Photoredox reaction of image with PctsH2 = phthalocyaninetetrasulfonate induced by peroxide to Fe(III) charge transfer excitation

The binuclear complex View the MathML source(Pcts)FeIII(O22-)FeIII(Pcts) with PctsH2 = phthalocyaninetetrasulfonate is stable in aqueous solution for some time (∼1 h) before it is irreversibly converted to (Pcts)FeIII–O–FeIII(Pcts). The photolysis of the peroxo complex in argon-saturated water leads to the release of oxygen and the formation of FeII(Pcts) with ϕ = 5 × 10−4 at λirr = 333 nm. It is suggested that this photoredox reaction originates from a peroxide to FeIII LMCT state. It is populated from Pcts IL states which are initially reached by light absorption.