School of Physical Science and Technology, ShanghaiTech University, 201210, Shanghai, China.
Nat Commun. 2020 Mar 27;11(1):1588. doi: 10.1038/s41467-020-15388-5.
Handedness or chirality determination is a challenging and important topic in various fields including chemistry and biology, as two enantiomers have the same composition and mirror symmetry related structures, but might show totally different activities and properties in enantioselective separations, catalysis and so on. However, current methods are unable to reveal the handedness locally of a nanocrystal at the atomic-level in real-space imaging due to the well-known fact that chiral information is lost in a two-dimensional projection. Herein, we present a method for handedness determination of chiral crystals by atomic-resolution imaging using Cs-corrected scanning transmission electron microscopy. In particular, we demonstrate that enantiomorphic structures can be distinguished through chirality-dependent features in two-dimensional projections by comparing a tilt-series of high-resolution images along different zone axes. The method has been successfully applied to certify the specific enantiomorphic forms of tellurium, tantalum silicide and quartz crystals, and it has the potential to open up new possibilities for rational synthesis and characterization of chiral crystals.
手性或手征性测定是化学和生物学等多个领域的一个具有挑战性和重要性的课题，因为两种对映异构体具有相同的组成和镜像对称相关结构，但在对映选择性分离、催化等方面可能表现出完全不同的活性和性质。然而，由于众所周知的事实，即手性信息在二维投影中丢失，当前的方法无法在原子级的实空间成像中揭示纳米晶体的局部手性。在此，我们提出了一种使用 Cs 校正扫描透射电子显微镜进行手性晶体手性测定的方法。具体来说，我们通过比较不同晶带轴的高分辨率图像倾斜系列，证明通过二维投影中的手性依赖特征可以区分对映体结构。该方法已成功应用于证明碲、硅化钽和石英晶体的特定对映体形式，并有可能为手性晶体的合理合成和表征开辟新的可能性。
