[Ag14]异构引发的纺锤形Ag58团簇的形成

1. a 华中科技大学材料科学与工程学院 材料成形与模具技术国家重点实验室 武汉 430074;
b 中原工学院 河南省功能盐材料重点实验室 先进材料研究中心 郑州 450007
• 发布日期:2020-08-05
• 通讯作者: 谢云鹏, 卢兴 E-mail:xieyp@hust.edu.cn;lux@hust.edu.cn
• 基金资助:
项目受国家自然科学基金（Nos.21771071，51672093 and 21925104）资助.

The Formation of Spindle-Like Ag58 Cluster Induced by Isomerization of [Ag14]

Shen Yang-Lina, Jin Jun-Lingb, Duan Guang-Xionga, Xie Yun-Penga, Lu Xinga

1. a State Key Laboratory of Materials Processing and Die & Mould Technology, School of Materials Science and Engineering, Huazhong University of Science and Technology (HUST), Wuhan 430074, China;
b Henan Key Laboratory of Functional Salt Materials, Center for Advanced Materials Research, Zhongyuan University of Technology, Zhengzhou, 450007, China
• Published:2020-08-05
• Supported by:
Project supported by the Name of Foundation (Nos. 21771071, 51672093 and 21925104).

The atomically precise silver(I)-thiolate clusters in nanoscale have attracted extensive attention for years due to their attractive aesthetic structures and potential applications. Herein, two novel core-shell structured silver(I)-thiolate clusters of[Ag56S12(tBuS)20(CF3CO2)12]·6CH3CN·8H2O (abbreviated as Ag56) and[Ag58S12(tBuS)20(CF3CO2)14(CH3CN)6]·6CH3CN (Ag58) are prepared by employing the self-assembly method in solution. Especially, with the introduction of dimethylformamide (DMF) and bis(diphenylphosphino)methane (DPPM), the tBuSAg precursor reacted with CF3CO2Ag to produce a novel cluster Ag58 instead of Ag56 that has a similar structure with previous reports. Single crystal XRD analysis indicates that both clusters have Ag14 core units. But different from the common dodecahedron structure in Ag56, the spindle-shaped Ag14 structure in Ag58 is discovered for the first time and then induces the shell structure of Ag58 to form a rare spindle shape, in which silver atoms are layered in a form of "Ag4-Ag8-Ag10-Ag10-Ag8-Ag4". The spindle-shaped Ag14 can be viewed as forming by the two vertices of the rhombic dodecahedron being pulled outwards symmetrically. Thus, there are obvious similarities and differences between the two Ag14 core structures. Compared with the previously reported the face-centered cubic Ag14 prepared by solvothermal methods, the rhombic dodecahedron and the rhombic dodecahedron-like (spindle) Ag14 were obtained at room temperature, which indicates that the formation of the clusters is a thermodynamic control. However, the change of solvent and auxiliary ligands also caused the Ag14 rhombohedral dodecahedron to deform and transform into a spindle-shaped structure, proving that the formation of the clusters is also a process controlled by kinetics. These prove that the synthesis of clusters is a process dominated by both of kinetics and thermodynamics. The UV-Vis absorption and fluorescence spectrums show that the structure discrepancies of the two clusters deriving from the isomerization of Ag14 units significantly affect the energy levels and fluorescence properties of the clusters. This study enriches the thiolate-silver cluster family and provides new samples and insights for understanding the formation mechanism and properties of such core-shell architectures.