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-η(1):η(1)-HN═NH)FeCp(†)][PF(6)] (Cp(†) = η(5)-C(5)Me(4)H or η(5)-C(5)Me(5)), 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.