Criegee中间体RCHOO(R=H,CH_3)与NO_2的反应机理
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- 英文论文题名：Theoretical Study on the Reaction Mechanism of Criegee Intermediates RCHOO(R=H, CH_3) with NO_2
- 论文作者：马倩 ; 赵强莉 ; 王渭娜 ; 刘峰毅 ; 王文亮
- 英文论文作者：MA Qian-Li ; ZHAO Qiang-Li ; WANG Wei-Na ; LIU Feng-Yi ; WANG Wen-Liang ; School of Chemistry and Chemical Engineering ; Shaanxi Normal University ; Key Laboratory for Macromolecular Science of Shaanxi Province
- 年：2016
- 作者机构：陕西省大分子科学重点实验室陕西师范大学化学化工学院;
- 论文关键词：Criegee中间体 ; NO_2 ; 反应机理 ; 速率常数
- 会议召开时间：2016-07-01
- 会议录名称：中国化学会第30届学术年会摘要集-第四十四分会：化学动力学
- 语种：中文
- 分类号：O643.12
- 学会代码：ZGHY
- 会议名称：中国化学会第30届学术年会-第四十四分会 ; 化学动力学
- 会议地点：中国辽宁大连
- 主办单位：中国化学会
- 学会名称：中国化学会
- 页数：1
- 文件大小：301k
- 原文格式：D
- 会议级别：全国
摘要
采用CCSD(T)//B3LYP/6-311+G(d,p)方法对Criegee中间体RCHOO(R=H,CH_3)与NO_2反应的机理进行了详细地理论研究。结果表明,上述反应主要存在加成-分解及氧化两类反应机理。加成-分解反应机理又包括NO_2中O和N分别加成到Criegee中间体α-C上的两种情况,而O加成反应能垒低,较易进行。NO_2上的O加成到CH_2OO的C上并分解生成NO+O_2+H_2CO,表观活化能为9.19 kJ·mol~(-1)(通道R1)。加成到syn-CH_3CHOOα-C(通道R7)和加到anti-CH_3CHOOα-C(通道R4)生成NO+O_2+CH_3CHO,表观活化能垒分别为31.58和15.32 kJ·mol~(-1)。另外,比较CH_2OO,syn-CH_3CHOO及anti-CH_3CHOO与NO_2中的O加成反应基元能垒发现,甲基取代使得反应不易进行;syn-CH_3CHOO与NO_2的反应能垒高于anti-CH_3CHOO。氧化反应中RCHOO(R=H,CH_3)首先转移端位氧生成NO_3,然后继续通过CH_2OO及syn-CH_3CHOO(β-H)中的H迁移生成产物HNO_3+HCO和HNO_3+CH2CHO,在(β-H)迁移过程中所需基元能垒为46.82 kJ·mol~(-1)而在CH_2OO中H迁移仅需11.05 kJ·mol~(-1),说明CH_2OO参与的H转移反应更容易进行。
A comprehensive theoretical study on the reaction mechanism of Criegee Intermediates RCHOO(R=H, CH_3)with NO_2 is performed at the CCSD(T)//B3LYP/6-311+G(d,p) level. The results show that the mechanism includes addition–decomposition and oxidation reactions. For the addition–decomposition, two reaction channels have been found which involves the α-C interacts with the NO_2 nitrogen and oxygen. The latter one shows lower reaction energy barrier. The calculated apparent activation energy(Eapp) for the addition of one oxygen on CH_2OO carbon,syn-CH_3CHOO and anti-CH_3CHOO are 9.19 k J·mol~(-1), 31.58 and 15.32 kJ ·mol~(-1), respectively. The reactions involve the methyl-substituted CI more difficultly. The barriers of syn-CH_3CHOO reaction with NO_2 is the highest. In the oxidation reaction, the reaction proceeds via terminal oxygen atom transfer to form NO_3, and followed by H-abstraction. The energy barriers of H-abstraction invloves the oxidation of CH_2OO and syn-CH_3CHOO are11.05 k J·mol~(-1)and 46.82 kJ ·mol~(-1), which suggest that the reaction involves CH_2OO proceeds more easily.
A comprehensive theoretical study on the reaction mechanism of Criegee Intermediates RCHOO(R=H, CH_3)with NO_2 is performed at the CCSD(T)//B3LYP/6-311+G(d,p) level. The results show that the mechanism includes addition–decomposition and oxidation reactions. For the addition–decomposition, two reaction channels have been found which involves the α-C interacts with the NO_2 nitrogen and oxygen. The latter one shows lower reaction energy barrier. The calculated apparent activation energy(Eapp) for the addition of one oxygen on CH_2OO carbon,syn-CH_3CHOO and anti-CH_3CHOO are 9.19 k J·mol~(-1), 31.58 and 15.32 kJ ·mol~(-1), respectively. The reactions involve the methyl-substituted CI more difficultly. The barriers of syn-CH_3CHOO reaction with NO_2 is the highest. In the oxidation reaction, the reaction proceeds via terminal oxygen atom transfer to form NO_3, and followed by H-abstraction. The energy barriers of H-abstraction invloves the oxidation of CH_2OO and syn-CH_3CHOO are11.05 k J·mol~(-1)and 46.82 kJ ·mol~(-1), which suggest that the reaction involves CH_2OO proceeds more easily.
引文
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