Resonance Emission Studies of Intra- and Intermolecular Ultrafast Dynamics

9316148齐格勒在化学系实验物理化学计划的这个项目中，波士顿大学的L.齐格勒教授将把以前对孤立分子中超快动力学的研究扩展到凝聚相和团簇，以研究嵌入浴对分子激发电子态过程的影响。自发拉曼和荧光光散射技术将被用来1)探测溶剂/浴描述的时间尺度、幅度和运动特性，并确定这些自由度如何与电子激发相耦合的微观细节，以及2)浴相互作用如何影响这些生色团的准束缚激发态光解离的光化学动力学。我们将研究嵌在团簇、溶液和高压气体中的特性良好的分子。共振线型、退偏率和量子产额将被测量以确定依赖于振动和转动能级的退相和弛豫速率。化学反应通常需要将分子提升到激发态的能量。由于分子在高压条件下、在溶液中、在固体基质中或在团簇中的化学受其环境的影响，了解和理解这些变化对于改进基于化学反应的技术是很重要的。本项目的研究将为特征良好的分子嵌入凝聚相介质中的反应动力学和动力学提供数据基础和理论模型。***

9316148 Ziegler In this project of the Experimental Physical Chemistry Program in the Chemistry Divison, Prof. L. Ziegler of Boston University will extend previous studies of ultrafast dynamics in isolated molecules to the condensed phase and clusters, so as to study the effects of the embedding bath on processes in the excited electronic state of the molecule. Spontaneous Raman and fluorescence light scattering techniques will be used to 1) probe the time scales, amplitudes and motional character of solvent/bath descriptions and to determine microscopic details of how these degrees of freedom couple to electronic excita- tions, and 2) how the bath interactions affect the photo- chemical dynamics of the quasi-bound excited state photodisso- ciation of these chromophores. Well characterized molecules embedded in clusters, solutions, and high pressure gases will be investigated. Resonance lineshapes, depolarization ratios, and quantum yields will be measured to determine the vibrational and rotational level dependent dephasing and relaxation rates. Chemical reactions usually require the elevation of molecules to excited states of energy. Since the chemistry of molecules under conditions of high pressure, in solution, or embedded in a solid matrix or in a cluster is affected by their environment, it is important to know and understand these changes in order improve the technology based on chemical reactions. The research undertaken in this project will provide a data base and theoretical model for the reaction kinetics and dynamics of well characterized molecules which are embedded in a condensed phase medium. ***