Chair of Inorganic and Metal-Organic Chemistry, Department of Chemistry, Technical University of Munich, Lichtenbergstraße 4, 85787, Garching, Germany.
Synchrotron Light Research Institute (Public Organization), 111 University Avenue, Muang District, Nakhon Ratchasima, 30000, Thailand.
Nat Commun. 2019 Jan 21;10(1):346. doi: 10.1038/s41467-018-08285-5.
Flexible metal-organic frameworks (MOFs) are structurally flexible, porous, crystalline solids that show a structural transition in response to a stimulus. If MOF-based solid-state and microelectronic devices are to be capable of leveraging such structural flexibility, then the integration of MOF thin films into a device configuration is crucial. Here we report the targeted and precise anchoring of Cu-based alkylether-functionalised layered-pillared MOF crystallites onto substrates via stepwise liquid-phase epitaxy. The structural transformation during methanol sorption is monitored by in-situ grazing incidence X-ray diffraction. Interestingly, spatially-controlled anchoring of the flexible MOFs on the surface induces a distinct structural responsiveness which is different from the bulk powder and can be systematically controlled by varying the crystallite characteristics, for instance dimensions and orientation. This fundamental understanding of thin-film flexibility is of paramount importance for the rational design of MOF-based devices utilising the structural flexibility in specific applications such as selective sensors.
柔性金属有机骨架（MOFs）是结构灵活、多孔、结晶的固体，它们会对刺激做出结构转变。如果基于 MOF 的固态和微电子设备能够利用这种结构灵活性，那么将 MOF 薄膜集成到设备配置中就至关重要。在这里，我们通过分步液相外延法，将基于 Cu 的烷氧基功能化层状支柱 MOF 晶体有针对性和精确地锚定在基底上。通过原位掠入射 X 射线衍射监测甲醇吸附过程中的结构转变。有趣的是，在表面上对柔性 MOFs 的空间控制固定会引起与体粉末不同的明显结构响应，并且可以通过改变晶体特性（例如尺寸和取向）来系统地控制。这种对薄膜灵活性的基本理解对于基于 MOF 的设备的合理设计至关重要，这些设备可以在特定应用中利用结构灵活性，例如选择性传感器。
