Two-dimensional sp2 carbon–conjugated covalent organic frameworks
- Japan Advanced Inst. of Science and Technology, Asahidai (Japan)
- Inst. for Molecular Science, Nishigo-naka, Myodaiji (Japan)
- Nottingham Trent Univ., Nottingham (United Kingdom)
- Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Advanced Light Source (ALS). Molecular Foundry
- Japan Advanced Inst. of Science and Technology, Asahidai (Japan); Inst. for Molecular Science, Nishigo-naka, Myodaiji (Japan)
- Leipzig Univ. (Germany). Wilhelm-Ostwald-Inst. for Physical and Theoretical Chemistry
In this work, 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.
- Research Organization:
- Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC), Basic Energy Sciences (BES); European Research Council (ERC); Ministry of Education, Culture, Sports, Science and Technology, Japan
- Grant/Contract Number:
- AC02-05CH11231; ERC-StG 256962C3ENV
- OSTI ID:
- 1379913
- Journal Information:
- Science, Vol. 357, Issue 6352; ISSN 0036-8075
- Publisher:
- AAASCopyright Statement
- Country of Publication:
- United States
- Language:
- English
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