Linkage conversions in single-crystalline covalent organic frameworks

Published

September 18, 2023

Author(s)

Baoqiu Yu, Rui-Biao Lin, Gang Xu, Zhi-Hua Fu, Hui Wu, Wei Zhou, Shanfu Lu, Qian-Wen Li, Yucheng Jin, Jing-Hong Li, Zhenguo Zhang, Hailong Wang, Zier Yan, Xiaolin Liu, Kang Wang, Banglin Chen, Jianzhuang Jiang

Abstract

Single-crystal X-ray diffraction is a powerful characterization technique that enables the determination of atomic arrangements in crystalline materials. Growing or retaining large single crystals amenable to it has, however, remained challenging with covalent organic frameworks (COFs), especially suffering from post-synthetic modifications. Here we show the synthesis of a flexible COF with interpenetrated qtz topology by polymerization of tetra(phenyl)bimesityl-based tetraaldehyde and tetraamine building blocks. The material is shown to be flexible through its large, anisotropic positive thermal expansion along the c axis (αc = +491 × 10–6 K–1), as well as through a structural transformation on the removal of solvent molecules from its pores. The as-synthesized and desolvated materials undergo single-crystal-to-single-crystal transformation by reduction and oxidation of its imine linkages to amine and amide ones, respectively. These redox-induced linkage conversions endow the resulting COFs with improved stability towards strong acid; loading of phosphoric acid leads to anhydrous proton conductivity up to ca. 6.0 × 10−2 S cm−1.

Citation

Nature Chemistry

Volume

16

Issue

1

Pub Type

Journals

Download Paper

https://doi.org/10.1038/s41557-023-01334-7

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Keywords

covalent organic frameworks, single crystal transformation, thermal expansion, proton conduction

Citation

Yu, B. , Lin, R. , Xu, G. , Fu, Z. , Wu, H. , Zhou, W. , Lu, S. , Li, Q. , Jin, Y. , Li, J. , Zhang, Z. , Wang, H. , Yan, Z. , Liu, X. , Wang, K. , Chen, B. and Jiang, J. (2023), Linkage conversions in single-crystalline covalent organic frameworks, Nature Chemistry, [online], https://doi.org/10.1038/s41557-023-01334-7, https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=936261 (Accessed October 21, 2025)