A mononuclear, terminal titanium(iii) imido

Abstract

We report the first mononuclear Ti^III complex possessing a terminal imido ligand. Complex [Tp^tBu,MeTi{NSi(CH₃)₃}(THF)] (2) (Tp^tBu,Me = hydridotris(3-tert-butyl-5-methylpyrazol-1-yl)borate) is prepared by reduction of [Tp^tBu,MeTi{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 ¹H NMR spectroscopies. The d¹ 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,MeTi{NSi(CH₃)₃}(F)] (4), respectively.