Studies of Vibrational Dynamics

实验物理化学中的这个项目旨在阐明当振动和旋转能量沉积在孤立的分子中时的流动，这些孤立的分子已经通过自由喷射膨胀冷却到低温。J·D·麦克唐纳博士将结合使用激光光谱和自由喷射膨胀技术进行各种实验，以探索分子内振动弛豫过程。其中一项实验将使用可见光或紫外光受激发射泵浦光谱来测量α-二酮分子基电子态的分子本征态光谱。第二个实验将使用红外线泵浦-可见光探测器双共振来获得类似的信息，并通过研究激发分子的可见荧光来了解松弛“浴态”的本质。第三个实验将通过光谱分辨红外荧光来探测与前一个实验相同的分子中不同的浴态子集。最后一个实验将尝试许多相同类型的研究，时间分辨率在皮秒尺度上。总而言之，这四种技术将提供几个分子体系中分子内振动和旋转弛豫过程的非常完整的视图。

This project in Experimental Physical Chemistry is designed to elucidate the flow of vibrational and rotational energy when it is deposited in isolated molecules which have been cooled to low temperatures by free-jet expansion. Dr. J. D. McDonald will conduct a variety of experiments using a combination of laser spectroscopic and free-jet expansion techniques to probe the intramolecular vibrational relaxation process. One experiment will use visible or ultraviolet stimulated emission pumping spectroscopy to measure the spectrum of molecular eigenstates in the ground electronic state of alpha-dicarbonyl molecules. A second experiment will use infrared pump-visible probe double resonance to gain similar information and to learn about the nature of the relaxed "bath states" by studying the visible fluorescence of the excited molecules. A third experiment will probe a different subset of the bath states in the same molecules as the previous experiment by spectrally resolving their infrared fluorescence. The last experiment will attempt many of the same types of studies with time resolution on a picosecond scale. Collectively these four techniques will provide a very complete view of the intramolecular vibrational and rotational relaxation process in several molecular systems.