A mononuclear, terminal titanium(III) imido.

We report the first mononuclear Ti III complex possessing a terminal imido ligand. Complex [Tp t Bu,Me Ti{NSi(CH 3 ) 3 }(THF)] (2) (Tp t Bu,Me = hydridotris(3- tert -butyl-5-methylpyrazol-1-yl)borate) is prepared by reduction of [Tp t Bu,Me Ti{NSi(CH 3 ) 3 }(Cl)] (1) with KC 8 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 1 H NMR spectroscopies. The d 1 complex [(Tp t Bu,Me )TiCl(OEt 2 )][B(C 6 F 5 ) 4 ] (3), was prepared to spectroscopically compare it to 2. Electrochemical studies of 1 and 2 reveal a reversible 1e - process, and chemical oxidants ClCPh 3 or 1/2 eq. XeF 2 react cleanly with 2 yielding 1 or the fluoride derivative [Tp t Bu,Me Ti{NSi(CH 3 ) 3 }(F)] (4), respectively.