Resonance Raman Studies of Excited-State Structure and Dynamics

在化学部门物理化学计划的这个项目中，加州大学伯克利分校的Richard Mathies教授将使用拉曼和飞秒激光方法的组合来试图阐明凝聚态光化学和光生物反应的分子机制和光生物反应的基态和激发态分子动力学。光激发后立即发生的核运动模式特定动力学将在飞秒时间尺度上进行跟踪，光化学反应中的关键中间体将使用皮秒拉曼光谱和吸收光谱进行识别和表征。有待探索的反应类型包括氢移位反应、视觉色素异构化、光色素异构化和细菌光合反应中心的电子转移。马蒂斯教授计划进行的这些研究旨在了解光激发特定成分时在液体或固体状态下发生的物理和化学过程。提出的系统和技术的结合应该有助于对化学反应中发生的原子运动进行完整的描述，从瞬态激发态的早期动力学到松弛平衡产物的动力学。这项研究包括对涉及感光色素的生物系统的研究。

In this project in the Physical Chemistry Program of the Chemistry Division, Professor Richard Mathies of the University of California, Berkeley, will use a combination of Raman and femtosecond laser methods to try to elucidate the molecular mechanism and the ground and excited-state molecular dynamics of condensed phase photochemical and photobiological reactions. The mode-specific dynamics of nuclear motion that occur immediately after optical excitation will be followed on a femtosecond time scale, and key intermediates in the photochemical reactions will be identified and characterized using picosecond Raman and absorption spectroscopy. The types of reaction to be explore include hydrogen shift reactions, visual pigment isomerization, photochrome isomerization, and electron transfer in bacterial photosynthetic reaction centers. %%% These planned studies by Professor Mathies aim at understanding the physical and chemical processes that take place in the liquid or solid state when light excites specific constituents. The proposed combination of systems and techniques should aid in developing a complete description of the atomic motions which occur during chemical reactions, from the early dynamics of the transient excited species to those of the relaxed equilibrium products. Included in this research are studies of biological systems involving light-sensing pigments.