Reactions of [Et_3NH][(μ-CO)(μ-RS)Fe_2(CO)_6] with acetylenes.Synthesis of(μ-σ,π-p-MeC_6H_4C=CHPh)(M-RS)Fe_2(CO)_6 and (μ-σ,π-PhC=CHC_6H_4Me-p)(μ-RS)Fe_2(CO)_6 The crystal structure of (μ-σ,π-p-MeC_6H_4C=CHPh)(μ-tBuS)Fe_2(CO)_6

The reactions of [Bt3NH][μ-CO)(μ-RS)Fe2(CO)6] (1a-d) (R=nPr,nBu,tBu, Ph) with p-MeC6H4C=CPh or m-NO2C6H4C=CPh were studied and products of the vinyl type (μ-σ,π-p-MeC6H4C=CHPh)(μ-RS)Fe2(CO)6 (2) and (μ-σ,π-phC=CHC6H4Me-p) (μ-RS)Fe2(CO)6 (3) (R=nPr, nBu, tBu, Ph) were obtained. While the structures of all the compounds 2a-d and 3a-d were characterized by elemental analysis, IR,1H NMR and MS spectroscopies, the single-crystal structure of 2c(R=tBu) was determined by X-ray diffraction method. The X-ray dim-action result of 2c showed that the substituted vinyl ligand p-MeC6H4C=CHPh bridges the two uon centers, being σ-bonded to one metal through the olefinic carbon attached to p-MeC6H44 group, while π-bonded to the other via olefinic linkage; the Fe2(CO)6 and proton units are in a cis fashion and the tBu group is bonded to sulfur atom through an e-type of bond.