Topological Isomerism in Three-Dimensional Covalent Organic Frameworks
Yaozu Liu1, Jingwei Li2, Jia Lv2
1State Key Laboratory of Inorganic Synthesis and Preparative Chemistry, Jilin University, Changchun 130012, People's Republic of China.
Journal of the American Chemical Society
|April 18, 2023
Summary
Researchers synthesized the first topological isomers in 3D covalent organic frameworks (COFs) using a tetrahedral building block. These isomers, JUC-620 (dia net) and JUC-621 (qtz net), exhibit distinct pore sizes and adsorption properties.
Area of Science:
- Materials Science
- Organic Chemistry
- Nanotechnology
Background:
- Isomerism is common in organic chemistry but rare in covalent organic frameworks (COFs).
- Controlling topological structures in 3D COFs remains a challenge.
Purpose of the Study:
- To report the first controllable synthesis of topological isomers in 3D COFs.
- To investigate the structural and property differences between these isomers.
Main Methods:
- Synthesis of 3D COFs using a distinctive tetrahedral building unit under different solvents.
- Structure determination via powder X-ray diffraction and transmission electron microscopy.
Main Results:
- Successfully synthesized two topological isomers: JUC-620 (dia net) and JUC-621 (qtz net).
- JUC-621 (qtz net) exhibits larger mesopores (∼23 Å) and higher surface area (∼2060 m² g⁻¹) compared to JUC-620 (dia net, ∼12 Å, 980 m² g⁻¹).
- JUC-621 shows superior performance in dye molecule removal and iodine adsorption (6.7 g g⁻¹) compared to JUC-620 (2.9 g g⁻¹).
Conclusions:
- A novel strategy for constructing COF isomers has been developed.
- Structural diversity in COFs can be achieved through isomeric control.
- These COF isomers demonstrate promising applications in adsorption and separation.
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