Small Titanium Oxo Clusters: Primary Structures of Titanium(IV) in Water

For sol–gel synthesis of titanium
oxide, the titanium­(IV) precursors are dissolved in water to form
clear solutions. However, the solution status of titanium­(IV) remains
unclear. Herein three new and rare types of titanium oxo clusters
are isolated from aqueous solutions of TiOSO4 and TiCl4 without using organic ligands. Our results indicate that
titanium­(IV) is readily hydrolyzed into oxo oligomers even in highly
acidic solutions. The present clusters provide precise structural
information for future characterization of the solution species and
structural evolution of titanium­(IV) in water and, meanwhile, are
new molecular materials for photocatalysis.