Bimetallic Cooperative Cleavage of Dinitrogen to Nitride and Tandem Frustrated Lewis Pair Hydrogenation to Ammonia.

Although reductive cleavage of dinitrogen (N ) to nitride (N ) and hydrogenation with dihydrogen (H ) to yield ammonia (NH ) is accomplished in heterogeneous Haber-Bosch industrial processes on a vast scale, sequentially coupling these elementary reactions together with a single metal complex remains a major challenge for homogeneous molecular complexes. Herein, we report that the reaction of a chloro titanium triamidoamine complex with magnesium effects complete reductive cleavage of N to give a dinitride dititanium dimagnesium ditriamidoamine complex. Tandem H splitting by a phosphine-borane frustrated Lewis pair (FLP) shuttles H atoms to the N , evolving NH . Isotope labelling experiments confirmed N and H fixation. Though not yet catalytic, these results give unprecedented insight into coupling N and H cleavage and N-H bond formation steps together, highlight the importance of heterobimetallic cooperativity in N activation, and establish FLPs in NH synthesis.