aromatic gossypol Schiff base derivatives.

    Science.gov (United States)

    Li, Ling; Li, Zheng; Wang, Kailiang; Zhao, Sheng; Feng, Jiming; Li, Jiarui; Yang, Peiwen; Liu, Yuxiu; Wang, Lizhong; Li, Yongqiang; Shang, Hui; Wang, Qingmin

    2014-11-19

    A series of aromatic gossypol Schiff bases have been successfully synthesized via a feasible chemical modification. The antiviral activity against tobacco mosaic virus (TMV) of these gossypol Schiff bases has been tested for the first time. The bioassay studies indicated most of these derivatives exhibited excellent anti-TMV activity, in which o-trifluoromethylaniline Schiff base (19) displayed the best antiviral activities. Furthermore, compound 19 exhibited an eminent anti-TMV effect in the field and low toxicity to mice. These results suggest it is a promising candidate for the inhibitor of plant virus.

  15. Kinetics and mechanisms of the oxidation of alcohols and hydroxylamines by hydrogen peroxide, catalyzed by methyltrioxorhenium, MTO, and the oxygen binding properties of cobalt Schiff base complexes

    Energy Technology Data Exchange (ETDEWEB)

    Zauche, Timothy [Iowa State Univ., Ames, IA (United States)

    1999-02-12

    Catalysis is a very interesting area of chemistry, which is currently developing at a rapid pace. A great deal of effort is being put forth by both industry and academia to make reactions faster and more productive. One method of accomplishing this is by the development of catalysts. Enzymes are an example of catalysts that are able to perform reactions on a very rapid time scale and also very specifically; a goal for every man-made catalyst. A kinetic study can also be carried out for a reaction to gain a better understanding of its mechanism and to determine what type of catalyst would assist the reaction. Kinetic studies can also help determine other factors, such as the shelf life of a chemical, or the optimum temperature for an industrial scale reaction. An area of catalysis being studied at this time is that of oxygenations. Life on this earth depends on the kinetic barriers for oxygen in its various forms. If it were not for these barriers, molecular oxygen, water, and the oxygenated materials in the land would be in a constant equilibrium. These same barriers must be overcome when performing oxygenation reactions on the laboratory or industrial scale. By performing kinetic studies and developing catalysts for these reactions, a large number of reactions can be made more economical, while making less unwanted byproducts. For this dissertation the activation by transition metal complexes of hydrogen peroxide or molecular oxygen coordination will be discussed.

  16. Synthesis biological screening and molecular docking studies of some tin (IV) Schiff base adducts.

    Science.gov (United States)

    Rehman, Wajid; Yasmeen, Rehana; Rahim, Fazal; Waseem, Muhammad; Guo, Cun-Yue; Hassan, Zonera; Rashid, Umer; Ayub, Khurshid

    2016-11-01

    The search for an alternative to platinum anticancer agents is a major motivation for continuing investigations concerning the antitumor properties of other transition metal-based compounds. Keeping this in view, synthesis, antitumor and antimicrobial activity of diorganotin (IV) complexes was studied. A novel series of diorganotin (IV) complexes of the Schiff base ligand derived from 7-methoxy-2-hydroxy-1-naphthaldehyde, 1,2-phenylenediamine, Salicylaldehyde were synthesized. Physical and spectral examination was done through various techniques using elemental analyses, IR, 1H, 13C, 119Sn NMR, and 119mSn Mössbauer techniques respectively. The results obtained are in good agreement with 1:1:1 stoichiometry of Schiff base and 2:1 stoichiometry of the complexes. Octahedral geometry was assigned to all the synthesized complexes within six (6) coordination number around the tin. Antitumor activity was screened against human oral epidermoid carcinoma (KB) cell line. The diethyltin (IV) complex 2 showed the most promising cytotoxic results (IC50=0.35μM) against the cell line which is comparable with cisplatin (IC50=0.37μM). Docking studies revealed that these complexes can bind favorably within cisplatin binding site and the binding energy of complex 2 is more than that of cisplatin. Furthermore, binding of these complexes on human topoisomerase IIα enzyme and revealed that these complexes intercalating within the inter-strand of DNA showing interactions with DNA as well as protein that may results in DNA damage and cell death. Copyright © 2016. Published by Elsevier B.V.

  17. Hexa- and heptacoordinated manganese(II) dicyanamide complexes containing a tetradentate N-donor Schiff base: Syntheses, composition tailored architectures and magnetic properties

    Science.gov (United States)

    Bhar, Kishalay; Sutradhar, Dipu; Choubey, Somnath; Ghosh, Rajarshi; Lin, Chia-Her; Ribas, Joan; Ghosh, Barindra Kumar

    2013-11-01

    Two 1D coordination polymers [Mn(L)(μ1,5-dca)(MeOH)]n(ClO4)n (1) and [Mn(L)(μ1,5-dca)]n(PF6)n (2) and a dinuclear compound [Mn2(L)2(μ1,5-dca)2(dca)2]ṡH2O (3) [L = N,N'-(bis-(pyridin-2-yl)benzylidene)-ethane-1,2-diamine; dca = dicyanamide] have been isolated using one-pot synthesis of the building components in appropriate molar ratios and characterized. X-ray structural studies reveal that 1 forms a zigzag 1D chain through single Mn-(NCNCN)-Mn units in which each heptacoordinated manganese(II) center adopts a distorted pentagonal bipyramidal geometry with an MnN6O chromophore occupied with four N atoms of L, two nitrile N atoms of monobridged μ1,5-dca and one O atom of MeOH. In 2, each hexacoordinated metal(II) center has a distorted octahedral coordination environment with an MnN6 chromophore bound by four N atoms of L and two nitrile N atoms of two different single bridged μ1,5-dca units; the latter connects other neighboring metal centers in a non-ending fashion affording a linear 1D chain. Complex 3 is dinuclear where two [Mn(L)]2+ units are connected by double μ1,5-dca bridges with a distorted pentagonal bipyramidal environment. Variable-temperature magnetic susceptibility measurements of 1-3 show weak antiferromagnetic interactions among the metal centers through μ1,5-dca bridges.

  18. Designing, structural elucidation, comparison of DNA binding, cleavage, radical scavenging activity and anticancer activity of copper(I) complex with 5-dimethyl-2-phenyl-4-[(pyridin-2-ylmethylene)-amino]-1,2-dihydro-pyrazol-3-one Schiff base ligand.

    Science.gov (United States)

    Sathiyaraj, Subbaiyan; Sampath, Krishnan; Butcher, Ray J; Pallepogu, Raghavaiah; Jayabalakrishnan, Chinnasamy

    2013-06-01

    A novel copper(I) Schiff base complex has been synthesized and fully characterized by spectral, analytical and structural modes. Single crystal X-ray diffraction studies revealed that the copper(I) complex [CuCl(PPh3)L] has a distorted tetrahedral geometry around the central copper(I) ion. The interaction of the ligand and the complex with CT-DNA has been explored by absorption titration method which revealed that the compounds could interact with CT-DNA through intercalation. A gel electrophoresis assay demonstrated the ability of the complex to cleave the pBR322 DNA. The antioxidative properties showed that the copper(I) complex has a strong radical-scavenging potency than ligands. Further the cytotoxic effect of the compounds examined on cancerous cell lines showed that the complex exhibited substantial anticancer activity. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

  19. Synthesis, characterization and adsorption behavior of cotton fiber based Schiff base.

    Science.gov (United States)

    Agathian, K; Kannammal, L; Meenarathi, B; Kailash, S; Anbarasan, R

    2018-02-01

    Structural modification of Cotton (Cot) fiber was carried out using ε-caprolactone (CL) as a monomer and oxydianiline (ODA) as a Schiff base forming agent in the presence of V2O5 catalyst in dimethylsulfoxide medium for 24h under air atmosphere (0.10MPa) at 80°C. The obtained products were analyzed for the characteristics and also for its adsorption of hexavalent chromium (Cr(VI)) and rhodamine 6G (R6G) dye molecules. The 1H NMR spectrum confirms the Schiff base formation at 8.7ppm. The adsorption study confirms the Pseudo second order kinetics with Langmuir adsorption model. The structurally modified Cot fiber based Schiff base exhibited the highest adsorption behavior through chemical interaction forces. The thermodynamic parameters were determined and confirmed the endothermic adsorption process. Copyright © 2017 Elsevier B.V. All rights reserved.

  20. Synthesis, characterization and biocidal activities of Schiff base polychelates containing polyurethane links in the main chain

    Science.gov (United States)

    Hasnain, Sumaiya; Nishat, Nahid

    The concept of combining metallo-polymers with urethanes offers a versatile approach for the synthesis of new polymeric materials. Polyurethane containing transition metals was synthesized by the reaction of Schiff base metal complex with toluene 2,4 diisocyanate. The proposed structures were confirmed by elemental analysis, 1H NMR, 13C NMR and FT-IR. The geometry is determined by UV-Visible spectra and magnetic moment measurements, which reveals that the Mn(II), Co(II) and Ni(II) complexes have octahedral geometry while square planer geometry is reported for Cu(II) and tetrahedral for Zn(II) complex. The antimicrobial activities are determined using the agar well diffusion method with Staphylococcus aureus, Escherichia coli, Bacillus subtilis (bacteria), Aspergillus niger, Candida albicans and Aspergillus flavus (yeast). All the polymeric metal complexes show comparatively good biocidal activity, which is further enhanced after polymerization.

  1. Heterocyclic Schiff bases as non toxic antioxidants: Solvent effect, structure activity relationship and mechanism of action.

