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Article Citation - WoS: 2Citation - Scopus: 3Spectroelectrochemical Investigations of Pyrimidine-2 Binuclear Platinum(iii) Complexes(Pergamon-elsevier Science Ltd, 2014) Ozbek, Ozge; Özalp Yaman, Şeniz; Ozalp-Yaman, Seniz; Ozkan, Ilker; Onal, Ahmet M.; Isci, Huseyin; Özalp Yaman, Şeniz; Chemical Engineering; Chemical EngineeringThe electrochemical behavior of the binuclear platinum(III-III) complexes [Pt-2(C4H3N2S)(4)X-2] (C4H3N2S- = pyrimidine-2-thionate; X- = Cl--,Cl- Br--,Br- I-) have been studied by cyclic voltammetry and insitu spectroelectrochemistry in an acetonitrile-tetrabutylammonium tetrafluoroborate solventelectrolyte couple. An irreversible metal based reduction appears during the cathodic scan for each of the three complexes. The changes in UV-Vis spectra observed in-situ during the reductive electrolysis indicate that all three complexes give the same product, [Pt-2(C4H3N2S)(4)], with a Pt(II)-Pt(II) system. The changes in the reduction potentials of the complexes on changing the axial ligands are interpreted by the changes in the energy of the LUMO level, which is determined by the degree of sigma- and it-interactions of the axial halide ligands with the metal atoms. DFT (B3LYP/LanL2DZ) calculations support our experimental data. (c) 2014 Elsevier Ltd. All rights reserved.Article Citation - WoS: 4Citation - Scopus: 4Radicalic Cleavage Pathway and Dna Docking Studies of Novel Chemotherapic Platinum Agent of 5,6-Di(Pergamon-elsevier Science Ltd, 2019) El Hag, Rabia; Abdusalam, Mohamed Musbah; Acilan, Ceyda; Kayi, Hakan; Ozalp-Yaman, SenizA new Pt(II) complex of the general formula ([PtCl2(L)]center dot H2O), where L is 5,6-di-2-thienyl-2,3-dihydropyrazine is synthesized as a potential antitumor agent and its structure is elucidated using a variety of physical and chemical procedures. DNA attaching ability of the complex is studied spectroscopically. UV and fluorometric titration, viscometric measurements and thermal decomposition studies agreed that two binding mode of actions, covalent and non-covalent bindings, are possible simultaneously. DNA helix cleavage studies clearly indicated OH center dot radical pathway in the presence of the reducing agent. Quantum mechanical calculations are carried out to call the minimum energy structures of the ligand and the complex, and to determine the FTIR, H-1 NMR and UV-Vis spectra using the density functional theory (DFT) at the B3LYP/LANL2DZ level of theory. Calculated geometrical parameters for the complex indicated a square-planar structure around the metallic center through the dithiopyridyl ring and two chlorine atoms. The minimum energy structure of the complex obtained from DFT conformational analysis is used in docking studies to investigate complex-DNA binding mechanisms. The complex interacts with DNA through three different mechanisms, namely, intercalation, covalent and electrostatic interaction. The most stable mode of interaction with lowest binding energy (-333.6 kcal/mol) was intercalation mode. Comparisons between theoretical and experimental findings are performed and a good agreement is obtained. (C) 2019 Elsevier Ltd. All rights reserved.Article Citation - WoS: 3Citation - Scopus: 3Spectroelectrochemical Investigation of Nuclease Active Pt(II) Complexes Containing Pyrrole Oxime(Pergamon-elsevier Science Ltd, 2015) Erdogan, Deniz Altunoz; Kayi, Hakan; Ozalp-Yaman, SenizIn this paper, the electrochemical oxidation of three Pt(II) complexes containing pyrrole oxime (HL) having a general formula of [Pt(NH3)Cl(L)] (1), [Pt(L)(2)] (2), and K[PtCl2(L)] (3) has been investigated by in-situ spectroelectrochemistry in dimethylformamide (DMF). An irreversible metal-based oxidation process occurs during the anodic scan for each of the three complexes. The electronic absorption spectral changes indicate that all the three complexes generate similar Pt(IV) compounds and free ligand. Our experimental data is supported by quantum chemistry calculations utilizing density functional theory. In addition, the frontier orbital energy distributions indicate that electron densities are localized on mainly platinum atom. (C) 2015 Elsevier Ltd. All rights reserved.
