Synthesis, characterization, and structural study of iron–sulfur core {Cp 2Fe 2(μ-SEt) 2} complexes

Abstract

The known complexes [Cp 2Fe 2(μ-SEt) 2(MeCN) 2](PF 6) 2 ( 1) and Cp 2Fe 2(μ-SEt) 2(CN) 2 ( 2) are prepared to investigate their reactivity. The reaction of complex 2 with equimolar amounts of MeOTf yields a monomethylation product [Cp 2Fe 2(μ-SEt) 2(CN)(CNMe)](OTf) ( 3). Dimethylation of complex 2 by 2 equiv. MeOTf gives a complex [Cp 2Fe 2(μ-SEt) 2(CNMe) 2](OTf) 2 ( 4). Complex 1 containing two labile MeCN ligands reacts with several bidentate phosphine ligands, such as dppm, dppa, and dppf, to afford complexes [Cp 2Fe 2(μ-SEt) 2(dppm)](PF 6) 2 ( 5), [Cp 2Fe 2(μ-SEt) 2(dppa)](PF 6) 2 ( 6), and [Cp 2Fe 2(μ-SEt) 2(dppf)](PF 6) 2 ( 7), respectively. The spectroscopic, electrochemical, and reactivity studies of iron–sulfur core complexes are performed. The structures of complexes 1– 7 were confirmed by X-ray crystallography.