Acta Chimica Sinica ›› 2010, Vol. 68 ›› Issue (14): 1363-1369. Previous Articles     Next Articles

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从头算量子化学计算方法对高氯酸镁溶液中存在的离子缔合物种及缔合过程的研究

张浩,于健康*,孙家锺   

  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 130023)
  • 投稿日期:2009-08-26 修回日期:2010-01-27 发布日期:2010-03-04
  • 通讯作者: 于健康 E-mail:zhanghao@email.jlu.edu.cn
  • 基金资助:

    国家自然科学基金

Ab-initio Investigation on the Ion-associated Species and Process in Mg(ClO4)2 Solution

ZHANG Hao, YU Jian-Kang, SUN Jia-Zhong   

  1. (State Key Laboratory of Theoretical and Computational Chemistry, Institute of Theoretical Chemistry, Jilin University, Changchun 130023)
  • Received:2009-08-26 Revised:2010-01-27 Published:2010-03-04

In the present article, the hydration of , ion-associated species and process in the Mg(ClO4)2 solution were investigated at the HF/6-31+G* level. The first aqueous sphere can be filled by 6 water molecules at least. When the hydrated number is less than 6, the blue-shift of the v1- frequency of 1.7 cm-1 can be resulted by each added water molecule. The direact contact of the first Mg2+ can lead the v1- frequency a large red-shift, and the second and the third Mg2+ will make the reversed shift. The shifts will be contributed to the polarization of the Mg2+. Some associated species will form between and aqueous Mg2+, such as solvent-shared ion pairings, contact ion pairings and triple ion clusters. In these species, the solvent-shared ion pairing and triple ion cluster with one aqueous Mg2+ and two ions can lead the v1- frequencies to small blue-shifts which are corresponding with the Raman spectra in experiment. The ion associated process which is not analogous with the MgSO4 but Mg(NO3)2 system, is predicted to be: free ions→solvent-shared ion pairing→solvent-shared triple ion cluster with one aqueous Mg2+ and two ions→Mg(ClO4)2•6H2O (crystal).

Key words: quantum chemical calculation, magnesium perchlorate, ion-associated species, associated process