Ionic and covalent mixed-metal complexes by reaction of transition metal MH acids (M=Mo, Mn, Fe, Co) with [Ir(PMe3)4CH3] or [Rh(PMe3)3CH3] and structurally related RhM and IrM heterobimetallics (M=Mn, Fe, Ru)

Treatment of [Ir(PMe3)4CH3] with equimolar quantities of the carbonyl hydrides [M(CO)nH] (M=Mn, Co; n=5, 4) or [CpM(CO)nH] (M=Mo, Fe; n=3, 2) resulted in clean protonation of the d8 substrate producing cis-[Ir(PMe3)4(H)(CH3)][X], where X−=[Mn(CO)5]− (1), [Co(CO)4]− (2), [CpMo(CO)3]− (3), and [CpFe(CO)2]− (4), respectively. Combination of [Rh(PMe3)3CH3] with [Mn(CO)5H] furnished [(Me3P)3Rh(μ-CO)2Mn(CO)3PMe3] (5), which was also isolated from the salt elimination reaction between [Rh(PMe3)4]Cl and Na[Mn(CO)5]. [(Me3P)2Rh(μ-CO)2Fe(PMe3)Cp] (6), [(Me3P)3Ir(μ-CO)2Fe(PMe3)Cp] (7), and [(Me3P)3Ir(μ-CO)2Ru(PMe3)Cp] (8) were obtained similarly by reacting [Rh(PMe3)4]Cl or [Ir(PMe3)4]Cl with the potassium salts K[CpM(CO)2] (M=Fe, Ru). The crystal structure analysis of 3 demonstrates that in the solid state the hexacoordinate [Ir(PMe3)4(H)(CH3)]+ cation and its [CpMo(CO)3]− counterion exist as well-separated ion pairs. The structures of 5–8 comprise (Me3P)nRh (n=3, 2) or (Me3P)3Ir groups attached to Mn(CO)3PMe3 or M(PMe3)Cp fragments (M=Fe, Ru) by doubly carbonyl-bridged metalmetal bonds of normal length: RhMn, 2.6695(14); RhFe, 2.5748(6); IrFe, 2.6470(7); IrRu, 2.7348(14) Å.