Spectroscopy and Reaction Dynamics of Open-Shell Complexes and Atmospheric Aerosols

宾夕法尼亚大学的Marsha I. Lester教授将研究开壳配合物的光谱学和反应动力学，以便：1)通过受激发射泵送和红外泛音激发获得分子间振动，绘制自由基和碰撞伙伴之间的分子间势能面；2)研究由于含有未配对电子的轨道的取向，自由基和碰撞伙伴之间的分子间相互作用的变化；3)通过羟基自由基的红外泛音激发，克服激活屏障，在羟基自由基与分子伴侣组成的络合物内诱导化学反应。要在分子水平上详细了解反应化学，就需要了解反应伙伴在短时间内的反应过程的行为。自由基，即带有未配对电子的原子或分子，在反应过程中起着重要作用，但由于其存在时间短，很难对其本身，特别是在反应过程中进行研究。目前的研究将为气态化学反应的过程提供基础知识和见解。

In this project in the Physical Chemistry program of the Chemistry Division, Professor Marsha I. Lester of the University of Pennsylvania will study the spectroscopy and reaction dynamics of open shell complexes in order to: 1) map out the intermolecular potential energy surfaces between a free radical and a collision partner by accessing intermolecular vibrations via stimulated emission pumping and infrared overtone excitation; 2) examine the change in the intermolecular interaction between a free radical and a collision partner due to the orientation of the orbital containing an unpaired electron; and 3) induce chemical reaction within a complex composed of a hydroxyl radical and a molecular partner by surmounting the activation barrier to reaction via infrared overtone excitation of that radical. Detailed understanding of reaction chemistry at the molecular level requires knowledge of the behavior of the reaction partners during the short duration of the reaction process. Free radicals, i.e., atoms or molecules with an unpaired electron, play an essential part in reaction processes but because of their short lived existence are difficult to study in themselves and, especially, in a reaction process. The present research will provide fundamental knowledge and insight into the process of chemical reactions taking place in the gaseous state.