Journal of Chemical Physics, Vol.115, No.6, 2652-2663, 2001
Reversible electron transfer in photochemistry and electrochemistry
A complete set of integral equations is used to describe the kinetics of reversible photoionization after instantaneous excitation, including geminate and bimolecular charge recombination, to either the ground or excited states of neutral products. The normalized distribution of ionization products, calculated taking into account reverse electron transfer, differs from that for irreversible photoionization. At low reorganization energy and slow diffusion, the reversibility of the quasiresonant ionization reduces its quantum yield, but does not affect the charge separation quantum yield. The excitations restored by bimolecular recombination of ions produce the delayed fluorescence which goes to zero as a second power of time. The quantum yield of the electroluminescence detected after injection of ions into solution has a sharp free energy dependence, like that observed experimentally.