Titanium Phosphinidene and Phosphide Moieties from Oxidative Phosphorylation and Desilylation.

A unique entry into mononuclear titanium complexes bearing phosphinidene and phosphide ligand moieties is reported. Reaction of [K(crypt)][(PN)TiCl] (, crypt = 2.2.2-cryptand) with [Na(OCP)] results in [K(crypt)][(PN)Ti(OCP)] () and such species can be oxidized to the derivative [(PN)Ti(OCP)] (), both of which do not undergo decarbonylation. However, the reaction of and [NaP(SiMe)] leads to an unprecedented Ti phosphinidene, [K(crypt)][(PN)Ti═PSiMe] (), through an oxidative phosphorylation reaction. To promote the formation of a Ti≡P bond, complex was treated with 0.5 equivalent XeF, resulting in an oxidative desilylation step forming a molecular titanium phosphide complex, [K(crypt)][(PN)Ti≡P] (), which showed a characteristic downfield chemical shift at 1449.8 pmm in the P NMR spectrum. Complex can be further functionalized to generate a terminal Ti phosphinidene, [(PN)Ti═PSiMe] (), and the latter can be independently accessed through oxidation of . All new complexes were characterized structurally and as appropriate by multinuclear NMR, CW X-band EPR (for Ti), and HFEPR (for Ti) spectroscopies.