Modeling a Nitrogenase Key Reaction: The N₂-Dependent HD Formation by D₂/H⁺ Exchange

How do FeMo nitrogenases function on the molecular level? Insights can be expected from elucidating the N₂-dependent HD formation from D₂ and H⁺. The stringent N₂ dependence proves that N₂ reduction and HD formation are inseparably coupled to each other via a specific N₂-reduction intermediate. The diazene complex 1 a and its reaction with D₂ to give 1 b and HD yield an explanation for this nearly 40-year-old enigma. The results also shed light on the functioning of the FeMo cofactors in nitrogenases.