The hydrolysis of pentamethylcyclopentadienyltitanium trihalides and the formation of di-nuclear, tri-nuclear, and tetra-nuclear µ-oxo complexes. Crystal structure of [(C5Me5)TiBr(µ-O)]4CHCL3, which contains a Ti4O4 ring

Abstract

Controlled hydrolysis of pentamethylcyclopentadienyltitanium trihalides Cp★TiX3 in toluene in the presence of NHEt2 leads to the isolation of compounds of the types [Cp★TiX2]2(μ-O) (X = Cl, Br, I), [Cp★TiX(μ-O)]n (X = Cl, n = 3; X = Br, n = 4] and finally [Cp★Ti]4(μ-O)6 depending upon the Ti/H2O stoichiometry. The crystal structure of [Cp★TiBr(μ-O)]4 has been determined: the compound crystallizes with one molecule of CHCl3 in the orthorhombic space group Pnca and contains a Ti4O4 ring of alternating Ti and O atoms. The four oxygen atoms lie in a plane, with the titanium atoms situated alternately ± 0.191(2) Å above and below this plane.