Dinitrogen Activation by Dihydrogen and a PNP-Ligated Titanium Complex.

The hydrogenolysis of the PNP-ligated titanium dialkyl complex {(PNP)Ti(CHSiMe)} (1, PNP = N(CH-2-PPr-4-CH)) with H (1 atm) in the presence of N (1 atm) afforded a binuclear titanium side-on/end-on dinitrogen complex {(PNP)Ti(μ-H)} (2) at room temperature, which upon heating at 60 °C with H gave a μ-imido/μ-nitrido/hydrido complex {(PNP)Ti(μ-N)H} (3) through the cleavage and partial hydrogenation of the N unit. The mechanistic aspects of the hydrogenation of the N unit in 2 with H have been elucidated by the density functional theory calculations.