Zhou Jun, Li Tianrong, Li Qinzhen, Zheng Peisen, Yang Sha, Chai Jinsong, Zhu Manzhou
Department of Chemistry and Centre for Atomic Engineering of Advanced Materials, Key Laboratory of Structure and Functional Regulation of Hybrid Materials of Ministry of Education, Institutes of Physical Science and Information Technology and Anhui Province Key Laboratory of Chemistry for Inorganic/Organic Hybrid Functionalized Materials, Anhui University, Hefei, Anhui 230601, China.
Inorg Chem. 2022 May 2;61(17):6493-6499. doi: 10.1021/acs.inorgchem.2c00246. Epub 2022 Apr 18.
Introduction of chiral ligands has been regarded as an effective strategy to obtain nanoclusters with optical purity. However, how the chiral ligands work is still unclear due to the lack of structural comparison between racemic nanoclusters and the corresponding optically active ones. In this work, three structurally related AuCd nanoclusters, including one racemic and two homochiral nanoclusters, were synthesized, and their crystal structures were characterized using single-crystal X-ray crystallography (SC-XRD). Based on their crystal structures, the origin of the chirality in AuCd was found to be the twist of the kernel and the chiral arrangement of the metal-ligand surface. AuCd protected with chiral ligands exhibits a more twisted kernel than the racemic one. Therefore, the chirality of chiral diphosphine was found to transfer from the ligands to the metal-ligand interface and then to the metal core, inducing its distortion to produce enhanced chirality. In addition, the optical properties including optical absorption and circular dichroism of these structurally related AuCd nanoclusters were compared.
引入手性配体被认为是获得具有光学纯度的纳米团簇的有效策略。然而，由于外消旋纳米团簇与相应的光学活性纳米团簇之间缺乏结构比较，手性配体的作用方式仍不清楚。在这项工作中，合成了三种结构相关的AuCd纳米团簇，包括一种外消旋纳米团簇和两种纯手性纳米团簇，并使用单晶X射线晶体学（SC-XRD）对它们的晶体结构进行了表征。基于它们的晶体结构，发现AuCd中手性的起源是内核的扭曲和金属-配体表面的手性排列。用手性配体保护的AuCd比外消旋的AuCd表现出更扭曲的内核。因此，发现手性二膦的手性从配体转移到金属-配体界面，然后再转移到金属核，导致其变形以产生增强的手性。此外，还比较了这些结构相关的AuCd纳米团簇的光学性质，包括光吸收和圆二色性。
