The E3 state of FeMoco: one hydride, two hydrides or dihydrogen?

Abstract

The E3 redox state of nitrogenase was systematically investigated by QM/MM calculations. The most stable structures feature an open belt-sulfide bridge and varying double-hydride coordination (or an H2 ligand).

Cryo-annealing of Photoreduced CdS Quantum Dot–Nitrogenase MoFe Protein Complexes Reveals the Kinetic Stability of the E4(2N2H) Intermediate

“…(B). Modified Lowe–Thorneley scheme of the N 2 reduction reaction; it is not the full scheme which includes N 2 binding to E 3 . ,− Stepwise proton and electron delivery to the MoFe protein FeMo-co site leads to reduction of E 0 to form E n -states. E 4 (4H) binds N 2 by reductive elimination ( re ) of H 2 to form E 4 (2N2H).…”