Au3Si4- and Au4Si4: Electronically Equivalent but Different Polarity Superatoms
Au3Si4- and Au4Si4: Electronically Equivalent but Different Polarity Superatoms
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Au3Si4- 和 Au4Si4：电子等效但极性不同的超原子
DOI：
10.1021/acs.jpca.0c05592
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发表时间：
2020
期刊：
影响因子：
2.9
通讯作者：
A.-P. Tsai and T. Tsukuda
中科院分区：
文献类型：
--
作者：
K. Koyasu;K. Tsuruoka;S. Kameoka;A.-P. Tsai and T. Tsukuda
通过激光烧蚀 Au4Si 合金靶材，可大量产生一系列 AuxSi4 簇阴离子 (x= 1–4)。 AuxSi4–(x= 1–4) 的光电子能谱和密度泛函理论 (DFT) 计算表明，Au3Si4– 可以被视为电子封闭的超原子，由 Si4 单元组成，其单个面的三个相邻边缘由三个 Au 原子桥接。这种相分离结构是由三个金原子之间的亲金相互作用促进的，并导致较大的永久偶极矩（4.43 D）。对电子等效超原子 Au4Si4 的 DFT 计算预测了一种新结构，其中 Au3Si4– 的不配位 Si 原子通过 Au+ 键合。这种 Au4Si4 比之前报道的立方结构稳定得多，并且具有大的 HOMO-LUMO 能隙 (1.68 eV) 和小的永久偶极矩 (0.41 D)。
A series of AuxSi4–cluster anions (x= 1–4) were generated most abundantly by laser ablation of a Au4Si alloy target. Photoelectron spectroscopy and density functional theory (DFT) calculation of AuxSi4–(x= 1–4) revealed that Au3Si4–can be viewed as an electronically closed superatom and is composed of a Si4unit whose three adjacent edges of a single facet are bridged by three Au atoms. Such phase-segregated structure is facilitated by aurophilic interaction between the three Au atoms and results in a large permanent dipole moment (4.43 D). DFT calculations on an electronically equivalent superatom Au4Si4predicted a new structure in which the uncoordinated Si atom of Au3Si4–is bonded by Au+. This Au4Si4is much more stable than a cubic structure previously reported and has a large HOMO–LUMO gap (1.68 eV) and a small permanent dipole moment (0.41 D).