Electrochemical and spectral properties of octakis(hexylthio)-substituted phthalocyanines

Abstract

Abstract The redox properties of octakis(hexylthio)-substituted phthalocyanines with 2H, ZnII and CuII in the phthalocyanine core have been investigated by cyclic voltammetry in dichloromethane and the energies of photo-excitation and oxido-reduction processes have been compared. Two successive one-electron reduction and one-electron oxidation processes were observed for the complexes used in this work. The displacement of two protons in the inner core with metal ion was found to shift the first reduction potential of phthalocyanine ring to more negative values as a result of the π-back donation of the filld dπ of metal ion into the empty pc-π ∗ orbitals. The evaluation of cyclic voltammetry data together with the absorption spectra showed that photoexciatation arises from the orbitals below the HOMO for all the complexes used in this work.