Iron(III) phthalocyanines: oxidation and spin states of iron in iron phthalocyanines with carboxyl groups

Abstract

Mössbauer and e.s.r. spectroscopy have revealed that 2,3,9,10,16,17,23,24-octacarboxy-(1), 2,9,16,23-tetracarboxy-(2), and 2,9 (or 10)- and 2,16 (or 17)-bis(3′,4′-dicarboxybenzoyl)-phthalocyaninatoiron (3) are mixtures of high-spin iron (III) and low-spin iron (III) complexes and that intermediate-spin species may be present in (2) in the solid state. However, the low-spin component disappears when the phthalocyanines are immobilized on poly(styrene). The properties of these compounds in solution are described on the basis of e.s.r., m.c.d., and u.v. spectroscopy.