Synthesis and electrochemistry of Co(III) and Co(I) complexes having C5Me5 auxiliary

The synthesis and electrochemistry of half-sandwich type of Co(III) complexes (C₅Me₅)Co(bidentate)(CH₃CN)](BF₄)₂ {bidentate = dppe (1,2-bis(diphenylphosphino)ethane), dppp (1,3-bis(diphenylphosphino)propane), bpy (2,2′-bipyridine), en (ethylenediamine)) are reported. Cyclic voltammograms of (C₅Me₅)Co(bidentate)(CH₃CN)](BF₄)₂ in CH₃CN s showed two redox couples assignable to Co(II)/Co(III) and Co(I)/Co(II). The Co(I) complex having C₅Me₅ and dppe was also prepared. Two redox couples of this Co(I) complex, (C₅Me₅)Co(dppe), in CH₃CN coincided with those of (C₅Me₅)Co(dppe)(CH₃CN)](BF₄)₂ in spite of the structural change around the metal center.