The Influence of Electronic Nonadiabaticity on Competing Chemical Reaction Pathways

在这个由化学部实验物理化学项目支持的项目中，巴特勒将继续研究电子非绝热化学反应途径。一组实验将寻求在分子官能团的局部电子激发下预测绝热和非绝热反应通道。例如，通过交叉激光分子束光解硝酸的光碎片速度和角分布测量，结合从头算计算，可以确定激光激发产生的硝酸的所有产物通道。其他需要检测的分子包括硝基甲烷、硝酸甲基和硝酰胺。在另一组实验中，一系列酰胺的光解通道的光碎片速度和角分布分析将使用解离分子的发射光谱来表征frank - condon区域的势能面形状。详细了解众所周知的光诱导键解理通道将获得。本项目的实验测量与计算相结合，将有助于我们了解复杂分子的光化学反应性。例如，有些反应是被禁止的，即使有足够的能量使它们进行。这个项目将提供一个基础，通过它我们可以解释一些意想不到的结果

In this project supported by the Experimental Physical Chemistry Program of the Chemistry Division, Butler will continue studies of electronically nonadiabatic chemical reaction pathways. One set of experiments will seek to predict adiabatic and nonadiabatic reaction channels upon local electronic excitation of a molecular functional group. As an example, photofragment velocity and angular distribution measurements from crossed-laser molecular beam photodissociation of nitric acid together with ab initio calculations will identify all the product channels of nitric acid resulting from laser excitation. Other molecules to be examined include nitromethane, methyl nitrate, and nitramide. In another set of experiments photofragment velocity and angular distribution analysis of the photodissociation channels of a series of amides will use emission spectroscopy of dissociating molecules to characterize the shape of the potential energy surface in the Franck-Condon region. Detailed insight into well-known photo-induced bond cleavage channels will be obtained. The experimental measurements in this project combined with calculations will help us understand the photochemical reactivity of complex molecules. For example, some reactions are forbidden even though there is enough energy available for them to proceed. This project will provide a basis by which we can explain some of these unexpected outcomes