The reaction of a cationic carbyne complex of manganese, [(η-C5H5)(CO)2Mn⋮CC6H5]BBr4 (1), with [(Ph3P)2N]2[Ru3(CO)11] (3) in THF at low temperature gave the heteronuclear trimetal bridging carbyne complex [MnRu2(μ-H)(μ-CO)2(μ3-CC6H5)(CO)6(η-C5H5)] (7). A cationic carbyne complex of rhenium, [(η-C5H5)(CO)2Re⋮CC6H5]BBr4 (2), reacts similarly with 3, affording the corresponding bridging carbyne complex [ReRu2(μ-H)(μ-CO)2(μ3-CC6H5)(CO)6(η-C5H5)] (8) and neutral Re−carbyne dimer [Re(CO)2(η-C5H5)(μ-CC6H5)]2 (9). The compound [(Ph3P)2N]2[Os3(CO)11] (4) only reacts with 1 to give the trimetal bridging carbyne complex [MnOs2(μ-H)(μ-CO)2(μ3-CC6H5)(CO)6(η-C5H5)] (10) and neutral Mn−carbyne dimer [Mn(CO)2(η-C5H5)(μ-CC6H5)]2 (11). [(Ph3P)2N]2[Fe4(CO)13] (5) also reacts with cationic carbyne complexes 1 and 2 to give the trimetal bridging carbyne complexes [MnFe2(μ-H)(μ-CO)2(μ3-CC6H5)(CO)6(η-C5H5)] (12) and [ReFe2(μ-H)(μ-CO)2(μ3-CC6H5)(CO)6(η-C5H5)] (13), respectively. Product 13, when treated with an excess of PPh3, gave the PPh3-substituted bridging carbyne complex [ReFe2(μ-H)(μ-CO)2(μ3-CC6H5)(CO)5(PPh3)(η-C5H5)] (14). In contrast to carbonylmetal anions 3−5, [Mo(η-C5H5)2(H)CO][Mn3(CO)9(μ-SC6H5)4] (6) reacts with 1 to produce not the analogous bridging carbyne complexes but rather the mercapto−carbene complex [(η-C5H5)(CO)2MnC(SC6H5)C6H5] (15) and the thiolato-bridged Mo−Mn carbonyl complex [Mo(η-C5H5)(CO)2(μ-SC6H5)2Mn(CO)3] (16), while the analogous reaction of 2 with 6 yields the mercaptocarbene complex [(η-C5H5)(CO)2ReC(SC6H5)C6H5] (17) and phenylcarbene complex [(η-C5H5)(CO)2ReC(H)C6H5] (18). The structures of 7, 9, 13, 14, and 16 have been established by X-ray diffraction studies.

The reaction of a cationic carbyne complex of manganese, [(η 5 -C 5 H 5 )(CO) 2 MntCC 6 H 5 ]BBr 4 (1), with [(Ph 3 P) 2 N][Ir(CO) 4 ] (3) in THF at low temperature gives a novel Mn 2 -Ir 2 mixedtetrametal bridging carbyne complex with µ and µ 3 bridging carbyne ligands, [Mn 2 Ir 2 (µ-CC 6 H 5 )(µ 3 -CC 6 H 5 )(µ-CO) 3 (CO) 3 (η 5 -C 5 H 5 ) 2 ] (5), and a related Mn 2 -Ir 2 mixed-tetranuclear cluster with a µ bridging carbene ligand and a µ 3 bridging carbyne ligand, [Mn 2 Ir 2 {µ-C(CO)-C 6 H 5 }(µ 3 -CC 6 H 5 )(µ-CO) 3 (CO) 4 (η 5 -C 5 H 5 ) 2 ] (6). A cationic carbyne complex of rhenium, [(η 5 -C 5 H 5 )(CO) 2 RetCC 6 H 5 ]BBr 4 (2), reacts similarly with 3 to afford the corresponding Re 2 -Ir 2 mixed-tetrametal cluster [Re 2 Ir 2 {µ-C(CO)C 6 H 5 }(µ 3 -CC 6 H 5 )(µ-CO) 3 (CO) 4 (η 5 -C 5 H 5 ) 2 ] (8) and a novel Re-Ir 2 mixed-trimetal bridging carbyne complex with an allyl ligand, [ReIr 