Department of Chemistry and Chemical Engineering, Heze University, Heze, Shandong Province 274015, China.
Beijing National Laboratory for Molecular Sciences, State Key Laboratory of Molecular Reaction Dynamics, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China.
J Chem Phys. 2018 Jun 28;148(24):244306. doi: 10.1063/1.5029870.
The photoelectron spectra of AuSi (n = 1-7) clusters were measured, and the structural evolution and bonding properties of AuSi anions and their corresponding neutral counterparts were investigated by theoretical calculations. The two Au atoms in AuSi prefer to occupy low coordinate sites and form fewer Au-Si bonds. The aurophilic interaction is fairly weak in these clusters. The most stable structures of both AuSi anions and AuSi neutrals can be described as the two Au atoms interacting with the Si frameworks. The most stable isomers of AuSi anions are in spin doublet states, while those of the neutral clusters are in spin singlet states. The lowest-lying isomers of AuSi have C symmetric V-shaped structures. The global minimum of the AuSi anion has a D symmetric planar rhombus structure, while that of the AuSi neutral adopts a C symmetric dibridged structure. In AuSi, the two Au atoms independently interact with the different Si-Si bonds of the Si triangular structure. The global minima of AuSi primarily adopt prismatic based geometries. Interestingly, AuSi have significant 3D aromaticity and possess σ plus π double bonding characters, which play important roles in their structural stability.
我们测量了 AuSi（n = 1-7）团簇的光电子能谱，并通过理论计算研究了 AuSi 阴离子及其相应中性体的结构演化和成键性质。AuSi 中的两个 Au 原子倾向于占据低配位点并形成较少的 Au-Si 键。这些团簇中的金键相互作用相当弱。AuSi 阴离子和 AuSi 中性体最稳定的结构都可以描述为两个 Au 原子与 Si 框架相互作用。AuSi 阴离子的最稳定异构体处于自旋双重态，而中性团簇的异构体处于自旋单重态。AuSi 的最低能异构体具有 C 对称的 V 形结构。AuSi 阴离子的全局最小值具有 D 对称的平面菱形结构，而 AuSi 中性体采用 C 对称的双桥结构。在 AuSi 中，两个 Au 原子独立地与 Si 三角结构的不同 Si-Si 键相互作用。AuSi 的全局最小值主要采用基于棱柱的几何形状。有趣的是，AuSi 具有显著的 3D 芳香性，并具有 σ 加 π 双键特征，这对其结构稳定性起着重要作用。
