Photooxidation of metallophthalocyanines: the effects of singlet oxygen and PcM-O2 complex formation

Abstract

The importance of singlet oxygen mechanism in photooxidation of phthalocyanine chromophore has been studied for promising singlet oxygen sensitizers: metal-free tetra-tert-butyl phthalocyanine and its Zn , Mg or Al complexes. It has been found that involvement of singlet oxygen in phthalocyanine photodegradation is dependent on the presence and character of the central metal atom, being the most prominent for the metal-free compound and almost negligible for the Al complex. The interaction of dioxygen with metal centers results in a sharp increase of phthalocyanine photooxidation rate.