Borgmans Sander, Rogge Sven M J, De Vos Juul S, Van Der Voort Pascal, Van Speybroeck Veronique
Center for Molecular Modeling (CMM), Ghent University, Technologiepark-Zwijnaarde 46, 9052, Zwijnaarde, Belgium.
Center for Ordered Materials, Organometallics and Catalysis (COMOC), Department of Inorganic and Physical Chemistry, Ghent University, Krijgslaan 281 (S3), 9000, Gent, Belgium.
Commun Chem. 2023 Jan 6;6(1):5. doi: 10.1038/s42004-022-00808-y.
Soft porous crystals, which are responsive to external stimuli such as temperature, pressure, or gas adsorption, are being extensively investigated for various technological applications. However, while substantial research has been devoted to stimuli-responsive metal-organic frameworks, structural flexibility in 3D covalent organic frameworks (COFs) remains ill-understood, and is almost exclusively found in COFs exhibiting the diamondoid (dia) topology. Herein, we systemically investigate how the structural decoration of these 3D dia COFs-their specific building blocks and degree of interpenetration-as well as external triggers such as temperature and guest adsorption may promote or suppress their phase transformations, as captured by a collection of 2D free energy landscapes. Together, these provide a comprehensive understanding of the necessary conditions to design flexible diamondoid COFs. This study reveals how their flexibility originates from the balance between steric hindrance and dispersive interactions of the structural decoration, thereby providing insight into how new flexible 3D COFs can be designed.
对温度、压力或气体吸附等外部刺激有响应的软质多孔晶体，正被广泛研究用于各种技术应用。然而，尽管大量研究致力于刺激响应型金属有机框架，但三维共价有机框架（COF）中的结构灵活性仍未得到充分理解，并且几乎仅在具有类金刚石（dia）拓扑结构的COF中发现。在此，我们系统地研究了这些三维dia COF的结构修饰——其特定的构建单元和互穿程度——以及温度和客体吸附等外部触发因素如何促进或抑制它们的相变，这些相变由一系列二维自由能景观所捕捉。这些共同提供了对设计柔性类金刚石COF所需条件的全面理解。这项研究揭示了它们的灵活性如何源于结构修饰的空间位阻和色散相互作用之间的平衡，从而为如何设计新型柔性三维COF提供了见解。
