260443-77-4Relevant academic research and scientific papers
Ammonolysis of mono(pentamethylcyclopentadienyl) titanium(IV) derivatives
Abarca, Angel,Gomez-Sal, Pilar,Martin, Avelino,Mena, Miguel,Poblet, Josep Maria,Yelamos, Carlos
, p. 642 - 651 (2000)
Ammonolyses of mono(pentamethylcyclopentadienyl) titanium(IV) derivatives [Ti(η5-C5Me5)X3] (X = NMe2, Me, Cl) have been carried out in solution to give polynuclear nitrido complexes. Reaction of the tris(dimethylamido) derivative [Ti(η5-C5Me5)(NMe2)3] with excess of ammonia at 80-100 °C gives the cubane complex [{Ti(η5-C5Me5)}4(μ3-N)4] (1). Treatment of the trimethyl derivative [Ti(η5-C5Me5)Me3] with NH3 at room temperature leads to the trinuclear imido-nitrido complex [{Ti(η5-C5Me5)(μ-NH)}3(μ3-N)] (2) via the intermediate [{Ti(η5-C5Me5)Me}2(μ-NH)2] (3). The analogous reaction of [Ti(η5-C5Me5)Me3] with 2,4,6-trimethylaniline (ArNH2) gives the dinuclear imido complex [{Ti(η5-C5Me5)Me}2(μ-NAr)2] (4) which reacts with ammonia to afford [{Ti-(η5-C5Me5)(NH2)}2(μ-NAr)2] (5). Complex 2 has been used, by treatments with the tris(dimethylamido) derivatives [Ti(η5-C5H5-(n)R(n))(NMe2)3], as precursor of the cubane nitrido systems [{Ti4(η5-C5Me5)3(η5-C5H5-(n)R(n))}(μ3-N)4] [R = Me n = 5 (1), R = H n = 0 (6), R = SiMe3 n = 1 (7), R = Me n = 1 (8)] via dimethylamine elimination. Reaction of [Ti(η5-C5Me5)Cl3] Or [Ti(ν5-C5Me5)(NMe2)Cl2] with excess of ammonia at room temperature gives the dinuclear complex [{Ti2(η5-C5Me5)2Cl3(NH3)}(μ-N)] (9) where an intramolecular hydrogen bonding and a nonlineal nitrido ligand bridge the 'Ti(η5-C5Me5)Cl(NH3)' and 'Ti(η5-C5Me5)Cl2' moieties. The molecular structures of [{Ti(η5-C5Me5)Me}2 (μ-NAr)2] (4.) and [{Ti2(η5-C5Me5)2Cl3(NH3)}(μ-N)] (9) have been determined by X-ray crystallographic 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 disposition.
