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Updated: Apr 11, 2026

The Synthesis, Characterization and Reactivity of a Series of Ruthenium N-triphosPh Complexes
Published on: April 10, 2015
Diiron bridged-thiolate complexes that bind N2 at the Fe(II)Fe(II), Fe(II)Fe(I), and Fe(I)Fe(I) redox states
Sidney E Creutz1, Jonas C Peters1
1Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125, United States.
Abstract:
All known nitrogenase cofactors are rich in both sulfur and iron and are presumed capable of binding and reducing N2. Nonetheless, synthetic examples of transition metal model complexes that bind N2 and also feature sulfur donor ligands remain scarce. We report herein an unusual series of low-valent diiron complexes featuring thiolate and dinitrogen ligands. A new binucleating ligand scaffold is introduced that supports an Fe(μ-SAr)Fe diiron subunit that coordinates dinitrogen (N2-Fe(μ-SAr)Fe-N2) across at least three oxidation states (Fe(II)Fe(II), Fe(II)Fe(I), and Fe(I)Fe(I)). The (N2-Fe(μ-SAr)Fe-N2) system undergoes reduction of the bound N2 to produce NH3 (∼50% yield) and can efficiently catalyze the disproportionation of N2H4 to NH3 and N2. The present scaffold also supports dinitrogen binding concomitant with hydride as a co-ligand. Synthetic model complexes of these types are desirable to ultimately constrain hypotheses regarding Fe-mediated nitrogen fixation in synthetic and biological systems.
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