Chemical Research in Chinese Universities ›› 2025, Vol. 41 ›› Issue (2): 326-332.doi: 10.1007/s40242-025-4244-4

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On Three-dimensional Electron Diffraction Data Quality for Probing Molecular Motions

WANG Weiyuan1, HUANG Zhehao1,2,3   

  1. 1. Center for Electron Microscopy, School of Emergent Soft Matter, South China University of Technology, Guangzhou 510640, P. R. China;
    2. Guangdong Basic Research Center of Excellence for Energy and Information Polymer Materials, South China University of Technology, Guangzhou 510640, P. R. China;
    3. Guangdong Provincial Key Laboratory of Functional and Intelligent Hybrid Materials and Devices, South China University of Technology, Guangzhou 510640, P. R. China
  • Received:2024-12-19 Accepted:2025-02-05 Online:2025-04-01 Published:2025-03-31
  • Contact: HUANG Zhehao,zhehaohuang@scut.edu.cn E-mail:zhehaohuang@scut.edu.cn
  • Supported by:
    This work was supported by the Guangdong Basic and Applied Basic Research Foundation, China (No. 2024B1515020078), the GJYC Program of Guangzhou, China (No. 2024D03J0001), the Recruitment Program of Guangdong Province, China (No. 2016ZT06C322), and the ‘111’ Project of China (No. B18023). We would like to thank Chris Affolter from Oslo University for the synthesis of MIL-140C, and Dr. Christian Jandl from ELDICO Scientific AG for collecting 3DED data.

Abstract: Molecular motions in metal-organic frameworks (MOFs) play important roles in guest diffusion processes, which is crucial for gas capture and separations. Three-dimensional electron diffraction (3DED) has emerged as an advanced method to probe molecular motions, such as linker librations. For a study of molecular motions by 3DED, data quality is the key to the analysis and interpretation. Herein, we present a systematic work to investigate the effects of data completeness, resolution, and signal-to-noise ratio on the identification of molecular motion in MIL-140C. We determine the limits of completeness and resolution required for reliably analyzing molecular motions. In addition, data processing can affect the signal-to-noise ratio of data, and we demonstrate their influence on probing molecular motions. This work provides reference conditions on 3DED data quality to obtain reliable information on molecular motions.

Key words: Metal-organic framework, Molecular motion, Threedimensional electron diffraction, Data quality, Thermal ellipsoid model