论文标题
揭示电子显微镜限制在多孔框架中的小芳香族的构型和宿主 - 环相互作用
Revealing the configurations and host-guest interactions of small aromatics confined in porous frameworks by electron microscopy
论文作者
论文摘要
直接对环境温度下的小分子的构型进行成像，将大大促进其化学和物理性质的研究，包括在吸附，催化和储能过程中有机物在多孔材料中的宿主 - 阵风相互作用。但是，由于（扫描）透射电子显微镜（（S）TEM）在小分子成像上面临的挑战，我们仍然缺乏对宿主 - 基因相互作用和其他分子行为的分子水平理解。在这里，我们通过使用集成的差异相比（IDPC）技术，实现了限制在MFI-Type沸石框架中的各种小芳烃的茎成像。由于MFI通道中的强限效应，一维固体样芳族柱显示了连贯的构型，通过增强宿主 - 阵线相互作用，可以清楚地解决它们。然后，我们还直接通过图像分析评估了宿主 - 阵线相互作用的强度，并揭示了在原位加热过程中受到约束芳香剂的解吸行为。这些结果不仅帮助我们揭示了多孔材料吸附/解吸过程中小芳香剂的构型和宿主 - 基因相互作用，而且还扩展了STEM在实际空间中进一步研究其他分子行为的应用。
Directly imaging the configurations of small molecules at the ambient temperatures will greatly promote the study of their chemical and physical properties, including the host-guest interactions of organics in porous materials during the adsorption, catalysis and energy storage. However, due to the current challenges on the small-molecule imaging by the (scanning) transmission electron microscopy ((S)TEM), we still have a lack of the molecular-level understandings on the host-guest interactions and other molecular behaviors. Here, we achieved the STEM imaging of various small aromatics confined in the MFI-type zeolite frameworks by using the integrated differential phase contrast (iDPC) technique. Due to the strong confinement effect in MFI channels, the 1D solid-like aromatic columns showed the coherent configurations, which were clearly resolved by enhancing the host-guest interactions. Then, we also evaluated the strength of host-guest interactions directly by the image analysis and revealed the desorption behaviors of confined aromatics during the in-situ heating process. These results not only helped us to reveal the configurations and host-guest interactions of small aromatics during the adsorption/desorption in porous materials, but also expanded the applications of STEM to further study other molecular behaviors in the real space.
