• 物理化学 •

### 金属离子Na+ , Li+ , Mg2+与硫酸根离子形成的无水缔合物种的从头算量子化学研究

1. 1. 吉林大学理论化学研究所, 理论化学计算国家重点实验室, 长春 130021;
2. 辽宁工程技术大学化工研究院, 葫芦岛 125000
• 收稿日期:2012-02-07 出版日期:2012-07-10 发布日期:2012-07-10
• 通讯作者: 张 浩, 男, 博士, 副教授, 主要从事理论化学基础理论及应用研究. E-mail: stringbell@jlu.edu.cn E-mail:stringbell@mail.jlu.edu.cn
• 基金资助:

吉林省自然科学基金(批准号: 20101552)和吉林大学自主研究课题项目(批准号: 450060481346)资助.

### Ab initio Investigation on Unhydrated Ion-associated Species Between Na+, Li+, Mg2+ and SO42- Ions

WAN Su-Qin1, ZHANG Yi2, ZHANG Hao1, SUN Chia-Chung1

1. 1. State Key Laboratory of Theoretical and Computational Chemistry, Institute of Theoretical Chemistry, Jilin University, Changchun 130021, China;
2. Research Institute of Chemical Industry, Liaoning Technical University, Huludao 125000, China
• Received:2012-02-07 Online:2012-07-10 Published:2012-07-10

Abstract: The structures of ion-associated species between Na+, Li+, Mg2+ and SO42- ions were optimized via ab initio calculations. And the influences of the cations to the ν1-SO42- frequencies were also investigated. For the ion-associated structures, when there are fewer cations, the repulsion between cations will decrease and thus the bidentate associated structures are easy to form, in which there is shorter distance between metal ion and SO42-. Contrarily, comparing with the increase of the number of cations in the ion clusters, especially for more Mg2+ ions which have more positive charge, the repulsions between metal ions would make the clusters instable and more monodentate structures are formed, in which the distances between metal and SO42- ions are longer. The metal ions could influence the ν1-SO42- frequencies via two ways. The first one is polarization of the cation, which leads the ν1-SO42- frequency red-shift, while another one is M-O bonding action, which lead the opposite blue-shift. When the number of metal ions ≤2, the first one is dominated. The first metal ion can lead the ν1-SO42- frequency red-shift, while more metal ions from different directions would decrease the red-shift. When the number of metal ions >2, the M-O bonding action is the main interaction manner. The increase of the monodentate associated structures in the quadruple or quintuple ion clusters, which can lead the more blue-shift than those of the bidentate ones, will make the ν1-SO42- frequency more blue-shift than those in the triple ion clusters.