Department of Chemistry, Wayne State University, Detroit, Michigan 48202, United States.
J Phys Chem A. 2012 Jan 26;116(3):938-42. doi: 10.1021/jp207096c. Epub 2012 Jan 17.
In this work, the primary product branching ratio (BR) for the reaction of state-prepared nitrogen cation (N(2)(+)) with acetonitrile (CH(3)CN), a possible minor constituent of Titan's upper atmosphere, is reported. The ion-molecule reaction occurs in the collision region of the supersonic nozzle expansion that is characterized by a rotational temperature of 45 ± 5 K. A BR of 0.86 ± 0.01/0.14 ± 0.01 is obtained for the formation CH(2)CN(+) and the CH(3)CN(+) product ions, respectively. The reported BR overwhelmingly favors the formation of CH(2)CN(+) product channel and is consistent with a simple capture process that is accompanied by a nonresonant dissociative charge transfer reaction. The BRs are independent of the N(2) rotational levels excited. Apart from providing insights onto the dynamics of the title ion-molecule reaction, the reported BR represents the most accurate available low-temperature experimental measurement for the reaction useful to aid in the accurate modeling of Titan's nitrile chemistry.
在这项工作中，报告了状态制备的氮阳离子（N(2)(+））与乙腈（CH(3)CN）反应的主要产物分支比（BR），乙腈可能是泰坦上层大气的少量成分。离子-分子反应发生在超音速喷嘴膨胀的碰撞区域，其特征是旋转温度为 45±5 K。分别形成 CH(2)CN(+)和 CH(3)CN(+)产物离子的 BR 为 0.86±0.01/0.14±0.01。报道的 BR 强烈有利于 CH(2)CN(+)产物通道的形成，并且与伴随非共振解离电荷转移反应的简单捕获过程一致。BR 与激发的 N(2)转动能级无关。除了提供对标题离子-分子反应动力学的深入了解外，报道的 BR 代表了最准确的可用低温实验测量，该测量对辅助泰坦腈化学的准确建模很有用。
