New phase of reaction dynamics studies on O(^1D) atom reaction by utilizing very slow O(^1D) atom

利用极慢的O(^1D)原子研究了O(^1D)的反应动力学。本研究的目的是阐明O(^1D)和反应物分子体系的激发势面的贡献。O(^1D)原子由于具有插入化学键的能力而具有较大的反应截面，是非常活泼的物种。插入反应无障碍，截面积大。因此，O(^1D)反应在大气化学和燃烧化学中是非常重要的。相比之下，O(^1D)反应体系的激发态通常具有降低反应截面的入射势垒。然而，最近的从头计算研究表明，系统激发态的入射势垒高度是。这些结果表明激发态对O(^1D)反应有一定的贡献。因此，O(^1D)反应中激发态的贡献是一个敏感的话题，它会对大气化学和燃烧化学中重要的O(^1D)反应速率常数的温度依赖性产生一定的影响。反应动力学研究一直以来都是利用O_3分子中N_2O紫外光解离产生的高能O(^1D)原子。激发态面高度较低表明，传统的研究并不能完全摆脱激发态面的贡献，尽管其大小尚不清楚。为了阐明激发态表面的贡献程度，通过比较高能和低能O(^1D)原子反应，研究了低能O(^1D)原子反应。利用接近O(^1D)产生阈值的O_3紫外吸收带的长波长翼，产生了低能O(^1D)原子。在本研究的初步结果中，高能和低能O(^1D)原子反应的产物振荡态分布比较相似，表明激发态在O(^1D)反应中的贡献较小，与计算研究的预测相反。

Reaction dynamics of O(^1D) is studied by utilizing very slow O(^1D) atom. The aim of this study is to elucidate the contribution of excited potential surfaces of O(^1D) and reactant molecule system. O(^1D) atom is very reactive species due to its large reactive cross section by virtue of its ability of insertion to chemical bonds. Insertion reaction has no barrier and large cross section. Thus, O(^1D) reaction is very important in atmospheric and combustion chemistry. By contrast, excited states of O(^1D) reaction system generally have entrance barrier that lowers reactive cross section. However, recent ab initio computational studies have indicated that the height of entrance barriers of excited states of system are. relatively low These results suggest excited states can have some contribution on O(^1D) reaction. Therefore, contribution of excited stated in O(^1D) reaction is a sensitive topic that can have some impact on temperature dependence of reaction rate constants of important O(^1D) reactions in atmospheric and combustion chemistry. Reaction dynamics studies so for have been utilizing high-energy O(^1D) atom produced from UV photodissociation of N_2O of O_3 molecules. Low height of excited state surface suggests that the traditional studies are not free from the contribution of excited state surface although its amount is not clear. To elucidate the extent of the contribution of excited state surface, this study is focused on low-energy O ^1D) atom reaction by comparing high-and low-energy O(^1D) atom reactions. Low-energy O(^1D) atom is generated by utilizing long-wavelength wing of UV absorption band of O_3 that is near O(^1D) production threshold. In the preliminarily results in this study, product rovibrational state distributions of high-and low-energy O(^1D) atom reaction are relatively similar, indicating low contribution of excited state in O(^1D) reaction as opposed to the prediction of computational studies.