Two-dimensional sp2 carbon–conjugated covalent organic frameworks

Enquan Jin, Mizue Asada, Qing Xu, Sasanka Dalapati, Matthew A. Addicoat, Michael A. Brady, Hong Xu, Toshikazu Nakamura, Thomas Heine, Qiuhong Chen, Donglin Jiang

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232 Citations (Scopus)


We synthesized a two-dimensional (2D) crystalline covalent organic framework (sp2c-COF) that was designed to be fully π-conjugated and constructed from all sp2 carbons by C=C condensation reactions of tetrakis(4-formylphenyl)pyrene and 1,4-phenylenediacetonitrile. The C=C linkages topologically connect pyrene knots at regular intervals into a 2D lattice with π conjugations extended along both x and y directions and develop an eclipsed layer framework rather than the more conventionally obtained disordered structures. The sp2c-COF is a semiconductor with a discrete band gap of 1.9 electron volts and can be chemically oxidized to enhance conductivity by 12 orders of magnitude. The generated radicals are confined on the pyrene knots, enabling the formation of a paramagnetic carbon structure with high spin density. The sp2 carbon framework induces ferromagnetic phase transition to develop spin-spin coherence and align spins unidirectionally across the material.

Original languageEnglish
Pages (from-to)673-676
Number of pages4
Issue number6352
Publication statusPublished - 2017 Aug 18

All Science Journal Classification (ASJC) codes

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    Jin, E., Asada, M., Xu, Q., Dalapati, S., Addicoat, M. A., Brady, M. A., Xu, H., Nakamura, T., Heine, T., Chen, Q., & Jiang, D. (2017). Two-dimensional sp2 carbon–conjugated covalent organic frameworks. Science, 357(6352), 673-676.