Homogeneous and heterogeneous optical and thermal electron transfer

Abstract A unified theory of optical and thermal outer-sphere electron-transfer processes is outlined, in which the equations are obtained as special cases of general expressions for radiative and radiationless transition probabilities. For a particular donor—acceptor ion system, this leads to correlations between the rate of homogeneous thermal electron exchange and the frequency and bandwidth of the corresponding optical intervalence transfer absorption. These in turn can be correlated with thermal and optical transfer at a metal/solution interface. The relationship between the transmission coefficient in adiabatic thermal exchange and the transition probability in the corresponding optical transfer is discussed, and a number of predictions are made for the optical transfer of electrons between a molecule or ion and an electrode, which has so far not been observed.