Hybrid organic–inorganic catalytic mesoporous materials with proton sponges as building blocks

Abstract

Non-ordered organic–inorganic mesoporous hybrid materials with basic sites have been synthesized following a fluoride-catalysed sol–gel process at neutral pH and low temperatures that avoids the use of structural directing agents (SDAs). Proton sponges have been used as the organic builder of the hybrids, while the inorganic part corresponds to silica tetrahedra. The proton sponges are diamines that exhibit very high basicity and, after functionalization, have been introduced as part of the walls of the mesoporous silica by one-pot synthesis. Several hybrids with different organic loadings have been synthesized and characterized by gas adsorption, thermogravimetric and elemental analysis, solid state MAS-NMR and FTIR spectroscopy. These hybrids show high activity as base catalysts and can be recycled.