A molybdenum-centred model for nitrogenase catalysis

Density functional theory has been used to relate the intrinsic N2 binding affinities of the Fe and Mo sites of the iron–molybdenum cofactor of nitrogenase (FeMoco) to those of known N2 complexes. The results indicate that initial N2 binding to FeMoco is reversible, and that Mo is the preferred site. A mechanism for N2 reduction is proposed in which a partially reduced MoNNH2 species undergoes cleavage across a MoFeS2 face of FeMoco.