Multidimensional Femtosecond Studies of Chemical Reaction Dynamics

在这个由化学学部化学结构、动力学和机制项目资助，由国际科学与工程办公室共同资助的项目中，科罗拉多大学博尔德分校的David Jonas教授将开发二维傅里叶变换飞秒光谱的方法，该方法的脉冲接近电磁波谱的光学和红外区域的倍频（2因子）频率跨度。该项目包括利用ICFO（西班牙）Jens Biegert实验室开发的脉冲激光源的国际合作。飞秒光谱学将用于研究两类分子在锥形交点处的电子和振动动力学：酞菁，其中锥形交点处动力学的温度依赖性可以测试振动波包宽度作用的理论预测；类胡萝卜素在保护许多生物系统免受过量阳光照射方面发挥着多种多样的作用，目前还不清楚其机理。希望在这个项目中开发的二维光谱方法将有助于确定化学反应中电子运动是如何驱动和被原子重排驱动的。参与项目的研究生和博士后将获得科研培训，获得国际合作的宝贵经验，并在国家科学专业学会会议和国际跨学科会议上展示项目成果。

In this project funded by the Chemical Structure, Dynamics and Mechanisms program of the Chemistry Division and co-funded by the Office of International Science and Engineering, Professor David Jonas of the University of Colorado at Boulder will develop approaches to two-dimensional Fourier transform femtosecond spectroscopy with pulses approaching octave (factor of 2) frequency spans in the optical and infrared regions of the electromagnetic spectrum. The project includes an international collaboration to use pulsed laser sources developed in the laboratory of Jens Biegert at ICFO (Spain). Femtosecond spectroscopy will be used to study the electronic and vibrational dynamics at conical intersections in two classes of molecules: phthalocyanines, where the temperature dependence of dynamics at conical intersections can test theoretical predictions about the role of vibrational wavepacket width; and carotenoids, which play diverse and not yet mechanistically understood roles in protecting many biological systems from excess sunlight. It is hoped that the approaches to two-dimensional spectroscopy developed in this project will become useful for determining how electronic motions both drive and are driven by atomic rearrangements in chemical reactions. Graduate students and a postdoctoral researcher participating in the project will be trained in scientific research, gain valuable experience in international collaboration, and present project results at national meetings of scientific professional societies and international interdisciplinary conferences.