A molybdenum-centred model for nitrogenase catalysis

Density functional theory has been used to relate the intrinsic N-2 binding affinities of the Fe and Mo sites of the iron-moryb-deaum cofactor of nitr ogenase (FeMoco) to those of known N-2 complexes. The results indicate that initial N-2 binding to FeMoco is reversible. and that Mo is the preferred site. A mechanism for N-2 reduction is proposed in which a partially reduce d MoNNH2 species undergoes cleavage across a MoFeS2 face of FeMoco. (C) 200 1 Elsevier Science B.V. All rights reserved.