Hydrazine Formation via Coupling of a Nickel(III)–NH <sub>2</sub> Radical
Nina X. Gu, Paul H. Oyala, Jonas C. Peters
Abstract
Abstract M(NH x ) intermediates involved in N−N bond formation are central to ammonia oxidation (AO) catalysis, an enabling technology to ultimately exploit ammonia (NH 3 ) as an alternative fuel source. While homocoupling of a terminal amide species (M‐NH 2 ) to form hydrazine (N 2 H 4 ) has been proposed, well‐defined examples are without precedent. Herein, we discuss the generation and electronic structure of a Ni III ‐NH 2 species that undergoes bimolecular coupling to generate a Ni II 2 (N 2 H 4 ) complex. This hydrazine adduct can be further oxidized to a structurally unusual Ni 2 (N 2 H 2 ) species; this releases N 2 in the presence of NH 3 , thus establishing a synthetic cycle for Ni‐mediated AO. Distribution of the redox load for H 2 N‐NH 2 formation via NH 2 coupling between two metal centers presents an attractive strategy for AO catalysis using Earth‐abundant, late first‐row metals.