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Kerim Serbest

Recep Tayyip Erdogan University, Faculty of Education, Chemistry, Faculty Member

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MUHAMMAD ARSHADALI ABBASI

University of sindh jamshoro

Kandasamy Ramamurthi

Youngstown State University

Dr Andreas Lemmerer aka Crystal Magician

University of the Witwatersrand

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Papers by Kerim Serbest

CCDC 972270: Experimental Crystal Structure Determination

An entry from the Cambridge Structural Database, the world's repository for small molecule cr... more An entry from the Cambridge Structural Database, the world's repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

Iron(III) Complexes Derived From Azo-Containing Salicylaldoxime Ligands: Synthesis, Structures and Biological Evaluations

El-Cezeri Fen ve Mühendislik Dergisi, 2021

Two novel mononuclear Fe(III) complexes derived from azo-containing salicylaldoxime ligands were ... more Two novel mononuclear Fe(III) complexes derived from azo-containing salicylaldoxime ligands were synthesized and characterized by elemental analyses, spectroscopic data i.e. IR, 1H NMR, UV-Vis, electrospray ionization mass spectra, molar conductivity, and magnetic susceptibility measurements. Both the experimental and theoretical results strongly suggest that the ligands have a major contribution to the azo enol imine form instead of the hydrazo keto imine and azo keto amine forms in solution/solid-state. The electronic spectra of the ligands and their iron(III) complexes were calculated theoretically for the band assignments by using DFT and TD-DFT/CPCM methods. DNA binding, cleavage, and antioxidative activities of the investigated compounds were studied. It has been shown that the ligands and their iron (III) complexes tested bind to DNA via the intercalative mode. It was observed that all molecules tested inhibited topoisomerase I almost to the same degree. One of the most striking results among the antioxidant activity tests is that the hydroxyl radical scavenging activities of the ligands and complexes are higher than the standard antioxidant mannitol.

Oxime derivative unsymmetrical azine, its Ni(II), Cu(II) and Zn(II) complexes: Synthesis, spectroscopy and catecholase activity

Heteroatom Chemistry, 2018

1-[(Z)-{(2E)-[(3E)-3-(hydroxyimino)butan-lidene]hydrazinylidene}methyl]naphthalen-2-ol, H2L (3) w... more 1-[(Z)-{(2E)-[(3E)-3-(hydroxyimino)butan-lidene]hydrazinylidene}methyl]naphthalen-2-ol, H2L (3) was synthesized by the agents of 2-hydroxy-1-naphtaldehyde, 2,3-butanedione monoxime and hydrazine in two steps. The structures of the compounds have been proposed by elemental analyses, spectroscopic data, that is, IR, 1 H NMR, UV-vis, X-ray, mass spectra (ESI or TOF), molar conductivities and magnetic susceptibility measurements. The ligand has potentially three nitrogens and an oxygen donor to be able to bind a metal center. In the light of analytical and physical results, it was suggested that the ligand may coordinate to by N,O/N2/N2O donor set to form square planar, octahedral, distorted square planar and tetrahedral complexes. Proton NMR evidence indicating that the ligand coordinates the metal ion through the phenolic oxygen and nitrogen of imine in the nickel and zinc complexes. Molar conductivity measurements reveal that all the complexes are non-electrolytes. In addition, catecholase activities of the complexes were studied. However, the only one of the complexes, 1b, behaves as an effective catalyst toward oxidation of 3,5-di-tert-butylcatechol (3,5-DTBC) to its corresponding quinone derivative in MeOH saturated with O 2. The reaction follows Michaelis-Menten enzymatic reaction kinetics with turnover numbers (kcat) 1.19 × 10 3 /hour. N(3)-N(2) 1.398 (4) C(7)-C(8)-C(9) 121.3 (4) N(3)-C(5) 1.285 (4) C(12)-C(11)-C(10) 121.4 (5) N(2)-C(3) 1.291 (4) C(15)-C(14)-C(13) 119.1 (4)

Heteroligand bivalent transition metal complexes with an azo-oxime ligand and 1,10-phenanthroline: Synthesis, spectroscopy, thermal analysis, DFT calculations and SOD-mimetic activities

Journal of Molecular Structure, 2020

This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

Synthesis, in vitro DNA interactions, cytotoxicities, antioxidative activities, and topoisomerase inhibition potentials of Mn(II), Co(II), Ni(II), Cu(II), and Zn(II) complexes with azo-oxime ligands

TURKISH JOURNAL OF CHEMISTRY, 2017

Mn(II), Co(II), Ni(II), Cu(II), and Zn(II) transition metal complexes of 2-hydroxy-5-[(E)-(4-phen... more Mn(II), Co(II), Ni(II), Cu(II), and Zn(II) transition metal complexes of 2-hydroxy-5-[(E)-(4-phenyl) diazenyl] benzaldehyde oxime and 2-hydroxy-5-[(E)-(4-nitrophenyl) diazenyl] benzaldehyde oxime ligands were synthesized and characterized through NMR, IR, ESI mass, and UV analysis. DNA binding abilities of the complexes were revealed using a UV-Vis spectrophotometer with the absorption titration and competitive binding techniques. Hydrolytic and oxidative DNA cleavage activities under different conditions were also proved. Topoisomerase I inhibition efficiencies and in vitro free radical scavenging activities of all complexes were examined. Finally, the selective cytotoxic potentials of all complexes were evaluated in human colon cancer, normal colon, and fibroblast cell lines using the water-soluble tetrazolium salt (WST-1) assay. The complexes had the ability to intercalate into stacked base pairs of DNA and topoisomerase I activity was reasonably inhibited in their presence in 0.4 mM concentrations. The abilities for scavenging of DPPH and hydroxyl radicals were found to be higher than those of known standard antioxidants (ascorbic acid, butylated hydroxyanisole, and mannitol). The results obtained from the cytotoxicity experiments are especially promising for further research, which must be carried out for the evaluation of the studied complexes as anticancer drugs.

