CN is known for its fast reactions with hydrocarbons at low temperatures, but relatively few studies have focused on the reactions between CN and aromatic molecules. The recent detection of benzonitrile in the interstellar medium, believed to be produced by the reaction of CN and benzene, has ignited interest in studying these reactions. Here, we report rate constants of the CN + toluene (C₇H₈) reaction between 15 and 294 K using a CRESU (Cinétique de Réaction en Ecoulement Supersonique Uniforme; reaction kinetics in uniform supersonic flow) apparatus coupled with the pulsed laser photolysis–laser-induced fluorescence (PLP–LIF) technique. We also present the stationary points on the potential energy surface of this reaction to study the available reaction pathways. We find the rate constant does not change over this temperature range, with an average value of (4.1 ± 0.2) × 10^–10 cm³ s^–1, which is notably faster than the only previous measurement at 105 K. While the reason for this disagreement is unknown, we discuss the possibility that it is related to enhanced multiphoton effects in the previous work.

中文翻译：

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CN +甲苯反应的速率常数（从15到294 K）和星际效应。

CN以其在低温下与烃类的快速反应而著称，但相对较少的研究集中在CN与芳族分子之间的反应上。人们最近在星际介质中检测到苄腈，据信这是由CN和苯的反应产生的，这引起了人们对研究这些反应的兴趣。在这里，我们报告了使用CRESU（均匀超滤均匀法）在15和294 K之间发生的CN +甲苯（C ₇ H ₈）反应的速率常数; 均匀超声速流中的反应动力学）与脉冲激光光解-激光诱导荧光（PLP-LIF）技术结合。我们还提出了该反应势能面上的固定点，以研究可用的反应途径。我们发现速率常数在此温度范围内没有变化，平均值为（4.1±0.2）×10 ^–10 cm ³ s ^–1，这明显快于之前在105 K下进行的唯一测量。这种分歧是未知的，在先前的工作中我们讨论了它与增强的多光子效应有关的可能性。