ORGANOMETALLIC COMPOUNDS AS SINGLE-SOURCE PRECURSORS TO NANOCOMPOSITEMATERIALS - AN OVERVIEW

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