Effect of excitation migration on the decay of excited states via electron transfer to acceptors

Simulation of fluorescence quenching due to electron transfer from a photoexcited donor to an acceptor, in a rigid matrix has been performed. The model assumes competition between processes of the electron transfer and the resonant excitation energy transfer among donors. Electron and energy transfers are described in terms of the Marcus and the Förster theories, respectively. Dependence of the fluorescence quenching on the donor concentration and on the parameters of the Marcus and Förster equations has been investigated at a fixed acceptor concentration. Fluorescence decay curves calculated for various concentrations of donors have been compared with experimental decays.