Salt effects on the electron transfer transition within the binuclear complex [(NH3)(5)Ru-III(mu-CN)Fe-II(CN)(5)](-)

By a combination of spectroscopic and electrochemical techniques the reorga nization and reaction free energies of the intramolecular electron transfer within the binuclear complex [(NH3)(5)Ru-III-NC-Fe-II(CN)(5)](-) in differ ent salt solutions were obtained. It is concluded that the variations of th ese parameters, as well as those in the energy of the maximum of the metal- to-metal charge transter (MMCT) band, are caused by ion pairing of the binu clear complex with the ions of the electrolytes. Also demonstrated was that the static, optical and electrochemical data permit reliable obtention of the activation free energies of the thermal electron transfer reactions.