Dinitrogen Activation by Dihydrogen and a PNP-Ligated Titanium Complex

Abstract

The hydrogenolysis of the PNP-ligated titanium dialkyl complex {(PNP)Ti(CH 2 SiMe 3 ) 2 } ( 1, PNP = N(C 6 H 3 -2-P i Pr 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.