Mechanical Engineering Department, Stanford University, Stanford, California 94305-3032, USA.
J Phys Chem A. 2010 Aug 19;114(32):8312-8. doi: 10.1021/jp104880u.
The reaction of hydroxyl (OH) radicals with 1,3-butadiene (C(4)H(6)) was studied behind reflected shock waves over the temperature range 1011-1406 K and at pressures near 2.2 atm. OH radicals were produced by shock-heating tert-butyl hydroperoxide, (CH(3))(3)-CO-OH, and were monitored by narrow line width ring dye laser absorption of the well-characterized R(1)(5) line of the OH A-X (0,0) band near 306.7 nm. OH time histories were modeled using a comprehensive 1,3-butadiene oxidation mechanism, and rate constants for the reaction of OH with 1,3-butadiene were extracted by matching modeled and measured OH concentration time histories. Detailed error analyses yielded an uncertainty estimate of +/-13% at 1200 K for the rate coefficient of the target reaction. The current data extends the temperature range of the only previous high-temperature study for this reaction. The rate coefficient and the branching fractions for the H-abstraction channels of the target reaction were also calculated over the temperature range 250-2500 K using variational transition-state theory based on QCISD(T)/cc-pVinfinityZ//B3LYP/6-311++G(d,p) quantum chemistry. The calculations are in good agreement with the experimental results above 1200 K.
羟基 (OH) 自由基与 1,3-丁二烯 (C(4)H(6)) 的反应在 1011-1406 K 的温度范围内和接近 2.2 大气压的压力下通过反射激波进行了研究。OH 自由基是通过冲击加热叔丁基过氧化物 ((CH(3))(3)-CO-OH) 产生的，并通过窄线宽环形染料激光吸收 OH A-X (0,0) 带在 306.7nm 附近的特征 R(1)(5) 线来监测。OH 时间历程是使用全面的 1,3-丁二烯氧化机理进行建模的，并通过匹配建模和测量的 OH 浓度时间历程来提取 OH 与 1,3-丁二烯反应的速率常数。详细的误差分析在 1200 K 时对目标反应的速率系数给出了 +/-13%的不确定度估计。当前的数据扩展了该反应仅有的先前高温研究的温度范围。使用基于 QCISD(T)/cc-pVinfinityZ//B3LYP/6-311++G(d,p)量子化学的变分过渡态理论，还计算了目标反应的 H 提取通道的速率系数和分支分数在 250-2500 K 的温度范围内。计算结果在 1200 K 以上与实验结果吻合良好。
