Direct gas-liquid interfacial dynamics: the reaction between O(3P) and a liquid hydrocarbon.
Direct gas-liquid interfacial dynamics: the reaction between O(3P) and a liquid hydrocarbon.
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直接气液界面动力学：O(3P) 和液态烃之间的反应。
DOI：
10.1021/jp056128q
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发表时间：
2006
期刊：
影响因子：
--
通讯作者：
K. McKendrick
中科院分区：
文献类型：
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作者：
Sven P K Köhler;M. Allan;M. Costen;K. McKendrick
我们报告的内部能量分布的OH产生的直接机制，从其他成分的飞行时间的基础上，在气相O（（3）P）原子和液态烃角鲨烷，C（30）H（62）之间的界面反应的第一次测量。通过激光光解NO（2）在液体上方产生O（3）P原子。由此产生的羟基自由基，从表面逃逸的激光诱导荧光检测。飞行时间曲线表明最快OH（nu' = 1）的动能低于（nu' = 0）的动能。对于OH（nu' = 0）和（nu' = 1），在它们出现的上升沿测量旋转分布。他们被发现有很大的不同，比在他们的档案的峰值。它们也较少依赖于本体液体温度。我们的结论是，新的数据有力地证实，至少有两种机制有助于生产的OH。高速分量具有平移和旋转能量分布，这是第一次干净地观察到，与直接机制一致。这些旋转分布与O（（3）P）与小分子烃的相应均相气相反应的旋转分布的密切对应表明了一种非常相似的、近共线的直接提取。这是伴随着一个较慢的组件与动能和旋转（但不是振动）的分布反映了液体的温度，符合一个独特的捕获-解吸机制。
We report the first measurements of internal energy distributions of the OH produced via a direct mechanism, isolated from other components on the basis of time-of-flight, in the interfacial reaction between gas-phase O((3)P) atoms and the liquid hydrocarbon squalane, C(30)H(62). O((3)P) atoms were generated by laser photolysis of NO(2) above the liquid. Resulting hydroxyl radicals that escape from the surface were detected by laser-induced fluorescence. Time-of-flight profiles demonstrate that the kinetic energy of the fastest OH (nu' = 1) is lower than that of (nu' = 0). Rotational distributions were measured at the rising edge of their appearance for both OH (nu' = 0) and (nu' = 1). They were found to differ substantially more than at the peak of their profiles. They were also less dependent on the bulk liquid temperature. We conclude that the new data confirm strongly that at least two mechanisms contribute to the production of OH. The higher-velocity component has translational and rotational energy distributions, observed cleanly for the first time, consistent with a direct mechanism. The close correspondence of these rotational distributions to those from the corresponding homogeneous gas-phase reaction of O((3)P) with smaller hydrocarbons suggests a very similar, near collinear direct abstraction. This is accompanied by a slower component with kinetic energy and rotational (but not vibrational) distributions reflecting the temperature of the liquid, consistent with a distinct trapping-desorption mechanism.