### NO3自由基与HNO及HONO反应机理研究

1. a 石河子大学 理学院物理系生态物理重点实验室 石河子 832003;
b 四川大学 原子与分子物理研究所 成都 610065
• 投稿日期:2012-11-12 发布日期:2012-12-06
• 通讯作者: 王海锋 E-mail:hfwang11@126.com
• 基金资助:

项目受国家自然科学基金(No. 11145004)资助.

### Theoretical Study on the Reaction Mechanism of Nitrate Radical with HNO and HONO

Zhang Jidonga, Wang Haifenga, Xue Xinyinga, Zhang Yanwena, Cheng Xinlub

1. a Key Laboratory of Ecophysics and Department of Physics, School of Science, Shihezi University, Shihezi 832003;
b Institute of Atomic and Molecular Physics, Sichuan University, Chengdu 610065
• Received:2012-11-12 Published:2012-12-06
• Supported by:

Project supported by the National Natural Science Foundation of China (No. 11145004).

NO3 radical is known as a dominant oxidant in the atmosphere at night, and plays an important role in atmospheric chemistry. Recently, NO3 radical is reported to be formed in the decomposition process of RDX, while it has never been detected in experiment up to now. The possible reason is that it would react with RDX or some RDX decomposition products once it is formed. This study for the first time theoretically investigated the bimolecular reactions of NO3 radical with two kinds of decomposition products of RDX (HNO and HONO) by computational chemistry methods, and the reaction mechanisms are studied using CCSD(T)/6-311++G(d,p) theoretical methods based on the geometric parameters optimized at the B3LYP/6-311++G(d,p) level. Same mechanisms are devised for the two reactions, such as oxygen abstraction and hydrogen abstraction. The two kinds of reaction pathways are of equal importance for the two reactions, because of similar barrier heights obtained in this study. The two pathways of the reation of NO3+HNO can result in two kinds of products HNO2+NO2 and HNO3+NO respectively, while the reaction of NO3+HONO only yields HNO3+NO2. The two reactions proceed with low barrier heights (0～0.5 kcal/mol, and 15.9～18.5 kcal/mol respectively), which are significantly lower than that of the reactions of RDX decomposition and NO3 formation. Moreover, the results show that the reaction of NO3 radical with HNO is barrierless and exothermic, implying it is energetically feasible to take place. The reaction may be responsible for the disappearance of NO3 radical during the decomposition process of RDX. Moreover, the isomerization reactions of HNO and HONO are also investigated by using the same methods, and a hydrogen atom intramolecular migration mechanism is found for these two isomerization reactions. The study is a necessary precursor for providing parameters for subsequent kinetic study and encourages further experimental investigation in future.

Key words: NO3, HNO, HONO, reaction mechanism