Connecting the dots: crafting porous organic polymeric materials from preporous cavitands and cages

Preporous molecules, such as cavitands and cages, possess well-defined cavities that can selectively host guest molecules. They have recently been used as functional building blocks for the fabrication of porous organic polymers (POPs), retaining guest-recognition properties while achieving high porosity, interpore connectivity, and physicochemical stability through judicious cross-linking with rigid aromatic linkers. In this feature article, we review diverse strategies developed by our group for advancing porous polymeric materials using various preporous building blocks, such as resorcin[4]arene-based cavitands and a hydroxyl-rich Noria cage. Additionally, a facile methodology for transforming an organic imine cage into crystalline covalent organic frameworks (COFs) via dynamic covalent chemistry at a liquid-liquid interface under ambient conditions has been discussed. These approaches lead to porous organic polymeric materials with significantly enhanced surface areas and greater application potential than their preporous building units. The resulting porous materials are explored for solvent-free, non-redox CO₂ fixation and for water treatment, specifically targeting the efficient removal of organic micropollutants. The article also highlights the current challenges and outlines promising future directions for cavitand- and cage-derived porous polymeric materials across a diverse range of applications.