Crystal and molecular structure of titanium (IV) ethoxide

BOTH speculation and controversy on the stereochemistry of the trimeric titanium (IV) alkoxides^1-6 have followed the discovery⁶ of their trimeric nature in solution. Opinions have differed on which structure is stereochemically reasonable and on which structure will account in a natural way for the hydrolysis products of titanium (IV) alkoxides, the so-called titanium oxide-alkoxides of composition Ti_3(x+1)O_4x(OR) _4(x+3). These titanium oxide-alkoxides have been characterized, at least for x = 1 and x = 3, as solids¹. The purpose of this communication is to indicate that titanium (IV) ethoxide is a tetramer in the solid, and hence that this long-awaited X-ray analysis of a titanium (IV) alkoxide not only fails to confirm one of the proposed structures, but also makes unreasonable the assumption, implicit in much of the recent discussions, that the species in solution are identical with those precipitated from solution.