Alkylimido complexes of titanium(IV)

Abstract

TiCl 4 reacts with t-butylamine in benzene to give [Ti(NCMe 3)Cl 2(NH 2CMe 3) 2] x and t-butylamine hydrochloride. The IR spectrum indicates both c/s and trans metal dichlorides (300; and 308, 208 cm −1). In the 13C NMR spectrum the t-butylimido quaternary carbon resonance occurs at 72.1 ppm. A dimeric structure incorporating symmetric t-butylimido bridges is proposed. TiCl 4 in benzene react under reflux with two equivalents of Me 3SiNHCMe 3 to give [Ti(NCMe 3)Cl 2(NH 2CMe 3)] x and with iso-propylamine and ethylamine to give complexes of the form [Ti(NR)Cl 2(NH 2R) 2] x . Broad bands below 800 cm −1 in the IR spectra suggest polymeric MNM bridges. For [Ti(NCHMe 2)Cl 2(NH 2CHMe 2)] x the iso-propylimido CH resonance in the 13C NMR spectrum occurs at 67 ppm. [Ti(NCMe 3)Cl 2(NH 2CMe 3) 2] 2 reacts with L=bipy or tmed to give [Ti(NCMe 3)Cl 2(L)] 2, and TiCl 4 reacts with two equivalents of Me 3SiNHCMe 3 in benzene and then tmed to give [Ti(NCMe 3)Cl 2(tmed)] 2. The 13C NMR spectrum shows the t-butylimido quaternary carbon resonance at 73.5 ppm and the tmed resonances are chemically equivalent. A dimeric μ-NCMe 3 bridging structure is proposed for the complex.