SOLUTION CHEMISTRY FOR THE ELABORATION OF SOLIDS

This paper is focused on some aspects of the sol-gel process as a solu tion chemistry route to the preparation of materials. This field is op ening new possibilities for molecular chemistry in the synthesis of me tastable solids. Three ways emphasizing these possibilities are presen ted here: (1) the use of precursors containing functional groups for t he preparation of solids with specific chemical reactivity leading to metastable phases; (2) the non-hydrolytic sol-gel process for the synt hesis of monocomponent oxides with various structures, and of homogene ous bicomponent oxides; (3) organic-inorganic hybrid solids containing covalent bonds. The chemical reactivity of these solids is used as ev idence for the presence of substructures which depend on the geometry of the organic moiety.