Crystalline Porous Organic Frameworks Based on Multiple Dynamic Linkages

Abstract

A novel class of crystalline porous materials has been developed utilizing multilevel dynamic linkages, including covalent B‐O, dative B←N and hydrogen bonds. Typically, boronic acids undergo in situ condensation to afford B3O3‐based units, which further extend to molecular complexes or chains via B←N bonds. The obtained superstructures are subsequently interconnected via hydrogen bonds and π‐π interactions, producing crystalline porous organic frameworks (CPOFs). The CPOFs display excellent solution processability, allowing dissolution and subsequent crystallization to their original structures, independent of recrystallization conditions, possibly due to the diverse bond energies of the involved interactions. Significantly, the CPOFs can be synthesized on a gram‐scale using cost‐effective monomers. In addition, the numerous acidic sites endow the CPOFs with high NH3 capacity, surpassing most porous organic materials and commercial materials.

Self-Healing B ← N-Based Hydrogen-Bonded Organic Framework for Exclusive Recognition and Separation of Toluene from Methyl-Cyclohexane

“…Dative B ← N bonds are widely acknowledged for their role in constructing supramolecular structures. − Although B ← N bonds can be stronger than hydrogen bonds, their capacity to create permanent porosity in frameworks has only been confirmed recently. − We refer to such materials as B ← N frameworks (BNF). , In previous studies, we observed significant electron transfer between N- and B-containing monomers during the formation of B ← N bonds. This process endows the N-containing monomers with obvious electron-deficient features, thereby creating specific binding sites for aromatic compounds, − such as Tol. , However, the separation of Tol from mixtures has not been achieved in B ← N materials to date.…”