Microwave-assisted synthesis and characterization and theoretical calculations of the first example of free and metallophthalocyanines from salen type Schiff base derivative bearing thiophen and triazole heterocyclic rings

Journal of Organometallic Chemistry, Dec 1, 2007

ABSTRACT Novel metal-free and metallophthalocyanine complexes of Co, Ni, Cu, and Zn have been syn... more ABSTRACT Novel metal-free and metallophthalocyanine complexes of Co, Ni, Cu, and Zn have been synthesized by exposure to microwave irradiation and reflux conditions and the products purified by several techniques. The newly prepared compounds have been characterized by elemental analyses, IR, 1H NMR, MS and UV–Vis spectroscopy. Furthermore, theoretical calculations of metallophthalocyanines CuPc, NiPc, ZnPc and CoPc were carried out to comparatively describe the molecular structures, molecular orbital and UV–Vis spectra of metallophthalocyanine complexes by the HF theory. A comparison between the different molecules for the geometry, molecular orbitals was made. The simulated order of the sizes of the central hole was CoPc&amp;gt;NiPcZnPc&amp;gt;CuPc. The calculated structures, electronic absorption spectra of metallophthalocyanine complexes are in good consistency with the experimental results.

Two novel unsymmetrical ferrocene based azines and their complexing abilities towards Cu(II): Spectroscopy, crystal structure, electrochemistry and DFT calculations

Polyhedron, 2015

Two new ferrocenyl-substituted unsymmetric azine ligands and their Cu(II) complexes were prepared... more Two new ferrocenyl-substituted unsymmetric azine ligands and their Cu(II) complexes were prepared. The redox active ferrocene-based azine ligands 1 and 2 were obtained by the condensation of 1-[(E)-hydrazinylidenemethyl]naphthalen-2-ol and 2-[(E)hydrazinylidenemethyl]-4-nitrophenol with ferrocene carboxaldehyde, respectively. The structures of the ligands and their Cu(II) complexes were characterized by IR, UV-Vis, NMR, Xray, magnetic measurements and TG techniques. The 2-[(E)-hydrazinylidenemethyl]-4nitrophenol derivative azine ligand (2) was found to be rearranged by the Cu(II) ion without water or acid/base catalyst. The redox behaviors of the ferrocene derivative compounds were investigated by cyclic voltammetry. Structural parameters and spectroscopic properties of the azine ligands (1 and 2) and the Cu(II) complex (1a) were calculated using DFT and TD-DFT/CPCM methods and the results were compared with the experimental data.

Synthesis and spectroscopic studies of homo-binuclear, alkoxo bridged homo- and hetero-tetranuclear metal complexes of a bis-N2O4 Schiff base ligand derived from ethanolamine and macroacyclic tetranaphthaldehyde

Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy, 2011

Three new homo-binuclear Ni(II), Cu(II), Zn(II) complexes (2-4), homo-tetranuclear Cu(II) complex... more Three new homo-binuclear Ni(II), Cu(II), Zn(II) complexes (2-4), homo-tetranuclear Cu(II) complex (5), and hetero-tetranuclear Cu(II)-Ni(II) complex (6) of a macroacyclic potentially bis-hexadentate N2O4 Schiff base have been synthesized. The imino-alcohol ligand, H4L was obtained by the condensation of ethanolamine with 2,2'-[2,3-bis(1-formyl-2-naphthyloxymethyl)-but-2-ene-1,4-diyldioxy]bis(naphthalene-1-carbaldehyde). The structures of both the Schiff base and its complexes have been proposed by elemental analyses, spectroscopic data i.e. IR, 1H and 13C NMR, UV-vis, electrospray ionisation mass spectra, molar conductivities and magnetic susceptibility measurements. The ligand has two similar compartments to bind first primary two metal ions, and acts bi- or tetra-negative, bis-tetradentate forming five membered chelate ring. However, secondary two metal ions (either Cu2+ or Ni2+) are ligated with dianionic oxygen atoms of the alcohol groups and are linked to the 1,10-phenanthr...

Novel phthalocyanines containing substituted salicyclic hydrazone-1,3-thiazole moieties: Microwave-assisted synthesis, spectroscopic characterization, X-ray structure and thermal characterization

Dyes and Pigments, 2010

Novel, metal-free and metallo(Cu, Co, Ni, Zn, Pb and Mn)phthalocyanine compounds were synthesized... more Novel, metal-free and metallo(Cu, Co, Ni, Zn, Pb and Mn)phthalocyanine compounds were synthesized by exposure to microwave irradiation and the products purified. The newly prepared compounds were characterized using elemental analyses, IR, 1 H/ 13 C NMR, 1 H-1 H COSY measurements, MS, UV-vis spectroscopy and DTA/TG analysis. The electronic spectra exhibited an intense p / p* transition with characteristic Q and B bands of the phthalocyanine core, as expected. All decomposition products obtained from DTA/TG analysis were identified; it was found that the thermal stability of each phthalocyanine compound followed the order: MnPc < Metal-free < ZnPc < PbPc < CuPc < CoPc < NiPc.

