Ag₂₉ nanoclusters capped with lipoic acid (LA) can be doped with Au. The doped clusters show enhanced stability and increased luminescence efficiency. We attribute the higher quantum yield to an increase in the rate of radiative decay. With mass spectrometry, the Au-doped clusters were found to consist predominantly of Au₁Ag₂₈(LA)₁₂^3–. The clusters were characterized using X-ray absorption spectroscopy at the Au L₃-edge. Both the extended absorption fine structure (EXAFS) and the near edge structure (XANES) in combination with electronic structure calculations confirm that the Au dopant is preferentially located in the center of the cluster. A useful XANES spectrum can be recorded for lower concentrations, or in shorter time, than the more commonly used EXAFS. This makes XANES a valuable tool for structural characterization.

中文翻译：

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银纳米团簇的单金原子掺杂

用硫辛酸（LA）封端的Ag ₂₉纳米团簇可以掺杂Au。掺杂的团簇显示出增强的稳定性和增加的发光效率。我们将较高的量子产率归因于辐射衰减率的增加。通过质谱分析，发现金掺杂的团簇主要由Au ₁ Ag ₂₈（LA）₁₂ ^3–组成。使用X射线吸收光谱在Au L _3上对团簇进行表征-边缘。扩展吸收精细结构（EXAFS）和近边缘结构（XANES）结合电子结构计算都证实了Au掺杂剂优先位于团簇的中心。与更常用的EXAFS相比，可以记录较低浓度或较短时间的有用XANES光谱。这使XANES成为用于结构表征的有价值的工具。