Unusual reactions of cationic carbyne complexes of manganese and rhenium with [NMe4][HFe(CO)4] to form heteronuclear dimetal carbene-bridged complexes

Abstract

The reaction of a cationic carbyne complex of manganese [Mn(CPh)(η-C5H5)(CO)2]BBr4 1 with the salt [NMe4][HFe(CO)4] 3 in thf at low temperature gave [Mn(η-C5H5)(CO)3] 4 and a novel dimetal carbene-bridged complex [MnFe{µ-C(H)Ph}(η-C5H5)(CO)5] 5. The cationic rhenium carbyne complex [Re(CPh)(η-C5H5)(CO)2]BBr4 2 similarly reacted with 3 to give [Re(η-C5H5)(CO)3] 6 and [ReFe{µ-C(H)Ph}(η-C5H5)(CO)6] 7. Complex 5 reacted with carbon monoxide gas leading to cleavage of the µ-C–Mn and Mn–Fe bonds to afford 4 and a novel benzene-co-ordinated acyltricarbonyliron complex [Fe(PhCHCO)(CO)3] 8. The reaction of 7 with PPh3 yielded [ReFe{µ-C(H)Ph}(η-C5H5)(CO)5(PPh3)] 9. The structures of complexes 5, 8 and 9 have been established by X-ray diffraction studies.