Hexamethyldisiloxane and hexamethyldisilathiane: reactions with co-valent metal halides

Abstract

Reactions of O(SiMe₃)₂(1) and S(SiMe₃)₂(2) with TiCl₄ and SnCl₄ are described. For (1), Si–O cleavage and release of SiMe₃Cl, as monitored by ¹H n.m.r. spectroscopy, occurs only in the case of TiCl₄ to give [Me₃SiO-(Cl)TiO]_n. Trichloromethylstannane is the major reaction product with SnCl₄. With (2), TiCl₄ gives monomeric complexes TiCl₂S·2L (L = MeCN) and TiCl₂S·3L [L = MeCN or tetrahydrofuran (thf)] following solvation of the polymeric (Cl₂TiS)_n formed initially. A six-co-ordinate formulation is proposed based on spectral data. The corresponding (Cl₂SnS)_n formed with SnCl₄ does not give similar lattice degradation with strong donors. The lower halides MCl₃·3thf (M = Ti, V, or Cl) react with (2) only to give SiMe₃Cl and polymeric complexes MCl(S)·nthf (M = Ti or Cr) and VClS₄.