Electrochemistry and spectroelectrochemistry of strongly electron-withdrawing metallated octanitrophthalocyanines

The spectral and electrochemical properties of metallated octanitrophthaloc yanines, [M-II{(NO2)(8)pc}] where M = Zn, Cu or Co, were studied by electro chemical and spectroelectrochemical methods as well as electronic absorptio n and magnetic circular dichroism spectroscopy. Aggregation is observed for several species. The octanitrophthalocyanines are easier to reduce and mor e difficult to oxidize than most other metallophthalocyanines. Indeed, the first ring-localized reduction potential observed with these phthalocyanine species, is the most positive of the metallated, neutral phthalocyanines i n the literature. These data are added to existing Hammett free energy rela tionship database to extend design protocols for substituted metallophthalo cyanines. Optical spectra for several redox series are presented and relate d to the existing literature.