Malola Sami, Häkkinen Hannu
Department of Physics, Nanoscience Center, University of Jyväskylä, FI-40014 Jyväskylä, Finland.
Chem Commun (Camb). 2019 Aug 7;55(64):9460-9462. doi: 10.1039/c9cc04914b.
The electronic structure and chiroptical properties of the recently isolated and structurally characterized all-alkynyl-protected gold nanocluster Au144(CCPhF)60 were analyzed via density functional theory (DFT) computations and compared to those of the structurally similar all-thiolate-protected Au144(SCH2Ph)60. While DFT predicts very strong CD signals of similar strength for both clusters, the origins of chiroptical activity are markedly different. The chiral response of Au144(CCPhF)60 originates only from the footprint of the outermost gold-ligand layer of 30 FPhCC-Au-CCPhF units covering an achiral Ih-symmetric Au114 core whereas the Au114 core of the Au144(SCH2Ph)60 cluster has a chiral I symmetry and it alone produces CD signals that are comparable to those of the well-studied chiral Au38(SR)24. These signals are then amplified by a chiral arrangement of the protecting 30 PhH2CS-Au-SCH2Ph units. These results shed light on the origins of chiroptical activity of ligand-protected gold clusters that form an important class of atom-precise nanomaterials with potential applications in chiral sensing and enantioselective catalysis.
通过密度泛函理论（DFT）计算分析了最近分离并进行结构表征的全炔基保护金纳米团簇Au144(CCPhF)60的电子结构和圆二色性性质，并与结构相似的全硫醇盐保护的Au144(SCH2Ph)60进行了比较。虽然DFT预测这两种团簇都有强度相似的非常强的CD信号，但圆二色性活性的起源明显不同。Au144(CCPhF)60的手性响应仅源于覆盖非手性Ih对称Au114核的30个FPhCC-Au-CCPhF单元的最外层金-配体层的印记，而Au144(SCH2Ph)60团簇的Au114核具有手性I对称性，其自身产生的CD信号与研究充分的手性Au38(SR)24相当。然后，这些信号通过保护30个PhH2CS-Au-SCH2Ph单元的手性排列而放大。这些结果揭示了配体保护金团簇的圆二色性活性的起源，这些金团簇是一类重要的原子精确纳米材料，在手性传感和对映选择性催化方面具有潜在应用。
