Crystallization in Hybrid Organic−Inorganic Materials Induced by Self-Organization in Basic Conditions

Abstract

Hybrid organic−inorganic crystalline materials have been obtained from a simple solvent-free synthesis in highly basic conditions. The formation of an organized hybrid structure has been achieved for the first time via sol−gel without employing bridged organosilica precursors. 3-glycidoxypropyltrimethoxysilane, which is an organically modified alkoxide bearing a terminal epoxy group, has been used for the synthesis. The opening of the epoxy has been observed to produce poly/oligo(ethylene oxide) chains or p-dioxane species. In the second case crystalline hybrids have been formed by self-organization during gelation. Analysis performed by wide-angle X-ray scattering and X-ray diffraction have confirmed the crystalline nature of the aggregates, epoxy ring opening/self-condensation which resulted in a pillared-type organic−inorganic hybrid structure with Si-substituted 2,5-bis(propoxymethyl)-1,4-dioxane organic spacer as pillar.