Studies of Vibrational Dynamics

这个实验物理化学项目的目的是阐明振动和旋转能量沉积在被自由射流膨胀冷却到低温的孤立分子中时的流动。J. D. McDonald博士将进行多种实验，使用激光光谱和自由射流膨胀技术的组合来探测分子内振动弛豫过程。一个实验将使用可见或紫外受激发射泵浦光谱来测量α -二羰基分子的基电子态的分子特征态光谱。第二个实验将使用红外泵浦-可见探针双共振来获得类似的信息，并通过研究受激分子的可见荧光来了解放松“浴态”的性质。第三个实验将通过光谱解析其红外荧光来探测相同分子中不同的浴态子集。最后一个实验将尝试在皮秒尺度上进行许多相同类型的时间分辨率研究。总的来说，这四种技术将提供一些分子系统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.