Synthesis of Vinylene‐Linked Thiopyrylium‐, Pyrylium‐, and Pyridinium‐Based Covalent Organic Frameworks by Acid‐Catalyzed Aldol Condensation

The development of new vinylene‐linked covalent organic frameworks (COFs) with special ionic structure and high stability is challenging. Herein, we report a facile, general method for constructing ionic vinylene‐linked thiopyrylium‐based COFs from 2,4,6‐trimethylpyrylium tetrafluoroborate and other common reagents by means of acid‐catalyzed Aldol condensation. Besides, pyrylium‐, and pyridinium‐based COFs also can be prepared from the same monomer under slightly different reaction conditions. The COFs exhibited uniform nanofibrous morphologies with excellent crystallinities, special ionic structures, well‐defined nanochannels, and high specific surface areas. Vinylene‐linked thiopyrylium‐based covalent organic frameworks (COFs) were synthesized from 2,4,6‐trimethylpyrylium tetrafluoroborate and other common reagents by means of acid‐catalyzed Aldol condensation. Besides, pyrylium‐, and pyridinium‐based COFs also can be prepared from the same monomer under slightly different reaction conditions.