Multidimensional Femtosecond Studies of Chemical Reaction Dynamics

在这个由化学系实验物理化学项目资助的奖项中，科罗拉多大学的David Jonas教授将使用二维光谱学来研究光激发脉冲的相位在分子系统动力学控制中的作用。具体而言，将审查三个广泛的领域。首先，将测试一种消除强吸收样品飞秒二维光谱中的传播畸变的方法。然后，二维光谱将用于探测电子通过锥形交叉从一个轨道运动到另一个轨道的速度，这是化学反应中促进键变化的重要机制。最后，将使用形状飞秒脉冲来确定弱激光场的相位控制是否可以在不改变光的强度谱的情况下改变凝聚相中的光驱动反应的结果。二维傅里叶变换红外光谱和光学光谱是一种相对较新的技术，有可能成为测量新分子性质的重要分析工具。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显示出二维模式的特征光谱，揭示了相邻键及其相对几何形状。特别是，这些研究将有助于建立多维电子能谱背后的理论，这些理论目前正应用于一系列科学问题。参与本研究的研究生和博士后研究助理获得新的知识和技能，为深造或进入科技就业市场做准备。

In this award funded by the Experimental Physical Chemistry Program of the Division of Chemistry, Professor David Jonas of University of Colorado will use two-dimensional spectroscopy to study the role of the phase of an optical excitation pulse on the dynamical control of molecular systems. In particular, three broad areas will be examined. First, an approach for removing propagation distortions in femtosecond 2D spectra of strongly absorbing samples will be tested. Two-dimensional spectroscopy will then be used to probe the speed of electronic motion from one orbital to another via conical intersections, which are an important mechanism that facilitates bonding changes during chemical reactions. Finally, shaped femtosecond pulses will be used to determine whether phase control of weak laser fields can modify the outcome of light-driven reactions in condensed phases without changing the intensity spectrum of the light.Two-dimensional Fourier transform infrared and optical spectroscopy is a relatively new technique that has the potential of becoming an important analytical tool for the measurement of new molecular properties. Just as in 2D-NMR, analogous 2D optical and infrared Fourier transform spectra show characteristic spectra in two-dimensional patterns that reveal adjacent bonds and their relative geometry. In particular, these studies will help establish the theory behind the types of multidimensional electronic spectroscopies currently being applied to a range of scientific problems. Graduate students and postdoctoral research associates who participate in this research acquire new knowledge and skills in preparation for advanced studies or entrance into the scientific/technological job market.