Ultrafast Nonlinear and Coherent Spectroscopic Studies of Molecular Motion in Liquids

Mark Berg博士由实验物理化学计划资助，研究溶液中溶质附近溶剂分子的分子运动。伯格将使用复杂的激光技术来研究溶质分子在其局部溶剂笼内的嘎嘎运动，以及局部溶质-溶剂结构的合作重排。本研究将探讨溶剂在溶质分子周围的运动，以及这种运动与溶质的电子、振动和取向态的耦合。超快激光技术将使液体基本运动的直接时间分辨成为可能。通过非线性和相干光谱技术的结合，将有可能区分不同类型溶剂动力学的影响。这些技术，特别是瞬态孔燃烧和拉曼回波，已经很好地理解了固态和气相的类似物，但以前还没有广泛应用于液态。这些实验将导致溶质重定向动力学的新测量，以及纯溶剂中振动运动的离域。

Dr. Mark Berg is supported by a grant from The Experimental Physical Chemistry Program to investigate the molecular motions of solvent molecules in the vicinity of a solute in solution. Berg will use sophisticated laser techniques to study the rattling motion of solute molecules within their local solvent cages, and the cooperative rearrangements of the local solute- solvent structure. This research will explore the solvent motion around a solute molecule and the coupling of that motion to the electronic, vibrational and orientational states of the solute. Ultrafast laser technology will permit the direct time resolution of the fundamental motion in liquids. Through a combination of nonlinear and coherent spectroscopic techniques it will be possible to discriminate between the effects of different types of solvent dynamics. These techniques, specifically transient hole burning and Raman echoes, have well understood analogues in the solid state and gas phase, but have not previously been widely applied to the liquid state. These experiments will lead to new measurements of solute reorientational dynamics, and the delocalization of vibrational motion in pure solvents.