Dinitrogen Cleavage by a Heterometallic Cluster Featuring Multiple Uranium–Rhodium Bonds

Reduction of dinitrogen (N 2 ) is a major challenge for chemists. Cooperation of multiple metal centers to break the strong N 2 triple bond has been identified as a crucial step in both the industrial and the natural ammonia syntheses. However, reports of the cleavage of N 2 by a multimetallic uranium complex remain extremely rare, although uranium species were used as catalyst in the early Harber–Bosch process. Here we report the cleavage of N 2 to two nitrides by a multimetallic uranium–rhodium cluster at ambient temperature and pressure. The nitride product further reacts with acid to give substantial yields of ammonium. The presence of uranium–rhodium bond in this multimetallic cluster was revealed by X-ray crystallographic and computational studies. This study demonstrates that the multimetallic clusters containing uranium and transition metals are promising materials for N 2 fixation and reduction.