A NEW ROUTE TO DIIRON BIS(MU-THIOCARBENE) COMPLEXES - MOLECULAR-STRUCTURE OF [(FE[MU-C(CN)SME](CP))(2)] (CP=ETA-C5H5) CONTAINING THE UNUSUALLY FOLDED 6-MEMBERED METALLACYCLE FE2C2S2

The bis(mu-thiocarbene) [(cp)(OC)Fe{mu-C(CN)SMe}{mu-C(SMe)X}Fe(cp)](X = H or CN; cp = eta-C5H5) and all the intermediate species obtained fr om the thiocarbyne derivative is-[Fe-2(mu-CS){mu-C(SMe)}(CO)(2)(cp)(2) ]-[SO3CF3] via mu-C stereoselective addition of X(-), photochemical fo rmation of [(cp)Fe{mu-C(SMe)X}(mu-CS)Fe-(CO)(cp)] followed by stepwise addition of MeSO(3)CF(3) and (NBu(4)(n))CN at the bridging CS group h ave been prepared and characterized. Attempts to obtain the bis(mu-thi ocarbene) [{Fe[mu-C(CN)SMe](CO)(cp)}(2)] failed. The crystal structure of [{Fe[mu-C(CN)SMe](cp)}(2)] which demonstrates the presence of two doubly bridging thiocarbene groups has been determined. The results sh ow that bis(mu-thiocarbene) derivatives are stable when at least one o f the ligands acts as a double bridge via a S-Fe bond.