Vibrational Spectroscopy at 4eV and Beyond

在化学学部实验物理化学项目中，普林斯顿大学的Kevin Lehmann将开发两种光谱工具来帮助研究小多原子分子中的分子内振动能量再分配（IVR）。第一种技术是光学-光学双共振方法，该方法允许填充基态的非常高的振动激发能级，以研究大非谐性对振动运动的影响。另一种技术是一种时间分辨的红外泵浦/拉曼探针方法，用于探索氢原子拉伸振动激发后的最终IVR分布。最后，Lehmann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效应的理解直接影响我们对许多类型的反应发生的基本过程的理解。在这项研究中，Lehmann将研究振动能量对分子中键运动的影响，以及阐明这些多余能量耗散的途径。这些信息对许多反应过程的基本理解产生了影响，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.