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  • Article
    Citation - WoS: 2
    Citation - Scopus: 3
    Spectroelectrochemical 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 Engineering
    The 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: 4
    Citation - Scopus: 7
    Simultaneous Novel Synthesis of Conducting and Non-Conducting Halogenated Polymers by Electroinitiation of (2,4,6-Trichloro or 2,6-Dichlorophenolato)ni(ii) Complexes
    (Elsevier Sci Ltd, 2005) Özalp-Yaman, S; Özalp Yaman, Şeniz; Bastürkmen, M; Kisakürek, D; Özalp Yaman, Şeniz; Chemical Engineering; Chemical Engineering
    NiL2(Ph)(2)(.)xH(2)O [L=3,5-dimethylpyrazole or N-methyl imidazole; Ph=DCP or TCP; x=0, 1 or 3] complexes were synthesised and characterised by analytical and spectroscopic methods using elemental analysis and FTIR. The electrochemical behavior of the complexes was studied by cyclic voltammetry in tetrabutylammoniumtetrafluoroborate-N,N-dimethylformamide electrolyte-sol vent couple. Cyclic voltammogram of the complexes displayed two-step oxidation processes under the nitrogen gas atmosphere. The polymerization of the complexes was accomplished in the same solvent-electrolyte couple by the constant potential electrolysis of NiL2(Ph)(2)(.)xH(2)O, synthesizing the poly(di- or monochlorophenylene oxide)s via free radical mechanism. The simultaneous polymerization of non-conducting polymer and conducting polymer (the conductivity of 0.7 S cm(-2)) were achieved by electroinitiated polymerization of Ni(DMPz)(2)(TCP)(2). The structural analysis of the polymers were performed using FTIR, H-1 NMR and C-13 NMR spectroscopic techniques and DSC for the thermal analysis. The kinetics of the polymerization was followed by in situ UV-vis spectrophotometer during the electrolysis. The low temperature ESR spectrum of the electrolysis solution also confirmed the formation of phenol radical (g=2.0028). One electron oxidation process of NiL2(DCP)(2)(.)xH(2)O produces a new Ni(II) complex, Ni(L-L)(DCP)(2)(S) by the rapid decomposition of (NiL2)-L-III(DCP)(2) into a ligand radical producing a singlet with the g value of 2.0015. Second electron oxidation process generates oligemers, which could not be isolated from the electrolyte solution. (c) 2005 Elsevier Ltd. All rights reserved.