PCP Pincer Complexes of Titanium in the +3 and +4 Oxidation States

[Image: see text] Ti(IV) and Ti(III) complexes using the (tBu)PCP ligand have been synthesized ((tBu)PCP = C(6)H(3)-2,6-(CH(2)P(t)Bu(2))(2)). The [(tBu)PCP]Li synthon can be reacted with TiCl(4)(THF)(2) to form ((tBu)PCP)TiCl(3) (1) in limited yields due to significant reduction of the titanium synthon. The Ti(III) complex ((tBu)PCP)TiCl(2) (2) has been further characterized. This can have half an equivalent of halide abstracted to form [{((tBu)PCP)TiCl}(2){μ-Cl}][B(C(6)F(5))(4)] (3) and can also be methylated, forming ((tBu)PCP)TiMe(2) (4). All the Ti(III) complexes have been characterized using EPR and X-ray crystallography, giving insight into their electronic structures, which are further supported by DFT calculations.