吉林大学方千荣研究团队报道了合成三维共价有机框架的对称还原策略。相关研究成果于2025年1月8日发表在国际知名学术期刊《自然—化学》。

三维（3D）共价有机框架（COFs）在各种应用中具有巨大的前景。然而，使用常规构建块的传统设计方法限制了3D COFs的结构多样性。

该文中，研究人员通过一种依赖于使用八个对称性降低的连接构建块的方法来设计和合成两个3D COFs，分别命名为JUC-644和JUC-645。使用连续旋转电子衍射和高分辨率透射电子显微镜分析了其结构，揭示了COFs中罕见的双链结构的独特连接。研究人员将这些结构分解为[4+3（+2）]-c网络，从而得到六种不同的拓扑结构。

此外，JUC-644对C₃H₈和n-C₄H₁₀的吸附能力很高（在298K和1bar下分别为11.28和10.45mmolg^-1），超过了大多数已知的多孔材料，对C₃H₈/C₂H₆和n-C₄H₁₀/C₂H₆具有显著的选择性。

该方法为设计复杂的架构开辟了道路，并展示了COFs在从天然气液体中回收C₂H₆中的潜力。

附：英文原文

Title: Synthesis of three-dimensional covalent organic frameworks through a symmetry reduction strategy

Author: Chang, Jianhong, Zhang, Zeyue, Zheng, Haorui, Li, Hui, Suo, Jinquan, Ji, Chunqing, Chen, Fenqian, Zhang, Shipeng, Wang, Zitao, Valtchev, Valentin, Qiu, Shilun, Sun, Junliang, Fang, Qianrong

Issue&Volume: 2025-01-08

Abstract: Three-dimensional (3D) covalent organic frameworks (COFs) hold significant promise for a variety of applications. However, conventional design approaches using regular building blocks limit the structural diversity of 3D COFs. Here we design and synthesize two 3D COFs, designated as JUC-644 and JUC-645, through a methodology that relies on using eight-connected building blocks with reduced symmetry. Their structures are solved using continuous rotation electron diffraction and high-resolution transmission electron microscopy, which reveal a unique linkage with a double chain structure, a rare phenomenon in COFs. We deconstruct these structures into [4+3(+2)]-c nets, which leads to six different topologies. Furthermore, JUC-644 demonstrates high adsorption capacity for C3H8 and n-C4H10 (11.28 and 10.45mmolg1 at 298K and 1bar, respectively), surpassing most known porous materials, with notable selectivity for C3H8/C2H6 and n-C4H10/C2H6. This approach opens avenues for designing intricate architectures and shows the potential of COFs in C2H6 recovery from natural gas liquids.

DOI: 10.1038/s41557-024-01715-6

Source: https://www.nature.com/articles/s41557-024-01715-6