Time and Frequency Domain Studies of Ultrafast Dynamics in Liquids and Solutions

液体和溶液中超快动力学的时域和频域研究

• 批准号: 9712725
• 负责人: Lawrence Ziegler
• 金额: --
• 依托单位: Trustees of Boston University
• 依托单位国家: 美国
• 项目类别: Continuing grant
• 财政年份: 1997
• 资助国家: 美国
• 起止时间: 1997-08-01 至 2001-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9712725&HistoricalAwards=false
• 关键词: Time; Frequency; Domain; Studies; Ultrafast

In this project of the Experimental Physical Chemistry Program in the Chemistry Division with support for instrumentation from the Office of Multidisciplinary Activities, Prof. L. Ziegler of Boston University will perform time-domain and spontaneous emission frequency-domain studies on ultrafast dynamics of solutions and neat liquids. The spontaneous resonance emission of short-lived photodissociative molecules in high-pressure gases (approaching liquid densities), liquids, and supercritical phases will be analyzed as a probe of time scales of solvation, optical dephasing and bath-induced nonadiabatic effects. Classical Molecular Dynamics simulation and instantaneous normal mode techniques will be used to analyze the experimental observations. Two extensions of femtosecond polarization spectroscopy, dispersed optical heterodyne detected (OHD) birefringence and dichroism of transparent liquids, will be developed. The role of two-photon absorption resonances in femtosecond pump-probe spectroscopy will be explored. 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. It also helps in the understanding of the outcome of many types of light-initiated chemical events.

在多学科活动办公室仪器支持下的化学系实验物理化学项目中，L。波士顿大学的齐格勒将对溶液和纯液体的超快动力学进行时域和自发辐射频域研究。在高压气体（接近液体密度），液体和超临界相的短寿命的光解分子的自发共振发射将被分析作为溶剂化，光学退相和浴引起的非绝热效应的时间尺度的探针。经典的分子动力学模拟和瞬时简正模技术将被用来分析实验观察。飞秒偏振光谱的两个扩展，分散光外差检测（OHD）的双折射和二向色性的透明液体，将被开发。双光子吸收共振在飞秒泵浦探测光谱中的作用将被探讨。化学反应通常需要将分子提升到能量的激发态。由于在高压条件下，在溶液中或嵌入固体基质或簇中的分子的化学性质受到其环境的影响，因此了解和理解这些变化对于改进基于化学反应的技术非常重要。本项目的研究工作将为表征好的嵌入凝聚相介质中的分子的反应动力学和动力学提供数据基础和理论模型。它还有助于理解许多类型的光引发的化学事件的结果。