    Science.gov (United States)

    Shanty, Angamaly Antony; Mohanan, Puzhavoorparambil Velayudhan

    2017-11-07

    Phenolic heterocyclic imine based Schiff bases from Thiophene-2-carboxaldehyde and Pyrrole-2-carboxaldehyde were synthesized and characterized as novel antioxidants. The solvent effects of these Schiff bases were determined and compared with standard antioxidants, BHA employing DPPH assay and ABTS assay. Fixed reaction time and Steady state measurement were used for study. IC50 and EC50 were calculated. Structure-activity relationship revealed that the electron donating group in the phenolic ring increases the activity where as the electron withdrawing moiety decreases the activity. The Schiff base derivatives showed antioxidant property by two different pathways namely SPLET and HAT mechanisms in DPPH assay. While in ABTS method, the reaction between ABTS radical and Schiff bases involves electron transfer followed by proton transfer (ET-PT) mechanism. The cytotoxicity of these compounds has been evaluated by MTT assay. The results showed that all these compounds are non toxic in nature. Copyright © 2017 Elsevier B.V. All rights reserved.

  2. and hetero-dinuclear complexes with a new septadentate Schiff ...

    Indian Academy of Sciences (India)

    Unknown

    with inner copper centre and outer nontransition/transition metal ions. The complexes have been characterised by elemental analyses, spectral (IR, absorption, diffused reflectance), thermal and magnetic data. Dinuclear copper complexes exhibit subnormal magnetic moments (≈ 0⋅80 BM), showing magnetic exchange, ...

  3. Direct catalytic hydrogenation of CO2 to formate over a Schiff-base-mediated gold nanocatalyst

    National Research Council Canada - National Science Library

    Qinggang Liu; Xiaofeng Yang; Lin Li; Shu Miao; Yong Li; Yanqin Li; Xinkui Wang; Yanqiang Huang; Tao Zhang

    2017-01-01

    ...dynamic stability of the bicarbonate intermediate. Here, we devise a route for the direct catalytic conversion of CO2 over a Schiff-base-modified gold nanocatalyst that is comparable to the fastest known nanocatalysts, with a turnover number (TON...

  4. Structural characterization, luminescence and electrochemical properties of the Schiff base ligands

    Energy Technology Data Exchange (ETDEWEB)

    Ceyhan, Goekhan [Chemistry Department, K. Maras Suetcue Imam University, 46100 K. Maras (Turkey); Tuemer, Mehmet, E-mail: mtumer@ksu.edu.tr [Chemistry Department, K. Maras Suetcue Imam University, 46100 K. Maras (Turkey); Koese, Muhammet; McKee, Vickie [Chemistry Department, Loughborough University, LE11 3TU Leics (United Kingdom); Akar, Seyhan [Chemistry Department, K. Maras Suetcue Imam University, 46100 K. Maras (Turkey)

    2012-11-15

    In this study, we prepared two Schiff base ligands N-(4-hydroxy phenyl)-2,4-di-methoxy benzaldimine (TS{sup 1}) and N-(4-hydroxy phenyl)-2,5-di-methoxybenzaldimine (TS{sup 2}) which were characterized by structural, spectroscopic and analytical methods. The ligands TS{sup 1} and TS{sup 2} were obtained as single crystals from ethanol solution. X-ray diffraction data for two compounds showed that the bond lengths are within the normal ranges. The electrochemical properties of the Schiff base ligands were studied in different solvents and at various scan rates. The luminescence properties of the ligands TS{sup 1} and TS{sup 2} in different solvents and at different pH values have been investigated. The results show that the ligands exhibit more efficient luminescence properties in CH{sub 3}CN and n-butanol. - Highlights: Black-Right-Pointing-Pointer Schiff base ligands were prepared and fully characterized. Black-Right-Pointing-Pointer X-ray crystal structures of Schiff base ligands were reported. Black-Right-Pointing-Pointer Electrochemical properties of Schiff base ligands were investigated. Black-Right-Pointing-Pointer Absorption and photoluminescence properties of the Schiff bases were examined.

  5. Synthesis and characterization of some metal complexes of a Schiff ...

    African Journals Online (AJOL)

    Sadtler Research Laboratories Inc. 1966 Standard Spectra, #21078K. 34. Bellamy, L.J. The Infrared Spectra of Complex Molecules, Vol. II, 2nd ed., Chapman and. Hall: New York; 1980. 35. Nakamoto, K. Infrared and Raman Spectra of Inorganic and Coordination Compounds, Part. B, 5th ed., John Wiley: New York; 1997.

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

    Indian Academy of Sciences (India)

    pyramidal geometry. Complex 2 intercalatively binds to calf-thymus (ct) DNA with a binding constant (b) of ∼105 M−1. It exhibited moderate chemical nuclease activity but excellent DNA photocleavage activity in red light of 647 nm forming ...

  7. Effects of copper ions on DNA binding and cytotoxic activity of a chiral salicylidene Schiff base.

    Science.gov (United States)

    Fei, Bao-Li; Xu, Wu-Shuang; Tao, Hui-Wen; Li, Wen; Zhang, Yu; Long, Jian-Ying; Liu, Qing-Bo; Xia, Bing; Sun, Wei-Yin

    2014-03-05

    A chiral Schiff base HL N-(5-bromo-salicylaldehyde)dehydroabietylamine (1) and its chiral dinuclear copper complex [Cu2L4]·4DMF (2) have been synthesized and fully characterized. The interactions of 1 and 2 with salmon sperm DNA have been investigated by viscosity measurements, UV, fluorescence and circular dichroism (CD) spectroscopic techniques. Absorption spectral (Kb=3.30 × 10(5)M(-)(1) (1), 6.63 × 10(5)M(-)(1)(2)), emission spectral (Ksv=7.58 × 10(3)M(-)(1) (1), 1.52 × 10(4)M(-)(1) (2)), and viscosity measurements reveal that 1 and 2 interact with DNA through intercalation and 2 exhibits a higher DNA binding ability. In addition, CD study indicates 2 cause a more evident perturbation on the base stacking and helicity of B-DNA upon binding to it. In fluorimetric studies, the enthalpy (ΔH>0) and entropy (ΔS>0) changes of the reactions between the compounds with DNA demonstrate hydrophobic interactions. 1 and 2 were also screened for their cytotoxic ability and 2 demonstrates higher growth inhibition of the selected cancer cells at concentration of 50 μM, this result is identical with their DNA binding ability order. All the experimental results show that the involvement of Cu (II) centers has some interesting effect on DNA binding ability and cytotoxicity of the chiral Schiff base. Copyright © 2014 Elsevier B.V. All rights reserved.

  8. Chemical reactivity and skin sensitization potential for benzaldehydes: can Schiff base formation explain everything?

    Science.gov (United States)

    Natsch, Andreas; Gfeller, Hans; Haupt, Tina; Brunner, Gerhard

    2012-10-15

    Skin sensitizers chemically modify skin proteins rendering them immunogenic. Sensitizing chemicals have been divided into applicability domains according to their suspected reaction mechanism. The widely accepted Schiff base applicability domain covers aldehydes and ketones, and detailed structure-activity-modeling for this chemical group was presented. While Schiff base formation is the obvious reaction pathway for these chemicals, the in silico work was followed up by limited experimental work. It remains unclear whether hydrolytically labile Schiff bases can form sufficiently stable epitopes to trigger an immune response in the living organism with an excess of water being present. Here, we performed experimental studies on benzaldehydes of highly differing skin sensitization potential. Schiff base formation toward butylamine was evaluated in acetonitrile, and a detailed SAR study is presented. o-Hydroxybenzaldehydes such as salicylaldehyde and the oakmoss allergens atranol and chloratranol have a high propensity to form Schiff bases. The reactivity is highly reduced in p-hydroxy benzaldehydes such as the nonsensitizing vanillin with an intermediate reactivity for p-alkyl and p-methoxy-benzaldehydes. The work was followed up under more physiological conditions in the peptide reactivity assay with a lysine-containing heptapeptide. Under these conditions, Schiff base formation was only observable for the strong sensitizers atranol and chloratranol and for salicylaldehyde. Trapping experiments with NaBH₃CN showed that Schiff base formation occurred under these conditions also for some less sensitizing aldehydes, but the reaction is not favored in the absence of in situ reduction. Surprisingly, the Schiff bases of some weaker sensitizers apparently may react further to form stable peptide adducts. These were identified as the amides between the lysine residues and the corresponding acids. Adduct formation was paralleled by oxidative deamination of the parent

  9. Synthesis, spectral, thermal, fluorescence, antimicrobial, anthelmintic and DNA cleavage studies of mononuclear metal chelates of bi-dentate 2H-chromene-2-one Schiff base.

    Science.gov (United States)

    Prabhakara, Chetan T; Patil, Sangamesh A; Kulkarni, Ajaykumar D; Naik, Vinod H; Manjunatha, M; Kinnal, Shivshankar M; Badami, Prema S

    2015-07-01

    The Co(II), Ni(II) and Cu(II) complexes have been synthesized with Schiff base (HL), derived from 8-formyl-7-hydroxy-4-methylcoumarin with benzylamine. The Schiff base and its metal complexes were structurally characterized based on IR, (1)H NMR, (13)C NMR, UV-visible, ESR, magnetic, thermal, fluorescence, mass and ESI-MS studies. The complexes are completely soluble in DMF and DMSO. The molar conductance values indicate that, all synthesized metal complexes are non-electrolytic in nature. Elemental analysis reveals [ML2(H2O)2] stoichiometry, here MCo(II), Ni(II) and Cu(II), L=deprotonated ligand. The coordination between metal ion and Schiff base was supported by IR data, through deprotonation of phenolic oxygen of coumarin and azomethine nitrogen atoms. Solution electronic spectral results unveiled that all the synthesized complexes posses six coordinated geometry around metal ion. Thermal studies suggest the presence of coordinated water molecules. The Schiff base and its metal complexes have been screened for their antibacterial (Escherichia coli, Pseudomonas aureginosa, Klebsiella pneumoniae and Staphylococcus aureus) and antifungal (Penicillium chrysogenum and Aspergillus niger), anthelmintic (Pheretima posthuma) and DNA cleavage (Calf Thymus DNA) activities. Copyright © 2015 Elsevier B.V. All rights reserved.

