Isostructural Three‐Dimensional Covalent Organic Frameworks

• Published in: Angewandte Chemie Vol. 131; no. 29; pp. 9872 - 9877
• Main Authors: Gao, Chao, Li, Jian, Yin, Sheng, Lin, Guiqing, Ma, Tianqiong, Meng, Yi, Sun, Junliang, Wang, Cheng
• Format: Journal Article
• Language: English
• Published: Weinheim Wiley Subscription Services, Inc 15.07.2019
• Subjects: Carbon dioxide; Chemistry; Crystal structure; Electron diffraction; Elektronenbeugung; Functional groups; Gastrennung; Kovalente organische 3D-Gerüste; Localization; Strukturaufklärung; Synthesis; Topology
• ISSN: 0044-8249; 1521-3757
• DOI: 10.1002/ange.201905591

Herein, we reported the designed synthesis of three isostructural three‐dimensional covalent organic frameworks (3D COFs) with ‐H, ‐Me, or ‐F substituents, which have similar crystallinity and topology. Their crystal structures were determined by continuous rotation electron diffraction (cRED), and all three 3D COFs were found to adopt a fivefold interpenetrated pts topology. More importantly, the resolution of these cRED datasets reached up to 0.9–1.0 Å, enabling the localization of all non‐hydrogen atomic positions in a COF framework directly by 3D ED techniques for the first time. In addition, the precise control of the pore environments through the use of different functional groups led to different selectivities for CO2 over N2. We have thus confirmed that polycrystalline COFs can be definitely studied to the atomic level as other materials, and this study should also inspire the design and synthesis of 3D COFs with tailored pore environments for interesting applications. COF‐Trio: Drei isostrukturelle dreidimensionale kovalente organische Gerüste mit H‐, Me‐ oder F‐Substituenten und ähnlicher Kristallinität und Topologie wurden synthetisiert. Elektronenbeugung unter kontinuierlicher Probenrotation lieferte Daten mit einer Auflösung von bis zu 0.9–1.0 Å und ermöglichte so die Lokalisierung aller Nicht‐Wasserstoffatome in einer polykristallinen COF‐Probe nur durch ED‐Methoden.