Assignment of absorption and magnetic circular dichroism spectra of solid, ? phase metallophthalocyanines

Abstract

Absorption and magnetic circular dichroism (m.c.d.) spectra of the α polymorphic form of a series of phthalocyanines CH2Pc, CoPe, NiPc and CuPc have been observed between 12 000 and 40 000 cm–1. Band shape analysis of both the absorption and m.c.d. data reveals Davydov splittings in both the Q and B (Soret) bands and suggests the existence of two π to π* transitions in the latter region. This lends support to previous assignments of the solution spectra of ZnPc. At higher energy no Davydov splittings are observed in the N band leading to a revised n→π* assignment.