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首页> 外文期刊>The journal of physical chemistry, A. Molecules, spectroscopy, kinetics, environment, & general theory >Mechanistic Study of the Reactions of Methyl Peroxy Radical with Methanol or Hydroxyl Methyl Radical
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Mechanistic Study of the Reactions of Methyl Peroxy Radical with Methanol or Hydroxyl Methyl Radical

机译：用甲醇或羟甲基的甲基过氧基团反应的机械研究

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An ab initio and direct dynamic study of the reactions of CH3O2 + CH3OH and CH3O2 + CH2OH has been carried out over the temperature range of 300-1500 K. All stationary points were calculated at the MP2/aug-cc-pVTZ level of theory for CH3O2 + CH3OH or at the M06-2X/MG3S level of theory for CH3O2 + CH2OH and identified for the local minimum. The energetic parameters were refined at the QCISD(T)/cc-pVTZ and CCSD(T)/aug-cc-pVTZ levels of theory. For the reaction of CH3OO + CH3OH, two hydrogen abstraction channels producing CH3OOH + CH2OH (R1) and CH3OOH + CH3O (R2) were confirmed. These two channels consist of the same reversible first step involving the formation of a prereactive complex in the entrance channel. The rate constants of these two channels have been calculated by canonical transition station theory (TST) and canonical variational transition station theory (VTST) with Eckart tunneling correction and compared with the available literature data. The positive temperature dependence of the rate constants was observed. The tunneling effect is important at low temperature and decreases with an increase of the temperature. The contribution of R1 to the total rate constant is dominant, with branching ratios of 0.93 at 500 K and 0.67 at 1000 K, although the branching ratio for R2 increases dramatically with the increase of the temperature from 500 K. For the reaction of CH3OO + CH2OH, eight channels were explored on the lowest singlet and triplet surfaces, and an excited intermediate was found to be formed on the singlet surface. A channel proceeding through the formation of an excited intermediate followed by its impulsive dissociation was confirmed as the dominant channels with a branching ratio more than 0.99 in the temperature range of 300-1500 K, where products of CH3O and OCH2OH were given. The rate constant of the dominant channel calculated by multichannel RRKM-VTST is comparable with the available literature data.
机译：一个从头算和CH3O2 + CH 3 OH和CH3O2 + CH2OH的反应的直接动态研究已经进行了在温度范围300-1500 K.所有驻点在MP2 / AUG-CC-pVTZ水平理论的用于计算CH3O2 + CH3OH，或在M06-2X / MG3S理论水平的CH3O2 + CH2OH并确定了当地最低。中的高能参数均在QCISD（T）/ CC-pVTZ和CCSD（T）理论的/ AUG-CC-pVTZ水平细化。对于CH3OO + CH 3 OH的反应中，产生测定醋酸+ CH2OH（R1）和测定醋酸+ CH 3 O（R 2）的两个氢抽象通道得到了证实。这两个通道由涉及的入口通道中的prereactive复合物的形成相同的可逆第一步。这两个信道的速率常数已被规范过渡站理论（TST）和正则变分过渡站理论（VTST）用埃卡特克莱隧道校正计算，并与可获得的文献数据进行比较。观察到的速率常数的正温度依赖性。隧道效应是在低温下重要的，随着温度的降低。 R1的总速率常数的贡献占主导地位，在500 K和0.67在1000的K 0.93分支比，尽管对于R2中的分支比与温度的从500 K.增加对于CH3OO +的反应显着增加CH2OH，八个信道进行了探索的最低单态和三重态表面，并发现激发中间被单线表面上形成。通过激发中间体接着其冲动离解的形成的信道程序被确认为与在温度范围300-1500 K，其中CH3O和OCH 2 OH的产品分别获得的分支比大于0.99的主导通道。通过多通道RRKM-VTST中计算出的占主导地位的信道的速率常数是与现有的文献数据具有可比性。

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