The binuclear complexes, trans-(isn)(NH3)4RuNCFe(5n (n = 2-, 1-, 0), were prepared both in aqueous solutions and as isolated salts. Their properties, particularly that of the mixed-valence species (M), were characterized by UV-Vis, infrared, electrochemical and kinetic studies. The results suggested that Ru(III)-Fe(II) was both thermodynamically and kinetically stable oxidation states. The extent of delocalization of M was estimated by analysis of the intervalence band on the basis of Hush's theory. The stabilization of M with respect to its oxidation state isomer (M′) was investigated and it was found that the electrostatic effect associated with the net charges of metal moieties constituted the dominant factor governing the stability of M. ? 2008 Taylor & Francis.
