Generation of substrate-binding sites by electrochemical reduction of cis-[Fe2(cp)2(μ-SMe)2(MeCN)(L)]2+ (L = CO or MeCN). Reactivity of the sites toward CO and tBuNC. Crystal structure of [Fe2(cp)2(μ-SMe)2(CO)(MeCN)][BF 4]2·CH2Cl2

Abstract : Iron complexes with the _Fe2(cp)2(μ-SMe)2_ core have been synthesized and their electrochemistry investigated. Electrochemical reduction of the acetonitrile-substituted complexes cis-[Fe2(cp)2(μ-SMe)2(MeCN2) 2]2+ and cis-[Fe2(cp)2(μ-SMe)2(CO)(MeCN)] 2+ labilizes the MeCN ligand(s) and generates vacant sites at which CO and isocyanide substrates can bind. The mechanism of the electrochemical reduction of both complexes has been investigated in the presence of these substrates. A single-crystal X-ray analysis established that cis-[Fe2(cp)2-(μ-SMe)2(CO)(MeCN)][BF 4]2 contains an unusual dication in which different ligands (CO, MeCN) occupy corresponding sites in the co-ordination polyhedra of the two iron centres of the Fe2(μ-S)2 ring. Aspects of the reactivity and electrochemistry of complexes with Fe2(μ-SMe)2 and Mo2(μ-SR)2 cores are compared.