AbstractThe reactions of [Et3NH][μ‐CO)(μ‐RS)Fe2(CO)6] (1a‐d) (RnPr,nBu,tBu, Ph) withp‐MeC6H4C°CPh orm‐NO2C6H4C°CPh were studied and products of the vinyl type (μ‐σ,π‐p‐MeC5H4C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 diffraction result of 2c showed that the substituted vinyl ligandp‐MeG6H4CCHPh bridges the two iron centers, being σ‐bonded to one metal through the olefinic carbon attached top‐MeC6H44 group, while π‐bonded to the other via olefinic linkage; the Fe2(CO)6and proton units are in acisfashio