Synthesis and Electrochemical Properties of C5H−Bridged Bimetallic Iron, Ruthenium, and Osmium Complexes

Treatment of [CpOs(PPh 3 ) 2 ]BF 4 in THF with 0.5 equiv of HC⋮CCH(OH)C⋮CH followed by Al 2 O 3 gave the C 5 H-bridged compound [Cp(PPh 3 ) 2 Os C C CHC⋮COs(PPh 3 ) 2 Cp]BF 4 . The analogous iron complex [Cp(dppe)Fe C C CHC⋮CFe(dppe)Cp]BPh 4 has been prepared similarly. The structure of [Cp(PPh 3 ) 2 Os C C CHC⋮COs(PPh 3 ) 2 Cp]BF 4 has been confirmed by X-ray diffraction. The electrochemical properties of [Cp(dppe)Fe C C CHC⋮CFe(dppe)Cp]BPh 4, [Cp(PPh 3 ) 2 Ru C C CHC⋮CRu(PPh 3 ) 2 Cp]BF 4, and [Cp(PPh 3 ) 2 Os C C CHC⋮COs(PPh 3 ) 2 Cp]BF 4 have been studied by cyclic voltammetry.