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Single-crystalline covalent organic frameworks (COFs) are highly desirable towards understanding their pore chemistry and functions. Herein, two 50100 μm single-crystalline three-dimensional (3D) COFs, TAM-TFPB-COF and TAPB-TFS-COF, were fabricated from the condensation of 4,4',4'',4'''-methanetetrayltetraaniline (TAM) with 3,3',5,5'- tetrakis(4-formylphenyl)bimesityl (TFPB) and 3,3',5,5'-tetrakis(4-aminophenyl)bimesityl (TAPB) with 4,4',4'',4'''- silanetetrayltetrabenzaldehyde (TFS), respectively, in 1,4-dioxane under the catalysis of acetic acid. Single-crystal 3D electron diffraction and synchrotron powder X-ray with Le Bail refinements reveal their isostructural doubly interpenetrated dia-b networks. The nitrogen sorption measurements at 77 K disclose the narrow distributed microporosity nature of both activated COFs centered at 1.36 nm for TAM-TFPB-COF and 1.48 nm for TAPB-TFS-COF together with their exceptionally high Brunauer−Emmett−Teller (BET) surface area of 3533 and 4107 m2 g−1, representing the thus far record high specific surface area among imine-bonded COFs. This enables the activated COFs to exhibit also the record high methane uptake capacities up to 28.9 wt.% (570 cm3 g−1) at 25 °C and 200 bar among all COFs reported thus far. This work not only presents the structures of two single-crystalline COFs with exceptional microporosity but also provides an example of atom engineering to adjust permanent microporous structures for methane storage
Yu, B.
, Tao, Y.
, Yao, X.
, Jin, Y.
, Liu, S.
, Xu, T.
, Wang, H.
, Wu, H.
, Zhou, W.
, Zhou, X.
, Wang, X.
, Ding, X.
, Xiao, X.
, Zhang, Y.
and Jiang, J.
(2024),
Single-Crystalline 3D Covalent Organic Frameworks with Exceptionally High Specific Surface Areas and Gas Storage Capacities, Journal of the American Chemical Society, [online], https://doi.org/10.1021/jacs.4c09680, https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=958470
(Accessed October 9, 2025)