Reactions of cationic carbyne complexes of manganese and rhenium with carbonylmetal anions containing cyclopentadienyl, PPh3, and NO ligands.: A route to dimetal bridging carbyne complexes

The reactions of cationic carbyne complexes of manganese and rhenium, [eta-C(5)H(5)(CO)(2)M=CC(6)H(5)]BBr(4) (1, M = Mn; 2, M = Re), with Na[eta-C(5)H(5)Mo(CO)(3)] (3) in THF at low temperature afford eta(1),eta(2)-ketene complexes [MnMo{C(CO)C(6)H(5)}(CO)(4)(eta-C(5)H(5))(2)] (8) and [ReMo{C(CO)C(6)H(5)}(CO)(4)(eta-C(5)H(5))(2)] (9), respectively. Analogous reactions of Na[eta-C(5)H(5)W(CO)3] (4) with 1 and 2 give the corresponding ketene complexes [MnW{C(CO)C(6)H(5)}(CO)(4)(eta-C(5)H(5))(2)] (10) and [ReW{C(CO)C(6)H(5)}(CO)(4)(eta-C(5)H(5))(2)] (11) Na[Co(CO)(3)PPh(3)] (5) also reacts with 1 and 2 to yield ketenyl-bridged complexes [MnCo{C(CO)C(6)H(5)}(CO)(4)(PPh(3))(eta-C(5)H(5))] (12) and [ReCo{C(CO)C(6)H(5)}(CO)(4)(PPh(3))(eta-C(5)H(5))] (13), respectively. However, compound Na[eta-C(5)H(5)Fe(CO)(2)] (6) reacts only with 2 to form a eta(1),eta(2)-ketene complex [ReFe{C(CO)C(6)H(5)}(CO)(3)(eta-C(5)H(5))(2)] (14), while the reactions of (Ph(3)P)(2)N[Fe(CO)(3)NO] (7) with 1 and 2 produce dimetal bridging carbyne complexes [MnFe(mu-CC(6)H(5))(CO)(4)(NO)(eta-C(5)H(5))] (15) and [ReFe(mu-CC(6)H(5))(CO)(4)(NO)(eta-C(5)H(5))] (16), respectively. Compound 15 treated with an excess of Fe(2)(CO)(9) gives a trimetallic bridging carbyne complex, [MnFe(2)(mu(3)-CC(6)H(5))(CO)(7)(NO)(eta-C(5)H(5))] (17). Complexes 12 and 13 also react with Fe(2)(CO)(9), leading to loss of the PPh(3) ligand to afford trimetallic bridging carbyne complexes [MnFeCo(mu(3)-CC(6)H(5))(CO)(8)(eta-C(5)H(5))] (18) and [ReFeCo(mu(3)-CC(6)H(5))(CO)(8)(eta-C(5)H(5))] (19), respectively. The structures of 10, 13, and 15 have been established by X-ray diffraction studies.