Institute of Physics, Czech Academy of Sciences, Prague, Czech Republic.
Department of Geosciences, University of Bremen, Bremen, Germany.
Nat Chem. 2023 Jun;15(6):848-855. doi: 10.1038/s41557-023-01186-1. Epub 2023 Apr 20.
Continuous-rotation 3D electron diffraction methods are increasingly popular for the structure analysis of very small organic molecular crystals and crystalline inorganic materials. Dynamical diffraction effects cause non-linear deviations from kinematical intensities that present issues in structure analysis. Here, a method for structure analysis of continuous-rotation 3D electron diffraction data is presented that takes multiple scattering effects into account. Dynamical and kinematical refinements of 12 compounds-ranging from small organic compounds to metal-organic frameworks to inorganic materials-are compared, for which the new approach yields significantly improved models in terms of accuracy and reliability with up to fourfold reduction of the noise level in difference Fourier maps. The intrinsic sensitivity of dynamical diffraction to the absolute structure is also used to assign the handedness of 58 crystals of 9 different chiral compounds, showing that 3D electron diffraction is a reliable tool for the routine determination of absolute structures.
连续旋转三维电子衍射方法越来越受欢迎,可用于分析非常小的有机分子晶体和结晶无机材料的结构。动力学衍射效应会导致与运动学强度的非线性偏差,这给结构分析带来了问题。本文提出了一种考虑多次散射效应的连续旋转三维电子衍射数据结构分析方法。对 12 种化合物(从小分子有机化合物到金属有机骨架到无机材料)进行了动力学和运动学精修,结果表明,对于多达四倍的噪声水平降低的差分傅立叶映射,新方法在准确性和可靠性方面显著提高了模型。动力学衍射对绝对结构的固有敏感性也被用于确定 9 种不同手性化合物的 58 个晶体的手性,表明 3D 电子衍射是一种可靠的常规绝对结构测定工具。