Cl + 丙烷、丁烷动力学的再研究：交叉束切片成像研究。

Dynamics of Cl + propane, butanes revisited: a crossed beam slice imaging study.

机构信息

Department of Chemistry, Wayne State University, Detroit, MI 48202, USA.

出版信息

Phys Chem Chem Phys. 2014 Jan 14;16(2):414-20. doi: 10.1039/c3cp51785c.

Abstract

We report velocity-flux contour maps for H-D abstraction in selected Cl + alkane reactions measured by means of crossed beam scattering combined with universal DC slice imaging. The studied hydrocarbons are propane and its two selectively deuterated isotopologues, namely 1,1,1,3,3,3-propane-d6 and 2,2-propane-d2, n-butane and isobutane (2-methyl-propane), with detection of the hydrocarbon radical product by 157 nm single photon ionization. Data are obtained at collision energies of 12-13 kcal mol(-1) using a high-density atomic chlorine radical source combining Cl2 photolysis with ablation. All presented scattering distributions involving secondary and tertiary abstractions show distinct differences. Their comparisons allow for revisiting the dynamical picture of these reactions in terms of the nature of the abstraction sites, radical product energy disposal, and H vs. D abstraction. Results are discussed in the light of previous work and ab initio thermochemical calculations, along with proposals to future directions for investigation.

摘要

我们报告了通过交叉束散射结合通用直流切片成像测量的选定 Cl + 烷烃反应中 H-D 抽取的速度通量等高线图。研究的碳氢化合物是丙烷及其两种选择性氘代同系物，即 1,1,1,3,3,3-丙烷-d6 和 2,2-丙烷-d2、正丁烷和异丁烷（2-甲基丙烷），通过 157nm 单光子电离检测烃自由基产物。使用高浓度原子氯自由基源，通过 Cl2 光解与烧蚀相结合，在 12-13 kcal mol(-1) 的碰撞能下获得数据。所有涉及仲和叔抽取的散射分布都显示出明显的差异。它们的比较允许根据抽象站点的性质、自由基产物能量处置以及 H 与 D 抽象来重新审视这些反应的动力学图景。结果根据以前的工作和从头算热化学计算进行了讨论，并提出了未来研究的方向。