循环硫化黄金集群的理论特征
Henrik Grönbeck1, Michael Walter, Hannu Häkkinen
1Department of Applied Physics and Competence Centre for Catalysis, Chalmers University of Technology, SE-412 96 Göteborg, Sweden. ghj@chalmers.se
Journal of the American Chemical Society
|August 3, 2006
概括
密度函数理论揭示了硫化黄金集群表现出高达四个单位的环状结构,成为聚合物. 连接物选择对这些黄金硫化合物的电子性质和光学间隙产生重大影响.
科学领域:
- 计算化学是一种计算化学.
- 材料科学是一种材料科学.
- 纳米技术纳米技术
背景情况:
- 化黄金集群由于其独特的结构和电子特性而引起人们的兴趣.
- 了解结构,粘合和特性之间的关系对于设计新材料至关重要.
研究的目的:
- 用密度函数理论研究甲基化黄金集群 (MeSAu) x 的结构,能量,振动和光学特性,x = 2-12 .
- 探索连接体置换对硫化黄金集群性质的影响,特别关注四聚合物.
主要方法:
- 使用密度函数理论 (DFT) 的计算.
- 结构性,能量性,振动性和光学性质被系统地探索.
- 通过将甲基thiolate与基thiolate,基thiolate和谷氨酸酸 (GS) 进行比较,研究了连接物替代效应.
主要成果:
- 集群 (MeSAu) x采用x ≤ 4的环形状和更大尺寸的冠状结构,表现出聚合物特性.
- 结构性质和能量性质在 (MeSAu) 4.4 汇聚.
- 这种Au-S键是极性共价的,具有循环电子脱局. 典型的Au-S振动发生在300厘米左右.
- 配体选择显著影响电子特性, (GSAu) 4 的光学间隙大约比 (MeSAu) 4.4 的光学间隙低1.5 eV.
结论:
- 化黄金集群显示尺寸依赖的结构转变和聚合物行为.
- 这些集群的电子和光学特性对封装配体的性质敏感.
- DFT提供了一个强大的框架来理解化黄金纳米集群的基本特性.
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