All known nitrogenase cofactors are rich in both sulfur and iron and are presumed capable of binding and reducing N-2. Nonetheless, synthetic examples of transition metal model complexes that bind N-2 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(mu-SAr)Fe diiron subunit that coordinates dinitrogen (N-2-Fe(mu-SAr)Fe-N-2) across at least three oxidation states ((FeFeII)-Fe-II, (FeFeI)-Fe-II, and (FeFeI)-Fe-I). The (N-2-Fe(mu-SAr)Fe-N-2) system undergoes reduction of the bound N-2 to produce NH3 (similar to 50% yield) and can efficiently catalyze the disproportionation of N2H4 to NH3 and N-2. 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.