Energy storage after photoinduced electron transfer in linked ‘triple-decker’ molecules

Abstract

A kinetic model, based on non-adiabatic theory of electron transfer, is used to calculate both the energy stored and yields produced, from the final charge-separated species, in the photoinduced electron transfer of ‘triple-decker’ molecules. These values have been calculated as a function of the reduction potentials of D, A and X, where the molecules have the form D^*AX and XD^*A, and D^* is the photoexcited species. With reasonable potentials, the stored energy and yields are large only over a narrow range of X reduction potentials, and elsewhere are small. This model can therefore be used as an aid in choosing species when synthesising molecules which will maximise both the yield of charge-separated molecules and the fraction of excitation energy stored. The model is also able to explain the overall features of the electron transfer in bacterial reaction centres.