Exploring Mode Selective Behavior in State-Resolved Unimolecular Reactions

在这个由化学部实验物理化学计划资助的项目中，Sinha将对偏离RRKM统计理论传统描述的单分子反应进行研究。 通过双共振激发，气相分子在高于基态电子态的解离极限的选定振转态中制备。 这些被激发的分子回复到较低的能量，以给定的速率解离，并呈现最终的产物状态分布。 共振能和线宽提供了势能面的信息，而最终产物态分布反映了系统从过渡态到产物的动态变化。 待研究的体系包括次氯酸、过硝酸和甲基碘，因为这些被认为表现出非统计反应动力学。 虽然许多反应可以用统计理论来描述，但有些反应的统计理论并不适用。 这项研究的重点是几个分子物种的非统计行为被怀疑的反应动力学。 这项工作的结果将增加对反应化学的基本理解，并可能适用于大气和燃烧化学问题。 学生将参加这项研究，从而获得知识和技能，为进入科学/技术劳动力市场做准备。

In this project, funded by the Experimental Physical Chemistry Program of the Chemistry Division, Sinha will conduct research on unimolecular reactions that deviate from the traditional description by the RRKM statistical theory. Gas phase molecules are prepared in selected ro-vibrational states above the dissociation limit of the ground electronic state by double resonance excitation. These excited molecules revert to lower energies, dissociate at a given rate, and present a final product state distribution. The resonance energy and the line widths provide information about the potential energy surface, whereas the final product state distribution reflects the dynamics of the system as it evolves from the transition state to the products. Systems to be investigated include hypochlorous acid, pernitric acid, and methyliodide, as these are believed to exhibit non-statistical reaction dynamics.This research deals with fundamental aspects of chemical reactions in the gas phase. Whereas many reactions can be described by a statistical theory, there are some for which a statistical theory of reactions does not apply. This research is focused on the reaction dynamics of several molecular species for which non-statistical behavior is suspected. The results of this work will add to the fundamental understanding of reaction chemistry, and may be applicable to problems of atmospheric and combustion chemistry. Students will participate in this research and thereby acquire knowledge and skills in preparation for entry into the scientific/technical workforce.