Bottom-Up Synthesis of Covalent Organic Frameworks with Quasi-Three-Dimensional Integrated Architecture via Interlayer Cross-Linking

Fazheng Jin; Tonghai Wang; Han Zheng; En Lin; Yunlong Zheng; Liqin Hao; Ting Wang; Yao Chen; Peng Cheng; Kuang Yu; Zhenjie Zhang

doi:10.1021/jacs.3c00550

Bottom-Up Synthesis of Covalent Organic Frameworks with Quasi-Three-Dimensional Integrated Architecture via Interlayer Cross-Linking

J Am Chem Soc. 2023 Mar 22;145(11):6507-6515. doi: 10.1021/jacs.3c00550. Epub 2023 Mar 12.

Authors

Fazheng Jin¹, Tonghai Wang^{2

3}, Han Zheng⁴, En Lin^{2

3}, Yunlong Zheng^{5

6}, Liqin Hao^{2

3}, Ting Wang^{2

3}, Yao Chen⁵, Peng Cheng^{2

6

3}, Kuang Yu⁷, Zhenjie Zhang^{2

5

6

3}

Affiliations

¹ MOE International Joint Laboratory of Materials Microstructure, Institute for New Energy Materials and Low Carbon Technologies, School of Material Science and Engineering, Tianjin University of Technology, Tianjin 300384, China.
² College of Chemistry, Nankai University, Tianjin 300071, China.
³ Key Laboratory of Advanced Energy Materials Chemistry (MOE), Nankai University, Tianjin 300071, China.
⁴ Tsinghua-Berkeley Shenzhen Institute, Tsinghua University, Shenzhen 518055, China.
⁵ State Key Laboratory of Medicinal Chemical Biology, Nankai University, Tianjin 300071, China.
⁶ Frontiers Science Center for New Organic Matter, Renewable Energy Conversion and Storage Center, Nankai University, Tianjin 300071, China.
⁷ Institute of Materials Research (iMR), Tsinghua Shenzhen International Graduate School, Shenzhen 518055, China.

PMID: 36908113
DOI: 10.1021/jacs.3c00550

Abstract

Developing strategies to enhance the structural robustness of covalent organic frameworks (COFs) is of great importance. Here, we rationally design and synthesize a class of cross-linked COFs (^CCOFs), in which the two-dimensional (2D) COF layers are anchored and connected by polyethylene glycol (PEG) or alkyl chains through covalent bonds. The bottom-up fabrication of these ^CCOFs is achieved by the condensation of cross-linked aldehyde monomers and tritopic amino monomers. All the synthesized ^CCOFs possess high crystallinity and porosity, and enhanced structural robustness surpassing the typical 2D COFs, which means that they cannot be exfoliated under ultrasonication and grinding due to the cross-linking effect. Furthermore, the cross-linked patterns of PEG units are uncovered by experimental results and Monte Carlo molecular dynamics simulations. It is found that all ^CCOFs are dominated by vertical cross-layer (interlayer) connections (clearly observed in high-resolution transmission electron microscopy images), allowing them to form quasi-three-dimensional (quasi-3D) structures. This work bridges the gap between 2D COFs and 3D COFs and provides an efficient way to improve the interlayered stability of COFs.