Electron transfer between benzenediols and aquapentachloro-, diaquatetrachloro-, and hexabromo-iridate(IV)

Abstract

The agreement of the kinetic data concerning the oxidation of benzenediols by aquapentachloro-, diaquatetrachloro-, and hexabromo-iridate(IV) with a model proposed in the light of the Marcus theory, suggests that an outer-sphere electron transfer is the operative mechanism. The same reorganizational parameter λ(26 kcal mol^–1) satisfies the reactions involving the chloro-complexes, whereas a lower value is valid for hexabromoiridate(IV)(21 kcal mol^–1). An estimation of the intrinsic parameters for the self-exchange reactions involving these Ir^IV–Ir^III pairs has been attempted.