Making highly crystalline covalent organic frameworks (COFs) is challenging and existing linkages used for constructing COFs are limited in terms of variety and functionality. Now, crystalline COFs with imidazopyridinium linkages, which serve as precursors to N-heterocyclic carbenes, have been synthesized, expanding the reactivity of COFs by incorporating chemical ambivalence (electrophilicity and nucleophilicity) into the linkages. The COFs are also used as cathode materials in lithium–sulfur batteries.
- Xing Li
- Kun Zhang
- Kian Ping Loh