Facile synthesis of heteroporous covalent organic frameworks with dual linkages: a “three-in-one” strategy

Covalent organic frameworks (COFs) with dual linkages can combine advantages and properties of two distinct connectors, enabling the development of multifunctional materials. However, due to challenges in simultaneously forming two types of linkages, the synthesis of COFs with dual linkages remains a significant challenge. Herein, we propose a “three-in-one” molecular design strategy for synthesizing COFs with dual linkages (4-amino-4"-(2,2-dioxan-1,3-dioxan-5-yl)-[1,1':3',1"-terphenyl]-5'-yl) boronic acid (ADTB)-COF and (4'-amino-5'-(4-(2,2-dioxan-1,3-dioxan-5-yl)phenyl)-[1,1':3',1'-teroxan]-5-yl) boronic acid (ADPB)-COF through reversible condensation between three distinct functionalization groups on the monomer. Benefitting from the abundant micropores and high surface area, ADPB-COF showed excellent selective adsorption capability of C3H8 over CH4 (174, 298 K/1 bar). The present work introduces a new approach for constructing COFs with dual linkages, which greatly simplifies the synthesis process and provides a novel opportunity to develop functional materials based on COFs with multi-linkages.