  10. Selective determination of trace copper(II) by cathodic adsorptive stripping voltammetry with a naphthol-derivative Schiff's base.

    Science.gov (United States)

    Shamsipur, Mojtaba; Saeidi, Mahboubeh; Sharghi, Hashem; Naeimi, Hossein

    2003-01-01

    A selective and sensitive stripping voltammetric method for the determination of trace amounts of copper(II) with a recently synthesized naphthol-derivative Schiff's base (2,2'-[1,2-ethanediylbis(nitriloethylidyne)]bis(1-naphthalene)) is presented. The method is based on adsorptive accumulation of the resulting copper-Schiff's base complex on a hanging mercury drop electrode, followed by the stripping voltammetric measurement at the reduction current of adsorbed complex at -0.15 V (vs. Ag/AgCl). The optimal conditions for the stripping analysis of copper include pH 5.5 to 6.5, 8 microM Schiff's base and an accumulation potential of -0.05 V (vs. Ag/AgCI). The peak current is linearly proportional to the copper concentration over a range 2.3-50.8 ng ml(-1) with a limit of detection of 1.9 ng ml(-1). The accumulation time and RSD are 90 s and (3.2-3.5)%, respectively. The method was applied to the determination of copper in some analytical grade salts, tap water, human serum and sheep's liver.

  11. Synthesis and Antibacterial Activities of Some Schiff Bases

    Directory of Open Access Journals (Sweden)

    Mohamed N. Ibrahim

    2011-01-01

    Full Text Available Schiff bases p-hydroxybenzylidene-2-carboxyaniline, p-nitrobenz-ylidene-2-carboxyaniline, p-(N, N-dimethylaminobenzylidene-2-carboxyaniline, N-(4-hydroxybezylidene-benzene-1,2-diamine, N--(4-nitrobezylidenebenzene-1,2-diamine, N-(4-(N, N-dimethylaminobezylidenebenzene-1,2-diamine, N-(4-(N,N-dimethylaminobenzylidenenaphthalen-1-amine,N-(4-nitrobenzylidenenaphthalen-1-amine,N--(4-chlorobenzylidenenaphthalen-1-amine,sodium-4-(4-(N,N-dimethyl aminobenzylideneaminonaphthalene-1-sulfonate,sodium -4-(4-nitrobenzylidene-aminonaphthalene-1-sulfonate and sodium-4-(4-chlorobenzylideneamino naphthalene-1-sulfonate obtained by condensation of aniline and naphthyl-amine derivatives with some aromatic aldehydes were characterized by physical and spectral methods. The biological activity of these products were as antibacterial agents against three species of human pathogenic bacteria such as Escherichia coli, Staphylococcus aureus and Klebsiella sp. Nearly 50% of these compounds showed reasonable activity against the bacterial species investigated and we found that the antibacterial activity is dependent on the molecular structure of the compounds.

  12. Chemical modification of silica gel with synthesized new Schiff base derivatives and sorption studies of cobalt (II) and nickel (II)

    Energy Technology Data Exchange (ETDEWEB)

    Kursunlu, Ahmed Nuri, E-mail: ankursunlu@gmail.com [Department of Chemistry, Selcuk University, Campus, 42075, Konya (Turkey); Guler, Ersin; Dumrul, Hakan; Kocyigit, Ozcan; Gubbuk, Ilkay Hilal [Department of Chemistry, Selcuk University, Campus, 42075, Konya (Turkey)

    2009-08-15

    In this study, three Schiff base ligands and their complexes were synthesized and characterized by infrared spectroscopy (IR), thermogravimetric analyses (TGA), nuclear magnetic resonance (NMR), elemental analysis and magnetic susceptibility apparatuses. Silica gel was respectively modified with Schiff base derivatives, (E)-2-[(2-chloroethylimino)methyl]phenol, (E)-4-[(2-chloroethylimino)methyl]phenol and N,N'-[1,4-phenilendi(E)methylidene]bis(2-chloroethanamine), after silanization of silica gel by (3-aminopropyl)trimethoxysilane (APTS) by using a suitable method. Characterization of the surface modification was also performed with IR, TGA and elemental analysis. The immobilized surfaces were used for Co(II) and Ni(II) sorption from aqueous solutions and values of sorption were detected by atomic absorption spectrometer (AAS).

  13. Synthesis, spectroscopic and voltammetric studies of a novel Schiff-base of cysteine and saccharin

    Science.gov (United States)

    Çakır, Semiha; Odabaşoğlu, Mustafa; Biçer, Ender; Yazar, Zehra

    2009-01-01

    In this study, a novel Schiff-base of cysteine and saccharin [( 2R)-2-(1, 1-dioxo-1, 2-dihydro-1λ6-benzo[ d]isothiazol-3-ylideneamino)-3-mercapto-propionic acid] was synthesized and characterized by UV-Vis, FT-IR, 1H NMR and elemental analysis. The voltammetric behaviour of Schiff-base was investigated on the static mercury drop electrode (SMDE) by using Square-Wave voltammetry (SWV) and Cyclic voltammetry (CV). The voltammograms of the Schiff-base gave three reduction waves in Britton-Robinson buffer (pH 5.0-9.0) for the potential range from 0.0 to -1.4 V. The first reversible cathodic peak is due to reduction of the mercury thiolate, produced by the thiol group of Schiff-base which adsorbs at Hg electrode surface, to metallic mercury and free thiol. The second reduction peak may be assigned to the reduction of azomethine center (>C dbnd N sbnd ) in the Schiff-base and the last peak may be related to the catalytic hydrogen reduction.

  14. Synthesis, characterization, crystal structure and HSA binding of two new N,O,O-donor Schiff-base ligands derived from dihydroxybenzaldehyde and tert-butylamine

    Science.gov (United States)

    Khosravi, Iman; Hosseini, Farnaz; Khorshidifard, Mahsa; Sahihi, Mehdi; Rudbari, Hadi Amiri

    2016-09-01

    Two new o-hydroxy Schiff-bases compounds, L1 and L2, were derived from the 1:1 M condensation of 2,3-dihydroxybenzaldehyde and 2,4-dihydroxybenzaldehyde with tert-butylamine and were characterized by elemental analysis, FT-IR, 1H and 13C NMR spectroscopies. The crystal structure of L2 was also determined by single crystal X-ray analysis. The crystal structure of L2 showed that the compound exists as a zwitterionic form in the solid state, with the H atom of the phenol group being transferred to the imine N atom. It adopts an E configuration about the central Cdbnd N double bond. Furthermore, binding of these Schiff base ligands to Human Serum Albumin (HSA) was investigated by fluorescence quenching, absorption spectroscopy, molecular docking and molecular dynamics (MD) simulation methods. The fluorescence emission of HSA was quenched by ligands. Also, suitable models were used to analyze the UV-vis absorption spectroscopy data for titration of HSA solution by various amounts of Schiff bases. The spectroscopic studies revealed that these Schiff bases formed 1:1 complex with HSA. Energy transfer mechanism of quenching was discussed and the values of 3.35 and 1.57 nm as the mean distances between the bound ligands and the HSA were calculated for L1 and L2, respectively. Molecular docking results indicated that the main active binding site for these Schiff bases ligands is in subdomain IB. Moreover, MD simulation results suggested that this Schiff base complex can interact with HSA, with a slight modification of its tertiary structure.

  15. Synthesis and Anion Binding Properties of a Novel 1,8-dipyrrolecarbazole Schiff-base

    Directory of Open Access Journals (Sweden)

    Marina Šekutor

    2015-12-01

    Full Text Available New anion receptor N1,N8-bis[1H-pyrro-2-yl-methylidene]-3,6-dichloro-9H-carbazole-1,8-diamine (3 was synthesized and its binding properties towards anions (Cl-, Br-, AcO- and H2PO4- investigated by UV/Vis spectroscopy. In order to find the most stable structure of receptor 3, geometries of all possible isomers of 3 were optimized by the DFT/B3LYP method. It has been determined that receptor 3 forms complexes with a 1:1 stoichiometry with all the studied anions and no significant selectivity with respect to anion geometry was found. However, 1,8-dipyrrolecarbazole Schiff-base 3 binds oxoanions (H2PO4- and AcO- more strongly than spherical halogenide (Cl- and Br- anions.

  16. New Molybdenum Epoxidation Catalyst Derived From Nanoporous MCM-41 Supported Glycine Schiff-Base

    Directory of Open Access Journals (Sweden)

    M. Masteri-Farahani

    2012-03-01

    Full Text Available Covalent grafting of the nanoporous molecular sieve MCM-41 with 3- aminopropyl trimethoxysilane and acetyl acetone (acac successively gave modified MCM-41 (acacAmpMCM-41. Reaction of the resulted material with glycine afforded the corresponding supported glycine Schiff base ligand and subsequent reaction with [bis(acetylacetonatodioxomolybdenum(VI] was lead to molybdenum complex supported on MCM-41 through propyl chain spacer. Characterization of the resulting material was carried out with FT-IR, atomic absorption spectroscopy, powder X-ray diffraction and BET nitrogen sorption methods. The XRD and BET analyses revealed that textural properties of support were preserved during the grafting experiments. The resulted material successfully catalyzed the epoxidation of olefins with  tert-butyl hydroperoxide to the corresponding epoxides.

