Linkage chemistry is important for the synthesis of covalent organic frameworks (COFs), since it not only plays vital roles in the formation of COFs, but also has a significant impact on the properties of resulting materials. Although a considerable effort has been devoted to developing novel linkages via covalent modification of imine bond, the resultant COFs often suffer from decreased porosity, irreversible transformation and limited functionalities. Thus, developing more general strategies for improving the crystallinity, stability and functionalities of COFs is highly desired. In this study, we reported supramolecular interaction-integrated linkage engineering to fabricate 2D hydrazone-linked COFs for the coordination of diverse transition metal ions, and demonstrated that different coordination modes in 2D COFs have a significant influence on the properties of the resultant frameworks toward advanced catalysis. Multiple supramolecular interactions, including intra-/intermolecular hydrogen bonding, electrostatic interactions in antiparallel stacking as well as metal coordination interactions, were utilized to restrict the bond rotation of linkages in COFs. After coordination with suitable divalent transition metal ions (M), the resultant M/COFs exhibited extended π-conjugation, improved crystallinity, enhanced stability and additional functionalities as compared to the parent COFs. In particular, the coordination mode in Pd/COF endowed it with excellent catalytic activity and cyclic stability for Suzuki-Miyaura cross-coupling reaction, outperforming its amorphous counterparts. This work not only demonstrates that subtle changes in the scaffolds of COFs could greatly affect the corresponding catalytic performance, but also provides a strategy for modulating physicochemical properties of 2D COFs via supramolecular linkage engineering.

Integrating supramolecular interactions into covalent organic frameworks toward advanced catalysis

Fall 2022 abstracts, posters, and presentations will launch in mid-September.

ACS Fall 2022

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.