Synthesis and characterization of dinuclear complexes of 3,3 ',4,4 '-tetraminobiphenyl with tetramminoruthenium and bis(bipyridine)ruthenium residuesand their two- and four-electron oxidized products including a ZINDO studyof orbital mixing as a function of ligand oxidation state

This paper reports the synthesis, characterisation and reactivity of new co mplexes of ruthenium, the symmetric dinuclear complex of ruthenium tetrammi ne [(Ru(NH3)(4))(2)(catH(4). catH(4))](PF6)(4) and the asymmetric dinuclear complex of ruthenium bis(bipyridine) and ruthenium tetrammine [Ru(NH3)(4)( catH(4). catH(4))Ru(bpy)(2)](PF6)(4) where (catH(4). catH(4)) represents th e bridging ligand 3,3',4,4'-tetraminobiphenyl. These complexes can be oxidi zed to the two-electron oxidized ligand mixed valence (qH(2). catH(4)) spec ies and the four-electron oxidized ligand (qH(2). qH(2)) species. Further o xidation yields a range of Ru(III) species. These complexes were studied by proton NMR, UV-VIS spectra, cyclic voltammetry and ZINDO/1 and ZINDO/S cal culations.