Acetate bridged dinuclear Cu(II) complexes with ferrocene based benzimidazol ligands: Synthesis, spectroscopy, electrochemistry, DFT calculations and catecholase activity

Polyhedron, 2016

Abstract Two new benzimidazole ligands, 1-[(E)-ferrocenylmethylidenehydrazino]-2-{5,6-dichloro-2-... more Abstract Two new benzimidazole ligands, 1-[(E)-ferrocenylmethylidenehydrazino]-2-{5,6-dichloro-2-[(o-chlorophenyl)methyl]-1,3-diaza-1H-inden-1-yl}-1-ethanone (1) and 1-[(E)-ferrocenylmethylidenehydrazino]-2-{2-[p-(trifluoromethyl)phenyl]-1,3-diaza-1H-inden-1-yl}-1-ethanone (2), and their copper(II) complexes (1a, 2a) have been prepared and characterized by IR, UV–Vis, NMR, TG/DTA and MALDI-TOF mass spectrometry. DFT-based molecular orbital energy calculations and the electrochemical behavior of the compounds have been also studied to explain the redox potentials of the compounds. The catecholase-mimetic activities of the complexes have been investigated by monitoring the formation of 3,5-di-tert-butyl-benzoquinone from 3,5-di-tert-butylcatechol. The catalytic activity of 1a is slightly lower than that of 2a, and the correlation between catalytic activity and electrochemical behaviors of the compounds has been established.

Microsoft Word - Talat Baran-özet

Talat BARAN, Kaan KARAOĞLU, Bayram DURAL ve Kerim SERBEST Rize Üniversitesi, Fen Edebiyat Fakülte... more Talat BARAN, Kaan KARAOĞLU, Bayram DURAL ve Kerim SERBEST Rize Üniversitesi, Fen Edebiyat Fakültesi, Kimya Bölümü 53100 Rize talatbaran_66@hotmail.com Özet; Bu çalışmada, aminoasit türevi yeni bir Schiff bazı ligandı ve geçiş metal kompleksleri hazırlanmıştır. Sentezlenen bileşiklerin yapıları H-NMR, IR, elementel analiz, UV, ICP, molar iletkenlik, manyetik duyarlılık, kütle spektrometresi verileri ile karakterize edilmiştir. Giriş; Son yıllarda oksijen ve azot atomu içeren Schiff bazı ligandlarındaki araştırmalar elektronik ve sterik çok yönlülüklerinden dolayı yoğun ilgi görmektedir [1]. Ayrıca biyokimyasal, analitik ve antimikrobiyal özelliklerinden dolayı Schiff bazları ve geçiş metal komplekslerine olan ilgi her geçen gün artmaktadır [2, 3]. Amino asit Schiff bazı kompleksleri biyolojik önemlerinden dolayı son yıllarda çok büyük ilgi görmüş, komplekslerinin anti bakteriyel ve anti kanser reaktif olarak kullanılabileceği de düşünülmektedir [4, 5]. Deneysel Kısım; Potasyum tuzu h...

Spectroscopic, electrochemical, theoretical characterization and biological evaluation of a ferrocenyl-substituted unsymmetric azine ligand and its Cu(II) complex

Journal of Coordination Chemistry, 2016

Abstract Ferrocenyl-substituted unsymmetrical azine and its Cu(II) complex were prepared. The red... more Abstract Ferrocenyl-substituted unsymmetrical azine and its Cu(II) complex were prepared. The redox active ferrocene-based azine was obtained by condensation of 1-[(E)-hydrazono]-5-bromo-2-hydroxybenzene with ferrocene carboxaldehyde. The ferrocenyl ligand and its Cu(II) complex were characterized by IR, UV–vis, NMR, X-ray, magnetic susceptibility, molar electrical conductivity measurements, and TG techniques. The redox behaviors of the ferrocene compounds were investigated by cyclic voltammetry. Structural parameters and spectroscopic properties of the ligand and the Cu(II) complex were calculated by employing density functional theory (DFT) and time-dependent DFT and compared with available experimental data. We found slightly stronger binding ability for Cu(II) complex than the free ligand. DNA binding abilities for ferrocenyl-substituted unsymmetrical azine ligand and its Cu(II) complex are higher than some reported ferrocene compounds. We also studied DNA cleavage, superoxide and DPPH radical scavenging abilities of the compounds. Furthermore, the synthesized organometallic compounds can be bound to DNA through an intercalative mode.

Mononuclear Cu(II) complex of an oxime ligand derived from N-Heterocyclic hydrazide: Synthesis, spectroscopy, electrochemistry, DFT calculations and catecholase activity

Journal of Molecular Structure

Abstract A new oxime derivative N-heterocyclic hydrazide ligand, N'-[(1E,2E)-2-(hydroxyimino)... more Abstract A new oxime derivative N-heterocyclic hydrazide ligand, N'-[(1E,2E)-2-(hydroxyimino)-1-methylpropylidene]-2-[(4-methyl-5-phenyl-4H-1,2,4-triazol-3-l)thio] acetohydrazide (1) and its mononuclear copper(II) complex (1a) have been synthesized and characterized by using IR, UV–Vis, NMR and MALDI-TOF mass spectrometry. DFT-based molecular orbital energy calculations and electrochemical behaviors of the compounds have been also studied to explain redox potential of the compounds. The catecholase-mimetic activity of the Cu(II) complex (1a) has been investigated by monitoring the formation of 3,5-di-tert-butyl-benzoquinone from 3,5-di-tert-butylcatechol. Irreversible electrochemical ring-closing of the ligand by oxidation is proposed. Electrochemical ring-closing reaction is shielded by the coordination of Cu(II) to the oxime moiety of the ligand and the title complex undergoes quasi-reversible oxidation and irreversible reduction. Under aerobic conditions, the title copper(II) complex behaves as an effective catalyst towards oxidation of 3,5-di-tert-butylcatechol to its corresponding quinone derivative in MeOH. The turnover number was found as 100.1 h−1.

