Xu Xiaoyi, Cui Qirui, Chen Hongzheng, Huang Ning
State Key Laboratory of Silicon and Advanced Semiconductor Materials, Department of Polymer Science and Engineering, Zhejiang University, Hangzhou 310058, China.
Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201, China.
J Am Chem Soc. 2023 Nov 8;145(44):24202-24209. doi: 10.1021/jacs.3c08541. Epub 2023 Oct 27.
The predesignable porous structure and high structural flexibility of covalent organic frameworks (COFs) render this material desirable as a platform for addressing various cutting-edge issues. Precise control over their composition, topological structure, porosity, and stability to realize tailor-made functionality still remains a great challenge. In this work, we developed a new kind of three-dimensional (3D) carborane-based COF with a 7-fold interpenetrating topological diagram. The resulting COFs exhibited high crystallinity, exceptional porosity, and strong robustness. The slightly lower electronegativity of boron (2.04) than that of hydrogen (2.20) can lead to the polarization of the B-H bond into a B-H mode, which renders these COFs as high-performance materials for the adsorption and separation of hexane isomers through the B-H···H-C interaction. Significantly, the carborane content of obtained COFs reached up to 54.2 wt %, which gets the highest rank among all the reported porous materials. Combining high surface area, strong robustness, and high content of carborane, the obtained COFs can work as efficient adsorbents for the separation of the five hexane isomers with high separation factors. This work not only enhances the diversity of 3D functional COFs but also constitutes a further step toward the efficient separation of alkane isomers.
共价有机框架材料（COFs）具有可预先设计的多孔结构和高度的结构灵活性，使其成为解决各种前沿问题的理想平台。精确控制其组成、拓扑结构、孔隙率和稳定性以实现定制功能仍然是一个巨大的挑战。在这项工作中，我们开发了一种新型的基于三维（3D）碳硼烷的COF，其具有七重穿插的拓扑图。所得的COFs表现出高结晶度、优异的孔隙率和强大的稳定性。硼（2.04）的电负性略低于氢（2.20），这会导致B-H键极化成为B-H模式，从而使这些COFs成为通过B-H···H-C相互作用吸附和分离己烷异构体的高性能材料。值得注意的是，所得COFs的碳硼烷含量高达54.2 wt%，在所有报道的多孔材料中排名最高。结合高比表面积、强大的稳定性和高含量的碳硼烷，所得的COFs可以作为高效吸附剂用于分离五种己烷异构体，具有高分离因子。这项工作不仅增加了三维功能性COFs的多样性，而且朝着烷烃异构体的高效分离又迈进了一步。
