Three-dimensional (3D) covalent organic frameworks (COFs) are a new type of crystalline organic porous material, which have great application potential in various fields due to their complex pore structures and fully exposed active sites. The synthesis of 3D COFs with novel topologies is still challenging on account of limited secondary building units. Herein, we report a 3D COF with hea topology, which has never been reported before, utilizing a D 3hsymmetric precursor [2,3,6,7,14,15-hexakis(4-formylphenyl)triptycene (HFPTP)] and [tetrakis(4-amino biphenyl)methane (TABPM)]. 3Dhea-COFs display permanent porosity and a Brunauer−Emmett− Teller surface area of 1804.0 m 2 g −1 . Owing to the huge internal free volume of triptycene, 3D-hea-COFs show good adsorption performance for H 2 , CO 2 , and CH 4 . Moreover, theoretical calculation reveals that both triptycene and tetraphenylmethane units contribute to enhance hydrogen storage capacity. The novel topology in this work expands the family of 3D COFs and provides new possibilities for designing efficient gas storage materials.

Three-dimensional (3D) covalent organic frameworks (COFs) possess great potential applications in various fields. Constructing 3D COFs with large pore sizes is extremely challenging due to the interpenetration and collapse. Herein, we report a series of crystalline imine-linked 3D COFs (3D-bor-COF-1, 3D-bor-COF-2, 3D-bor-COF-3) with mesoporous channels through rationally designing the topology configuration. These 3D-bor-COFs display permanent porosity and Brunauer-Emmett-Teller (BET) surfaces of 3205.5, 1752.7, and 2077.3 m 2 g −1 (S Langmuir = 4277.7, 2480.3, and 2698.0 m 2 g −1 ), respectively. The pore sizes of 3Dbor-COFs were confirmed by the lattice fringes from high-resolution transmission electron microscopy, as well as structural simulation and nitrogen adsorption isotherm analysis. 3D-bor-COFs display large pore sizes (3.8 nm for 3D-bor-COF-3), which is among the highest record of 3D COFs. Owing to the unstackedaromatic pore environment and high specific surface area, 3D-bor-COFs display excellent adsorption capacity for benzene vapor (1203.9 mg g −1 for 3D-bor-COF-3) under 298 K, which is three times higher than that of the best-reported 2D COF. This work not only provides inspiration for designing 3D mesoporous imine-COFs, but also demonstrates a strategy for constructing aromatics adsorption materials.

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