Dinitrogen Cleavage and Hydrogenation by a Uranium Hydride Complex Enabled through Metal–Ligand Cooperativity

Dinitrogen cleavage and hydrogenation by metal hydride complexes are relevant to both enzymatic and industrial dinitrogen (N 2 ) fixation but remain limited to a few examples. Here, we report the cleavage and functionalization of N 2 mediated by a pincer ligand-supported diuranium(IV) hydride complex [{(Dipp-NON)U IV (η 4 -HDipp)}( μ- H){(η 6 -Dipp)U IV (NON-Dipp)}], 1 . In this complex, a total of six electrons and two protons are stored in two flanking arms of the bis(anilido)xanthene scaffolds and in the bridging hydride, which are stabilized by two uranium(IV) centers. The reaction of complex 1 with dinitrogen results in concomitant N 2 cleavage and functionalization, affording the bis-imido complex [{(Dipp 2 -NON)U IV } 2 (μ-NH) 2 ], 3, via an unprecedented cooperative metal–ligand pathway and without involving a change of the uranium oxidation state during the overall transformation.