Department of Chemistry, Emory University , Atlanta, Georgia 30322, United States.
J Phys Chem A. 2013 Oct 3;117(39):9548-54. doi: 10.1021/jp3122402. Epub 2013 May 16.
We present here the instrument design and first experimental results from a multipass millimeter/submillimeter spectrometer designed to probe dissociative reaction dynamics. This work focuses on benchmarking the instrument performance through detection of the CH3O and H2CO products from methanol dissociation induced by a high-voltage plasma discharge. Multiple rotational lines from CH3O and H2CO were observed when this plasma discharge was applied to a sample of methanol vapor seeded in an argon supersonic expansion. The rotational temperature of the dissociation products and their abundance with respect to methanol were determined using a Boltzmann analysis. The minimum detectable absorption coefficient for this instrument was determined to be αmin ≤ 5 × 10(-9) cm(-1). We discuss these results in the context of future applications of this instrument to the study of photodissociation branching ratios for small organic molecules that are important in complex interstellar chemistry.
我们在此介绍一种多通毫米波/亚毫米波光谱仪的仪器设计和初步实验结果，该光谱仪旨在探测离解反应动力学。这项工作的重点是通过检测甲醇离解产生的 CH3O 和 H2CO 产物来基准测试仪器性能，甲醇离解是由高压等离子体放电引起的。当将这种等离子体放电施加到甲醇蒸气在氩超音速膨胀中形成的样品时，观察到 CH3O 和 H2CO 的多个转动线。使用玻尔兹曼分析确定了离解产物的转动温度及其相对于甲醇的丰度。该仪器的最小可探测吸收系数确定为 αmin ≤ 5 × 10(-9) cm(-1)。我们将这些结果置于未来将该仪器应用于研究在复杂星际化学中很重要的小分子光离解分支比的背景下进行讨论。
