The effect of magnetic and spin interactions on outer-sphere electron transfer Original Research Article

A simple dynamical model of electron transfer in a donor-acceptor pair in the presence of a paramagnetic center placed in the vicinity of the acceptor is considered. A detailed numerical study of the influence of an external magnetic field and the exchange interaction between the transferred electron and the paramagnetic center on the electron transfer rate and coherent spin states formation is carried out. It is found that if the exchange interaction is sufficiently strong then the magnetic field effect can be observed only in the transition region between the adiabatic and nonadiabatic limits. If the exchange interaction is weak, then the effect is considerable in the whole adiabatic region and it exhibits a multiple-resonance-like dependence on both the magnetic field strength and the exchange integral. The physical mechanism of the magnetic field and exchange interaction influence on the dynamics of the electron transfer elementary act are discussed in detail.