Structural fluctuations, spin, reorganization energy, and tunneling energy control of intramolecular electron transfer: The surprising case of electron transfer in a d⁸-d⁸ bimetallic system

Theoretical analysis of the ET rates in di-iridium complexes with covalently linked pyridinium acceptors has shown the crucial role of the conformational dynamics. ET is fast enough to occur in the extended conformations of molecules with short spacers while it is gated by the conformational changes in species with longer, more flexible, spacers. Reorganization energies and electronic coupling were calculated to be larger then expected from the analysis of the singlet ET rate dependence on the reaction driving force indicating that all the ET reactions studied occur in the normal Marcus region. Electronic coupling is almost the same for the reaction from the spin-singlet and -triplet excited states of the Ir2 unit. A dip on the dependence of the electroniccoupling term on the tunneling energy was predicted.

Duke Scholars

Author David N. Beratan Chemistry