Ammonolysis of mono(pentamethylcyclopentadienyl) titanium(IV) derivatives

Ammonolyses of mono(pentamethylcyclopentadienyl) titanium(IV) derivatives [ Ti(eta(5)-C5Me5)X-3] (X = NMe2 Me, Cl) have been carried out in solution to give polynuclear nitrido complexes. Reaction of the tris(dimethylamido) de rivative [Ti(eta(5)-C5Me5)(NMe2)(3)] With excess of ammonia at 80-100 degre es C gives the cubane complex [(Ti(eta(5)-C5Me5))(4)(mu(3)-N)(4)] (1). Trea tment of the trimethyl derivative [Ti(eta(5)-C5Me5)Me-3] with NH3 at room t emperature leads to the trinuclear imido-nitrido complex [(Ti(eta(5)-C5Me5) (mu-NH)(3)(mu(3)-N)] (2) via the intermediate [(Ti(eta(5)-C5Me5)Me)(2)(mu-N H)(2)] (3). The analogous reaction of [Ti(eta(5)-C5Me5)Me-3] with 2,3,6-tri methylaniline (ArNH2) gives the dinuclear imido complex [(Ti(eta(5)-C5Me5)M e)(2)(mu-NAr)(2)] (4) which reacts with ammonia to afford [(Ti (eta(5)-C5Me 5)(NH2))(2)(mu-NAr)(2)] (5). Complex 2 has been used, by treatments with th e tris(dimethylamido) derivatives [Ti(mu(5)-C5H5-nRn)(NMe2)(3)], as precurs or of the cubane nitrido systems [(Ti-4(eta(5)-C5Me5)(3)(eta(5)-C5H5-nRn))( mu(3)-N)(4)] [R = Me n = 5 (1), R = H n = 0 (6), R = SiMe3 n = 1 (7), R = M e n 1 (8)] via dimethylamine elimination. Reaction of [Ti(eta(5)-C5Me5)Cl-3 ] or [Ti(eta(5)-C5Me5)(NMe2)Cl-2] with excess of ammonia at room temperatur e gives the dinuclear complex [(Ti-2(eta(5)-C5Me5)(2)Cl-3(NH3))(mu-N)] (9) where an intramolecular hydrogen bending and a nonlineal nitrido ligand bri dge the "Ti(eta(5)-C5Me5)Cl(NH3)" and "Ti(eta(5)-C5Me5)Cl-2" moieties. The molecular structures of [(Ti(eta(5)-C5Me5)Me)(2) (mu-NAr)(2)] (4) and [(Ti- 2(eta(5)-C5Me5)(2)Cl-3(NH3))(mu-N)] (9) have been determined by X-ray cryst allographic studies. Density functional theory calculations also have been conducted on complex 9 to confirm the existence of an intramolecular N-H .. . Cl hydrogen bond and to evaluate different aspects of its molecular dispo sition.