Vibrational Spectroscopy at 4eV and Beyond

在化学系实验物理化学项目中，普林斯顿大学的凯文·莱曼将开发两种光谱工具，以帮助研究小多原子分子中的分子内振动能量重新分配(IVR)。第一种技术是光学-光学双共振方法，它允许填充非常高的振动激发基态能级，以便研究大的非谐性对振动运动的影响。另一种技术是时间分辨的红外泵浦/拉曼探测方法，用于研究氢原子伸展振动激发后的最终IVR分布。最后，莱曼将开发理论工具来解释新获得的光谱。对分子中大量振动激发的影响的理解直接影响我们对许多类型反应发生的基本过程的理解。在这项研究中，莱曼将研究振动能量对分子中键运动的影响，以及解释这种过剩能量的消散途径。这些信息影响了对许多反应过程的基本理解，从大气化学到燃烧再到使用等离子体的合成。

In this project in the Experimental Physical Chemistry Program of the Chemistry Division, Kevin Lehmann of Princeton University will develop two spectroscopic tools to aid in studying intramolecular vibrational energy redistribution (IVR) in small polyatomic molecules. The first technique is an optical-optical double resonance method which allows very highly vibrationally excited levels of the ground state to be populated in order to study the effect of the large anharmonicity on the vibrational motion. The other technique is a time-resolved, infrared-pump/Raman probe method for exploring the final IVR distributions after vibrational excitation of hydrogen atom stretches. Finally, Lehmann will develop theoretical tools to interpret the newly acquired spectra. %%% An understanding of the effects of large amounts of vibrational excitation in a molecule directly impacts our understanding of the fundamental processes by which many types of reactions occur. In this research Lehmann will study the effects of vibrational energy on the motions of bonds in a molecule as well as the elucidation of the pathways by which this excess energy is dissipated. This information has impact on the basic understanding of many reactive processes, from atmospheric chemistry to combustion to synthesis using plasmas.