Dinitrogen Activation by Dihydrogen and a PNP-Ligated Titanium Complex

摘要

The hydrogenolysis of the PNP-ligated titanium dialkyl complex {(PNP)Ti(CH_2SiMe_3)_2} (1, PNP = N(C_6H_3-2-P~iPr_2-4-CH_3)_2) with H_2 (1 atm) in the presence of N_2 (1 atm) afforded a binuclear titanium side-on/end-on dinitrogen complex {[(PNP)Ti]_2(μ_2,η~1,η~2-N_2)(μ_2-H)_2} (2) at room temperature, which upon heating at 60 °C with H_2 gave a μ_2-imido/μ_2-nitrido/ hydrido complex {[(PNP)Ti]_2(μ_2-NH)(μ_2-N)H} (3) through the cleavage and partial hydrogenation of the N_2 unit. The mechanistic aspects of the hydrogenation of the N_2 unit in 2 with H_2 have been elucidated by the density functional theory calculations.