A family of iron(II) complexes that coordinate dinitrogen, diazene, hydrazine, and ammonia are presented. This series of complexes is unusual in that the complexes within it feature a common auxiliary ligand set and differ only by virtue of the nitrogenous NxHy ligand that occupies the sixth binding site. The ability of an iron center to bind N-2, N2H2, N2H4, and NH3 is important to establish in the context of evaluating catalytic N-2 reduction schemes that invoke these nitrogenous species. Such a scenario has been proposed as an iron-mediated, alternating reduction scheme within the cofactor of nitrogenase enzymes.