Syntheses, structures and conformation of butylene‐bridged butterfly‐shaped Fe‐S cluster complexes

Di‐Grignard reagent BrMg(CH 2 ) 4 MgBr can reductively cleave the SS bond of two molecules of μ‐S 2 Fe 2 (CO) 6 to give a double Fe‐S cluster core intermediate A which contains a bridging butylene group. Reactions of A with alkyl halides, chloromethyl methyl ether, chloroketones, chloroesters or acyl chlorides in situ give ten structurally novel butylene‐bridged double Fe‐S core complexes B. For all the complexes B , the structures were confirmed by IR, 1 H NMR and elemental analysis while the conformers of some complexes B were deduced based on related 1 H NMR data. In addition, for Z = Me the structure and conformation of the complex B have been firmly established by an X‐ray diffraction technique.