Sabbah Hassan, Biennier Ludovic, Sims Ian R, Georgievskii Yuri, Klippenstein Stephen J, Smith Ian W M
Institut de Physique de Rennes, Laboratoire PALMS, UMR 6627 du CNRS-Université de Rennes 1, Equipe Astrochimie Expérimentale, Bat. 11c, Campus de Beaulieu, 35042 Rennes Cedex, France.
Science. 2007 Jul 6;317(5834):102-5. doi: 10.1126/science.1142373.
A remarkable number of reactions between neutral free radicals and neutral molecules have been shown to remain rapid down to temperatures as low as 20 kelvin. The rate coefficients generally increase as the temperature is lowered. We examined the reasons for this temperature dependence through a combined experimental and theoretical study of the reactions of O(3P) atoms with a range of alkenes. The factors that control the rate coefficients were shown to be rather subtle, but excellent agreement was obtained between the experimental results and microcanonical transition state theory calculations based on ab initio representations of the potential energy surfaces describing the interaction between the reactants.
大量中性自由基与中性分子之间的反应已被证明，即使在低至20开尔文的温度下仍能快速进行。速率系数通常会随着温度的降低而增加。我们通过对O(³P)原子与一系列烯烃反应的实验和理论相结合的研究，探究了这种温度依赖性的原因。结果表明，控制速率系数的因素相当微妙，但基于描述反应物间相互作用的势能面从头算表示的实验结果与微正则过渡态理论计算之间取得了很好的一致性。
