ELECTRON-TRANSFER AND INTRAMOLECULAR RADIATIONLESS TRANSITIONS

We outline the conceptual framework for the description of long-range photoinduced electron transfer in isolated solvent-free supermolecules and explore the dependence of the intramolecular electron transfer ra tes from photoselected states on the molecular parameters, i.e. energy gaps and mode-specific intramolecular reorganization energies. An ene rgy gap law for the microscopic electron transfer rate was derived whi ch, for relaxation from the electronic origins, exhibits a poissonian energy gap dependence, with an exponential energy gap law for large ga ps. The exponential energy gap law manifests the dominant role of nucl ear tunnelling in the weak electron-nuclear coupling limit, being quan titatively distinct from the thermal gaussian energy gap dependence.