3D Covalent Organic Frameworks Selectively Crystallized through Conformational Design
- UAE Univ., Al-Ain (United Arab Emirates). Joint UAEU-UC Berkeley Laboratories for Materials Innovations; Kavli Energy NanoScience Institute, Berkeley, CA (United States); Univ. of California, Berkeley, CA (United States). Berkeley Global Science Inst.
- Kavli Energy NanoScience Institute, Berkeley, CA (United States); Univ. of California, Berkeley, CA (United States). Berkeley Global Science Inst.
- ShanghaiTech Univ. (China)
- Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
In this work, we present a strategy whereby selective formation of imine covalent organic frameworks (COFs) based on linking of triangles and squares into the fjh topology was achieved by the conformational design of the building units. 1,3,5-Trimethyl-2,4,6-tris(4-formylphenyl)benzene (TTFB, triangle) and 1,1,2,2-tetrakis(4-aminophenyl)ethene (ETTA, square) were reticulated into [(TTFB)4(ETTA)3]imine, termed COF-790, which was fully characterized by spectroscopic, microscopic, and X-ray diffraction techniques. COF-790 exhibits permanent porosity and a Brunauer-Emmett-Teller (BET) surface area of 2650 m2 g-1. Key to the formation of this COF in crystalline form is the pre-designed conformation of the triangle and the square units to give dihedral angles in the range of 75-90°, without which the reaction results in the formation of amorphous product. We demonstrate the versatility of our strategy by also reporting the synthesis and characterization of two isoreticular forms of COF-790, COF-791 and COF-792, based on other square building units.
- Research Organization:
- Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC), Basic Energy Sciences (BES); Swiss National Science Foundation (SNSF); National Natural Science Foundation of China (NSFC); National Institutes of Health (NIH)
- Grant/Contract Number:
- AC02-05CH11231; P2EZP2-184380; 21875140; S10OD024998
- OSTI ID:
- 1838626
- Journal Information:
- Journal of the American Chemical Society, Vol. 142, Issue 48; ISSN 0002-7863
- Publisher:
- American Chemical Society (ACS)Copyright Statement
- Country of Publication:
- United States
- Language:
- English
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