Product Imaging of Photodissociations and Reactions of Atmospherically Important Molecules

在这个由实验物理化学项目资助的奖项中，康奈尔大学的Paul Houston和他的学生将使用产品成像技术来研究涉及原子氧的小分子和双分子反应的紫外光解。康奈尔大学的研究小组研究了二氧化氮的单光子和双光子解离，并将原子产物的速度和角度分布与理论预测进行了比较。NO2在臭氧的催化破坏中起着重要的作用，更好地了解其光解机制将提高我们模拟高层大气化学的能力。这项工作的一个主要新推力是将产物成像技术应用于双分子反应的研究，特别是高能氧原子与各种大气物质（包括分子氮和氧）之间的反应。休斯敦和他的学生还将研究受激发的氧原子与N2O的反应，产生N2和O2或2NO。在这些研究中，Houston将测量激发态氧原子失活后分子碰撞伙伴的振动和旋转分布，并将这些结果与反应效率的理论预测联系起来。这项工作解决了化学物理学中的基本实验问题，并有望提供关于氮氧化物和受激氧原子化学的详细结果，这些氧原子在高层大气的化学和光化学中起着重要作用。该研究将为实验物理化学方面的研究生和博士后提供良好的培训，特别是在产品成像技术的进一步发展方面。

In this award, funded by the Experimental Physical Chemistry program, Paul Houston of Cornell University and his students will use product imaging techniques to study the ultraviolet photolysis of small molecules and bimolecular reactions involving atomic oxygen. The Cornell group investigate the one- and two-photon dissociation of NO2 and compare the speed and angular distributions of the atomic products with theoretical predictions. NO2 plays an important role in the catalytic destruction of ozone, and a better understanding of the mechanism of its photodissociation will improve our ability to model the chemistry of the upper atmosphere. A major new thrust of the work is to apply product imaging techniques to the study of bimolecular reactions, in particular reactions between high energy oxygen atoms and a variety of atmospheric species, including molecular nitrogen and oxygen. Houston and his students also will study the reaction of excited oxygen atoms with N2O to produce N2 and O2 or 2NO. In these studies, Houston will measure the vibrational and rotational distributions of the molecular collision partners following deactivation of excited oxygen atoms and relate these results to theoretical predictions of reaction efficiencies. This work addresses fundamental experimental issues in chemical physics and promises to provide detailed results on the chemistry of the oxides of nitrogen and of excited oxygen atoms, species that play important roles in the chemistry and photochemistry of the upper atmosphere. The research will provide excellent training for graduate students and postdoctoral fellows in experimental physical chemistry, particularly in the further development of product imaging techniques.