Unusually Strong Binding of Dinitrogen to a Ruthenium Center

Stuck on Ru: The lability of the N2 ligand is thought to limit the efficacy of late-transition-metal complexes for the catalytic activation of N2. However, complex 1 is found to bind N2 with unprecedented strength. This species resists displacement of N2 by CO at room temperature, while computational and experimental data suggest that the Ru–N2 binding is stronger than the Ru–IMes binding. IMes=N,N′-bis(mesityl)imidazol-2-ylidene.