Recent developments of molecular chemistry for sol-gel processes

This review focuses on some aspects of the chemistry involved in the preparation of oxides by sol-gel methods. This field is opening interesting possibilities for molecular chemistry and among those presented herein are: 1) the use of precursors containing functional groups for the preparation of solids with specific chemical reactivity; 2) the nonhydrolytic gelation (NHG) route, a new general method for the synthesis of oxides that allows the use of oxygen donors (ethers, alcohols, alkoxides) other than water; the mechanism is based on oxygen-carbon bond cleavage; 3) organic-inorganic hybrid solids containing covalent bonds for which the chemical reactivity is used to demonstrate the presence of substructure in the globally amorphous solid; the substructure greatly depends on the geometry of the organic moiety. © Verlagsgesellschaft mbH, D-69451 Weinheim, 1996.