Reactions of cationic bridging carbyne complexes of bis(η-cyclopentadienyl)diiron tricarbonyl with nucleophiles.: A route to diiron bridging carbene complexes

The reactions of the cationic carbyne complex of diiron, (Fe(2)(mu-CO)(mu-C-Ph)(CO)(2)(eta-C(5)H(5))(2)]-BBr(4) (3), with NaSMe, NaSEt, NaSPh, NaSC(6)H(4)Me-p, and NaSC(6)H(4)NO(2)-p in THF at low temperature afforded diiron bridging thiocarbene complexes [Fe(2)(mu-CO){mu-C(SR)Ph}(CO)(2)(eta-C(5)H(5))(2)] (5, R = Me; 6, R = Et; 7, R = Ph; 8, R = p-MeC(6)H(4); 9, R = p-NO(2)C(6)H(4)). Complex [Fe2(mu-CO)(mu-CC(6)H(4)Me-p)(CO)(2)(eta-C(5)H(5))(2)]BBr(4) (4) reacted similarly with NaSPh and NaSC(6)H(4)Me-p to give corresponding bridging carbene complexes [Fe2(mu-CO){mu-C(SR)C(6)H(4)Me-p}(CO)(2)(eta-C(5)H(5))(2)] (10, R = Ph; 11, R = p-MeC(6)H(4)). Complex 3 also reacted with NaOPh and NaN(SiMe(3))(2) to yield bridging carbene complexes [Fe(2)(mu-CO){mu-C(OPh)Ph}(CO)(2)(eta-C(5)H(5))(2)] (12) and [Fe(2)(mu-CO){mu-C(N(SiMe(3))(2))Ph}(CO)(2)(eta-C(5)H(5))(2)] (13), respectively. Complexes 3 and 4 reacted with reactive salt [Et(3)NH][Fe(2)(mu-CO)(mu-SBu(n))(CO)(6)] to yield the bridging mercaptocarbene complex Fe(2)(mu-CO){mu-C(SH)Ph}(CO)(2)(eta-C(5)H(5))(2)] (14) and the bridging butylthiocarbene complex [Fe(2)(mu-CO){mu-C(SBu(n))C(6)H(4)Me-p}(CO)(2)(eta-C(5)H(5))(2)] (15), respectively. The analogous reactions of [Et(3)NH][Fe(2)(mu-CO)(mu-SPh)(CO)(6)] with 3 and 4 afforded the thiolato-bridged iron carbonyl compound Fe(2)(mu-SPh)(2)(CO)(6)] (16) and the bridging arylcarbene complexes [Fe(2)(mu-CO){mu-C(H)Ar}(CO)(2)(eta-C(5)H(5))(2)] (17, AT = Ph; 18, Ar = p-MeC(6)H(4)), while [Et(3)NH][Fe(2)(mu-CO)(mu-SC(6)H(4)Me-p)(CO)(6)] reacted with 3 to yield 17 and [Fe(2)(mu-SC(6)H(4)Me-p)(2)(CO)(6)] (19). The reaction of metal carbonyl anion compounds Na(2)W(CO)(5) and Na(2)Fe(CO)(4) with 3 gave the same product, 17. The structures of 6, 7, 15, and 17 have been established by X-ray diffraction studies.