Wang Yongtian, Han Changcai, Fei Zejie, Dong Changwu, Liu Hongtao
Key Laboratory of Interfacial Physics and Technology, Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800, P. R. China.
University of Chinese Academy of Sciences, Beijing 100049, P. R. China.
J Phys Chem A. 2020 Jul 9;124(27):5590-5598. doi: 10.1021/acs.jpca.0c03746. Epub 2020 Jun 29.
The microsolvation of gold anions in different alcohol solvents is demonstrated by the combination of anion photoelectron spectroscopy and quantum chemical calculations on the Au(Solv) (Solv = CHOH, -CHOH; = 1-3 for Au; = 1 for Au). The microsolvation structures of these clusters and their corresponding neutrals are assigned by comparing calculations with experiments. In terms of overall regularity, the increasing solvation number () and carbon chain extension both can increase the stability of the anion. When ≥ 2, these clusters have low-energy isomers, where conventional hydrogen bonds (HBs) compete with nonconventional HBs (NHBs). NHBs are dominant when ≤ 2 and when is increased, vice versa. Interestingly, a variety of theoretical calculations show that after the hydroxy H atom of the ethanol molecule forms a weak ionic HB with Au, there are two lowest conformations of ethanol, trans and gauche, which could be coexisting in the molecular beams. Some theoretical methods also suggest that the gauche isomer is more stable than the trans one, which indicates that Au may exist as a gold gauche effect similar to fluorine.
通过对Au(Solv)（Solv = CHOH, -CHOH；对于Au， = 1 - 3；对于Au， = 1）进行阴离子光电子能谱和量子化学计算，证明了金阴离子在不同醇类溶剂中的微溶剂化作用。通过将计算结果与实验结果进行比较，确定了这些团簇及其相应中性物质的微溶剂化结构。从整体规律来看，溶剂化数（）的增加和碳链的延长都能提高阴离子的稳定性。当≥2时，这些团簇具有低能量异构体，其中传统氢键（HBs）与非常规氢键（NHBs）相互竞争。当≤2且增加时，NHBs占主导，反之亦然。有趣的是，各种理论计算表明，乙醇分子的羟基H原子与Au形成弱离子型HB后，乙醇存在反式和顺式两种最低构象，它们可能共存于分子束中。一些理论方法还表明，顺式异构体比反式异构体更稳定，这表明Au可能以类似于氟的金顺式效应存在。
