Abstract:

In this study, the synthesis, electrochemical and spectroelectrochemical properties of new peripherally 1,2,4-triazole substituted metal-free 4, Zn(II) 5, Ti(IV) 6, Ni(II) 7 and Co(II) 8 phthalocyanine derivatives were reported. Voltammetric and in situ spectroelectrochemical characterization of the complexes were performed in solution. Since nickel and zinc phthalocyanines gave common phthalocyanine ring based electron transfer reactions with the characteristic “energy gaps”, “peak to peak potential separations” and “half wave peak potential values”, CoII and TiIVO metal ions behaved as redox active cations in the core of the cobalt and titanium phthalocyanine complexes, respectively. While cobalt phthalocyanine gave a one-electron [CoIIPc-2]/[CoIPc-2]-1 reduction reaction, titanium phthalocyanine illustrated two metal based reduction reactions, [TiIVOPc-2]/[TiIIIOPc-2]-1 and [TiIIIOPc-2]-1/[TiIIIOPc-2]-2, in addition to the Pc ligand reduction processes. Electron transfer reactions altered the spectra of the complexes considerably, which is one of the most important expectations for the practical applications of the complexes especially in display technologies. Redox and spectral responses of cobalt and titan complexes were affected by the molecular oxygen present in the electrolyte, which indicates electrocatalytic and electrosensing activity of the complexes towards the molecular oxygen.

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