  17. Nickel Oxide (NiO nanoparticles prepared by solid-state thermal decomposition of Nickel (II schiff base precursor

    Directory of Open Access Journals (Sweden)

    Aliakbar Dehno Khalaji

    2015-06-01

    Full Text Available In this paper, plate-like NiO nanoparticles were prepared by one-pot solid-state thermal decomposition of nickel (II Schiff base complex as new precursor. First, the nickel (II Schiff base precursor was prepared by solid-state grinding using nickel (II nitrate hexahydrate, Ni(NO32∙6H2O, and the Schiff base ligand N,N′-bis-(salicylidene benzene-1,4-diamine for 30 min without using any solvent, catalyst, template or surfactant. It was characterized by Fourier Transform Infrared spectroscopy (FT-IR and elemental analysis (CHN. The resultant solid was subsequently annealed in the electrical furnace at 450 °C for 3 h in air atmosphere. Nanoparticles of NiO were produced and characterized by X-ray powder diffraction (XRD at 2θ degree 0-140°, FT-IR spectroscopy, scanning electron microscopy (SEM and transmission electron microscopy (TEM. The XRD and FT-IR results showed that the product is pure and has good crystallinity with cubic structure because no characteristic peaks of impurity were observed, while the SEM and TEM results showed that the obtained product is tiny, aggregated with plate-like shape, narrow size distribution with an average size between 10-40 nm. Results show that the solid state thermal decomposition method is simple, environmentally friendly, safe and suitable for preparation of NiO nanoparticles. This method can also be used to synthesize nanoparticles of other metal oxides.

  18. Design of cinnamaldehyde amino acid Schiff base compounds based on the quantitative structure–activity relationship

    Science.gov (United States)

    Wang, Hui; Jiang, Mingyue; Hse, Chung-Yun; Jin, Chunde; Sun, Fangli; Li, Zhuo

    2017-01-01

    Cinnamaldehyde amino acid Schiff base (CAAS) is a new class of safe, bioactive compounds which could be developed as potential antifungal agents for fungal infections. To design new cinnamaldehyde amino acid Schiff base compounds with high bioactivity, the quantitative structure–activity relationships (QSARs) for CAAS compounds against Aspergillus niger (A. niger) and Penicillium citrinum (P. citrinum) were analysed. The QSAR models (R2 = 0.9346 for A. niger, R2 = 0.9590 for P. citrinum,) were constructed and validated. The models indicated that the molecular polarity and the Max atomic orbital electronic population had a significant effect on antifungal activity. Based on the best QSAR models, two new compounds were designed and synthesized. Antifungal activity tests proved that both of them have great bioactivity against the selected fungi. PMID:28989758

  19. Kinetics of formation of acrylamide and Schiff base intermediates from asparagine and glucose

    DEFF Research Database (Denmark)

    Hedegaard, Rikke Susanne Vingborg; Frandsen, Henrik; Skibsted, Leif H.

    2008-01-01

    From the concentration of glucose and asparagine as reactants and of acrylamide as product each determined by LC-MS during reaction in an acetonitrile/water (68:32) model system at pH 7.6 (0.04 M phosphate buffer) and from the relative concentration of the Schiff base intermediate, the decarboxyl......From the concentration of glucose and asparagine as reactants and of acrylamide as product each determined by LC-MS during reaction in an acetonitrile/water (68:32) model system at pH 7.6 (0.04 M phosphate buffer) and from the relative concentration of the Schiff base intermediate...... of acrylamide from the decarboxylated Schiff base, rather than including dissociation of ammonia from aminopropionamide. (c) 2007 Elsevier Ltd. All rights reserved....

  20. Spectroscopic studies and PM5 semiempirical calculations of tautomeric forms of gossypol schiff base with ( R)-tetrahydrofurfurylamine

    Science.gov (United States)

    Przybylski, Piotr; Włodarz, Magdalena; Brzezinski, Bogumil; Bartl, Franz

    2004-03-01

    A new Schiff base of gossypol with ( R)-tetrahydrofurfurylamine (GSTF) was synthesised and its structure was studied by FT-IR, 1H NMR, 13C NMR, 15N NMR as well as PM5 semiempirical methods. It is shown that in the solution Schiff base exists in enamine-enamine tautomeric form. The structure of this tautomer is discussed in details.

  1. Crossing the Traditional Boundaries: Salen-Based Schiff Bases for Thermal Protective Applications.

    Science.gov (United States)

    Naik, Anil D; Fontaine, Gaëlle; Bellayer, Séverine; Bourbigot, Serge

    2015-09-30

    A broad spectrum of applications of "Salen"-based Schiff bases tagged them as versatile multifunctional materials. However, their applicability is often bounded by a temperature threshold and, thus, they have rarely been used for high temperature applications. Our investigation of a classical Schiff base, N,N'-bis(4-hydroxysalicylidene)ethylenediamine (L2), reveals that it displays an intriguingly combative response to an elevated temperature/fire scenario. L2 resists and regulates thermal degradation by forming an ablative surface, and acts as a thermal shield. A polycondensation via covalent cross-linking, which forms a hyperbranched cross-linked resin is found to constitute the origin of the ablative surface. This is a unique example of a resin formation produced with a Schiff base, that mimicks the operational strategy of a high-heat resistant phenolic resin. Further applicability of L2, as a flame retardant, was tested in an engineering polymer, polyamide-6. It was found that it reinforces the polymer against fire risks by the formation of an intumescent coating. This paves the way for a new strategic avenue in safeguarding polymeric materials toward fire risks. Further, this material represents a promising start for thermal protective applications.

  2. Spectroscopic Studies of Amino Acid Ionic Liquid-Supported Schiff Bases

    Directory of Open Access Journals (Sweden)

    Paula Ossowicz

    2013-04-01

    Full Text Available Amino acid ionic liquid-supported Schiff bases, derivatives of salicylaldehyde and various amino acids (L-threonine, L-valine, L-leucine, L-isoleucine and L-histidine have been investigated by means of various spectroscopic techniques (NMR, UV-Vis, IR, MS and deuterium isotope effects on 13C-NMR chemical shifts. The results have shown that in all studied amino acid ionic liquid-supported Schiff bases (except the L-histidine derivative a proton transfer equilibrium exists and the presence of the COO− group stabilizes the proton transferred NH-form.

  3. An efficient synthesis and spectroscopic characterization of Schiff bases containing 9,10-anthracenedione moiety

    Directory of Open Access Journals (Sweden)

    Fareed Ghulam

    2013-01-01

    Full Text Available A new method has been developed for the synthesis of novel Schiff bases containg anthraquinone moiety using dodeca-Tungstosilicic acid/P2O5 under solvent free conditions at room temperature. The reaction was completed in 1-3 minutes with excellent yields. This method was found to be more efficient, easy and hazardous free for the synthesis of azomethines. The development of these type of methadologies in synthetic chemistry may contribute to green chemistry. The structures of synthesized novel Schiff bases was elucidated using 1H-NMR, 13C-NMR, LCMS, FTIR and CHN analysis.

  4. Synthesis, antimicrobial and antioxidant activities of some 5-pyrazolone based Schiff bases

    Directory of Open Access Journals (Sweden)

    Narsidas Parmar

    2015-01-01

    Full Text Available A series of nine new biologically active Schiff bases 5a–i were synthesized by a condensation of 4-acyl-5-pyrazolones 3a–c with aromatic diamines 4a–d, and characterized by elemental analysis, mass and spectroscopic data. All the compounds showed antibacterial activity against Bacillus subtilis and Escherichia coli, good antifungal activity against Phytophthora infestanse and Aspergillus niger, and ferric-reducing antioxidant power (FRAP.

  5. Synthesis and characterization of Schiff base contained dextran microgels in water-in-oil inverse microemulsion.

    Science.gov (United States)

    Su, Hongying; Jia, Qingming; Shan, Shaoyun

    2016-11-05

    Polysaccharide-based microgels with high water content, excellent biocompatibility and controllable particle size have been widely studied as ideal candidates for drug release and delivery. In this study, microgels based on dextran were developed via the Schiff base formation between aldehyded dextran and ethylenediamine in a water-in-oil (W/O) microemulsion. Particle size of the resulted microgel was controllable between 800 and 1100nm by modulating the amount of the employed co-surfactants (Span 80/Tween 80). Furthermore, fluoresceins (e.g., aminofluorescein) and drugs (e.g., doxorubicin) with free amino groups can be conjugated onto the network of the dextran-based microgel via Schiff base linkages. Since the Schiff base linkages are degradable via hydrolysis and their stability decreases with the environmental pH decreases, the resulted Schiff bases contained microgel showed a pH dependent degradation profile. These results indicated that the pH-sensitive microgel based on dextran could be used as promising drug delivery systems for biomedical applications. Copyright © 2016 Elsevier Ltd. All rights reserved.

