Multicomponent one-pot construction of benzo[f]quinoline-linked covalent organic frameworks for HO photosynthesis.

The exploration of stable and functional linkages by multicomponent reactions to enrich the stability and diversity of covalent organic frameworks (COFs) and to broaden their potential applications is of fundamental significance to the development of COFs. Herein, we report the facile construction of a set of benzo[f]quinoline-linked COFs (B[f]QCOFs) via one-pot three-component [4 + 2] cyclic condensation of aldehydes and aromatic amines with easy-to-handle triethylamine as the vinyl source. These B[f]QCOFs possess high crystallinity, good physico-chemical stability as well as significant light absorption ability. More importantly, the obtained B[f]QCOF-1 exhibits a superior HO production rate of 9025 μmol g h in pure water without any sacrificial agent under visible-light irradiation, surpassing most of the previously reported COF-based photocatalysts under comparable conditions. This work not only provides a general synthetic route for the preparation of fully conjugated COFs, but also helps the rational design of COF-based photocatalysts for efficient HO photosynthesis.