Reticular Synthesisof Covalent Organic Frameworkswith kgd‑v Topology and Trirhombic Pores

Two-dimensional (2D) covalent organic frameworks (COFs) with designable pore structures can be synthesized under the guidance of topology diagrams. Among the five existing edge-transitive topological nets, <b>kgd</b> topology is considered a fine candidate for constructing COFs with ultramicropores. However, all of the reported COFs with <b>kgd</b> topology need the use of <i>C</i>₆-symmetric monomers, which are limited in compound type and difficult to synthesize. Here, we first develop a new approach to construct 2D COFs (clv-COFs) with a similar geometrical shape of <b>kgd</b> topology, named <b>kgd-v</b> topology, through the combination of <i>C</i>_2<i>v</i>- and <i>C</i>₃-symmetric monomers. The size of micropores in these clv-COFs is consistent with the rhombic pores in <b>kgd</b> topology and can be easily tuned by varying the length of <i>C</i>_2<i>v</i>- and <i>C</i>₃-symmetric monomers. These clv-COFs exhibit excellent atmospheric water harvesting (AWH) ability due to regular small micropores. An efficient water harvester based on clv-COF-1 can produce 1.73 L kg^–1 day^–1 at 45% relative humidity under solar illumination. Our approach enriches the reticular chemistry and can facilitate the research of COF-based AWH systems.