Solution chemistry for the elaboration of solids

This paper is focused on some aspects of the sol-gel process as a solution chemistry route to the preparation of materials. This field is opening new possibilities for molecular chemistry in the synthesis of metastable solids. Three ways emphasizing these possibilities are presented here: (1) the use of precursors containing functional groups for the preparation of solids with specific chemical reactivity leading to metastable phases; (2) the non-hydrolytic sol-gel process for the synthesis of monocomponent oxides with various structures, and of homogeneous bicomponent oxides; (3) organic-inorganic hybrid solids containing covalent bonds. The chemical reactivity of these solids is used as evidence for the presence of substructures which depend on the geometry of the organic moiety.