Mechanistic aspects of the hydrolysis and condensation of titanium alkoxides complexed by tripodal ligands

摘要

Titaniumalkoxides Ti(OR)_4 (R = Et, Pr~i and Bu~n) react with tris(hydroxymethyl)nitromethane (THMNM-H_3) with retention of their basic tetrameric structural unit even after hydrolysis and condensation. The chemical reactivity of these molecular precursors are anlayzed using a model based on a point charge approximation of density functional equations. Based on these theoretical results plausible reaction pathways can be anticipated, providing deep insight into the mechanism of formation of these new molecular structures. Consequences for the sol-gel processing of titania-based material and for the rational design of novel solid-state materials are also briefly addressed.