Department of Chemical and Biomolecular Engineering, Rice University, 6100 Main Street, MS-362, Houston, TX, 77005, USA.
Department of Materials Science and NanoEngineering, Rice University, 6100 Main Street, MS-325, Houston, TX, 77005, USA.
Nat Commun. 2023 May 19;14(1):2865. doi: 10.1038/s41467-023-38538-x.
Three-dimensional (3D) covalent organic frameworks (COFs) possess higher surface areas, more abundant pore channels, and lower density compared to their two-dimensional counterparts which makes the development of 3D COFs interesting from a fundamental and practical point of view. However, the construction of highly crystalline 3D COF remains challenging. At the same time, the choice of topologies in 3D COFs is limited by the crystallization problem, the lack of availability of suitable building blocks with appropriate reactivity and symmetries, and the difficulties in crystalline structure determination. Herein, we report two highly crystalline 3D COFs with pto and mhq-z topologies designed by rationally selecting rectangular-planar and trigonal-planar building blocks with appropriate conformational strains. The pto 3D COFs show a large pore size of 46 Å with an extremely low calculated density. The mhq-z net topology is solely constructed from totally face-enclosed organic polyhedra displaying a precise uniform micropore size of 1.0 nm. The 3D COFs show a high CO adsorption capacity at room temperature and can potentially serve as promising carbon capture adsorbents. This work expands the choice of accessible 3D COF topologies, enriching the structural versatility of COFs.
三维（3D）共价有机骨架（COFs）与二维 COFs 相比具有更高的比表面积、更丰富的孔道和更低的密度，这使得从基础和实际角度来看，开发 3D COFs 非常有趣。然而，高度结晶的 3D COF 的构建仍然具有挑战性。同时，3D COFs 中的拓扑选择受到结晶问题的限制，缺乏具有适当反应性和对称性的合适构建块，以及晶体结构确定的困难。在此，我们报道了两种具有 pto 和 mhq-z 拓扑结构的高度结晶 3D COFs，它们是通过合理选择具有适当构象应变的矩形平面和三角平面构建块设计而成的。pto 3D COFs 具有 46Å 的大孔径和极低的计算密度。mhq-z 网络拓扑结构完全由完全封闭的有机多面体构成，显示出精确均匀的微孔尺寸为 1.0nm。3D COFs 在室温下表现出高 CO 吸附容量，有望成为有前途的碳捕获吸附剂。这项工作扩展了可获得的 3D COF 拓扑结构的选择范围，丰富了 COFs 的结构多功能性。
