Structural Fluctuations, Spin, Reorganization Energy, and Tunneling Energy Control of Intramolecular Electron Transfer: The Surprising Case of Electron Transfer in a d~8-d~8 Bimetallic System

摘要

A considerable body of unimolecular electron-transfer rate data has been reported recently for Ir_2 excited- state donors linked to substituted pyridinium acceptors. These data pose a substantial paradox. Simple analysis suggested that donor-acceptor coupling matrix elements differ by 1 order of magnitude for the excited triplet and singlet states. Yet, there is no fundamental reason to expect this large electronic coupling dependence on spin state.