Unexpected Reactions of Cationic Carbyne Complexes of Manganese and Rhenium with Mixed-Dimetal Carbonyl Anions. A New Route to Dimetal Bridging Carbyne Complexes

Abstract

The reaction of a cationic carbyne complex of manganese, [η-C5H5(CO)2Mn⋮CC6H5]BBr4 (1), with (Ph3P)2NFeCo(CO)8 (3) in THF at low temperature gave a heteronuclear dimetal bridging carbyne complex [MnCo(μ-CC6H5)(CO)5(η-C5H5)] (5) and a bridging carbene complex [MnCo{μ-C(CO)C6H5}(CO)5(η-C5H5)] (6). Ph3P)2NWCo(CO)9 (4) also reacted with 1 to give the same products 5 and 6. The analogous reaction of the cationic carbyne complex of rhenium, [η-C5H5(CO)2Re⋮CC6H5]BBr4 (2), with 3 or 4 afforded the corresponding bridging carbyne complex [ReCo(μ-CC6H5)(CO)5(η-C5H5)] (7) and bridging carbene complex [ReCo{μ-C(CO)C6H5}(CO)5(η-C5H5)] (8). 5 can convert to 6 by reaction with carbon monoxide gas. 5 or 6 reacted with Fe2(CO)9 to afford a trimetal bridging carbyne complex [MnFeCo(μ3-CC6H5)(μ-CO)(CO)7(η-C5H5)] (9). Analogous reaction of 7 or 8 with Fe2(CO)9 yielded the trimetal bridging carbyne complex [ReFeCo(μ3-CC6H5)(CO)8(η-C5H5)] (10). The structures of 5, 7, 8, 9 and 10 have been established by X-ray diffraction studies.