Theoretical investigation of optimized structures of thiolated gold cluster [Au25(SCH3)18]+
Theoretical investigation of optimized structures of thiolated gold cluster [Au25(SCH3)18]+
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DOI：
10.1021/jp063532w
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发表时间：
2007-01-11
影响因子：
3.7
通讯作者：
Nobusada, Katsuyuki
中科院分区：
文献类型：
--
作者：
Iwasa, Takeshi;Nobusada, Katsuyuki
用密度泛函理论研究了一个金-甲硫醇配合物[Au-25（SCH 3）（18）]（+）的几何结构和电子结构.三种类型的优化结构来自两个不同的Au 25核心集群保护的18甲硫醇。最可能的优化结构由Au-7核簇和Au-S络合物样环簇Au-12（SCH 3）（12）和Au-3（SCH 3）（3）组成。Au-7核簇被Au-12（SCH 3）（12）环簇包围，然后Au-7-Au-12（SCH 3）（12）核-环子系统被两个Au-3（SCH 3）（3）环簇从顶部和底部的两侧覆盖。这种结构特征与金-硫醇盐簇的一般概念相反，即核心金簇表面上受到硫醇盐分子的保护。优化的结构提供了一个大的HOMO-LUMO带隙，其X射线衍射和吸收光谱成功地再现了实验结果。
Geometric and electronic structures of a gold-methanethiolate [Au-25(SCH3)(18)](+) are investigated by using density functional theory. Three types of optimized structures are derived from two different Au25 core clusters protected by 18 methanethiolates. The most probable optimized structure consists of a Au-7 core cluster and Au-S complex-like ring clusters, Au-12(SCH3)(12) and Au-3(SCH3)(3). The Au-7 core cluster is enclosed by the Au-12(SCH3)(12) ring cluster and then the Au-7-Au-12(SCH3)(12) core-ring subsystem is capped with the two Au-3(SCH3)(3) ring clusters from both sides of the top and the bottom. This structural feature is in contrast to a general notion of gold-thiolate clusters that a core gold cluster is superficially protected by thiolate molecules. The optimized structure provides a large HOMO-LUMO gap, and its X-ray diffraction and absorption spectra successfully reproduce the experimental results.