Synthesis and Characterization of Cu(II) Complexes of Two Ligands Derived from Malonyl Dichloride

Turkish Journal of Chemistry, Mar 16, 2004

Two different mononucleating ligands incorporating N4 and N2S2 donor units, 2-(1,3-benzothiazole-... more Two different mononucleating ligands incorporating N4 and N2S2 donor units, 2-(1,3-benzothiazole-2-yl-methyl)-1,3-benzothiazole (L 1 ) and N,N'-bis-(2-amino-phenyl)-malonamide (H2L 2 ) were synthesized by a new method from malonyl dichloride as starting material, and their mononuclear copper(II) complexes were prepared and characterized by elemental analyses, 1 H-and 13 C-NMR, IR, magnetic moments and mass spectral studies. Elemental analyses, and stochiometric and spectroscopic data of the metal complexes indicate that the metal ions are coordinated to the nitrogen and sulfur atoms and the data support the proposed structure of L 1 , H2L 2 and their mononuclear copper(II) complexes. Moreover, the copper(II) complexes of L 1 and H2L 2 have a 1:1 metal to ligand ratio. In addition, the total energy and heat of formation calculated for complexes (2-3) by the semiempirical ZINDO/1 calculations showed that complexes 2 and 3 having penta coordinations are more stable than complexes of tetra coordinations.

Ferrocenyl-Substituted Dinuclear Cu(II) Complex: Synthesis, Spectroscopy, Electrochemistry, DFT Calculations and Catecholase Activity

Journal of Molecular Structure, 2015

Copper(II)–nickel(II) complexes of novel 1,9-dioxa-3,6-dithiacyclotridecane-10,12-dione and 1,4-dioxa-7,10-dithiacyclododecane-2,3-dione ligands

Transition Metal Chemistry, 2003

1,9-Dioxa-3,6-dithiacyclotridecane-10,12-dione (L1), and 1,4-dioxa-7,10-dithiacyclododecane-2,3-d... more 1,9-Dioxa-3,6-dithiacyclotridecane-10,12-dione (L1), and 1,4-dioxa-7,10-dithiacyclododecane-2,3-dione, (L2), two novel ligands, and their mono- and di-nuclear copper(II) and/or nickel(II) complexes have been prepared and characterized by elemental analyses, 1H- and 13C-n.m.r., i.r., magnetic moments and mass spectral studies. Elemental analyses, stochiometric and spectroscopic data on the complexes indicate that the metal ions are coordinated to the nitrogen, oxygen and sulphur atoms and the

DNA Hydrolysis by Homo- and Heteronuclear Cu(II)?Ni(II) Complexes of Two Diester-type Ligands

Monatshefte f�r Chemie/Chemical Monthly, 2004

Nucleolytic activities of novel mononuclear Cu(II), homo-and heterodinuclear Cu(II)-Ni(II) comple... more Nucleolytic activities of novel mononuclear Cu(II), homo-and heterodinuclear Cu(II)-Ni(II) complexes with two diester-type ligands were investigated on pCYTEXP by neutral agarose gel electrophoresis. The analyses of the cleavage products obtained electrophoretically indicate that the examined complexes induce very similar conformational changes on supercoiled DNA by converting supercoiled form to nicked form. At concentrations greater than 100 M, the complexes possessed effective nucleolytic activities for 10 min of incubation time. However, their nucleolytic activities did not increase significantly with longer periods of incubation. The pH-nucleolytic activity profiles of the complexes differed significantly. Metal complex induced DNA cleavage was also tested for inhibition by various radical scavengers. It could be proposed from the data that diffusible intermediate oxidants are not involved in these reactions or they are not necessary for DNA cleavage since none of antioxidants inhibited DNA cleaving activities of the complexes.

Binuclear transition metal complexes of a novel lateral N-methylthiosemicarbazone through the central ethylene bridge: Synthesis, structural characterization and the response of ligand molecule to different solvent media

Journal of Molecular Structure, 2008

Binuclear transition metal complexes of a novel lateralAN-methylthiosemicarbazone through the cen... more

Spectroscopic and theoretical study of 1,2,4-triazole-3-one based salicylaldimine complexes and evaluation of superoxide-scavenging properties

Journal of Molecular Structure, 2009

Five mononuclear metal complexes of Fe(III), Co(II), Ni(II), Cu(II) and Zn(II) have been synthesi... more Five mononuclear metal complexes of Fe(III), Co(II), Ni(II), Cu(II) and Zn(II) have been synthesized with a triazole-based Schiff base ligand, 4-{[(1E)-(2-hydroxyphenyl)methylene]amino}-5-(2-thienyl-methyl)-2,4-dihydro-3H-1,2,4-triazol-3-one. The structure of the compounds have been proposed by elemental analyses, spectroscopic data i.e. IR, 1 H and 13 C NMR, UV-vis, electrospray ionisation mass spectra, molar conductivities and magnetic susceptibility measurements. The molecular structure and vibrational frequencies of the compounds in the ground state has been calculated by density functional using Becke's three-parameter hybrid method with the Lee, Yang and Parr correlation functional methods with the Standard B3LYP/6-31GÃ(d,p) basis set. The computational frequencies are in good agreement with the experimental results. The superoxide dismutase (SOD) mimetic activity of the complexes have been investigated by utilizing xanthine-xanthine oxidase assay. The results indicate that the Co(II) complex is the most potent SOD mimetic of all synthesized complexes. j o u r n a l h o m e p a g e : w w w . e l s e v i e r . c o m / l o c a t e / m o l s t r u c

Two novel macroacyclic schiff bases containing bis-N2O2 donor set and their binuclear complexes: synthesis, spectroscopic and magnetic properties

Journal of Molecular Structure, 2009

Herein, we report two novel macroacyclic Schiff bases derived from tetranaphthaldehyde derivative... more Herein, we report two novel macroacyclic Schiff bases derived from tetranaphthaldehyde derivative compound and their binuclear Mn(II), Ni(II), Cu(II) and Zn(II) complexes. The structures of the compounds have been proposed by elemental analyses, spectroscopic data i.e. IR, 1 H and 13 C NMR, UV-Vis, electrospray ionisation mass spectra, molar conductivities and magnetic susceptibility measurements. The stoichiometries of the complexes derived from mass and elemental analysis correspond to the general formula [M 2 L(ClO 4 ) n ](ClO 4 ) 4Àn , (where M is Mn(II), Ni(II), Cu(II), Zn(II) and L represents the Schiff base ligands).

