Description:
<jats:p>Perturbation molecular orbital (PMO) theory is used to approximate the electronic matrix element in the semiclassical expression for the rate of nonadiabatic electron transfer (ET). The resulting expression gives a satisfactory account of the intramolecular ET rate data reported by Closs, Miller, and co-workers. We develop the idea of electron-transfer efficiency for the contribution of electron transfer to the observed kinetics of ion–molecule collisions followed by electron transfer. Electron-transfer efficiency comes from the calculated ET rate divided by the maximum calculated ET rate. Electron-transfer efficiency values are also obtained by dividing the observed reaction rate by the collision rate, calculated by the PMO treatment of ion–molecule collision rates. We applied this approach to data on electron transfer from sulfurhexafluoride or perfluoromethylcyclohexane anions to aromatic acceptors. The structural reorganization energies, λs, for these reactions were 0.016 and 0.046 eV, respectively. The vibrational reorganization energies, λv, for the reactions were 1.01 and 1.00 eV, respectively. Electron transfer from either of the donor anions to fluoranil occurs in the inverted region.</jats:p>