Department of Chemical and Biomolecular Engineering, National University of Singapore , Singapore 119260.
J Am Chem Soc. 2014 Jul 30;136(30):10577-80. doi: 10.1021/ja505429f. Epub 2014 Jul 21.
Despite 20 years of progress in synthesizing thiolated gold nanoclusters (Au NCs), the knowledge of their growth mechanism still lags behind. Herein the detailed process from reduction of Au(I)-thiolate complex precursors to the eventual evolution of and focusing to the atomically precise Au25 NCs was revealed for the first time by monitoring the time evolution of Au(I) precursor and Au NC intermediate species with ESI-MS. A two-stage, bottom-up formation and growth process was proposed: a fast stage of reduction-growth mechanism, followed by a slow stage of intercluster conversion and focusing. Balanced reactions of formation for each identified NC were suggested, backed by theoretical calculations of the thermodynamic driving force. This work advances one step further toward understanding the mechanism of formation and growth of thiolated Au NCs.
尽管在合成巯基化金纳米簇（Au NCs）方面已经取得了 20 年的进展，但对其生长机制的了解仍落后于其他领域。在此，通过电喷雾质谱（ESI-MS）监测 Au（I）前体和 Au NC 中间体的时间演变，首次首次揭示了从还原 Au（I）-硫醇配合物前体到最终演化并聚焦到原子精确的 Au25 NC 的详细过程。提出了一个两阶段的自下而上的形成和生长过程：一个快速的还原-生长机制阶段，随后是一个缓慢的簇间转化和聚焦阶段。通过对热力学驱动力的理论计算，为每个鉴定出的 NC 的形成平衡反应提供了支持。这项工作朝着理解巯基化 Au NCs 的形成和生长机制又迈进了一步。