CCDC 972270: Experimental Crystal Structure Determination

An entry from the Cambridge Structural Database, the world's repository for small molecule cr... more An entry from the Cambridge Structural Database, the world's repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

Iron(III) Complexes Derived From Azo-Containing Salicylaldoxime Ligands: Synthesis, Structures and Biological Evaluations

El-Cezeri Fen ve Mühendislik Dergisi, 2021

Two novel mononuclear Fe(III) complexes derived from azo-containing salicylaldoxime ligands were ... more Two novel mononuclear Fe(III) complexes derived from azo-containing salicylaldoxime ligands were synthesized and characterized by elemental analyses, spectroscopic data i.e. IR, 1H NMR, UV-Vis, electrospray ionization mass spectra, molar conductivity, and magnetic susceptibility measurements. Both the experimental and theoretical results strongly suggest that the ligands have a major contribution to the azo enol imine form instead of the hydrazo keto imine and azo keto amine forms in solution/solid-state. The electronic spectra of the ligands and their iron(III) complexes were calculated theoretically for the band assignments by using DFT and TD-DFT/CPCM methods. DNA binding, cleavage, and antioxidative activities of the investigated compounds were studied. It has been shown that the ligands and their iron (III) complexes tested bind to DNA via the intercalative mode. It was observed that all molecules tested inhibited topoisomerase I almost to the same degree. One of the most striking results among the antioxidant activity tests is that the hydroxyl radical scavenging activities of the ligands and complexes are higher than the standard antioxidant mannitol.

Oxime derivative unsymmetrical azine, its Ni(II), Cu(II) and Zn(II) complexes: Synthesis, spectroscopy and catecholase activity

Heteroatom Chemistry, 2018

1-[(Z)-{(2E)-[(3E)-3-(hydroxyimino)butan-lidene]hydrazinylidene}methyl]naphthalen-2-ol, H2L (3) w... more 1-[(Z)-{(2E)-[(3E)-3-(hydroxyimino)butan-lidene]hydrazinylidene}methyl]naphthalen-2-ol, H2L (3) was synthesized by the agents of 2-hydroxy-1-naphtaldehyde, 2,3-butanedione monoxime and hydrazine in two steps. The structures of the compounds have been proposed by elemental analyses, spectroscopic data, that is, IR, 1 H NMR, UV-vis, X-ray, mass spectra (ESI or TOF), molar conductivities and magnetic susceptibility measurements. The ligand has potentially three nitrogens and an oxygen donor to be able to bind a metal center. In the light of analytical and physical results, it was suggested that the ligand may coordinate to by N,O/N2/N2O donor set to form square planar, octahedral, distorted square planar and tetrahedral complexes. Proton NMR evidence indicating that the ligand coordinates the metal ion through the phenolic oxygen and nitrogen of imine in the nickel and zinc complexes. Molar conductivity measurements reveal that all the complexes are non-electrolytes. In addition, catecholase activities of the complexes were studied. However, the only one of the complexes, 1b, behaves as an effective catalyst toward oxidation of 3,5-di-tert-butylcatechol (3,5-DTBC) to its corresponding quinone derivative in MeOH saturated with O 2. The reaction follows Michaelis-Menten enzymatic reaction kinetics with turnover numbers (kcat) 1.19 × 10 3 /hour. N(3)-N(2) 1.398 (4) C(7)-C(8)-C(9) 121.3 (4) N(3)-C(5) 1.285 (4) C(12)-C(11)-C(10) 121.4 (5) N(2)-C(3) 1.291 (4) C(15)-C(14)-C(13) 119.1 (4)

Heteroligand bivalent transition metal complexes with an azo-oxime ligand and 1,10-phenanthroline: Synthesis, spectroscopy, thermal analysis, DFT calculations and SOD-mimetic activities

Journal of Molecular Structure, 2020

This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

Synthesis, in vitro DNA interactions, cytotoxicities, antioxidative activities, and topoisomerase inhibition potentials of Mn(II), Co(II), Ni(II), Cu(II), and Zn(II) complexes with azo-oxime ligands

TURKISH JOURNAL OF CHEMISTRY, 2017

Mn(II), Co(II), Ni(II), Cu(II), and Zn(II) transition metal complexes of 2-hydroxy-5-[(E)-(4-phen... more Mn(II), Co(II), Ni(II), Cu(II), and Zn(II) transition metal complexes of 2-hydroxy-5-[(E)-(4-phenyl) diazenyl] benzaldehyde oxime and 2-hydroxy-5-[(E)-(4-nitrophenyl) diazenyl] benzaldehyde oxime ligands were synthesized and characterized through NMR, IR, ESI mass, and UV analysis. DNA binding abilities of the complexes were revealed using a UV-Vis spectrophotometer with the absorption titration and competitive binding techniques. Hydrolytic and oxidative DNA cleavage activities under different conditions were also proved. Topoisomerase I inhibition efficiencies and in vitro free radical scavenging activities of all complexes were examined. Finally, the selective cytotoxic potentials of all complexes were evaluated in human colon cancer, normal colon, and fibroblast cell lines using the water-soluble tetrazolium salt (WST-1) assay. The complexes had the ability to intercalate into stacked base pairs of DNA and topoisomerase I activity was reasonably inhibited in their presence in 0.4 mM concentrations. The abilities for scavenging of DPPH and hydroxyl radicals were found to be higher than those of known standard antioxidants (ascorbic acid, butylated hydroxyanisole, and mannitol). The results obtained from the cytotoxicity experiments are especially promising for further research, which must be carried out for the evaluation of the studied complexes as anticancer drugs.

