In situ studies on controlling an atomically-accurate formation process of gold nanoclusters.
In situ studies on controlling an atomically-accurate formation process of gold nanoclusters.
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DOI：
10.1039/c5nr03711e
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发表时间：
2015-08
期刊：
影响因子：
6.7
通讯作者：
Lina Yang;Hao-Sheng Cheng;Yong Jiang;Ting Huang;Jie Bao;Zhihu Sun;Zheng Jiang;Jingyuan Ma;Fanfei Sun;Qinghua Liu;T. Yao;Huijuan Deng;Shuxin Wang;Manzhou Zhu;Shiqiang Wei
中科院分区：
文献类型：
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作者：
Lina Yang;Hao-Sheng Cheng;Yong Jiang;Ting Huang;Jie Bao;Zhihu Sun;Zheng Jiang;Jingyuan Ma;Fanfei Sun;Qinghua Liu;T. Yao;Huijuan Deng;Shuxin Wang;Manzhou Zhu;Shiqiang Wei
了解金属纳米团簇的分子形成机制对于发展化学以精确控制其合成是必不可少的。本文采用X射线/紫外-可见吸收光谱和时间依赖质谱相结合的方法，研究了多分散Au 13纳米团簇（15 ≤ n ≤ 65）经盐酸刻蚀后的“自上而下”合成过程。实验结果表明，盐酸诱导合成Au 13是通过精确控制刻蚀过程中的两个独特的步骤来实现的，与传统的通过释放Au（i）络合物的硫醇刻蚀机制形成鲜明对比。第一步是将初始较大的Aun团簇直接分裂成亚稳的中间Au 8-Au 13较小的团簇。这是一个关键的步骤，它允许通过将反应性Au（i）-Cl物种引入溶液中，使中间体向原子单分散Au 13簇的二次尺寸生长步骤。这种二次生长途径进一步证实了通过在HCl环境中与AuClPPh 3反应的孤立Au 11簇的Au 13的成功生长。这项工作解决了反应中间体的重要性，在指导的方式走向可控合成的金属纳米团簇。
Knowledge of the molecular formation mechanism of metal nanoclusters is essential for developing chemistry for accurate control over their synthesis. Herein, the "top-down" synthetic process of monodisperse Au13 nanoclusters via HCl etching of polydisperse Aun clusters (15 ≤ n ≤ 65) is traced by a combination of in situ X-ray/UV-vis absorption spectroscopy and time-dependent mass spectrometry. It is revealed experimentally that the HCl-induced synthesis of Au13 is achieved by accurately controlling the etching process with two distinctive steps, in sharp contrast to the traditional thiol-etching mechanism through release of the Au(i) complex. The first step involves the direct fragmentation of the initial larger Aun clusters into metastable intermediate Au8-Au13 smaller clusters. This is a critical step, which allows for the secondary size-growth step of the intermediates toward the atomically monodisperse Au13 clusters via incorporating the reactive Au(i)-Cl species in the solution. Such a secondary-growth pathway is further confirmed by the successful growth of Au13 through reaction of isolated Au11 clusters with AuClPPh3 in the HCl environment. This work addresses the importance of reaction intermediates in guiding the way towards controllable synthesis of metal nanoclusters.