Nonlinear Vibronic and Electronic Spectroscopy of Molecules in the Condensed Phase

9311959 Albrecht康奈尔大学的A. Albrecht教授将利用四波混合非线性光谱学研究分子凝聚相。本文将研究中大型多原子分子的电子特性，为量子化学计算的不同理论模型的持续测试提供数据。还将研究通过探测负责振动和电子线形的随机过程的凝聚相动力学。这些研究将使用的非线性技术是使用相位噪声光的干涉相干光谱学（ICS）和飞秒相干光谱学。这项研究将有助于提取各种复杂体系中激发态分子动力学和溶质-溶剂相互作用的信息。ICS技术仍处于早期发展阶段，但有望揭示由于拉曼跃迁而被溶液相展宽相互作用所隐藏的信号。这对于生物材料的研究具有特殊的意义，因为拉曼光谱技术不受水的强吸收的影响，这使得红外光谱方法不合适。在可见光脉冲的远程相干探测有利的情况下，额外的好处就产生了。＊＊＊

9311959 Albrecht In this project of the Physical Chemistry Program of the Chemistry Division, Prof. A. Albrecht of Cornell University will use four-wave-mixing nonlinear spectroscopies to study the molecular condensed phase. The electronic properties of medium -to-large polyatomic molecules will be investigated to provide data for the continued testing of different theoretical models for quantum chemical calculations. Also studied will be the dynamics in the condensed phase by probing the stochastic processes that are responsible for vibrational and electronic lineshaping. The nonlinear techniques that will be used in these studies are interferometric coherent spectroscopy (ICS) using phase-noisy light and femtosecond coherent spectroscopy. %%% This research will contribute to the ability to extract information about the molecular dynamics in excited electronic states and solute-solvent interactions in various complex systems. The ICS technique is still in its early developmental stage but promises to reveal signals due to Raman transitions that are hidden by solution-phase broadening interactions. This has special significance for the study of biological materials for which the technique of Raman spectroscopy is preferred since it is not affected by the strong absorptions due to water which renders the method of infrared spectroscopy inappropriate. Additional advantages accrue for situations where remote coherent detection with pulses of visible light is advantageous. ***