The Role of Oxidation during the Synthesis of Silver‐Glutathione Monolayer‐Protected Clusters
The Role of Oxidation during the Synthesis of Silver‐Glutathione Monolayer‐Protected Clusters
复制标题
氧化在银-谷胱甘肽单层-受保护簇的合成过程中的作用
DOI：
10.1002/smll.202005663
复制
发表时间：
2021
期刊：
影响因子：
13.3
通讯作者：
Bigioni, Terry P.
中科院分区：
文献类型：
--
作者：
Zaker, Yeakub;Bhattarai, Badri;Brewer, Timothy R.;Bigioni, Terry P.
金属单层保护簇（MPC）的合成仍然没有很好的理解。最近表明，MPC形成的机制涉及顺序生长，其中小MPC首先形成，然后逐渐生长成更大的尺寸。然而，序贯增长模型并不能完全解释所有的实验观察结果。例如，MPC产物尺寸的演变被发现是反应动力学的非单调函数，而顺序生长模型预测单调行为。在合成反应的动力学范围很广的MPC的尺寸演变进行了研究，它被发现，所有的合成开始与MPC的顺序增长，但也发现，如果还原动力学足够快，让位于环境氧化的增长过渡到降解。据鉴定，MPC可以在合成期间通过氧化并且以与顺序生长相反的方式降解，即通过从较大的MPC物质形成较小的已知MPC物质。因此，这种连续降解过程在确定快速还原动力学反应的最终MPC产物中发挥了重要作用。总之，互补的氧化和还原过程提供了一个更完整的描述MPC合成以及控制金属MPC合成的新工具。
The synthesis of metal monolayer‐protected clusters (MPCs) is still not well understood. It was recently shown that the mechanism of MPC formation involves sequential growth, wherein small MPCs form first and then grow into progressively larger sizes. The sequential growth model does not entirely explain all experimental observations, however. For example, the evolution of MPC product sizes is found to be a non‐monotonic function of reaction kinetics, whereas the sequential growth model predicts monotonic behavior. Size evolution of MPCs is studied during synthetic reactions for a wide range of kinetics and it is found that all syntheses began with the sequential growth of MPCs but also found that growth transitioned to degradation if reduction kinetics are fast enough to give way to ambient oxidation. It is identified that MPCs can degrade via oxidation during syntheses and in a manner that is opposite to sequential growth, namely by forming smaller known MPC species from larger MPC species. This sequential degradation process therefore played an important role in determining final MPC products for reactions with fast reduction kinetics. Together, complementary oxidative and reductive processes provide a more complete description of MPC synthesis as well as new tools for controlling metal MPC synthesis.