Chemical Sciences and Engineering Division, Argonne National Laboratory, 9700 S. Cass Avenue, Argonne, IL-60439, USA.
Phys Chem Chem Phys. 2011 Dec 28;13(48):21288-300. doi: 10.1039/c1cp21073d. Epub 2011 Oct 24.
The pyrolysis of ethylene glycol vinyl ether (EGVE), an initial product of 1,4-dioxane dissociation, was examined in a diaphragmless shock tube (DFST) using laser schlieren densitometry (LS) at 57 ± 2 and 122 ± 3 Torr over 1200-1800 K. DFST/time-of-flight mass spectrometry experiments were also performed to identify reaction products. EGVE was found to dissociate via two channels: (1) a molecular H atom transfer/C-O scission to produce C(2)H(3)OH and CH(3)CHO, and (2) a radical channel involving C-O bond fission generating ˙CH(2)CH(2)OH and ˙CH(2)CHO radicals, with the second channel being strongly dominant over the entire experimental range. A reaction mechanism was constructed for the pyrolysis of EGVE which simulates the LS profiles very well over the full experimental range. The decomposition of EGVE is clearly well into the falloff region for these conditions, and a Gorin model RRKM fit was obtained for the dominant radical channel. The results are in good agreement with the experimental data and suggest the following rate coefficient expressions: k(2,∞) = (6.71 ± 2.6) × 10(27) × T(-3.21)exp(-35512/T) s(-1); k(2)(120 Torr) = (1.23 ± 0.5) × 10(92) × T(-22.87)exp(-48 248/T) s(-1); k(2)(60 Torr) = (2.59 ± 1.0) × 10(88) × T(-21.96)exp(-46283/T) s(-1).
在无膜激波管 (DFST) 中，通过激光纹影密度测量 (LS) 在 57 ± 2 和 122 ± 3 托下研究了 1,4-二恶烷离解的初始产物乙烯基乙二醇醚 (EGVE) 的热解，温度范围为 1200-1800 K。还进行了 DFST/飞行时间质谱实验以鉴定反应产物。发现 EGVE 通过两个通道解离：(1) 分子 H 原子转移/C-O 断裂，生成 C(2)H(3)OH 和 CH(3)CHO，和 (2) 自由基通道，涉及 C-O 键断裂，生成 ˙CH(2)CH(2)OH 和 ˙CH(2)CHO 自由基，后一个通道在整个实验范围内占主导地位。为 EGVE 的热解构建了一个反应机理，该机理很好地模拟了 LS 曲线在整个实验范围内的情况。EGVE 的分解显然在这些条件下已经进入了衰退区域，并且为主要的自由基通道获得了 Gorin 模型 RRKM 拟合。结果与实验数据吻合良好，表明以下速率系数表达式：k(2,∞) = (6.71 ± 2.6) × 10(27) × T(-3.21)exp(-35512/T) s(-1); k(2)(120 Torr) = (1.23 ± 0.5) × 10(92) × T(-22.87)exp(-48 248/T) s(-1); k(2)(60 Torr) = (2.59 ± 1.0) × 10(88) × T(-21.96)exp(-46283/T) s(-1)。
