New bonding mode of tricyclohexylphosphoniodithiocarboxylate (S2CPCy3) as an eight-electron donor. Synthesis, reactivity, and X-ray crystal structure of [Mn2(CO)6(S2CPCy3)]

Abstract

The reaction of Mn₂(CO)₁₀ with the tricyclohexylphosphine–carbon disulphide adduct S₂CPCy₃ in refluxing toluene affords the dinuclear complex [Mn₂(CO)₆(S₂CPCy₃)](1) in good yield, the structure of which, determined by X-ray crystallography, shows a new mode of co-ordination of the S₂CPCy₃ ligand which is bonded to an Mn atom by two sulphur atoms and to the other Mn atom by two sulphur and one carbon atom donating 8 electrons; thermal reactions of (1) with neutral monodentate ligands L yield [Mn₂(CO)₅(S₂CPCy₃)(L)]via CO displacement.