物理化学学报 >> 1998, Vol. 14 >> Issue (11): 988-994.doi: 10.3866/PKU.WHXB19981106

研究论文 上一篇    下一篇

硝酸氯在冰表面上反应的研究

徐四川, 赵新生   

  1. 北京大学化学系,北京 100871
  • 收稿日期:1998-02-04 修回日期:1998-04-24 发布日期:1998-11-15
  • 通讯作者: 赵新生

Investigation of the Reaction of Chlorine Nitrate on lce Surface

Xu Si-Chuan, Zhao Xin-Sheng   

  1. Department of Chemistry,Peking University,Beijing 100871
  • Received:1998-02-04 Revised:1998-04-24 Published:1998-11-15
  • Contact: Zhao Xin-Sheng

摘要:

对硝酸氯与一,二,三个水分子的反应作为硝酸氯在冰表面上反应的模型进行了理论研究.MP2/HF/6-31G(d) 水平的理论计算给出:在气相反应中,硝酸氯与水反应活化能为248.8 kJ•mol-1; 反应活化能随水分子参与数的增加而迅速下降;解释了硝酸氯在冰表面上存在反应产物次氯酸前体的实验结果. 根据多分子形成的过渡态机理,讨论了水化进一步降低硝酸氯在冰表面上的反应的活化能的可能性. 本机理可以解释目前所有已知的实验现象.

关键词: 硝酸氯, 反应机理, 冰表面, 臭氧洞

Abstract:

The reactions of CIONO2 with mH2O (n=1.2,3) as model reactions of CIONO2 on ice surface were investigated by theoretical ab initio calculations. In the gas phase, the barrier of the reaction of CIONO2 with H2O is 284.8 kJ•mol-1 at MP2/HF/6-31G(d) level. The barrier of the reaction is dramatically reduced as the number of water involved in the reaction is increased. The experimental result of the precursor of the product HOCl in the reaction of CIONO2 on ice surface was explained. On the line of multi-molecule-formed transition state (MTS) mechanism, the possibility of hydration further reducing the barrier was discussed. The MTS mechanism can explain all the experimental results up to date.

Key words: Chlorine nitrate, Reaction mechanism, Ice surface, Ozone hole