Effects of the donor-acceptor distance distribution on the energy gap laws of charge separation and charge recombination reactions in polar solutions

The energy gap laws of charge separation (CS) and charge recombination (CR) are analyzed in terms of donor-acceptor distance distribution in this paper. The energy gap dependence of the CS reaction rate constant, which has a large and flat shape, is explained. Close contact of the donor-acceptor (D-A ms) molecules cause the sharp increase in the normal region. The large mutual distances of the donor-acceptor molecules cause the flat shapes of the top and inverted regions. The bell-shaped CR energy gap law is due to the narrow distance distribution of the germinate radical ion pair produced by the photoinduced CS reaction. 35 refs., 6 figs., 1 tab