Consecutive Chemical Activation Steps in the OH‐Initiated Atmospheric Degradation of Isoprene: An Analysis with Coupled Master Equations
Consecutive Chemical Activation Steps in the OH‐Initiated Atmospheric Degradation of Isoprene: An Analysis with Coupled Master Equations
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OHâ 引发的异戊二烯大气降解中的连续化学活化步骤：耦合主方程的分析
DOI：
10.1002/kin.20849
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发表时间：
2014
影响因子：
1.5
通讯作者：
M. Olzmann
中科院分区：
文献类型：
--
作者：
M. Pfeifle;M. Olzmann
用主方程分析方法研究了两步化学活化对异戊二烯大气光氧化生成的羟基过氧基的1，5-H和1，6-H变换反应的影响。为了解释多个化学活化过程，耦合了三个主方程。描述了这种耦合的一般方法，并考察了稳态状态下的结果。具体计算表明，在对流层条件下，化学活化对上述反应的速率系数没有实质性影响。然而，在动力学模拟中必须使用热速率系数的高压极限，而不是衰减修正值。这是在稳态条件下，生成反应使异戊二烯-OH-O2加合物分布的高能部分连续布居的结果。计算得到异构化反应的速率系数At=298K，分别为3a∞=1.5x 10−3S−1(1，2-异构体的1，5-H位移)和k4a∞=6.5-S−1((Z)-1，4-异构体的1，6-H位移)。K4a∞的计算值比最近报道的羟基-过氧基中间体氢转移反应的速率系数大三个数量级。结果表明，这种差异的部分原因是实验没有区分不同的结构异构体。实验测定的同位素效应与计算值的比较显示出合理的一致性。
The influence of a two‐step chemical activation on 1,5‐H and 1,6‐H shift reactions of hydroxyl‐peroxy radicals formed in the atmospheric photooxidation of isoprene was investigated by means of a master equation analysis. To account for multiple chemical activation processes, three master equations were coupled. The general approach of this coupling is described, and consequences for steady‐state regimes are examined. The specific calculations show that chemical activation has no substantial influence on the rate coefficients of the above‐mentioned reactions under tropospheric conditions. However, it is demonstrated that high‐pressure limits of the thermal rate coefficients instead of the falloff‐corrected values have to be used for kinetic modeling. This is a consequence of the continuous population of the high‐energy part of the isoprene‐OH‐O2adduct distribution by the forming reactions under steady‐state conditions. The rate coefficients of the isomerization reactions atT= 298 K were calculated to bek3a∞= 1.5 × 10−3s−1(1,5‐H‐shift of the 1,2‐isomer) andk4a∞= 6.5 s−1(1,6‐H‐shift of the (Z)‐1,4‐isomer). The calculated value ofk4a∞is three orders of magnitude larger than a recently reported experimentally observed rate coefficient for the hydrogen shift reactions of the hydroxyl‐peroxy intermediates. It is shown that this discrepancy is in part due to the fact that the experiment does not distinguish between different structural isomers. A comparison of the experimentally determined isotope effect with the calculated value shows a reasonable agreement.
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影响因子：
1.5
作者：
M. Olzmann;J. Gebhardt;K. Scherzer
通讯作者：
K. Scherzer
氧气存在下 2-丁氧基和 1-丁氧基自由基反应的新视角。
DOI：
10.1039/b806591h
发表时间：
2008
期刊：
Physical chemistry chemical physics : PCCP
影响因子：
--
作者：
F. Caralp;W. Forst;A. Bergeat
通讯作者：
A. Bergeat
异戊二烯氧化中的 HOx 再生 III：Z-δ-羟基过氧异戊二烯自由基关键异构化的理论研究。
DOI：
10.1002/cphc.201000480
发表时间：
2010
期刊：
Chemphyschem : a European journal of chemical physics and physical chemistry
影响因子：
--
作者：
T. Nguyen;L. Vereecken;J. Peeters
通讯作者：
J. Peeters
化学活化环烷氧基自由基分解中环烷基 O 反应和产物支化的速率系数：实验和理论研究。
DOI：
10.1039/b925920a
发表时间：
2010
期刊：
Physical chemistry chemical physics : PCCP
影响因子：
--
作者：
K. Hoyermann;Sven Maarfeld;Frank Nacke;Jörg Nothdurft;M. Olzmann;J. Wehmeyer;O. Welz;T. Zeuch
通讯作者：
T. Zeuch
影响因子：
2.9
作者：
da Silva, Gabriel
通讯作者：
da Silva, Gabriel