Laboratoire de Planétologie, Observatoire de Grenoble, Université Joseph Fourier, CNRS UMR5109, B.P. 53, 38041 Grenoble Cedex 09, France.
J Phys Chem A. 2009 Dec 10;113(49):13694-9. doi: 10.1021/jp905609x.
The description of Titan's chemistry relies strongly on reaction rate data collected at room temperature or above. However, the temperature in the atmosphere of Titan ranges from 70 to 200 K. We describe here a simple theoretical method to extend the available measurements toward those temperatures. It is based on the long-range capture theory combined with room temperature data. First results are presented for 28 neutral reactions involving atomic carbon, CN, CH, and C(2)H radicals and are compared to low-temperature Cinétique de Réaction en Ecoulement Supersonique Uniforme measurements. A good agreement is observed, to within a factor of 2, for most reactions in the temperature range 13-295 K. Predictions are made for reactions of the CN radical with hydrocarbons and nitriles of particular importance in Titan's atmosphere.
土卫六的化学性质描述很大程度上依赖于在室温或更高温度下收集的反应速率数据。然而，土卫六大气层的温度范围在 70 到 200K 之间。我们在这里描述了一种简单的理论方法，可将可用的测量结果扩展到这些温度。该方法基于长程捕获理论，并结合了室温数据。首先给出了涉及原子碳、CN、CH 和 C2H 自由基的 28 个中性反应的初步结果，并与超声速均匀流反应动力学的低温测量结果进行了比较。在 13-295K 的温度范围内，大多数反应的观测结果与预测结果的比值在 2 以内。还对 CN 自由基与在土卫六大气中具有特殊重要性的碳氢化合物和腈的反应进行了预测。
