Networked Cages for Enhanced CO₂ Capture and Sensing

It remains a great challenge to design and synthesize a porous material for CO₂ capture and sensing simultaneously. Herein, strategy of "cage to frameworks" is demonstrated to synthesize fluorescent porous organic polymer (pTOC) by using tetraphenylethylene-based oxacalixarene cage (TOC) as the monomer. The networked cages (pTOC) have improved porous properties, including Brunauer-Emmett-Teller surface area and CO₂ capture compared with its monomer TOC, because the polymerization overcomes the window-to-arene packing modes of cages and turns on their pores. Moreover, pTOC displays prominent reversible fluorescence enhancement in the presence of CO₂ in different dispersion systems and fluorescence recovery for CO₂ release in the presence of NH₃·H₂O, and is thus very effective to detect and quantify the fractions of CO₂ in a gaseous mixtures.