The reactivity of trimethylsilyliminophosphines towards titanium and zirconium halides

Zirconium tetrachloride reacted with C2H4(Ph2PNSiMe3)2-1,2 1 under C–H activation to give the NCN chelate complex ZrCl3{κ3-N,C,N′-C2H3(Ph2PNSiMe3)2}, while the reaction with C5H3N(Ph2PNSiMe3)2-2,6 gave an N-donor adduct. Cp*TiCl3 reacts with trimethylsilyliminophosphines under dehalosilylation in all cases. In contrast to 1, the potentially C–N chelating benzylphosphinimine (4-ButC6H4CH2)Ph2PNSiMe3 undergoes dehalosilylation with TiCl4 in preference to C–H activation, while prolonged reflux with ZrCl4 affords the salt [4-ButC6H4CH2P(Ph)2NHSiMe3]2[Zr2Cl10]. The molecular structures of the latter, ZrCl3{C2H3(Ph2PNSiMe3)2}, C5H3N(Ph2PNTiCl2Cp*)2-2,6, and TiCl2Cp*{NPPh2CH2C6H4But-4} have been determined by X-ray diffraction.