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A Solid Transformation into Carboxyl Dimers Based on a Robust Hydrogen-Bonded Organic Framework for Propyne/Propylene
Baoqiu Yu1, Shubo Geng2, Hailong Wang1
1Beijing Advanced Innovation Center for Materials Genome Engineering, Beijing Key Laboratory for Science and Application of Functional Molecular and Crystalline Materials, Department of Chemistry and Chemical Engineering, School of Chemistry and Biological Engineering, University of Science and Technology Beijing, Beijing, 100083, China.
Angewandte Chemie (International Ed. in English)
|September 9, 2021
Summary
Researchers created hydrogen-bonded organic frameworks (HOFs) that can selectively adsorb propyne over propylene. This selective adsorption is achieved through a reversible transformation of hydrogen bonds within the material.
Area of Science:
- Materials Science
- Supramolecular Chemistry
- Crystallography
Background:
- Hydrogen-bonded organic frameworks (HOFs) are crystalline porous materials constructed from organic building blocks linked by hydrogen bonds.
- The precise control over the framework's structure and properties is crucial for targeted applications, such as gas separation.
Purpose of the Study:
- To synthesize and characterize novel isostructural hydrogen-bonded organic frameworks (HOFs) using N,N,N',N'-tetrakis(4-carboxyphenyl)-1,4-phenylenediamine.
- To investigate the structural transformations and hydrogen bonding dynamics within the HOFs.
- To evaluate the selective gas adsorption capabilities of the synthesized HOFs, specifically for propyne over propylene.
Main Methods:
- Single-crystal X-ray diffraction (SCXRD) for detailed structural analysis.
- Powder X-ray diffraction (PXRD) to study structural changes upon treatment.
- Single-component sorption and breakthrough experiments for gas adsorption evaluation.
Main Results:
- The self-assembly of the organic linker yielded isostructural HOF-30, featuring a 3D ten-fold interpenetrated dia network with two types of hydrogen bonds.
- Degassing HOF-30 produced HOF-30a, which retains the same network topology but exclusively features carboxyl⋅⋅⋅carboxyl dimers, indicating a reversible hydrogen bond transformation.
- HOF-30a demonstrated selective adsorption of propyne over propylene, with the specific binding site of propyne identified via SCXRD.
Conclusions:
- A reversible hydrogen-bond-to-hydrogen-bond transformation was successfully demonstrated in HOFs, allowing for tunable framework properties.
- The resulting HOF-30a exhibits excellent selectivity for propyne adsorption, making it a promising material for gas separation applications.
- The study highlights the potential of rationally designed HOFs for selective gas capture and storage.
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