Remarkable Reactions of Cationic Carbyne Complexes of Manganese and Rhenium with Diiron Anions [Fe2(μ-CO)(μ-SeR)(CO)6]-. A Route to RSe-Bridged Dimetal Bridging Carbene Complexes

Abstract

The reactions of cationic carbyne complexes of manganese and rhenium, [η-C5H5(CO)2M⋮CC6H5]BBr4 (1, M = Mn; 2, M = Re), with diiron anionic compounds [Et3NH][Fe2(μ-CO)(μ-SeR)(CO)6] (3, R = C6H5; 4, R = p-CH3C6H4) in THF at low temperature gave the dimetal bridging carbene complexes [MFe{μ-C(SeR)C6H5}(CO)5(η-C5H5)] (10, M = Mn, R = C6H5; 11, M = Mn, R = p-CH3C6H4; 13, M = Re, R = C6H5; 14, M = Re, R = p-CH3C6H4), [η-C5H5M(CO)3] (7, M = Mn; 12, M = Re), and [Fe2(μ-SeR)2(CO)6] (8, R = C6H5; 9, R = p-CH3C6H4). Complexes 1 and 2 also react with [MgBr][Fe2(μ-CO)(μ-SeC2H5)(CO)6] (5) to produce [Fe2(μ-SeC2H5)2(CO)6] (15) and dimetal bridging carbene complexes [MnFe{μ-C(SeC2H5)C6H5}(CO)5(η-C5H5)] (17) and [ReFe{μ-C(SeC2H5)C6H5}(CO)5(η-C5H5)] (18), respectively. 2 reacts similarly with [MgBr][Fe2(μ-CO)(μ-SeC4H9-n)(CO)6] (6) to give [Fe2(μ-SeC4H9-n)2(CO)6] (16) and a Re−Fe bridging carbene complex [ReFe{μ-C(SeC4H9-n)C6H5}(CO)5(η-C5H5)] (19), while the analogous reaction of 1 with 6 produced an unexpected trimetal bridging carbyne complex [MnFe2(μ-H)(μ-CO)2(μ3-CC6H5)CO)6(η-C5H5)] (20). The structures of complexes 9, 10, 13, 18, and 20 have been established by X-ray diffraction studies.