Unusual Thiolate-Bridged Diiron Clusters Bearing the cis-HNNH Ligand and Their Reactivities with Terminal Alkynes

A series of well-defined thiolate-bridged diiron clusters bearing the cis-HNNH ligand, [Cp^†Fe(μ-SEt)₂(μ-η¹:η¹-HNNH)FeCp^†][PF₆] (Cp^† = η⁵-C₅Me₄H or η⁵-C₅Me₅), are successfully prepared in high yields and fully characterized by spectroscopy and X-ray crystallography. Under moderate conditions, these new Fe/S clusters exhibit high activity, not only for the catalytic cleavage of the N−N bond of hydrazines but also for the activation and coupling of terminal alkynes.