Syntheses, X-ray structures and CVD of titanium(iv) arsine complexes

Abstract

Five titanium arsine compounds have been synthesised via the reaction of TiCl(4) with AsPh(3) (1 : 1 and 1 : 2 equivalents), or one equivalent of Ph(2)AsCH(2)AsPh(2), (t)BuAsH(2) and As(NMe(2))(3). In general, 1 : 1 and 1 : 2 adducts of the type [TiCl(4)(L)(n)] (n = 1, L = AsPh(3), Ph(2)AsCH(2)AsPh(2), and (t)BuAsH(2); n = 2, L = AsPh(3)), were isolated and characterised. However, the reaction of TiCl(4) with As(NMe(2))(3) resulted in a novel exchange between a Cl and an NMe(2) group, yielding the product [TiCl(3)(NMe(2))(mu-NMe(2))(2)AsCl]. The crystal structure of [TiCl(3)(NMe(2))(mu-NMe(2))(2)AsCl] has been determined and showed that the titanium and arsenic atoms are linked via two bridging NMe(2) groups. Additionally, crystal structures for the 1 : 1 and 1 : 2 adducts, [TiCl(4)(AsPh(3))] and [TiCl(4)(AsPh(3))(2)] have been obtained, with Ti-As bond lengths of 2.7465(13) and 2.7238(7) A observed respectively. The decomposition of the compounds has been investigated using thermogravimetric analysis, aerosol-assisted and low pressure chemical vapour deposition.