Resolution of enantiomers of chiral compounds via crystallization is the dominant method in chemical industry, but chiral recognition at the molecular level during this process is still poorly understood. Using single metal surfaces in ultrahigh vacuum as model system, the enantio‐related transition from the monolayer structure into a double layer of the racemic mixture of heptahelicene has been studied with scanning tunneling microscopy. Submolecular resolution reveals enantiopure second layers on Ag(111) and almost enantiopure second layers on Au(111). In analogy to previous results on Cu(111), it is concluded that transition from the 2D first layer racemate into a layered racemate occurs.

中文翻译：

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庚二烯在贵金属表面上的双层结晶。

通过结晶拆分手性化合物的对映异构体是化学工业中的主要方法，但是在该过程中在分子水平上的手性识别仍然知之甚少。使用超高真空中的单个金属表面作为模型系统，已通过扫描隧道显微镜研究了从庚烷的单层结构到外消旋混合物的双层的对映体相关跃迁。亚分​​子分辨率揭示了Ag（111）上的对映纯第二层和Au（111）上的几乎对映纯第二层。与先前关于Cu（111）的结果类似，得出的结论是发生了从二维第一层外消旋体到层状外消旋体的转变。