Simultaneous novel synthesis of conducting and non-conducting halogenated polymers by electroinitiation of (2,4,6-trichloro- or 2,6-dichlorophenolato)Ni(II) complexes

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

Electrochemical and quantum chemical studies on mitomycin and adriamycin

In-situ spectroelectrochemical redox behaviour of two prominent chemotherapeutic agents, mitomycin and adriamycin were studied at constant potential. AM 1 (UHF) type quantum chemical calculations on the neutral as well as radical anion and cation forms of mitomycin and adriamycin were performed

Electrochemistry of nickel(II) complexes with N,N'-bis(3,5-di-tert-butylsalicylidene)polymethylenediamines

The electrochemical oxidation of several N,N'-polymethylenebis(3,5-di-tert- butylsalicylaldiminato)nickel(II) complexes, Ni(L-x), has been studied by cyclic voltammetry and in situ UV-Vis spectroscopy in DMF Cyclic voltammograms of Ni(L-x) (x = 1-4) complexes displayed two-step oxidation processes under nitrogen gas atmosphere. The first oxidation peak potentials of all the Ni(II) complexes corresponds to the reversible one-electron oxidation process of the metal center, yielding Ni(III) species. EPR spectrum of the electrolysis solution was recorded after one electron transfer at liquid nitrogen temperature also confirms the formation of [Ni-III (L-3)](+) species (g(x) > g(y) > g(z)) with a (2)A(1)(d(z)(2))(1) ground state. Upon addition of pyridine to one electron oxidised solutions a new penta coordinated species, [Ni-III(L-3)Py](+) (g(perpendicular to) > g(parallel to), a(parallel to)(N-14) = 8 G), was produced. The second oxidation peak of the complexes was assigned as the ligand based oxidation, generating a coordinated phenoxy radical species