  6. Skin Sensitization QMM for HRIPT NOEL Data: Aldehyde Schiff-Base Domain.

    Science.gov (United States)

    Roberts, David W; Schultz, Terry W; Api, Anne Marie

    2017-06-19

    The general chemistry principles underlying skin sensitization for Schiff base (SB) electrophiles may be used to develop a quantitative mechanistic model (QMM), based on reactivity supplemented with a hydrophobicity parameter for some but not all structures within the SB reaction domain. For aliphatic Schiff base electrophiles, the log of the no observed effect level (NOEL) values (pNOEL) from the human repeated insult patch test (HRIPT) can be calculated by the reactivity parameter summation of sigma star values (Σσ*) and a hydrophobicity parameter (logP). Specifically, the QMM, pNOEL = 2.34(±0.33) Σσ* + 0.19(±0.07) logP - 2.62(±0.22), n = 19, R2 = 0.77, R2(adj) = 0.74, s = 0.20, F = 27, was developed. Not all parts of the Schiff base domain are modeled with one equation. Particularly, predicting aromatic aldehydes and ketones appears to require a separate equation. Interestingly, the same physical organic chemical properties originally applied to modeling the local lymph node assay potency of Schiff base electrophiles apply to human potency as represented by the HRIPT.

  7. Photoresponse of the protonated Schiff-base retinal chromophore in the gas phase

    DEFF Research Database (Denmark)

    Toker, Jonathan; Rahbek, Dennis Bo; Kiefer, H V

    2013-01-01

    The fragmentation, initiated by photoexcitation as well as collisionally-induced excitation, of several retinal chromophores was studied in the gas phase. The chromophore in the protonated Schiff-base form (RPSB), essential for mammalian vision, shows a remarkably selective photoresponse. The sel...

  8. Laser-induced absorption and fluorescence studies of photochromic Schiff bases

    DEFF Research Database (Denmark)

    Kownacki, K.; Mordzinski, A.; Wilbrandt, R.

    1994-01-01

    Three photochromic Schiff bases: N-salicylideneaniline (SA), N-salicylidene-1-naphthylamine (SN), and N,N-bis-(salicylidene)-p-phenylenediamine (Bsp), were studied in acetonitrile by means of steady-state and time-resolved absorption and fluorescence spectroscopy, as well as semiempirical quantum...

  9. Small-molecule azomethines : Organic photovoltaics via Schiff base condensation chemistry

    NARCIS (Netherlands)

    Petrus, M.L.; Bouwer, R.K.M.; Lafont, U.; Athanasopoulos, S.; Greenham, N.C.; Dingemans, T.J.

    2014-01-01

    Conjugated small-molecule azomethines for photovoltaic applications were prepared via Schiff base condensation chemistry. Bulk heterojunction (BHJ) devices exhibit efficiencies of 1.2% with MoOx as the hole-transporting layer. The versatility and simplicity of the chemistry is illustrated by

  10. Monodentate Schiff base ligands: their structural characterization, photoluminescence, anticancer, electrochemical and sensor properties.

    Science.gov (United States)

    Köse, Muhammet; Ceyhan, Gökhan; Tümer, Mehmet; Demirtaş, Ibrahim; Gönül, İlyas; McKee, Vickie

    2015-02-25

    Two Schiff base compounds, N,N'-bis(2-methoxy phenylidene)-1,5-diamino naphthalene (L(1)) and N,N'-bis(3,4,5-trimethoxy phenylidene)-1,5-diamino naphthalene (L(2)) were synthesized and characterized by the analytical and spectroscopic methods. The electrochemical and photoluminescence properties of the Schiff bases were investigated in the different conditions. The compounds L(1) and L(2) show the reversible redox processes at some potentials. The sensor properties of the Schiff bases were examined and color changes were observed upon addition of the metal cations, such as Hg(II), Cu(II), Co(II) and Al(III). The Schiff base compounds show the bathochromic shift from 545 to 585 nm. The single crystals of the compounds (L(1)) and (L(2)) were obtained from the methanol solution and characterized structurally by the X-ray crystallography technique. The molecule L(2) is centrosymmetric whereas the L(1) has no crystallographically imposed molecular symmetry. However, the molecular structures for these compounds are quite similar, differing principally in the conformation about methoxy groups and the dihedral angle between the two aromatic rings and diamine naphthalene. Copyright © 2014 Elsevier B.V. All rights reserved.

  11. Spectroscopic characterization, antimicrobial activity, DFT computation and docking studies of sulfonamide Schiff bases

    Science.gov (United States)

    Mondal, Sudipa; Mandal, Santi M.; Mondal, Tapan Kumar; Sinha, Chittaranjan

    2017-01-01

    Schiff bases synthesised from the condensation of 2-(hydroxy)naphthaldehyde and sulfonamides (sufathiazole (STZ), sulfapyridine (SPY), sulfadiazine (SDZ), sulfamerazine (SMZ) and sulfaguanidine (SGN)) are characterized by different spectroscopic data (FTIR, UV-Vis, Mass, NMR) and two of them, (E)-4-(((2-hydroxynaphthalen-1-yl)methylene)amino)-N-(thiazol-2-yl)benzenesulfonamide (1a) and (E)-N-(diaminomethylene)-4-(((2-hydroxynaphthalen-1-yl)methylene)amino)benzenesulfonamide (1e) have been confirmed by single crystal X-ray structure determination. Antimicrobial activities of the Schiff bases have been evaluated against certified and resistant Gram positive (Staphylococcus aureus, Enterococcus facelis) and Gram negative (Streptococcus pyogenes, Salmonella typhi, Shigella dysenteriae, Shigella flexneri, Klebsiella pneumonia) pathogens. Performance of Schiff base against the resistant pathogens are better than standard stain and MIC data lie 32-128 μg/ml while parent sulfonamides are effectively inactive (MIC >512 μg/ml). The DFT optimized structures of the Schiff bases have been used to accomplish molecular docking studies with DHPS (dihydropteroate synthase) protein structure (downloaded from Protein Data Bank) to establish the most preferred mode of interaction. ADMET filtration, Cytotoxicity (MTT assay) and haemolysis assay have been examined for evaluation of druglike character.

  12. N,N′-Dipyridoxyl(1,8-diamino-3,6-dioxaoctane) Schiff-base

    African Journals Online (AJOL)

    The N,N′-dipyridoxyl(1,8-diamino-3,6-dioxaoctane) (=H2L) Schiff-base has been synthesized and characterized by IR, 1H NMR, mass spectrometry and elemental analysis. Its optimized geometry and theoretical vibrational frequencies have been computed using density functional theory (DFT) method via the B3LYP ...

  13. A Langmuir study of novel Schiff Base ligand for ion sensor application

    African Journals Online (AJOL)

    Two novel Schiff Base ligands are used in this work. These amphiphilic ligands were being chosen because of the suitability in forming Langmuir film by using Langmuir-Blodgett (LB) technique. Characterizations of these ligands were carried out through LB technique to obtain the surface pressure-mean molecular area ...

  14. Spectral and physico-chemical investigations of novel homo-dinuclear di-μ 2-alkoxo bridged Schiff base complexes: 57Fe Mössbauer parameters of the Fe(III) complex

    Science.gov (United States)

    Siddiqi, Zafar A.; Khalid, Mohd; Kumar, Sarvendra; Shahid, M.; Noor, Shabana

    2010-02-01

    Spectral and molecular model computations on homo-dinuclear complexes [M 2L 2(H 2O) 2Cl 2] [L = 1-(salicylaldeneamino)-3-hydroxypropane, M = Cr 3+, Mn 3+, Fe 3+, Co 3+, Ni 3+ or Cu 3+] are consistent with a distorted hexa-coordinate geometry. X-band EPR spectral data indicated a rhombic distortion around Cu(II) ion. Magnetic moment and 57Fe Mössbauer data confirmed a high-spin state electronic configuration (t 2g3e g2, S = 5/2) and asymmetric ligand environment around Fe(III) with nuclear transitions Fe(±3/2 → 1/2) exhibiting Kramer's double degeneracy. The neighboring Fe(III) nuclei in the homo-dinuclear species are antiferromagnetically coupled.

  15. Amido-Schiff base derivatives as colorimetric fluoride sensor: Effect of nitro substitution on the sensitivity and color change.

    Science.gov (United States)

    Ghosh, Soumen; Alam, Md Akhtarul; Ganguly, Aniruddha; Guchhait, Nikhil

    2015-01-01

    A series of Schiff bases synthesized by the condensation of benzohydrazide and -NO2 substituted benzaldehyde have been used as selective fluoride ion sensor. Test paper coated with these synthetic Schiff bases (test kits) can detect fluoride ion selectively with a drastic color change and detection can be achieved by just using the naked-eye without the help of any optical instrument. Interestingly, the position of -NO2 group in the amido Schiff bases has an effect on the sensitivity as well as on the change of color of species. Copyright © 2015 Elsevier B.V. All rights reserved.

  16. Schiff Base-Poloxamer P85 Combination Prevents Prostate Cancer Progression in C57/Bl6 Mice.

    Science.gov (United States)

    Doğan, Ayşegül; Demirci, Selami; Türkmen, Neşe Başak; Çağlayan, Ahmet Burak; Aydın, Safa; Telci, Dilek; Kılıç, Ertuğrul; Şahin, Kazım; Orhan, Cemal; Tuzcu, Mehmet; Ekici, Asiye Işın Doğan; Şahin, Fikrettin

    2016-11-01

    Prostate cancer which is the second most common cause of death among men has a high incidence in recent years. Current therapeutic regimens should be improved to overcome drug resistance. At the metastatic stage, tumors become refractory to established chemotherapeutic treatments and cause serious problems at the clinics. Development of new drug molecules that are able to transport through the membrane easily and kill tumor cells rapidly is of great interest. In the current study, a novel Heterodinuclear copper(II)Mn(II) Schiff base complex combined with P85 was used for prostate cancer treatment in vivo. Tramp-C1 cells injected animals were subjected to chemotherapeutic formulation treatment and results were analyzed by toxicology analysis, tumor volume measurements, and histopathological analysis. 0.5 mg/kg Schiff base was selected and combined with 0.05% P85 according to the toxicology analysis showing the enzyme levels, blood parameters, and multiple organ toxicity. Results demonstrated that Heterodinuclear copper(II)Mn(II) complex-P85 combination decreased tumor formation and tumor volume steadily over the course of experiments. Overall, Heterodinuclear copper(II)Mn(II) complex-P85 exerted remarkable anti-cancer activity in vivo in C57/B16 mice. Prostate 76:1454-1463, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  17. Schiff bases of putrescine with methylglyoxal protect from cellular damage caused by accumulation of methylglyoxal and reactive oxygen species in Dictyostelium discoideum.

