Silsesquioxane–Carbazole-Corbelled Hybrid Porous Polymers with Flexible Nanopores for Efficient CO₂ Conversion and Luminescence Sensing

A series of silsesquioxane–carbazole-corbelled hybrid porous polymers (SCHPPs) with controllable porosity and excellent luminescence property were synthesized through Friedel–Crafts reaction between octavinyl-silsesquioxane (OVS) and carbazole. These SCHPPs exhibit tunable Brunauer–Emmett–Teller surface areas range from 279 to 799 m2 g–1 and good thermal stability in air. Notably, a large number of mesopores at around 7.4 nm appear in SCHPP-2, and it could serve as a metal-free heterogeneous catalyst for the cycloaddition reaction of CO2 with epoxide to form cyclic carbonate. The reactions are effectively proceeded under solvent-free conditions. Moreover, it shows superior recyclability, high stability and good substrate compatibility. In addition, the strongest luminescence of SCHPP-3 supported it to be a good selective luminescent probe, with high luminescent quenching coefficient (KSV) for picric acid (3.98 × 104 M–1). This work could prompt the design and synthesis of more POSS-based hybrid porous polymer catalysts for the cycloaddition of CO2 and luminescent probes.