Multidimensional Femtosecond Studies of Chemical Reaction Dynamics in Condensed Phases

本项目由化学学部实验物理化学专业资助。将进行实验和理论研究，以开发二维（2D）傅立叶变换光学和红外光谱技术，类似于已建立的二维傅立叶变换核磁共振（NMR）方法。为此，工作将集中在四个方面：1)将对样品中的脉冲传播和信号产生进行理论研究，以便对光密集样品进行定量实验；2)将进行实验，试图证明在磁共振中发现的“分子内”和“分子间”双量子相干的光学类似物；3)测量具有相同振子的一系列分子在不同几何形状下的二维振动相关谱；4)利用高稳定性可见光放大器的飞秒脉冲，利用二维光谱和偏振相关的泵浦探测实验来探测一些分子简并态的电子动力学。二维傅里叶变换红外光谱学是一门相对较新的技术，具有成为重要分析工具的潜力。就像在二维核磁共振中一样，类似的二维光学和红外傅里叶变换光谱可以显示二维模式的特征振动频率，从而揭示相邻键及其相对几何形状。这项工作的长期目标是开发新的二维光谱仪，用于测量新的分子性质。研究生和本科生以及博士后研究助理将参与本研究。他们将获得新的知识和技能，为深造或进入科技就业市场做准备。

The Experimental Physical Chemistry Program of the Chemistry Division funds this project. Experimental and theoretical studies will be undertaken to develop techniques for two-dimensional (2D) Fourier transform optical and infrared spectroscopies in analogy to the well-established 2D Fourier transform nuclear magnetic resonance (NMR) methods. To this end work will focus on four broad areas: 1) theoretical studies will be undertaken of pulse propagation and signal generation in a sample to enable quantitative experiments on optically dense samples; 2) experiments will be done to attempt a demonstration of optical analogs of the "intramolecular" and "intermolecular" double quantum coherence found in magnetic resonance; 3) 2D vibrational correlation spectra will be measured for a series of molecules with identical oscillators in various geometries; and 4) the electronic dynamics in the degenerate states of a few molecules will be probed by 2D spectroscopy and polarization dependent pump-probe experiments using femtosecond pulses from a high stability visible optical amplifier.2D Fourier transform infrared and optical spectroscopy is a relatively new t that has the potential of becoming an important analytical tool. Just as in 2D-NMR, analogous 2D-optical and infrared Fourier transform spectra may show characteristic vibrational frequencies in two-dimensional patterns that reveal adjacent bonds and their relative geometry. A long-term goal of this work is to develop of new 2D optical spectrometers for the measurement of new molecular properties. Graduate and undergraduate students as well as postdoctoral research associates will participate in this research. They will acquire new knowledge and skills in preparation for advance studies or entrance into the scientific/technological job market.