Comparison of observed and calculated barriers for optical electron transfer in a binuclear ruthenium(II)--ruthenium(III) complex

For mixed-valence materials in which the degree of coupling is moderate, the energy of the intervalence transition (IT) is related to the barrier for thermal electron transfer. A simple model in which the binuclear ion of the complex, (NH3)5Ru(4,4'-bipyridine)(Ru(NH3)55+, is treated as a pair of spheres of mean radius, was successful in calculating the organic solvent dependence of the (IT) spectral band. The value of the spectral properties of mixed-valence ions in assessing some of the parameters for thermal electron-transfer reactions is discussed. 2 figures, 1 table