Microwave-assisted synthesis and characterization and theoretical calculations of the first example of free and metallophthalocyanines from salen type Schiff base derivative bearing thiophen and triazole heterocyclic rings

Journal of Organometallic Chemistry, Dec 1, 2007

ABSTRACT Novel metal-free and metallophthalocyanine complexes of Co, Ni, Cu, and Zn have been syn... more ABSTRACT Novel metal-free and metallophthalocyanine complexes of Co, Ni, Cu, and Zn have been synthesized by exposure to microwave irradiation and reflux conditions and the products purified by several techniques. The newly prepared compounds have been characterized by elemental analyses, IR, 1H NMR, MS and UV–Vis spectroscopy. Furthermore, theoretical calculations of metallophthalocyanines CuPc, NiPc, ZnPc and CoPc were carried out to comparatively describe the molecular structures, molecular orbital and UV–Vis spectra of metallophthalocyanine complexes by the HF theory. A comparison between the different molecules for the geometry, molecular orbitals was made. The simulated order of the sizes of the central hole was CoPc&amp;gt;NiPcZnPc&amp;gt;CuPc. The calculated structures, electronic absorption spectra of metallophthalocyanine complexes are in good consistency with the experimental results.

Two novel unsymmetrical ferrocene based azines and their complexing abilities towards Cu(II): Spectroscopy, crystal structure, electrochemistry and DFT calculations

Polyhedron, 2015

Two new ferrocenyl-substituted unsymmetric azine ligands and their Cu(II) complexes were prepared... more Two new ferrocenyl-substituted unsymmetric azine ligands and their Cu(II) complexes were prepared. The redox active ferrocene-based azine ligands 1 and 2 were obtained by the condensation of 1-[(E)-hydrazinylidenemethyl]naphthalen-2-ol and 2-[(E)hydrazinylidenemethyl]-4-nitrophenol with ferrocene carboxaldehyde, respectively. The structures of the ligands and their Cu(II) complexes were characterized by IR, UV-Vis, NMR, Xray, magnetic measurements and TG techniques. The 2-[(E)-hydrazinylidenemethyl]-4nitrophenol derivative azine ligand (2) was found to be rearranged by the Cu(II) ion without water or acid/base catalyst. The redox behaviors of the ferrocene derivative compounds were investigated by cyclic voltammetry. Structural parameters and spectroscopic properties of the azine ligands (1 and 2) and the Cu(II) complex (1a) were calculated using DFT and TD-DFT/CPCM methods and the results were compared with the experimental data.

Synthesis and spectroscopic studies of homo-binuclear, alkoxo bridged homo- and hetero-tetranuclear metal complexes of a bis-N2O4 Schiff base ligand derived from ethanolamine and macroacyclic tetranaphthaldehyde

Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy, 2011

Three new homo-binuclear Ni(II), Cu(II), Zn(II) complexes (2-4), homo-tetranuclear Cu(II) complex... more Three new homo-binuclear Ni(II), Cu(II), Zn(II) complexes (2-4), homo-tetranuclear Cu(II) complex (5), and hetero-tetranuclear Cu(II)-Ni(II) complex (6) of a macroacyclic potentially bis-hexadentate N2O4 Schiff base have been synthesized. The imino-alcohol ligand, H4L was obtained by the condensation of ethanolamine with 2,2'-[2,3-bis(1-formyl-2-naphthyloxymethyl)-but-2-ene-1,4-diyldioxy]bis(naphthalene-1-carbaldehyde). The structures of both the Schiff base and its complexes have been proposed by elemental analyses, spectroscopic data i.e. IR, 1H and 13C NMR, UV-vis, electrospray ionisation mass spectra, molar conductivities and magnetic susceptibility measurements. The ligand has two similar compartments to bind first primary two metal ions, and acts bi- or tetra-negative, bis-tetradentate forming five membered chelate ring. However, secondary two metal ions (either Cu2+ or Ni2+) are ligated with dianionic oxygen atoms of the alcohol groups and are linked to the 1,10-phenanthr...

Novel phthalocyanines containing substituted salicyclic hydrazone-1,3-thiazole moieties: Microwave-assisted synthesis, spectroscopic characterization, X-ray structure and thermal characterization

Dyes and Pigments, 2010

Novel, metal-free and metallo(Cu, Co, Ni, Zn, Pb and Mn)phthalocyanine compounds were synthesized... more Novel, metal-free and metallo(Cu, Co, Ni, Zn, Pb and Mn)phthalocyanine compounds were synthesized by exposure to microwave irradiation and the products purified. The newly prepared compounds were characterized using elemental analyses, IR, 1 H/ 13 C NMR, 1 H-1 H COSY measurements, MS, UV-vis spectroscopy and DTA/TG analysis. The electronic spectra exhibited an intense p / p* transition with characteristic Q and B bands of the phthalocyanine core, as expected. All decomposition products obtained from DTA/TG analysis were identified; it was found that the thermal stability of each phthalocyanine compound followed the order: MnPc < Metal-free < ZnPc < PbPc < CuPc < CoPc < NiPc.

Acetate bridged dinuclear Cu(II) complexes with ferrocene based benzimidazol ligands: Synthesis, spectroscopy, electrochemistry, DFT calculations and catecholase activity

Polyhedron, 2016

Abstract Two new benzimidazole ligands, 1-[(E)-ferrocenylmethylidenehydrazino]-2-{5,6-dichloro-2-... more Abstract Two new benzimidazole ligands, 1-[(E)-ferrocenylmethylidenehydrazino]-2-{5,6-dichloro-2-[(o-chlorophenyl)methyl]-1,3-diaza-1H-inden-1-yl}-1-ethanone (1) and 1-[(E)-ferrocenylmethylidenehydrazino]-2-{2-[p-(trifluoromethyl)phenyl]-1,3-diaza-1H-inden-1-yl}-1-ethanone (2), and their copper(II) complexes (1a, 2a) have been prepared and characterized by IR, UV–Vis, NMR, TG/DTA and MALDI-TOF mass spectrometry. DFT-based molecular orbital energy calculations and the electrochemical behavior of the compounds have been also studied to explain the redox potentials of the compounds. The catecholase-mimetic activities of the complexes have been investigated by monitoring the formation of 3,5-di-tert-butyl-benzoquinone from 3,5-di-tert-butylcatechol. The catalytic activity of 1a is slightly lower than that of 2a, and the correlation between catalytic activity and electrochemical behaviors of the compounds has been established.

