[Au7(SR)7] Ring as a New Type of Protection Ligand in a New Atomic Structure of Au15(SR)13 Nanocluster
[Au7(SR)7] Ring as a New Type of Protection Ligand in a New Atomic Structure of Au15(SR)13 Nanocluster
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DOI：
10.1021/acs.jpca.1c04026
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发表时间：
2021-06-30
影响因子：
2.9
通讯作者：
Xu, Wen Wu
中科院分区：
文献类型：
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作者：
Liu, Pengye;Han, Wenhua;Xu, Wen Wu
我们首次基于环模型提出了[Au-7(SR)(7)]环作为Au-15(SR)(13)纳米团簇新原子结构中的新型保护配体，该模型旨在了解界面相互作用如何决定硫醇盐保护的金纳米团簇中的保护基序和金核心的结构。这种新的 Au-15(SR)(13) 模型显示了由一个 [Au-7(SR)(7)] 环和两个 [Au-2(SR)(3)]“钉书”基序保护的四面体 Au-4 核心。密度泛函理论 (DFT) 计算表明，新预测的 Au-15(SR)(13) (R = CH3/Ph) 的能量比之前提出的异构体低 0.24/0.68 eV。通过将计算的光学吸收光谱（UV）、圆二色性（CD）光谱和粉末X射线衍射（XRD）图谱与相关实验光谱进行比较，新预测的Au-15(SR)(13)（R = CH3/Ph）的计算的CD光谱无法再现实验结果，表明新预测的Au-15(SR)(13)是一种需要实验证实的新结构。此外，DFT计算还表明，新预测的Au-15(SR)(13) (R = CH3/Ph)表现出较大的HOMO-LUMO能隙，表明其具有较高的化学稳定性。新预测的Au-15(SR)(13)中[Au-7(SR)(7)]环作为保护配体的提出，不仅丰富了硫醇盐保护的金纳米团簇中保护配体的类型，而且进一步证实了环模型对于理解硫醇盐保护的金纳米团簇中保护基序与金核之间的界面相互作用的有效性和合理性。
We present a [Au-7(SR)(7)] ring as a new type of protection ligand in a new atomic structure of Au-15(SR)(13) nanocluster for the first time based on the ring model developed to understand how interfacial interaction dictates the structures of protection motifs and gold cores in thiolate-protected gold nanoclusters. This new Au-15(SR)(13) model shows a tetrahedral Au-4 core protected by one [Au-7(SR)(7)] ring and two [Au-2(SR)(3)] "staple" motifs. Density functional theory (DFT) calculations show that the newly predicted Au-15(SR)(13) (R = CH3/Ph) has a lower energy of 0.24/0.68 eV than previously proposed isomers. By comparing calculated optical absorption spectra (UV), circular dichroism (CD) spectra, and powder X-ray diffraction (XRD) patterns with related experimental spectra, the calculated CD spectra of the newly predicted Au-15(SR)(13) (R = CH3/Ph) cannot reproduce the experimental results, indicating that the newly predicted Au-15(SR)(13) is a new structure that needs to be confirmed by experiment. In addition, DFT calculations also show that the newly predicted Au-15(SR)(13) (R = CH3/Ph) exhibits a large HOMO-LUMO gap, suggesting its high chemical stability. The proposition of the [Au-7(SR)(7)] ring as a protection ligand in the newly predicted Au-15(SR)(13) not only enriches the types of protection ligands in thiolate-protected gold nanoclusters but also further confirms the effectiveness and rationality of the ring model for understanding the interfacial interaction between the protection motifs and gold cores in thiolate-protected gold nanoclusters.