Super-microporous organosilicas synthesized from well-defined nanobuilding units

Abstract

Super-microporous organosilica with bridging ethylene and pendant vinyl groups has been synthesized by assembling predefined nanobuilding block polyhedral oligomeric silsesquioxanes (POSS) with nonionic surfactant Brij-76 as the template. The material shows wormhole-like super-micropores with uniform size of 1.9 nm, high BET surface area of 872 m² g^–1 and pore volume of 0.52 cm³ g^–1. IR and NMR results show that the bridging ethylene, the pendant vinyl groups and the double-4-membered ring structure were successfully transferred from the building blocks to the super-microporous organosilica material. The material shows high hydrothermal stability and can further react with Br₂. The advantage of the present approach lies in that the relative contents and proximity of the different organic functionalities in the final material can be well controlled through the starting nanobuilding blocks.