School of Physical Science and Technology, ShanghaiTech University, 393 Middle Huaxia Road, Pudong, Shanghai 201210, China.
Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050, China.
Int J Mol Sci. 2019 Apr 24;20(8):2018. doi: 10.3390/ijms20082018.
Chiral recognition among helical molecules is of essential importance in many chemical and biochemical processes. The complexity necessitates investigating manageable model systems for unveiling the fundamental principles of chiral recognition at the molecular level. Here, we reported chiral recognition in the self-assembly of enantiopure and racemic hexahelicene on a Au(111) surface. Combing scanning tunneling microscopy (STM) and atomic force microscopy (AFM) measurements, the asymmetric heterochiral trimers were observed as a new type of building block in racemic helicene self-assembly on Au(111). The intermolecular recognition of the heterochiral trimer was investigated upon manual separation so that the absolute configuration of each helicene molecule was unambiguously determined one by one, thus confirming that the trimer was "2+1" in handedness. These heterochiral trimers showed strong stability upon different coverages, which was also supported by theoretical calculations. Our results provide valuable insights for understanding the intermolecular recognition of helical molecules.
手性分子之间的手性识别在许多化学和生物化学过程中至关重要。由于其复杂性，需要研究可管理的模型体系，以揭示分子水平上手性识别的基本原理。在这里，我们报道了手性纯和外消旋六螺旋烯在 Au(111)表面自组装过程中的手性识别。通过扫描隧道显微镜(STM)和原子力显微镜(AFM)测量，观察到不对称的杂手性三聚体作为一种新的构筑块，存在于外消旋螺旋烯在 Au(111)上的自组装中。通过手动分离研究了三聚体之间的分子间识别，从而逐一明确确定每个螺旋烯分子的绝对构型，从而证实三聚体的手性为“2+1”。这些杂手性三聚体在不同覆盖率下表现出很强的稳定性，这也得到了理论计算的支持。我们的结果为理解螺旋分子的分子间识别提供了有价值的见解。