    Science.gov (United States)

    Park, Seong-Jun; Kwak, Min-Kyu; Kang, Sa-Ouk

    2017-05-01

    Polyamines protect protein glycation in cells against the advanced glycation end product precursor methylglyoxal, which is inevitably produced during glycolysis, and the enzymes that detoxify this α-ketoaldehyde have been widely studied. Nonetheless, nonenzymatic methylglyoxal-scavenging molecules have not been sufficiently studied either in vitro or in vivo. Here, we hypothesized reciprocal regulation between polyamines and methylglyoxal modeled in Dictyostelium grown in a high-glucose medium. We based our hypothesis on the reaction between putrescine and methylglyoxal in putrescine-deficient (odc - ) or putrescine-overexpressing (odc oe ) cells. In these strains, growth and cell cycle were found to be dependent on cellular methylglyoxal and putrescine contents. The odc - cells showed growth defects and underwent G1 phase cell cycle arrest, which was efficiently reversed by exogenous putrescine. Cellular methylglyoxal, reactive oxygen species (ROS), and glutathione levels were remarkably changed in odc oe cells and odc̄ cells. These results revealed that putrescine may act as an intracellular scavenger of methylglyoxal and ROS. Herein, we observed interactions of putrescine and methylglyoxal via formation of a Schiff base complex, by UV-vis spectroscopy, and confirmed this adduct by liquid chromatography with mass spectrometry via electrospray ionization. Schiff bases were isolated, analyzed, and predicted to have molecular masses ranging from 124 to 130. We showed that cellular putrescine-methylglyoxal Schiff bases were downregulated in proportion to the levels of endogenous or exogenous putrescine and glutathione in the odc mutants. The putrescine-methylglyoxal Schiff base affected endogenous metabolite levels. This is the first report showing that cellular methylglyoxal functions as a signaling molecule through reciprocal interactions with polyamines by forming Schiff bases. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. The role of a Schiff base scaffold, N-(2-hydroxy acetophenone) glycinate-in overcoming multidrug resistance in cancer.

    Science.gov (United States)

    Ganguly, Avishek; Chakraborty, Paramita; Banerjee, Kaushik; Choudhuri, Soumitra Kumar

    2014-01-23

    Drug resistance is a problem that hinders the numerous successes of chemotherapeutic intervention of cancer and continues to be a major obstacle for cures. Till date, several attempts have been made to develop suitable multidrug resistance (MDR) reversing agents. But, throughout the clinical development of MDR reversing agents, patients repeatedly suffer from toxicities. So far, some anticancer activity of Schiff bases which are the condensation products of carbonyl compounds and primary amines and their metal complexes has been described. But, overcoming multidrug resistance, by the use of such small molecules still remain unexplored. Under this backdrop, in search of less toxic and more effective MDR reversing agents our laboratory has developed the different metal chelates of Schiff base N-(2-hydroxy acetophenone)glycinate (NG) which is structurally similar to azatyrosine [L-β-(5-hydroxy-2-pyridyl)-alanine] that inhibits tumor formation by deactivating the c-Raf-1 kinase and c-Ha-ras signalling pathway. A decade-long research proposes possible strategies to overcome MDR by exploiting the chemical nature of such metal chelates. In this review we have catalogued the success of metal chelates of NG to overcome MDR in cancer. The review depict that the problem of MDR can be circumvent by synchronized activation of immunogenic cell death pathways that utilize the components of a host's immune system to kill cancer cells in combination with other conventional strategies. The current wealth of preclinical information promises better understanding of the cellular processes underlying MDR reversing activity of metal derivatives of NG and thus exposes several cellular targets for rational designing of new generation of Schiff base metal chelates as MDR reversing agents. Copyright © 2013 Elsevier B.V. All rights reserved.

  19. Coordination behavior of new bis Schiff base ligand derived from 2-furan carboxaldehyde and propane-1,3-diamine. Spectroscopic, thermal, anticancer and antibacterial activity studies.

    Science.gov (United States)

    Mohamed, Gehad G; Zayed, Ehab M; Hindy, Ahmed M M

    2015-06-15

    Novel bis Schiff base ligand, [N1,N3-bis(furan-2-ylmethylene)propane-1,3-diamine], was prepared by the condensation of furan-2-carboxaldehyde with propane-1,3-diamine. Its conformational changes on complexation with transition metal ions [Co(II), Ni(II), Cu(II), Mn(II), Cd(II), Zn(II) and Fe(III)] have been studied on the basis of elemental analysis, conductivity measurements, spectral (infrared, (1)H NMR, electronic), magnetic and thermogravimetric studies. The conductance data of the complexes revealed their electrolytic nature suggesting them as 1:2 (for bivalent metal ions) and 1:3 (for Fe(III) ion) electrolytes. The complexes were found to have octahedral geometry based on magnetic moment and solid reflectance measurements. Thermal analysis data revealed the decomposition of the complexes in successive steps with the removal of anions, coordinated water and bis Schiff base ligand. The thermodynamic parameters were calculated using Coats-Redfern equation. The Anticancer screening studies were performed on human colorectal cancer (HCT), hepatic cancer (HepG2) and breast cancer (MCF-7) cell lines. The antimicrobial activity of all the compounds was studied against Gram negative (Escherichia coli and Proteus vulgaris) and Gram positive (Bacillus vulgaris and Staphylococcus pyogones) bacteria. It was observed that the coordination of metal ion has a pronounced effect on the microbial activities of the bis Schiff base ligand. All the metal complexes have shown higher antimicrobial effect than the free bis Schiff base ligand. Copyright © 2015 Elsevier B.V. All rights reserved.

  20. Ultrasensitive and highly selective detection of Cu2 + ions based on a new carbazole-Schiff

    Science.gov (United States)

    Yin, Jun; Bing, Qijing; Wang, Lin; Wang, Guang

    2018-01-01

    A new chemosensor for Cu2 + based on Schiff base with high sensitivity and selectivity was designed and synthesized. The fluorescence intensity of the chemosensor in CH3CN solution was enhanced 160-fold after the addition of 10 equiv. Cu2 + over other metal ions. In addition, it also facilitates colorimetric detection for Cu2 + in CH3CN solution. The chemosensor displayed low detection limit and fast response time to Cu2 +.

  1. Facile, mild and convenient preparation and characterization of some novel Schiff base ligands from synthetic diamines and salicylaldehyde

    OpenAIRE

    H. Naeimi; A. Heidarnezhad

    2015-01-01

    Some novel Schiff base ligands have been prepared through condensation of salicylaldehyde with synthetic various primary diamines under mild reaction conditions. The used aromatic diamines were synthesized in good yields starting from low-cost commercially available materials. In these reactions, the Schiff base products have been afforded with excellent yields and appropriate reaction times. The structure of these ligands has been characterized by IR, 1H NMR and 13C NMR techniques. DOI: http...

  2. Schiff Base Ligand Coated Gold Nanoparticles for the Chemical Sensing of Fe(III Ions

    Directory of Open Access Journals (Sweden)

    Abiola Azeez Jimoh

    2015-01-01

    Full Text Available New Schiff base-coated gold nanoparticles (AuNPs of type AuNP@L (where L: thiolated Schiff base ligand have been synthesized and characterized using various spectroscopic techniques. The AuNPs and AuNP@L were imaged by transmission electron microscopy (TEM and were confirmed to be well-dispersed, uniformly distributed, spherical nanoparticles with an average diameter of 8–10 nm. Their potential applications for chemosensing were investigated in UV-Vis and fluorescence spectroscopic studies. The AuNP@L exhibited selectivity for Fe3+ in an ethanol/water mixture (ratio 9 : 1 v/v. The absorption and emission spectral studies revealed a 1 : 1 binding mode for Fe3+, with binding constants of 8.5×105 and 2.9×105 M−1, respectively.

  3. Synthesis, spectroscopic characterization and pH dependent photometric and electrochemical fate of Schiff bases.

    Science.gov (United States)

    Rauf, Abdur; Shah, Afzal; Abbas, Saghir; Rana, Usman Ali; Khan, Salah Ud-Din; Ali, Saqib; Zia-Ur-Rehman; Qureshi, Rumana; Kraatz, Heinz-Bernhard; Belanger-Gariepy, Francine

    2015-03-05

    A new Schiff base, 1-((4-bromophenylimino) methyl) naphthalen-2-ol (BPIMN) was successfully synthesized and characterized by (1)H NMR, (13)C NMR, FTIR and UV-Vis spectroscopy. The results were compared with a structurally related Schiff base, 1-((4-chlorophenylimino) methyl) naphthalen-2-ol (CPIMN). The photometric and electrochemical fate of BPIMN and CPIMN was investigated in a wide pH range. The experimental findings were supported by quantum mechanical approach. The redox mechanistic pathways were proposed on the basis of results obtained electrochemical techniques. Moreover, pH dependent UV-Vis spectroscopy of BPIMN and CPIMN was carried out and the appearance of isosbestic points indicated the existence of these compounds in different tautomeric forms. Copyright © 2014 Elsevier B.V. All rights reserved.

