Periodic bifunctional organosilicas synthesised using cationic supramolecular templating

Bifunctional periodic mesoporous organosilicas containing –CH2–CH2– and –CHCH– bridges have been synthesised via direct synthesis using cationic surfactant templates. The mesoscopic ordering of the products was confirmed using powder X-ray diffraction and nitrogen adsorption. The local structure of mesocomposites was probed via 13C and 29Si solid-state NMR methods. The application of 1H–13C and 1H–29Si CP/MAS NMR dynamics revealed a complex structure of hybrid walls; organic bridges with different mobilities have been identified. The component with fast CP/MAS kinetics represents organic bridges in the bulk of the pore walls, while the component with slow CP/MAS NMR kinetics is attributable to the organic bridges on the hybrid wall interface. 1H–29Si CP/MAS dynamics also indicates that both bridges are incorporated into the same hybrid framework. The strength of template-framework interactions depends on the nature of incorporated organic bridges.