U-shaped temperature dependence of rate constant of intramolecular photoinduced charge separation in zinc-porphyrin-bridge-quinone compounds.

The multichannel stochastic point transition model of photoinduced electron transfer from both a vibrationally unrelaxed and a relaxed states involving the vibrational relaxation in donor-acceptor pairs has been elaborated. The U-shaped temperature dependencies of the rate constants of the intramolecular photoinduced charge separation from both the vibrationally unrelaxed and the relaxed states observed in Zn-porphyrin-bridge-quinone compounds in 2-methyltetrahydrofuran solvent have been reproduced in the framework of the proposed model that accounts for the temperature dependencies of the charge separation free energy gap and the medium reorganization energy. This modeling has allowed uncovering the mechanism of such a variation of the rate constant with the temperature.

Kinetics of nonequilibrium electron transfer in photoexcited ruthenium(II)-cobalt(III) complexes.

Kinetics of photoinduced electron transfer reactions in [Ru(II)(L-L)Co(III)](5+) complexes have been investigated in the framework of the stochastic point-transition model. The model involves the medium and intramolecular nuclear reorganization as well as fast relaxation of intramolecular high frequency vibrations and description of the medium relaxation in terms of two time scales. The model has allowed reproducing the experimental data (Torieda, H.