ELECTROCHEMICAL AND SPECTRAL PROPERTIES OF OCTAKIS(HEXYLTHIO)-SUBSTITUTED PHTHALOCYANINES

The redox properties of octakis(hexylthio)-substituted phthalocyanines with 2H, Zn-II and Cu-II in the phthalocyanine core have been investi gated by cyclic voltammetry in dichloromethane and the energies of pho to-excitation and oxide-reduction processes have been compared. Two su ccessive one-electron reduction and one-electron oxidation processes w ere 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 fi rst reduction potential of phthalocyanine ring to more negative values as a result of the pi-back donation of the filled d(pi) of metal ion into the empty pc-pi orbitals. The evaluation of cyclic voltammetry d ata together with the absorption spectra showed that photoexcitation a rises from the orbitals below the HOMO for all the complexes used in t his work. (C) 1997 Elsevier Science Ltd.