Organic-inorganic materials by nonhydrolytic sol-gel processes: Organosilsesquioxane-metal oxide hybrids

Organosilsesquioxane-metal oxide hybrid materials prepared by the Sol-Gel process are mainly heterogeneous. In this paper we report the preparation of methylsilsesquioxane-titanium oxide, and methylsilsesquioxane-aluminium oxide hybrid materials by a nonhydrolytic sol-gel process involving the etherolysis-condensation of a mixture of methyltrichlorosilane and metal chloride. The Si/M ration in the xerogels were very closed to the one of the starting solutions. Si-29 MAS NMR study has revealed that the methylsilsesquioxane-titanium oxide xerogel was heterogeneous at the atomic level. The spectrum of the hybrid containing aluminium, has shown beside a peak at -66 ppm corresponding to MeSi(OSi)(3) environment, another peak at -47 ppm which was ascribed to MeSi(OAl)(3) environment. The presence of only these two sites might be due to their stability.