Periodic bifunctional organosilicas synthesised using cationic supramolecular templating

Bifunctional periodic mesoporous organosilicas containing -CH₂-CH₂- and -CH{double bond, long}CH- 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. Crown