REACTIONS OF TITANIUM TETRACHLORIDE WITH MODIFIED SILICA-GEL SURFACES STUDIED BY DIFFUSE REFLECTANCE FT-IR SPECTROSCOPY

Silica gel surface structures resulting from silylation, thermal treatment and reaction with TiCl4 have been investigated by variable temperature diffuse reflectance FT-IR spectroscopy. The surface selectivity of the diffuse reflectance technique provides the capability of obtaining useful information in regions of strong silica absorptions by spectral subtraction. Singly and doubly bonded surface titanium groups are identified. With knowledge of silica gel surface structure after silylation and/or thermal treatments, it is possible to synthesize predominantly singly or doubly bonded titanium surface species. The approach described should be generally applicable for a variety of surface modification reactions.