Multidimensional Femtosecond Studies of Chemical Reaction Dynamics

在这项由化学系实验物理化学计划资助的奖项中，科罗拉多大学的大卫·乔纳斯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态控制中的作用。特别是，将研究三个广泛的领域。首先，将测试一种消除强吸收样品的飞秒2D光谱中传播失真的方法。然后将使用二维光谱学来探测电子通过锥形交点从一个轨道到另一个轨道的运动速度，这是促进化学反应中键变化的重要机制。最后，整形飞秒脉冲将被用来确定弱激光场的相位控制是否可以在不改变光的强度光谱的情况下改变凝聚相光驱动反应的结果。二维傅里叶变换红外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2D-核磁共振中一样，类似的2D光学和红外傅里叶变换光谱以二维模式显示特征光谱，揭示了相邻的键及其相对几何形状。特别是，这些研究将有助于建立目前应用于一系列科学问题的多维电子光谱仪类型背后的理论。参与这项研究的研究生和博士后研究助理获得新的知识和技能，为深造或进入科学/技术就业市场做准备。

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.