Urea/Thiourea Imine Linkages Provide Accessible Holes in Flexible Covalent Organic Frameworks and Dominates Self-Adaptivity and Exciton Dissociation

Chencheng Qin; Xiaodong Wu; Wenyan Zhou; Miao Li; Shuai Bi; Lin Tang; Hao Huang; Wenguang Tu; Xingzhong Yuan; Edison Huixiang Ang; Weiling Sun; Long Chen; Zhaoli Liu; Bing He; Lai Lyu; Yan Wu; Wen Liu; Hou Wang

doi:10.1002/anie.202418830

Urea/Thiourea Imine Linkages Provide Accessible Holes in Flexible Covalent Organic Frameworks and Dominates Self-Adaptivity and Exciton Dissociation

Angew Chem Int Ed Engl. 2024 Nov 5:e202418830. doi: 10.1002/anie.202418830. Online ahead of print.

Authors

Chencheng Qin¹, Xiaodong Wu², Wenyan Zhou¹, Miao Li¹, Shuai Bi³, Lin Tang¹, Hao Huang⁴, Wenguang Tu⁴, Xingzhong Yuan¹, Edison Huixiang Ang⁵, Weiling Sun⁶, Long Chen⁶, Zhaoli Liu⁶, Bing He⁷, Lai Lyu⁸, Yan Wu⁹, Wen Liu^{6

10}, Hou Wang¹

Affiliations

¹ College of Environmental Science and Engineering and Key Laboratory of Environmental Biology and Pollution Control (Ministry of Education), Hunan University, Changsha, 410082, China.
² College of Materials Science and Engineering, Nanjing Tech University, Nanjing, 211816, China.
³ School of Chemistry, Chemical Engineering and Biotechnology, Nanyang Technological University, 21 Nanyang Link, Singapore, 637371, Singapore.
⁴ School of Science and Engineering, The Chinese University of Hong Kong, Shenzhen, 518172, Guangdong, P. R. China.
⁵ Natural Sciences and Science Education, National Institute of Education, Nanyang Technological University, Singapore, 637616, Singapore.
⁶ The Key Laboratory of Water and Sediment Sciences, Ministry of Education, College of Environmental Sciences and Engineering, Peking University, Beijing, 100871, China.
⁷ State Key Laboratory of New Textile Materials and Advanced Processing Technologies, Wuhan Textile University, 430200, Wuhan, China.
⁸ Institute of Rural Revitalization, Guangzhou University, Guangzhou, 510006, China.
⁹ College of Environment and Ecology, Hunan Agricultural University, Changsha, 410128, P. R China.
¹⁰ National Laboratory for Molecular Sciences, Peking University, Beijing, 100871, China.

PMID: 39501715
DOI: 10.1002/anie.202418830

Abstract

Unraveling the robust self-adaptivity and minimal energy-dissipation of soft reticular materials for environmental catalysis presents a compelling yet unexplored avenue. Herein, a top-down strategy, tailoring from the unique linkage basis, flexibility degree, skeleton electronics to trace-guest adaptability, is proposed to fill the understanding gap between micro-soft covalent organic frameworks (COFs) and photocatalytic performance. The thio(urea)-basis-dominated linkage within benzotrithiophene-based COFs induce the framework contraction/swelling (intralayer micro-flexibility) in response to tetrahydrofuran or water. Adaptability of micro-flexible thiourea-COF with pore hydrophilicity not only contributes to the favorable mass transfer, but also enhances the accessible redox active sites, culminating in nearly 100 % removal of micropollutant with low-energy dissipation in wastewater. The incorporating urea/thiourea into imine linkage facilitates polarization reduction and exciton dissociation within skeleton wall, inducing strong localization for holes. This transformation facilitates interchain charge transport and unbalanced distribution conducive to oxidative holes-mediated micropollutant decomposition.

Keywords: conformation; micro-flexible COFs; photocatalysis; self-adaptivity.