Shen Hui, Selenius Elli, Ruan Pengpeng, Li Xihua, Yuan Peng, Lopez-Estrada Omar, Malola Sami, Lin Shuichao, Teo Boon K, Häkkinen Hannu, Zheng Nanfeng
State Key Laboratory for Physical Chemistry of Solid Surfaces, Collaborative Innovation Center of Chemistry for Energy Materials and, National & Local Joint Engineering Research Center for, Preparation Technology of Nanomaterials, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, P.R. China.
Departments of Physics and Chemistry, Nanoscience Center, University of Jyväskylä, 40014, Jyväskylä, Finland.
Chemistry. 2020 Jul 8;26(38):8465-8470. doi: 10.1002/chem.202001753. Epub 2020 Jun 15.
The conventional synthetic methodology for atomically precise gold nanoclusters by using reduction in solution offers only the thermodynamically most stable nanoclusters. Herein, a solubility-driven isolation strategy is reported to access a metastable gold cluster. The cluster, with the composition of [Au (PPh ) ] (1), displays an unusual, nearly perfect body-centered cubic (bcc) structure. As revealed by ESI-MS and UV/Vis measurements, the cluster is metastable in solution and converts to the well-known [Au (PPh ) Cl ] (2) within just 90 min. DFT calculations revealed that although both 1 and 2 are eight-electron superatoms, there is a driving force to convert 1 to 2 as shown by the increased cohesion and larger HOMO-LUMO energy gap of 2. The isolation and crystallization of the metastable gold cluster were achieved in a biphasic reaction system in which reduction of gold precursors and crystallization of 1 took place concurrently. This synthetic protocol represents a successful strategy for investigations of other metastable species in metal nanocluster chemistry.
通过溶液还原制备原子精确的金纳米团簇的传统合成方法只能得到热力学上最稳定的纳米团簇。在此，我们报道了一种溶解度驱动的分离策略来制备亚稳金团簇。该团簇的组成为[Au (PPh ) ] (1)，呈现出一种不寻常的、近乎完美的体心立方（bcc）结构。正如电喷雾电离质谱（ESI-MS）和紫外/可见光谱（UV/Vis）测量所显示的，该团簇在溶液中是亚稳的，并且在仅仅90分钟内就会转化为著名的[Au (PPh ) Cl ] (2)。密度泛函理论（DFT）计算表明，尽管1和2都是八电子超原子，但由于2具有更高的内聚能和更大的最高占据分子轨道-最低未占分子轨道（HOMO-LUMO）能隙，存在将1转化为2的驱动力。在双相反应体系中实现了亚稳金团簇的分离和结晶，其中金前驱体的还原和1的结晶同时发生。这种合成方法代表了金属纳米团簇化学中研究其他亚稳物种的一种成功策略。
