catena-Di-µ-chloro-bis-µ-(trimethylsilylamino)-di[chlorotitanium(IV)]: preparation, properties, and crystal structure

Abstract

The preparation of the title compound is reported from the slow reaction of TiCl₄ and N(SiMe₃)₃, and its crystal structre has been determined by direct methods from diffractometer data (1 298 reflections, R 0·090). Crystals are monoclinic, space group P2₁/c, a= 17.74, b= 18.52. c= 11.46 Å, β= 102.71°. Z= 8. It contains planar four-membered (Ti–N)₂ rings with planar geometry at N apparently with considerable π-bonding in the rings. These are linked by Cl-bridges to give five-co-ordinate Ti atoms in appromixately trigonal bipyramidal geometry. Depending on the donor nature or otherwise of the solvent, this polymeric structure breaks down in solution to give discrete (Ti–N)₂ units in which the metal atoms are either four- or six-co-ordinate. As an example of the latter a 1 : 2 adduct with pyridine is described.