  4. Deuterium isotope effect on 13C chemical shifts of tetrabutylammonium salts of Schiff bases amino acids.

    Science.gov (United States)

    Rozwadowski, Z

    2006-09-01

    Deuterium isotope effects on 13C chemical shift of tetrabutylammonium salts of Schiff bases, derivatives of amino acids (glycine, L-alanine, L-phenylalanine, L-valine, L-leucine, L-isoleucine and L-methionine) and various ortho-hydroxyaldehydes in CDCl3 have been measured. The results have shown that the tetrabutylammonium salts of the Schiff bases amino acids, being derivatives of 2-hydroxynaphthaldehyde and 3,5-dibromosalicylaldehyde, exist in the NH-form, while in the derivatives of salicylaldehyde and 5-bromosalicylaldehyde a proton transfer takes place. The interactions between COO- and NH groups stabilize the proton-transferred form through a bifurcated intramolecular hydrogen bond. Copyright (c) 2006 John Wiley & Sons, Ltd.

  5. Synthesis, antimicrobial activity of Schiff base compounds of cinnamaldehyde and amino acids.

    Science.gov (United States)

    Wang, Hui; Yuan, Haijian; Li, Shujun; Li, Zhuo; Jiang, Mingyue

    2016-02-01

    The purpose of this study was to synthesize hydrophilic cinnamaldehyde Schiff base compounds and investigate those bioactivity. A total of 24 Schiff base compounds were synthesized using a simple approach with 3 cinnamaldehyde derivates and 8 amino acids as raw materials. The structures of synthesized compounds were confirmed using FTIR, (1)HNMR, HRMS purity and melting point. The antimicrobial activities of new compounds were evaluated with fluconazole and ciprofloxacin as the control against Aspergillus niger, Penicillium citrinum, Escherichia coli and Staphylococcus aureus. Findings show that major compounds exhibited significant bioactivity. Results from the structure-activity relationship suggest that both -p-Cl on benzene ring of cinnamaldehyde and the number of -COOK of amino acid salts significantly contributed to antimicrobial activity. Copyright © 2015 Elsevier Ltd. All rights reserved.

  6. Preparation, regulation and biological application of a Schiff base fluorescence probe.

    Science.gov (United States)

    Yin, Ninghua; Diao, Haipeng; Liu, Wen; Wang, Jingru; Feng, Liheng

    2016-01-15

    A facile fluorescence switch with Schiff base units was designed and achieved by nucleophilic addition and dehydration reaction. The fluorescence of the probe can be regulated by metal ions (Al(3+) and Cu(2+)). The whole process shows that the weak fluorescence of the probe enhances with the addition of Al(3+), and then the strong fluorescence of the probe/Al(3+) ensemble reduces by introducing Cu(2+). Meanwhile, the solution color changes of the probe with metal ions can be observed under 365 nm UV-vis light from weak light, pale green, green, pale green to weak light. Noticeably, the photo regulation processes of the probe by metal ions can be realized in the biological system and applied in cells imaging. The work provides a new strategy for designing facile regulation probe and develops a new application for Schiff base derivatives. Copyright © 2015 Elsevier B.V. All rights reserved.

  7. Synthesis, characterization and biological behavior of some Schiff's and Mannich base derivatives of Lamotrigine

    Directory of Open Access Journals (Sweden)

    A.A. Kulkarni

    2017-02-01

    Full Text Available A series of various Schiff's and Mannich base derivatives (N1–2 & ND1–6 of Lamotrigine with isatin and substituted isatin were synthesized to get more potent anticonvulsant agents. The starting material for the synthesis of various new Schiff's and Mannich base derivatives was isatin (1H-indole- 2, 3-dione which in turn was prepared from substituted isonitrosoacetanilide using aniline. Lamotrigine reacts with isatin & substituted isatin gave Schiff's bases (N1–2 which on reaction with various secondary amines (dimethylamine, diethylamine, morpholine produced Mannich bases (ND1–6. The structures of newly synthesized compounds were characterized by using TLC, UV, FT-IR, 1HNMR and studied for their anticonvulsant activity. Anticonvulsant activity of all the derivatives was evaluated by MES method using phenobarbitone sodium & Lamotrigine as standard drugs and % reduction of time spent by animals in extension, flexion, clonus, and stupor phase were noted. Compounds ND-4 and ND-6 showed significant anticonvulsant activity when compared with that of standard drugs. The remaining all compounds show moderate activity. Biological activity data of the synthesized derivatives revealed that, the synthesized derivatives are good anticonvulsant agents as compared to Lamotrigine.

  8. Femtosecond spectroscopy of the photoisomerisation of the protonated Schiff base of all-trans retinal

    Science.gov (United States)

    Hamm, P.; Zurek, M.; Röschinger, T.; Patzelt, H.; Oesterhelt, D.; Zinth, W.

    1996-12-01

    The light-induced isomerisation reaction of the protonated Schiff base retinal molecule in solution (PSBR-s) was studied by femtosecond absorption spectroscopy. After electronic excitation, ultrafast reactions on the excited electronic state occur on a 100 fs time-scale. The decay of S 1 exhibits a biphasic dependence with a 2.0 and a 7.2 ps process. The photoreaction of PSBR-s is compared with the processes found in the retinal proteins rhodopsin, bacteriorhodopsin and halorhodopsin.

  9. Synthesis and Antimicrobial Activity of New Schiff Base Compounds Containing 2-Hydroxy-4-pentadecylbenzaldehyde Moiety

    Directory of Open Access Journals (Sweden)

    Gadada Naganagowda

    2014-01-01

    Full Text Available Various novel Schiff base compounds have been synthesized by reaction of 2-hydroxy-4-pentadecylbenzaldehyde with substituted benzothiophene-2-carboxylic acid hydrazide and different substituted aromatic or heterocyclic amines in the presence of acetic acid in ethanol. The structures of all these compounds were confirmed by elemental analysis, IR, 1H-NMR, 13C-NMR, and mass spectral data and have been screened for antibacterial and antifungal activity.

  10. Schiff Base Proton Acceptor Assists Photoisomerization of Retinal Chromophores in Bacteriorhodopsin.

    Science.gov (United States)

    Hung, Chih-Chang; Chen, Xiao-Ru; Ko, Ying-Kuan; Kobayashi, Takayoshi; Yang, Chii-Shen; Yabushita, Atsushi

    2017-06-20

    In this study, we investigated the ultrafast dynamics of bacteriorhodopsins (BRs) from Haloquadratum walsbyi (HwBR) and Haloarcula marismortui (HmBRI and HmBRII). First, the ultrafast dynamics were studied for three HwBR samples: wild-type, D93N mutation, and D104N mutation. The residues of the D93 and D104 mutants correspond to the control by the Schiff base proton acceptor and donor of the proton translocation subchannels. Measurements indicated that the negative charge from the Schiff base proton acceptor residue D93 interacts with the ultrafast and substantial change of the electrostatic potential associated with chromophore isomerization. By contrast, the Schiff base proton donor assists the restructuring of the chromophore cavity hydrogen-bond network during the thermalization of the vibrational hot state. Second, the ultrafast dynamics of the wild-types of HwBR, HmBRI, and HmBRII were compared. Measurements demonstrated that the hydrogen-bond network in the extracellular region in HwBR and HmBRII slows the photoisomerization of retinal chromophores, and the negatively charged helices on the cytoplasmic side of HwBR and HmBRII accelerate the thermalization of the vibrational hot state of retinal chromophores. The similarity of the correlation spectra of the wild-type HmBRI and D104N mutant of HwBR indicates that inactivation of the Schiff base proton donor induces a positive charge on the helices of the cytoplasmic side. Copyright © 2017 Biophysical Society. Published by Elsevier Inc. All rights reserved.

  11. A novel Schiff base: Synthesis, structural characterisation and comparative sensor studies for metal ion detections.

    Science.gov (United States)

    Köse, Muhammet; Purtas, Savas; Güngör, Seyit Ali; Ceyhan, Gökhan; Akgün, Eyup; McKee, Vickie

    2015-02-05

    A novel Schiff base ligand was synthesized by the condensation reaction of 2,6-diformylpyridine and 4-aminoantipyrine in MeOH and characterised by its melting point, elemental analysis, FT-IR, (1)H, (13)C NMR and mass spectroscopic studies. Molecular structure of the ligand was determined by single crystal X-ray diffraction technique. The electrochemical properties of the Schiff base ligand were studied in different solvents at various scan rates. Sensor ability of the Schiff base ligand was investigated by colorimetric and fluorometric methods. Visual colour change of the ligand was investigated in MeOH solvent in presence of various metal ions Na(+), Mg(2+), Al(3+), K(+), Cr(3+), Mn(2+), Fe(3+), Co(2+), Ni(2+), Cu(2+), Zn(2+), Cd(2+), Hg(2+) and Pb(2+). Upon addition of Al(3+) ion into a MeOH solution of the ligand, an orange colour developed which is detectable by naked eye. Fluorescence emission studies showed that the ligand showed single emission band at 630-665nm upon excitation at 560nm. Addition of metal ions Na(+), Mg(2+), K(+), Cr(3+), Mn(2+), Fe(3+), Co(2+), Ni(2+), Cu(2+), Zn(2+), Cd(2+), Hg(2+) and Pb(2+) (1:1M ratio) cause fluorescence quenching, however addition of Al(+3) resulted in an increase in fluorescence intensity. No significant variation was observed in the fluorescence intensity caused by Al(3+) in presence of other metal ions. Therefore, the Schiff base ligand can be used for selective detection of Al(3+) ions in the presence of the other metal ions studied. Copyright © 2014 Elsevier B.V. All rights reserved.

