Nonlinear Vibronic and Electronic Spectroscopy of Molecules in the Condensed Phase

9311959阿尔布雷希特在化学系物理化学计划的这个项目中，康奈尔大学的阿尔布雷希特教授将使用四波混频非线性光谱来研究分子凝聚相。将研究中大型多原子分子的电子性质，为继续测试用于量子化学计算的不同理论模型提供数据。还将通过探索导致振动和电子线形的随机过程来研究凝聚相中的动力学。将在这些研究中使用的非线性技术是使用相位噪声光的干涉相干光谱(ICS)和飞秒相干光谱。这项研究将有助于提取各种复杂体系中激发电子态和溶质-溶剂相互作用的分子动力学信息。ICS技术仍处于早期发展阶段，但有望揭示被溶液-相展宽相互作用掩盖的拉曼跃迁信号。这对于首选拉曼光谱技术的生物材料的研究具有特殊的意义，因为它不受水的强吸收的影响，这使得红外光谱方法变得不合适。在利用可见光脉冲进行远程相干检测是有利的情况下，会产生额外的优点。***

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. ***