过氧氢自由基HO_2与CH_2S的反应机理及动力学  

Reaction Mechanisms and Kinetics for the Reaction of HO_2+CH_2S

作　　者：刘占荣[1,2] 许保恩[1,2] 曾艳丽[1] 李晓艳[1] 孟令鹏[1] 孙政[1] 张雪英[1] 张萍[2] 

机构地区：[1]河北师范大学计算量子化学研究所,石家庄050016 [2]石家庄学院化工学院,石家庄050035

出　　处：《化学学报》2011年第17期1957-1964,共8页Acta Chimica Sinica

基　　金：国家自然科学基金(Nos.20973053;20801017;21073051);河北省自然科学基金(Nos.B2010000371;B2011205058);河北省高等学校科学研究项目(No.Z2010166);石家庄学院自然科学研究基金项目(No.10ZDA001)资助项目

摘　　要：采用密度泛函理论B3LYP方法,在6-311++G(d,p)基组水平研究了HO2与CH2S的微观反应机理.在CCSD(T)/6-311++G(d,p)//B3LYP/6-311++G(d,p)水平上获得了势能面.利用经典过渡态理论(TST)与变分过渡态理论(CVT)并结合小曲率隧道效应模型(SCT),计算了反应通道在200～2500 K温度范围内的速率常数kTST,kCVT和kCVT/SCT.找到了该反应体系的6个反应通道,其中HO2的端位O进攻CH2S中C生成的HOOCH2S及其异构化得到的OOCH2SH均为主反应产物.动力学数据也表明,当温度低于1400 K时,通道(1a)HO2+CH2S→TS1/P1→HOOCH2S是主反应通道,高于1400 K时,通道(2a)HO2+CH2S→TS2/P1→HOOCH2S占优势.The reaction mechanism of HO2 with CH2S was investigated at the B3LYP/6-311＋＋G（d,p） level.Energetic information of stationary points and the points along the minimum energy path is further re-fined at the CCSD（T）/6-311＋＋G（d,p） level.The rate constants of these channels in the temperature range of 200～2500 K were evaluated by means of the classical transition state theory（TST） and the canonical variational transition state theory（CVT） conjunction with the small-curvature tunneling correction（SCT）.Six possible reaction channels have been identified for the title reaction.Based on the potential energy sur-face and the kinetics,it can be concluded that HOOCH2S,formed via the end O atom of the HO2 radical at-tacking on the C atom of the CH2S molecule,and its isomer OOCH2SH are the major products.When the temperature is lower than 1400 K,the channel（1a） HO2＋CH2S→TS1/P1→HOOCH2S is the major reaction path,while the channel（2a） HO2＋CH2S→TS2/P1→HOOCH2S becomes the favorable reaction path when the temperature is higher than 1400 K.

关 键 词：HO2 CH2S 反应机理 速率常数 

分 类 号：O643.12[理学—物理化学]