Correlating the crystal structure of A thiol-protected Au25 cluster and optical properties
Correlating the crystal structure of A thiol-protected Au25 cluster and optical properties
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DOI：
10.1021/ja801173r
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发表时间：
2008-05-07
影响因子：
15
通讯作者：
Jin, Rongchao
中科院分区：
文献类型：
--
作者：
Zhu, Manzhou;Aikens, Christine M.;Jin, Rongchao
长期以来，由受硫醇保护的AU簇的总结构确定一直是集群研究中的主要问题。本文中，我们报告了一个不寻常的单晶体结构，该晶体的簇（直径为1.27 nm，地表到表面距离）受18个苯乙醇配体保护。 AU-25簇具有一个中心的二十面体AU-13核心，该核心由十二个金原子盖住，这些金原子位于三个相互垂直的2倍的二十面体轴周围，六对。在独特的桥接模式下，硫醇酸盐配体与AU-25芯结合。这种高度对称的结构与密度功能理论的最新预测明显不同，并且也违反了簇的经验金规则群，它将通过两个Icosahedral M-13构建块进行预测的生物面体结构，如先前在由磷酸配体保护的各种25个原子簇AU-25（SR）（18）簇表现出多种分子样吸收带，我们发现结果与观察到的结构的时间依赖性密度功能理论计算良好。
The total structure determination of thiol-protected Au clusters has long been a major issue in cluster research. Herein, we report an unusual single crystal structure of a 25-gold-atom cluster (1.27 nm diameter, surface-to-surface distance) protected by eighteen phenylethanethiol ligands. The Au-25 cluster features a centered icosahedral Au-13 core capped by twelve gold atoms that are situated in six pairs around the three mutually perpendicular 2-fold axes of the icosahedron. The thiolate ligands bind to the Au-25 core in an exclusive bridging mode. This highly symmetric structure is distinctly different from recent predictions of density functional theory, and it also violates the empirical golden rule-cluster of clusters", which would predict a biicosahedral structure via vertex sharing of two icosahedral M-13 building blocks as previously established in various 25-atom metal clusters protected by phosphine ligands. These results point to the importance of the ligand-gold core interactions. The Au-25(SR)(18) clusters exhibit multiple molecular-like absorption bands, and we find the results are in good correspondence with time-dependent density functional theory calculations for the observed structure.