Microsoft Word - Talat Baran-özet

Talat BARAN, Kaan KARAOĞLU, Bayram DURAL ve Kerim SERBEST Rize Üniversitesi, Fen Edebiyat Fakülte... more Talat BARAN, Kaan KARAOĞLU, Bayram DURAL ve Kerim SERBEST Rize Üniversitesi, Fen Edebiyat Fakültesi, Kimya Bölümü 53100 Rize talatbaran_66@hotmail.com Özet; Bu çalışmada, aminoasit türevi yeni bir Schiff bazı ligandı ve geçiş metal kompleksleri hazırlanmıştır. Sentezlenen bileşiklerin yapıları H-NMR, IR, elementel analiz, UV, ICP, molar iletkenlik, manyetik duyarlılık, kütle spektrometresi verileri ile karakterize edilmiştir. Giriş; Son yıllarda oksijen ve azot atomu içeren Schiff bazı ligandlarındaki araştırmalar elektronik ve sterik çok yönlülüklerinden dolayı yoğun ilgi görmektedir [1]. Ayrıca biyokimyasal, analitik ve antimikrobiyal özelliklerinden dolayı Schiff bazları ve geçiş metal komplekslerine olan ilgi her geçen gün artmaktadır [2, 3]. Amino asit Schiff bazı kompleksleri biyolojik önemlerinden dolayı son yıllarda çok büyük ilgi görmüş, komplekslerinin anti bakteriyel ve anti kanser reaktif olarak kullanılabileceği de düşünülmektedir [4, 5]. Deneysel Kısım; Potasyum tuzu h...

Spectroscopic, electrochemical, theoretical characterization and biological evaluation of a ferrocenyl-substituted unsymmetric azine ligand and its Cu(II) complex

Journal of Coordination Chemistry, 2016

Abstract Ferrocenyl-substituted unsymmetrical azine and its Cu(II) complex were prepared. The red... more Abstract Ferrocenyl-substituted unsymmetrical azine and its Cu(II) complex were prepared. The redox active ferrocene-based azine was obtained by condensation of 1-[(E)-hydrazono]-5-bromo-2-hydroxybenzene with ferrocene carboxaldehyde. The ferrocenyl ligand and its Cu(II) complex were characterized by IR, UV–vis, NMR, X-ray, magnetic susceptibility, molar electrical conductivity measurements, and TG techniques. The redox behaviors of the ferrocene compounds were investigated by cyclic voltammetry. Structural parameters and spectroscopic properties of the ligand and the Cu(II) complex were calculated by employing density functional theory (DFT) and time-dependent DFT and compared with available experimental data. We found slightly stronger binding ability for Cu(II) complex than the free ligand. DNA binding abilities for ferrocenyl-substituted unsymmetrical azine ligand and its Cu(II) complex are higher than some reported ferrocene compounds. We also studied DNA cleavage, superoxide and DPPH radical scavenging abilities of the compounds. Furthermore, the synthesized organometallic compounds can be bound to DNA through an intercalative mode.

Mononuclear Cu(II) complex of an oxime ligand derived from N-Heterocyclic hydrazide: Synthesis, spectroscopy, electrochemistry, DFT calculations and catecholase activity

Journal of Molecular Structure

Abstract A new oxime derivative N-heterocyclic hydrazide ligand, N'-[(1E,2E)-2-(hydroxyimino)... more Abstract A new oxime derivative N-heterocyclic hydrazide ligand, N'-[(1E,2E)-2-(hydroxyimino)-1-methylpropylidene]-2-[(4-methyl-5-phenyl-4H-1,2,4-triazol-3-l)thio] acetohydrazide (1) and its mononuclear copper(II) complex (1a) have been synthesized and characterized by using IR, UV–Vis, NMR and MALDI-TOF mass spectrometry. DFT-based molecular orbital energy calculations and electrochemical behaviors of the compounds have been also studied to explain redox potential of the compounds. The catecholase-mimetic activity of the Cu(II) complex (1a) has been investigated by monitoring the formation of 3,5-di-tert-butyl-benzoquinone from 3,5-di-tert-butylcatechol. Irreversible electrochemical ring-closing of the ligand by oxidation is proposed. Electrochemical ring-closing reaction is shielded by the coordination of Cu(II) to the oxime moiety of the ligand and the title complex undergoes quasi-reversible oxidation and irreversible reduction. Under aerobic conditions, the title copper(II) complex behaves as an effective catalyst towards oxidation of 3,5-di-tert-butylcatechol to its corresponding quinone derivative in MeOH. The turnover number was found as 100.1 h−1.

Synthesis and Characterization of Cu(II) Complexes of Two Ligands Derived from Malonyl Dichloride

Turkish Journal of Chemistry, Mar 16, 2004

Two different mononucleating ligands incorporating N4 and N2S2 donor units, 2-(1,3-benzothiazole-... more Two different mononucleating ligands incorporating N4 and N2S2 donor units, 2-(1,3-benzothiazole-2-yl-methyl)-1,3-benzothiazole (L 1 ) and N,N'-bis-(2-amino-phenyl)-malonamide (H2L 2 ) were synthesized by a new method from malonyl dichloride as starting material, and their mononuclear copper(II) complexes were prepared and characterized by elemental analyses, 1 H-and 13 C-NMR, IR, magnetic moments and mass spectral studies. Elemental analyses, and stochiometric and spectroscopic data of the metal complexes indicate that the metal ions are coordinated to the nitrogen and sulfur atoms and the data support the proposed structure of L 1 , H2L 2 and their mononuclear copper(II) complexes. Moreover, the copper(II) complexes of L 1 and H2L 2 have a 1:1 metal to ligand ratio. In addition, the total energy and heat of formation calculated for complexes (2-3) by the semiempirical ZINDO/1 calculations showed that complexes 2 and 3 having penta coordinations are more stable than complexes of tetra coordinations.

