Thermal decomposition of 1,1,1-trifluoroethane revisited.
Thermal decomposition of 1,1,1-trifluoroethane revisited.
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重新审视 1,1,1-三氟乙烷的热分解。
DOI：
10.1021/jp510227k
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发表时间：
2014
期刊：
影响因子：
--
通讯作者：
H. Shiina
中科院分区：
文献类型：
--
作者：
A. Matsugi;K. Yasunaga;H. Shiina
1,1,1-三氟乙烷（CH3CF3）在激波管研究中经常用作化学温度计或内标，以确定化学反应的相对速率。最近有报道称，CH3CF3的热分解速率常数在高温衰减区具有异常的压力依赖性。本文利用激波管/激光吸收（ST/LA）光谱和单脉冲激波管（SPST）方法，在95 ~ 290 kPa压力下，在1163 ~ 1831 K温度范围内对CH3CF3的分解动力学进行了研究。目前的速率常数比以往在高压极限条件下进行的单脉冲实验报告的速率常数小2-3倍。在1000 ~ 1600 k的温度范围内，得到推荐的速率常数表达式k = 5.71 × 10(46)T(-9.341) exp(-47073 k /T) s(-1)，在1300 k以下的温度下不确定度为±40%，在1600 k时不确定度为±32%。高温区域的速率常数表现出明显的衰减行为，与最近的高温实验结果吻合较好。标准RRKM/主方程模型不能再现衰减速率常数；这项研究为先前报道的这种反应的异常压力依赖性提供了额外的证据。此外，确定了1,1-二氟乙烯（CH2CF2）在1650-2059 K温度范围内，在100和205 kPa压力下的分解速率常数，并通过RRKM/主方程计算再现了平均向下传递900 cm（-1）的速率常数。
1,1,1-Trifluoroethane (CH3CF3) has been frequently used as a chemical thermometer or an internal standard in shock tube studies to determine relative rates of chemical reactions. The rate constants for the thermal decomposition of CH3CF3 were recently reported to have anomalous pressure dependence in the high-temperature falloff region. In the present study, the kinetics of the CH3CF3 decomposition were reinvestigated using shock tube/laser absorption (ST/LA) spectroscopy and single-pulse shock tube (SPST) methods over the temperature range 1163-1831 K at pressures from 95 to 290 kPa. The present rate constants are 2-3 times smaller than those reported in previous single-pulse experiments performed at near high-pressure limit conditions. The recommended rate constant expression, k = 5.71 × 10(46)T(-9.341) exp(-47073 K/T) s(-1), was obtained over the temperature range 1000-1600 K with uncertainties of ±40% at temperatures below 1300 K and ±32% at 1600 K. The rate constants at the high-temperature region showed clear falloff behavior and were in good agreement with recent high-temperature experiments. The falloff rate constants could not be reproduced by a standard RRKM/master-equation model; this study provides additional evidence for the unusual pressure dependence previously reported for this reaction. Additionally, the rate constants for the decomposition of 1,1-difluoroethylene (CH2CF2) were determined over the temperature range 1650-2059 K at pressures of 100 and 205 kPa, and were reproduced by the RRKM/master-equation calculation with an average downward energy transfer of 900 cm(-1).
影响因子：
2.9
作者：
Sirjean, Baptiste;Fournet, Rene;Glaude, Pierre-Alexandre;Battin-Leclerc, Frederique;Wang, Weijing;Oehlschlaeger, Matthew A.
通讯作者：
Oehlschlaeger, Matthew A.