2 (µ-η 1 :η 2 -C 3 H 5 )(µ 3 -CC 6 H 5 )(µ-CO) 2 (CO) 4 (η 5 -C 5 H 5 )] (7). The cationic carbyne complex 1 also reacts with the anionic compound Na 2 [Ru(CO) 4 ] (4) to give a heterotrimetal bridging carbyne complex with a µ-H ligand, [MnRu 2 (µ-H)(µ-CO) 2 (µ 3 -CC 6 H 5 )(CO) 6 (η 5 -C 5 H 5 )] ( 10), and the manganese aminocarbene complex [(η 5 -C 5 H 5 )(CO) 2 MndC(C 6 H 5 )NH 2 ] (11), while the analogous reaction of the cationic carbyne complex 2 with 4 produces a novel Re 2 -Ru 2 mixed-tetrametal cluster with a µ 3 -C(CC 6 H 5 )(µ-CC 6 H 5 ) bridging carbene ligand, [Re 2 Ru 2 {µ 3 -C(CC 6 H 5 )(µ-CC 6 H 5 )}(µ-CO)(CO) 8 (η 5 -C 5 H 5 ) 2 ] (13), in addition to the corresponding heterotrimetal bridging carbyne complex [ReRu 2 (µ 3 -CC 6 H 5 )(µ-H)(µ-CO) 2 (CO) 6 (η 5 -C 5 H 5 )] ( 12) and aminocarbene complex [η 5 -C 5 H 5 (CO) 2 RedC(C 6 H 5 )NH 2 ] (14). The structures of complexes 6, 7, 11, 13, and 14 have been established by X-ray diffraction studies.

Heating a solution of the isomerized (butadiene)(alkoxycarbene)iron complexes [C 4 H 6 (CO) 2 -FeC(OC 2 H 5 )Ar] (1, Ar ) o-CH 3 C 6 H 4 ; 2, Ar ) p-CF 3 C 6 H 4 ) in benzene in a sealed tube at 70-80 °C for 70-72 h gave the H-migrating pyrolytic productsThe isomerized (limonene)(alkoxycarbene)iron complex [η 3 -C 10 H 16 (CO) 2 -FeC(OC 2 H 5 )C 6 H 5 ] (9) was thermally decomposed to produce the η 4 cyclic olefin coordinated tricarbonyliron complex [{η 4 -C 10 H 15 CH(OC 2 H 5 )C 6 H 5 }Fe(CO) 3 ] (23). Interestingly, the thermolysis of the (limonene)(alkoxycarbene)iron complex [η 4 -C 10 H 16 (CO) 2 FeC(OC 2 H 5 )C 6 H 4 CH 3o] (10) can also give the analogous cyclic olefin coordinated tricarbonyliron complex [{η 4 -C 10 H 15 CH(OC 2 H 5 )C 6 H 4 CH 3 -o}Fe(CO) 3 ] (24). The thermolysis of the isomerized 1,5-cyclooctadiene (trimethylsiloxy)carbene iron complex [(CO) 2 Fe{η 6 -p-C 6 H 5 C 6 H 4 C(OSiMe 3 )C 8 H 12 }] (11) yields 9-aryl-9-(trimethylsiloxy)bicyclo[4.2.1]non-2-ene, [p-C 6 H 5 C 6 H 4 C-{OSi(CH 3 ) 3 }C 8 H 12 ] (25). The thermolyses of the isomerized products of the (cyclooctatetraene)(ethoxycarbene)iron complexes [η 3 -C 8 H 8 (CO) 2 FeC(OC 2 H 5 )Ar] (12, Ar ) o-CH 3 C 6 H 4 ; 13, Ar ) C 6 H 5 ) and [η 4 -C 8 H 8 (CO) 2 FeC(OC 2 H 5 )C 6 H 4 CH 3 -p] (14) produced the head-bridged cyclooctatriene derivatives [C 8 H 8 C(OC 2 H 5 )C 6 H 4 CH 3 -o] (26) and [C 8 H 7 (OC 2 H 5 )C(H)Ar] (27, Ar ) C 6 H 5 ; 28, Ar ) p-CH 3 C 6 H 4 ), respectively, via C-C bond formation or ethoxy migration. The structures of compounds 15-17, 20, 23, 25, 26, and 28 were established by X-ray diffraction studies.