Ferrocenyl-Substituted Dinuclear Cu(II) Complex: Synthesis, Spectroscopy, Electrochemistry, DFT Calculations and Catecholase Activity

Journal of Molecular Structure, 2015

Copper(II)–nickel(II) complexes of novel 1,9-dioxa-3,6-dithiacyclotridecane-10,12-dione and 1,4-dioxa-7,10-dithiacyclododecane-2,3-dione ligands

Transition Metal Chemistry, 2003

1,9-Dioxa-3,6-dithiacyclotridecane-10,12-dione (L1), and 1,4-dioxa-7,10-dithiacyclododecane-2,3-d... more 1,9-Dioxa-3,6-dithiacyclotridecane-10,12-dione (L1), and 1,4-dioxa-7,10-dithiacyclododecane-2,3-dione, (L2), two novel ligands, and their mono- and di-nuclear copper(II) and/or nickel(II) complexes have been prepared and characterized by elemental analyses, 1H- and 13C-n.m.r., i.r., magnetic moments and mass spectral studies. Elemental analyses, stochiometric and spectroscopic data on the complexes indicate that the metal ions are coordinated to the nitrogen, oxygen and sulphur atoms and the

DNA Hydrolysis by Homo- and Heteronuclear Cu(II)?Ni(II) Complexes of Two Diester-type Ligands

Monatshefte f�r Chemie/Chemical Monthly, 2004

Nucleolytic activities of novel mononuclear Cu(II), homo-and heterodinuclear Cu(II)-Ni(II) comple... more Nucleolytic activities of novel mononuclear Cu(II), homo-and heterodinuclear Cu(II)-Ni(II) complexes with two diester-type ligands were investigated on pCYTEXP by neutral agarose gel electrophoresis. The analyses of the cleavage products obtained electrophoretically indicate that the examined complexes induce very similar conformational changes on supercoiled DNA by converting supercoiled form to nicked form. At concentrations greater than 100 M, the complexes possessed effective nucleolytic activities for 10 min of incubation time. However, their nucleolytic activities did not increase significantly with longer periods of incubation. The pH-nucleolytic activity profiles of the complexes differed significantly. Metal complex induced DNA cleavage was also tested for inhibition by various radical scavengers. It could be proposed from the data that diffusible intermediate oxidants are not involved in these reactions or they are not necessary for DNA cleavage since none of antioxidants inhibited DNA cleaving activities of the complexes.

Binuclear transition metal complexes of a novel lateral N-methylthiosemicarbazone through the central ethylene bridge: Synthesis, structural characterization and the response of ligand molecule to different solvent media

Journal of Molecular Structure, 2008

Binuclear transition metal complexes of a novel lateralAN-methylthiosemicarbazone through the cen... more

Spectroscopic and theoretical study of 1,2,4-triazole-3-one based salicylaldimine complexes and evaluation of superoxide-scavenging properties

Journal of Molecular Structure, 2009

Five mononuclear metal complexes of Fe(III), Co(II), Ni(II), Cu(II) and Zn(II) have been synthesi... more Five mononuclear metal complexes of Fe(III), Co(II), Ni(II), Cu(II) and Zn(II) have been synthesized with a triazole-based Schiff base ligand, 4-{[(1E)-(2-hydroxyphenyl)methylene]amino}-5-(2-thienyl-methyl)-2,4-dihydro-3H-1,2,4-triazol-3-one. The structure of the compounds have been proposed by elemental analyses, spectroscopic data i.e. IR, 1 H and 13 C NMR, UV-vis, electrospray ionisation mass spectra, molar conductivities and magnetic susceptibility measurements. The molecular structure and vibrational frequencies of the compounds in the ground state has been calculated by density functional using Becke's three-parameter hybrid method with the Lee, Yang and Parr correlation functional methods with the Standard B3LYP/6-31GÃ(d,p) basis set. The computational frequencies are in good agreement with the experimental results. The superoxide dismutase (SOD) mimetic activity of the complexes have been investigated by utilizing xanthine-xanthine oxidase assay. The results indicate that the Co(II) complex is the most potent SOD mimetic of all synthesized complexes. j o u r n a l h o m e p a g e : w w w . e l s e v i e r . c o m / l o c a t e / m o l s t r u c

Two novel macroacyclic schiff bases containing bis-N2O2 donor set and their binuclear complexes: synthesis, spectroscopic and magnetic properties

Journal of Molecular Structure, 2009

Herein, we report two novel macroacyclic Schiff bases derived from tetranaphthaldehyde derivative... more Herein, we report two novel macroacyclic Schiff bases derived from tetranaphthaldehyde derivative compound and their binuclear Mn(II), Ni(II), Cu(II) and Zn(II) complexes. The structures of the compounds have been proposed by elemental analyses, spectroscopic data i.e. IR, 1 H and 13 C NMR, UV-Vis, electrospray ionisation mass spectra, molar conductivities and magnetic susceptibility measurements. The stoichiometries of the complexes derived from mass and elemental analysis correspond to the general formula [M 2 L(ClO 4 ) n ](ClO 4 ) 4Àn , (where M is Mn(II), Ni(II), Cu(II), Zn(II) and L represents the Schiff base ligands).