MEASUREMENTS OF STATE-RESOLVED DIFFERENTIAL CROSS SECTIONS VIA HIGH-RESOLUTION POLARIZED DOPPLER SPECTROSCOPY

通过高分辨率偏振多普勒光谱测量状态分辨差分截面

基本信息

批准号：
09640600
负责人：
FUJIMURA Yo
金额：
$ 2.11万
依托单位：
KYOTO UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1997
资助国家：
日本
起止时间：
1997 至 1998
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-09640600/
关键词：
Oxygen Nitrous Oxide Hydrogen Hydrocarbon Water Reaction Dynamics Doppler Spectroscopy Differential Cross Sections

项目摘要

Chemical reaction dynamics of elementary gas phase reactions have been studied via Dopplerresolved polarization spectroscopy. By using this technique, differential cross sections can be measured state-resolved manner. Furthermore, this method enables us to measure the polarization of the rotational angular momentum of reaction products.Collision-free diatomic product molecules were probed with high-resolution dye laser excitation and its Doppler-broadened line profiles were analyzed to extract the information of vector properties such as differential cross sections and rotational angular momentum polarization, We investigated the reaction of O(^1D) atom with some several simple molecules. Following results are shown. 1) For H_2 reaction, differential cross sections and collision energy dependence of reaction probability strongly depend on ro-vibrational states of product OH molecules. Critical comparison with a quasi-classical trajectory calculation on a recent state-of-the-art ab init … More io potential energy surfaces. 2) For N_2O reaction, efficient energy randomization within all the degrees of freedom of reaction intermediates leads apparent statistical ro-vibrational state distribution of product NO molecules despite the absence of a deep potential well. Such a behavior is generally interpreted in terms of intermolecular vibrational-energy redistribution, with the emphasis of the light (hydrogen) atom effect. 3) For C_2H_4 and C_2H_6 reaction, the difference of the structural change of reactive intermediates after the insertion of 0 atom forming alcohol type intermediates is reflected in the difference of the polarization of rotational angular momentum of product OH molecules. 4) For H_2O reaction, the main reaction path is an insertion of O atom into HO bond of H_2O forming HOGH as an intermediate.To obtain such findings becomes possible only by the use of the state-resolved polarized Doppler spectroscopy. In addition, some of the findings in this study give new understandings which are opposite to the previous ones based on insufficient state-resolved measurements. The study elucidating elementary bimolecular reactions in this manner is essential for the fundamental understanding of chemical reaction dynamics. Less

通过多普勒分辨偏振光谱研究了基本气相反应的化学反应动力学，通过使用该技术，可以以状态分辨的方式测量微分截面，此外，该方法使我们能够测量反应产物的旋转角动量的偏振。 .利用高分辨率染料激光激发探测无碰撞双原子产物分子，并分析其多普勒展宽线轮廓，以提取微分截面和旋转角等矢量特性信息动量极化，我们研究了 O(^1D) 原子与一些强简单分子的反应 1) 对于 H_2 反应，反应概率的微分截面和碰撞能量依赖于产物的振动状态。 OH 分子。与最近最先进的 ab init … 更多 io 势能表面上的准经典轨迹计算进行批判性比较 2) 对于 N_2O 反应，在所有自由度内进行有效的能量随机化。尽管不存在深势阱，但中间体导致产物 NO 分子出现明显的统计振动状态分布，这种行为通常用分子间振动能量重新分布来解释，重点是轻（氢）原子效应 3。）对于C_2H_4和C_2H_6，0原子形成醇型中间体反应后反应性中间体结构变化的差异体现在旋转极化的差异上4）对于H_2O反应，主要反应路径是O原子插入H_2O的HO键中，形成HOGH作为中间体。只有使用状态分辨极化才能获得这样的发现。此外，这项研究中的一些发现给出了与之前基于不充分的状态分辨测量的相反的新理解。这种方式对于化学反应动力学的基本理解至关重要。