Synthesis, structure and DFT study of dinuclear iron, cobalt and nickel complexes with cyclopentadienyl-metal moieties†
Abstract
Reactions of 1,1′-bis(dipheny1phosphino)cobaltocene with Co(PMe3)4, Ni(PMe3)4, Fe(PMe3)4, Ni(COD)2, FeMe2(PMe3)4 or NiMe2(PMe3)3 afford a series of novel dinuclear complexes [((Me3P)Co(η5-C5H4PPh2))((Me3P)M(η5-C5H4PPh2))] (M = Co(1), Ni(2) and Fe(3)) [Co(η5-C5H4PPh2)2Ni(COD)](4), [Co(η5-C5H4PPh2)2Ni(PMe3)2] (5) and [((Me3P)Co(Me)(η5-C5H4PPh2))((Me3P)Fe(Me)(η5-C5H4PPh2))] (6). Reactions of 1,1′-bis(dipheny1phosphino)ferrocene with Ni(PMe3)4, NiMe2(PMe3)3, or Co(PMe3)4 gives rise to complexes [Fe(η5-C5H4PPh2)2M(PMe3)2] (M = Ni (7), Co (8)). The complexes 1–8 were spectroscopically investigated and studied by X-ray single crystal diffraction. The possible reaction mechanisms and structural characteristics are discussed. Density functional theory (DFT) calculations strongly support the deductions.