Ultrafast Spectroscopy and Other Applications of Lasers in Chemistry

宾夕法尼亚大学的Robin Hochstrasser得到了实验物理化学计划的支持，继续他对液体中超快动力学的研究。飞秒激光光谱技术将用于两个中心主题：化学反应的溶剂控制和分子激发的驰豫。将开发的具体技术包括低频飞秒瞬变红外光谱；在分子泵-探测器实验中探测低频运动的太赫兹光谱；以及飞秒时间分辨X射线在液体样品上的散射。重点是溶剂辅助的单分子和双分子反应动力学以及电子和振动弛豫。还将进行势能面的量子化学计算和经典的分子动力学模拟。研究凝聚相中高能激发分子从一种分子异构体构型到另一种分子同分异构体构型的转变将极大地扩展我们对复杂分子如何进行内部重排以及这些重排是如何由周围的溶剂介导的知识。

Robin Hochstrasser of the University of Pennsylvania is supported by the Experimental Physical Chemistry Program to continue his studies on ultrafast dynamics in liquids. Femtosecond (fs) laser spectroscopic techniques will be brought to bear on two central themes: solvent control of chemical reactions and the relaxation of molecular excitations. Specific techniques to be developed include fs transient infrared spectroscopy at low frequencies; terahertz spectroscopy to probe low frequency motions in molecular pump-probe experiments; and fs time-resolved X-ray scattering on liquid samples. Focus is on solvent-assisted uni- and bimolecular reaction dynamics and electronic and vibrational relaxation. Quantum chemical calculations of the potential energy surfaces and classical molecular dynamics simulations will also be carried out. The study of the transformation of energetically excited molecules in condensed phases from one molecular isomeric configuration to another will significantly expand our knowledge of how a complex molecule undergoes internal rearrangements and how these are mediated by a surrounding solvent.