{1,1'-(Dimethylsilylene)bis[methanechalcogenolato]}diiron complexes [2Fe2E(Si)] (E=S, Se, Te)-[FeFe] hydrogenase models

(Bis-selenolato) and (bis-tellurolato)diiron complexes [2Fe2E(Si)] were prepared and compared with the known (bis-thiolato)diiron complex A to assess their ability to produce hydrogen from protons. Treatment of [Fe ₃(CO)₁₂] with 4,4-dimethyl-1,2,4-diselenasilolane (1) in boiling toluene afforded hexacarbonyl{μ-{[1,1'-(dimethylsilylene) bis[methaneselenolato-κSe: κSe]](2 -)}}diiron(Fe-Fe) (2). The analog bis-tellurolato complex hexacarbonyl{μ-{[1,1'-(dimethylsilylene) bis[methanetellurolato-κTe: κTe]](2 -)}}diiron(Fe-Fe) (3) was obtained by treatment of [Fe₃(CO)₁₂] with dimethylbis(tellurocyanatomethyl)dimethylsilane, which was prepared in situ. All compounds were characterized by NMR, IR spectroscopy, mass spectrometry, elemental analysis and single-crystal X-ray analysis. The electrocatalytic properties of the [2Fe2X(Si)] (X=S, Se, Te) model complexes A, 1, and 2 towards hydrogen formation were evaluated.