Isotope effect, energy gap law and temperature effect in resonance energy transfer

The purpose of this paper is to derive an expression for the energy transfer probability that differs from that of Förster and Dexter in that it can be used explicitly for discussing the effects of deuteration and temperature on the rate of energy transfer, and the relation between the energy gap of the donor and acceptor molecules and the rate of energy transfer. It is found that, as in radiationless transitions, the temperature dependence of the rate of energy transfer can be expressed as and effects of isotope substitution, and the energy gap between the excited donor and unexcited acceptor molecules on the energy transfer probability, are determined mainly by the Franck-Condon factor.