日本东北大学Yonekura, Koji团队用连续X射线自由电子激光和电子晶体学分析有机小分子的结构。相关研究成果于2023年3月20日发表在国际顶尖学术期刊《自然—化学》。

小晶体的结构分析在从合成有机化学到药物和材料科学的各个领域都很重要，因为许多化合物不会产生大晶体。

该文中，研究人员介绍了通过X射线自由电子激光器（XFEL）以0.82分辨率测定的有机分子罗丹明-6G结构的详细表征。使用电子晶体学将这种结构与从同一批微晶样品中获得的结构进行直接比较表明，这两种方法都可以准确区分一些氢原子的位置，这取决于它们所涉及的化学键的类型。通过XFEL和电子衍射测量的距离的变化反映了X射线和电子散射的预期差异。发现XFEL对原子坐标的可靠性更好，但电子束对电荷的敏感性更高。

附：英文原文

Title: Structural resolution of a small organic molecule by serial X-ray free-electron laser and electron crystallography

Author: Takaba, Kiyofumi, Maki-Yonekura, Saori, Inoue, Ichiro, Tono, Kensuke, Hamaguchi, Tasuku, Kawakami, Keisuke, Naitow, Hisashi, Ishikawa, Tetsuya, Yabashi, Makina, Yonekura, Koji

Issue&Volume: 2023-03-20

Abstract: Structure analysis of small crystals is important in areas ranging from synthetic organic chemistry to pharmaceutical and material sciences, as many compounds do not yield large crystals. Here we present the detailed characterization of the structure of an organic molecule, rhodamine-6G, determined at a resolution of 0.82 by an X-ray free-electron laser (XFEL). Direct comparison of this structure with that obtained by electron crystallography from the same sample batch of microcrystals shows that both methods can accurately distinguish the position of some of the hydrogen atoms, depending on the type of chemical bond in which they are involved. Variations in the distances measured by XFEL and electron diffraction reflect the expected differences in X-ray and electron scatterings. The reliability for atomic coordinates was found to be better with XFEL, but the electron beam showed a higher sensitivity to charges.

DOI: 10.1038/s41557-023-01162-9

Source: https://www.nature.com/articles/s41557-023-01162-9