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Poly(pyridinium salts) (PPSs) with positive charges on the backbones were designed and synthesized from the transformation of bispyrylium salts. Such materials exhibited good uptake capacity for rhenium capture from water, and excellent selectivity of ReO 4 − from competing anions. Furthermore, the advantages of facile synthesis and large-scale preparation make this material promising for practical use in industry. 

A helical metal‐organic framework was prepared by using a conformationally rigid tetratopic benzoic acid ligand with binding units pointing toward each other (concave ligand). To avoid the obvious intramolecular interactions between binding units, matching spacing groups were applied to introduce atropic repulsion, thereby allowing the formation of extended frameworks for the first time. With this new ligand design, a helical‐shaped MOF with significantly improved air and moisture stability was successfully prepared, thus providing a new strategy for ligand design toward porous material constructions.

 

Extended tetratopic benzoic acid ligands with “orthogonal‐twisted‐arms” conformations were designed and synthesized for the construction of new MOF structures (OTA‐MOF). Upon coordination with Cd²⁺and Cu²⁺cations, two well‐defined new MOFs were prepared. X‐ray single crystal structures were successfully obtained, demonstrating the formation of a new topology (4,4,4‐c). The OTA2‐MOF‐Cu gave moderate stability in organic solvents and good gas sorption ability toward CO₂. This new MOF showed superior catalytic reactivity toward the epoxide‐CO₂cycloaddition, giving >50 folds yield enhancement over the controlled reaction without MOF. It is expected that this new ligand design, porous structure, and excellent CO₂catalytic reactivity will make OTA‐MOF promising new materials for applications in catalysis and separation.