Reaction of [Fe3(CO)12] with bidentate phosphines: Redox behavior of products

Article abstract of DOI:10.1016/S0022-328X(96)06457-1

The reactions of [Fe₃(CO)₁₂] with the bidentate phosphines 1,2-bis(diphenylphosphino)ethane (dppe), 1,4-bis(diphenylphosphino)butane (dppb), 1,1′-bis(diphenylphosphino)ferrocene (dppf) and 1,4-bis(diphenylphosphino)benzene (dppbz) using trimethylamine N-oxide as decarbonylating agent produce the chelated [Fe₃(CO)₈(μ-CO)₂(μ,η²-diphosphine)] and the new series of symmetrical [{Fe₃(CO)₉(μ,-CO)₂}₂(μ,η²-diphosphine)] and unsymmetrical [Fe₃(CO)₉(μ-CO)₂](μ,η²-diphosphine)[Fe(CO)₄] bridged complexes, in reasonable yield. The complexes were characterized by IR, ³¹P and ¹³C NMR spectroscopy, and elemental analysis. Electrochemical studies on these compounds reveal that the substitution of one or more phosphine ligands for carbon monoxide of [Fe₃(CO)₁₂] results in a more cathodic potential for the first reduction peak, but is insensitive to the σ-donor capabilities of the ligands.