摘要
采用CBS-QB3方法对二硝酰胺酸(HDN)裂解过程中的HNNO2自由基自身氢迁移及N—N键断裂异构化反应机理进行了研究.结果表明,HNNO2自由基自身氢迁移反应经历了N(4)—O(2)间的氢迁移、O(2)—O(3)间的氢迁移及内转化3个不同类型的基元反应,最终生成N2O分子与OH自由基.其中N(4)—O(2)间的氢迁移为HNNO2自由基自身氢迁移反应中的速率决定步.HNNO2自由基通过N(1)—N(4)键断裂以及O(2)—N(4)键形成异构化成产物NO+HNO,该过程的能垒为176.17kJ·mol-1,比氢迁移通道决速步能垒高出了47.59kJ·mol-1,表明氢迁移通道为HNNO2裂解过程中的优势通道.
Hydrogen abstraction and isomerization mechanisms for the dinitranide（HNNO2）radical were studied at the CBS-QB3 level of theory.The results show that,for hydrogen abstraction,HNNO2 radical can form the product N2O＋OH by occurring through three kinds of elementary reactions of H（5）abstraction by O（2）from N（4）,H（5）abstraction by O（3）from O（2）and internal conversion.The reaction of H（5）abstraction by O（2）from N（4）is the determining step for hydrogen reaction.For isomerization reaction,HNNO2 radical can form the product NO＋HNO by the N（1）—N（4）bond breaking and the O（2）—N（4）bond forming.The energy barrier of isomerization reaction is176.17kJ·mol-1,which is higher by 47.59kJ·mol-1 than that of the rate determining step of hydrogen abstraction.Therefore,H-atom migration reaction channel of HNNO2 radical is favorable than isomerization reaction kinetically.
出处
《分子科学学报》
CAS
CSCD
北大核心
2015年第4期342-347,共6页
Journal of Molecular Science
基金
陕西省教育厅基金资助项目(14JK1154)
陕西理工学院科研基金启动项目(SLGQD13(2)-3
SLGQD13(2)-4)
973项目(613209)
关键词
CBS-QB3
氢迁移
异构化
反应机理
能垒
CBS-QB3
hydrogen abstraction
isomerization
reaction mechanism
energy barrier
