PHOTOCHEMICAL ACCUMULATION AND RECOMBINATION OF ION-PAIRS UNDERGOING THE SINGLET-TRIPLET CONVERSION

Real time resolved kinetics of photoinduced electron transfer in solut ion is investigated theoretically. The results confirm that within the unified theory of bimolecular photoionization followed by geminate re combination the slow diffusional tails in long time kinetics of charge d products are unavoidable, if ion pairs constitute a one component sy stem. We demonstrate that observed quasi-exponential asymptotics can o nly be due to the multi-component nature of the reaction products. For the reaction under consideration we expect these components to be ion pairs in singlet and tripler spin states. The reaction pathway of spi n interconversion and subsequent recombination of ions to both ground and triplet states of neutral reactants is proposed, whose prediction can be directly checked experimentally. (C) 1998 Elsevier Science B.V. All rights reserved.