Reactions of cationic bridging carbyne complexes of bis(eta-cyclopentadienyl)diiron tricarbonyl with nucleophiles. A route to diiron bridging carbenecomplexes

The reactions of the cationic carbyne complex of diiron, (Fe-2(mu-CO)(mu-C- Ph)(CO)(2)(eta-C5H5)(2)]-BBr4 (3), with NaSMe, NaSEt, NaSPh, NaSC6H4Me-p, a nd NaSC6H4NO2-p in THF at low temperature afforded diiron bridging thiocarb ene complexes [Fe-2(mu-CO){mu-C(SR)Ph}(CO)(2)(eta-C5H5)(2)] (5, R = Me; 6, R = Et; 7, R = Ph; 8, R = p-MeC6H4; 9, R = p-NO2C6H4). Complex [Fe2(mu-CO)( mu-CC6H4Me-p)(CO)(2)(eta-C5H5)(2)]BBr4 (4) reacted similarly with NaSPh and NaSC6H4Me-p to give corresponding bridging carbene complexes [Fe2(mu-CO){m u-C(SR)C6H4Me-p}(CO)(2)(eta-C5H5)(2)] (10, R = Ph; 11, R = p-MeC6H4). Compl ex 3 also reacted with NaOPh and NaN(SiMe3)(2) to yield bridging carbene co mplexes [Fe-2(mu-CO){mu-C(OPh)Ph}(CO)(2)(eta-C5H5)(2)] (12) and [Fe-2(mu-CO ){mu-C(N(SiMe3)(2))Ph}(CO)(2)(eta-C5H5)(2)] (13), respectively. Complexes 3 and 4 reacted with reactive salt [Et3NH][Fe-2(mu-CO)(mu-SBun)(CO)(6)] to y ield the bridging mercaptocarbene complex Fe-2(mu-CO){mu-C(SH)Ph}(CO)(2)(et a-C5H5)(2)] (14) and the bridging butylthiocarbene complex [Fe-2(mu-CO){mu- C(SBun)C6H4Me-p}(CO)(2)(eta-C5H5)(2)] (15), respectively. The analogous rea ctions of [Et3NH][Fe-2(mu-CO)(mu-SPh)(CO)(6)] with 3 and 4 afforded the thi olato-bridged iron carbonyl compound Fe-2(mu-SPh)(2)(CO)(6)] (16) and the b ridging arylcarbene complexes [Fe-2(mu-CO){mu-C(H)Ar}(CO)(2)(eta-C5H5)(2)] (17, AT = Ph; 18, Ar = p-MeC6H4), while [Et3NH][Fe-2(mu-CO)(mu-SC6H4Me-p)(C O)(6)] reacted with 3 to yield 17 and [Fe-2(mu-SC6H4Me-p)(2)(CO)(6)] (19). The reaction of metal carbonyl anion compounds Na2W(CO)(5) and Na2Fe(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.