A mononuclear, terminal titanium(iii) imido

We report the first mononuclear Ti-III complex possessing a terminal imido ligand. Complex [Tp(tBu,Me)Ti{=NSi(CH3)(3)}(THF)] (2) (Tp(tBu,Me) = hydridotris(3-tert-butyl-5-methylpyrazol-1-yl)borate) is prepared by reduction of [Tp(tBu,Me)Ti{=NSi(CH3)(3)}(Cl)] (1) with KC8 in high yield. The connectivity and metalloradical nature of 2 were confirmed by single crystal X-ray diffraction studies, Q- and X-band EPR, UV-Vis and H-1 NMR spectroscopies. The d(1) complex [(Tp(tBu,Me))TiCl(OEt2)][B(C6F5)(4)] (3), was prepared to spectroscopically compare it to 2. Electrochemical studies of 1 and 2 reveal a reversible 1e(-) process, and chemical oxidants ClCPh3 or 1/2 eq. XeF2 react cleanly with 2 yielding 1 or the fluoride derivative [Tp(tBu,Me)Ti{=NSi(CH3)(3)}(F)] (4), respectively.

Automated summary

We report the synthesis of the first mononuclear Ti-III complex with a terminal imido ligand. This complex was prepared through reduction of [Tp(tBu,Me)Ti{=NSi(CH3)(3)}(Cl)] with KC8, and its connectivity and metalloradical nature were confirmed by various spectroscopic techniques. Electrochemical studies showed a reversible 1e(-) process for the complex, and chemical oxidants reacted cleanly with it to produce other derivatives.