Organometallic compounds as single-source precursors to nanocomposite materials: an overview

Molecularly doped silica xerogels are prepared by adding either main-group or transition metal organometallic compounds containing bifunctional ligands to conventional sol-gel formulations. These bifunctional ligands contain distal (alkoxy or hydroxy)silyl groups, so that the dopant molecules become covalently incorporated into the silica xerogel matrix as it is being formed. Subsequent thermal treatment under reducing or oxidizing-then-reducing conditions leads to the decomposition of molecular precursor and to the formation of a nanoparticulate material with precise stoichiometry highly dispersed throughout the xerogel matrix. (C) 1998 Elsevier Science S.A. All rights reserved.