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，康奈尔大学的保罗·休斯顿和他的学生将使用产品成像技术来研究小分子的紫外线光解和涉及原子氧的双分子反应。康奈尔研究小组研究了NO2的单光子和双光子解离，并将原子产物的速度和角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，对其光解机理的深入了解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的主旨是将产品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种之间的反应，包括分子氮和氧。休斯顿和他的学生还将研究激发氧原子与N2O的反应，以产生氮气和O2或2NO。在这些研究中，休斯顿将测量激发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。这项工作涉及化学物理中的基本实验问题，并有望提供关于氮氧化物和激发氧原子的化学的详细结果，这些物种在高层大气的化学和光化学中发挥重要作用。这项研究将为研究生和博士后提供实验物理化学方面的优秀培训，特别是在进一步开发产品成像技术方面。

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.