Free-energy dependence of the ion yield of photo-induced electron-transfer reactions in solution

A study of photo-induced electron-transfer reactions in MeCN with 9,10-dicyanoanthracene as acceptor and 21 electron donors with transient photoconductivity measurements is reported. The free-ion yield and the rate constant of back electron transfer are determined. For exergonic reactions, the 'Marcus-inverted' region is observed. The fit with the theory is best, when a nearly solvent-independent Coulomb term is used in the calculation of the energy balance. (author) 27 refs., 4 figs., 1 tab