Three-Dimensional\nCovalent Organic Framework with ceq Topology

Three-dimensional\ncovalent organic frameworks (3D-COFs) are emerging\nas designable porous materials because of their unique structural\ncharacteristics and porous features. However, because of the lack\nof 3D organic building units and the less reversible covalent bonds,\nthe topologies of 3D-COFs to date have been limited to dia, ctn, ffc, bor, rra, srs, pts, lon, stp, acs, tbo, bcu, and fjh. Here we report a 3D-COF with the ceq topology\nutilizing a D3h-symmetric\ntriangular prism vertex with a planar triangular linker. The as-synthesized\nCOF displays a twofold-interpenetrated structure with a Brunauer–Emmett–Teller\nsurface area of 1148.6 m2 g–1. Gas sorption\nmeasurements revealed that 3D-ceq-COF could efficiently absorb CO2, CH4, and H2 under a moderate surface\narea. This work provides new building units and approaches for structural\nand application exploration of 3D-COFs.