Charged Porous Polymers using a Solid C-O Cross-Coupling Reaction

Herein, we report a green, fast, efficient mechanochemical strategy for charged porous polymers (CPPs). A cationic CPP with basic anions and an anionic CPP with Li⁺ cations were fabricated by solid grinding under solvent-free conditions. Compared with solution-based synthesis, mechanochemical grinding can shorten the reaction time from dozens of hours to several minutes (60-90 min) to form polymers possessing a high molecular mass and low polydispersity. During the construction of CPPs, a Pd-catalyzed solid polycondensation based on unactivated organic linkers was introduced. In particular, CPPs with basic phenolic or proline anions showed good activity and stability in SO₂ capture, and Li⁺-functionalized CPPs can be post-modified to CPPs with other metal ions by ion exchange, highlighting the tailorable feature of ionic-modified CPPs. A versatile and clean mechanochemical strategy has been developed for the dibenzodioxane-forming reaction toward charged porous polymers (see scheme). Charged polymers with cationic or anionic skeletons were synthesized in a fast (60-90 min) and solvent-free manner. The intrinsically charged character makes these polymers ideal matrices for introducing various cations or anions with specific tasks (e.g., basic anions for SO₂ capture or metal ions).