  12. Synthesis, spectroscopic characterization and DFT calculations of novel Schiff base containing thiophene ring

    Science.gov (United States)

    Ermiş, Emel

    2018-03-01

    In this study, a new Schiff base derivative, 2-[(2-hydroxy-5-thiophen-2-yl-benzylidene)-amino]-6-methyl-benzoic acid (5), which has a thiophene ring and N, O donor groups, was successfully prepared by the condensation reaction of 2-hydroxy-5-(thiophen-2-yl)benzaldehyde (3) and 2-amino-6-methylbenzoic acid (4). The characterization of a Schiff base derivative (5) was performed by experimentally the UV-Vis., FTIR, 1H and 13C NMR spectroscopic methods and elemental analysis. Density Functional Theory (DFT/B3LYP/6-311+G(d, p)) calculations were used to examine the optimized molecular geometry, vibrational frequencies, 1H and 13C NMR chemical shifts, UV-Vis. spectroscopic parameters, HOMO-LUMO energies and molecular electrostatic potential (MEP) map of the compound (5) and the theoretical results were compared to the experimental data. In addition, the energetic behaviors such as the sum of electronic and thermal free energy (SETFE), atomic charges, dipole moment of the compound (5) in solvent media were investigated using the B3LYP method with the 6-311+G(d, p) basis set. The obtained experimental and theoretical results were found to be compatible with each other and they were supported the proposed molecular structure for the synthesized Schiff base derivative (5).

  13. Synthesis, molecular docking and biological evaluation of bis-pyrimidine Schiff base derivatives.

    Science.gov (United States)

    Kumar, Sanjiv; Lim, Siong Meng; Ramasamy, Kalavathy; Vasudevan, Mani; Shah, Syed Adnan Ali; Selvaraj, Manikandan; Narasimhan, Balasubramanian

    2017-09-18

    Heterocyclic pyrimidine nucleus, which is an essential base component of the genetic material of deoxyribonucleic acid, demonstrated various biological activities. A series of bis-pyrimidine Schiff bases were synthesized and screened for its antimicrobial and anticancer potentials. The molecular docking study was carried to find the interaction between active molecules with receptor. The structures of synthesized bis-pyrimidine Schiff bases were confirmed by spectral studies. The synthesized bis-pyrimidine derivatives were evaluated for their antimicrobial activity (MIC = µmol/mL) against selected Gram positive; Gram negative bacterial and fungal strains by tube dilution method. The anticancer activity (IC50 = µmol/mL) of the synthesized compounds was determined against human colorectal carcinoma (HCT116) cancer cell line by Sulforhodamine B (SRB) assay. Molecular docking studies provided information regarding the binding mode of active bis-pyrimidine Schiff bases with the cyclin-dependent kinase 8 (CDK8) receptor. The antimicrobial screening results indicated that compounds, q1 (MICbs = 0.83 µmol/mL), q16 (MICan = 1.54 µmol/mL and MICec = 0.77 µmol/mL), q1 and q19 (MICca = 0.41 µmol/mL) and q20 (MIC = 0.36 µmol/mL) are the most active ones. Compounds q1 (IC50 = 0.18 µmol/mL) have emerged as potent anticancer molecule against human colorectal carcinoma cancer cell line than the reference drug, 5-fluorouracil. Molecular docking studies indicated that compound q1 (the most active molecule) has the maximum hydrogen bond interaction (four) and π-π stacking (three) network among the bis-pyrimidine Schiff bases. Graphical abstract Graphical illustration of predicted binding mode of bis-pyrimidine Schiff bases in the active site of CDK8. a. Compound 1 (magenta color), b. Compound 5 (green color), c. Compound 8 (red color), d. Compound 13 (split pea color).

  14. Synthesis, spectral characterization of Schiff base transition metal ...

    Indian Academy of Sciences (India)

    ... copper and vanadyl complexes was studied by cyclic voltammetry. Antimicrobial screening tests gave good results in the presence of metal ion in the ligand system. The nuclease activity of the above metal complexes shows that Cu, Ni and Co complexes cleave DNA through redox chemistry whereas other complexes are ...

  15. Coordination chemistry of pyrazolone based Schiff bases relevant to uranyl sequestering agents: Synthesis, characterization and 3D molecular modeling of some octa-coordinate mono- and binuclear-dioxouranium(VI complexes

    Directory of Open Access Journals (Sweden)

    R.C. Maurya

    2015-09-01

    Full Text Available Synthesis of two new series of octa-coordinate dioxouranum(VI chelates: (i mononuclear chelates of compositions, [UO2(L12(H2O2] (where L1H = N-(4′-butyrylidene-3′-methyl-1′-phenyl-2′-pyrazolin-5′-one-p-anisidine (bumphp-paH, I, N-(4′-butyrylidene-3′-methyl-1′-phenyl-2′-pyrazolin-5′-one-m-phenetidine (bumphp-mpH, II or N-(4′-butyrylidene-3′-methyl-1′-phenyl-2′-pyrazolin-5′-one-p-toluidine (bumphp-ptH, III, and [UO2(L2(H2O2] (where L2H2 = N,N′-bis(4′-butyrylidene-3′-methyl-1′-phenyl-2′-pyrazo-lin-5′-one-o-phenylenediamine (bumphp-ophdH2, IV, and (ii the ligand bridged binuclear chelate of composition [UO2(μ-L3(H2O2]2 (where L3H2 = N,N′-bis(4′-butyrylidene-3′-methyl-1′-phenyl-2′-pyrazo-lin-5′-one-benzidine (bumphp-bzH2, V, are described. These complexes have been characterized by elemental analyses, uranium determination, molar conductance, decomposition temperature and magnetic measurements, thermogravimetric studies, 1H NMR, IR, and electronic spectral studies. The 3D molecular modeling and analysis for bond lengths and bond angles have also been carried out for the two representative compounds, [UO2(bumphp-pa2(H2O2] (1 and [UO2(bumphp-bz(H2O2]2 (5 to substantiate the proposed structures.

  16. Synthesis, characterization, biological and electrochemical evaluation of novel ether based ON donor bidentate Schiff bases

    Science.gov (United States)

    Shabbir, Muhammad; Akhter, Zareen; Ahmad, Iqbal; Ahmed, Safeer; Ismail, Hammad; Mirza, Bushra; McKee, Vickie; Bolte, Michael

    2016-07-01

    Four novel ON donor Schiff bases (E)-2-((4-phenoxyphenylimino)methyl)phenol (HL1), (E)-2-((4-(4-biphenyloxy)phenylimino)methyl)phenol(HL2), (E)-2-((4-(naphthalen-1-yloxy) phenylimino)methyl)phenol(HL3)and(E)-2-((4-(2-naphthoxy)phenylimino)methyl)phenol (HL4)have been synthesized and characterized by various spectroscopic, analytical and electro-analytical techniques. Single crystal X-ray diffraction analysis of Schiff base (HL3) revealed that phenol and anthracene rings are inclined at 30.25(9)° and 89.64(4)° to the central phenyl ring, respectively. Intra and inter molecular interactions are observed in single crystal analysis of HL3 Intramolecular interactions are hydrogen bonding but most of the intermolecular interactions are of the C-H … π type. There is a bit of π … π stacking between the anthracene groups. Only compounds (HL1) and (HL3) have been investigated for the biological activities due to slight solubility of (HL2) and (HL4) in DMSO. The results of brine shrimp cytotoxicity assay indicated LD50 values <1 μg/ml showing significant antitumor activity with IC50 values 14.20 and 4.54 μg/ml respectively. The compounds were highly active in protecting DNA against hydroxyl free radicals in concentration dependent manner. Voltammetric results indicated that one electron irreversible oxidation product is formed due to hydroxyl moiety and the process is diffusion controlled. On exposing to DNA environment the electrooxidised product developed electrostatic linkage and groove binding intercalation while consuming the DNA concentration substantially. The binding strength was quantitative in terms of drug-DNA binding of the order of 104 M-1.

  17. Synthesis and stereochemical assignments of diastereomeric Ni(II complexes of glycine Schiff base with (R-2-(N-{2-[N-alkyl-N-(1-phenylethylamino]acetyl}aminobenzophenone; a case of configurationally stable stereogenic nitrogen

    Directory of Open Access Journals (Sweden)

    Hiroki Moriwaki

    2014-02-01

    Full Text Available A family of chiral ligands derived from α-phenylethylamine and 2-aminobenzophenone were prepared by alkylation of the nitrogen atom. Upon reaction with glycine and a Ni(II salt, these ligands were transformed into diastereomeric complexes, as a result of the configurational stability of the stereogenic nitrogen atom. Different diastereomeric ratios were observed depending on the substituent R introduced in the starting ligand, and stereochemical assignments were based on X-ray analysis, along with NMR studies and optical rotation measurements.

  18. Another step toward DNA selective targeting: NiII and CuII complexes of a Schiff base ligand able to bind gene promoter G-quadruplexes† †Electronic supplementary information (ESI) available. CCDC 1451694–1451696. For ESI and crystallographic data in CIF or other electronic format see DOI: 10.1039/c6dt00648e Click here for additional data file. Click here for additional data file.

    Science.gov (United States)

    Lötsch, Daniela; van Schoon