Structure of organic–inorganic hybrid solids: influence of the hydrophilicity and hydrophobicity of precursors

Abstract

The catalytic polycondensation of the lamellar organized α,ω-organo-bis-silanetriols, 4,4′-bis(trihydroxysilyl)stilbene 1H and 4,4′-bis(trihydroxysilyl)diphenylbut-1,3-diyne 2H is described. The resulting polysilsesquioxane materials X1H and X2H were compared with those obtained by sol–gel route (X1M and X2M) from the corresponding bis(trimethoxysilyl)precursors 1M and 2M. Both spectroscopic and textural properties of the polysilsesquioxane solids obtained were very similar. In contrast the level of organization studied by X-ray and TEM is highly dependent on the route employed: the solids obtained from bis-silanetriols exhibit a better organization at the nanometric scale. We suggest that the better degree of organization obtained from bis-silanetriols relative to the corresponding methoxy precursors is due to the higher hydrophilicity around the precursor which favors the self-organization of organic units during polycondensation.