Resonance Raman Studies of Excited-State Structure and Dynamics

激发态结构和动力学的共振拉曼研究

• 批准号: 9419714
• 负责人: Richard Mathies
• 金额: $ 44万
• 依托单位: University of California-Berkeley
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1995
• 资助国家: 美国
• 起止时间: 1995-02-15 至 1998-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9419714&HistoricalAwards=false
• 关键词: Resonance; Raman; Studies; Excited; State

In this project in the Physical Chemistry Program of the Chemistry Division, Professor Richard A. Mathies of the University of California at Berkeley will conduct a series of investigations to determine the ground and excited-state nuclear dynamics and structural changes that occur in condensed phase photochemical and photobiological reactions and thereby understand their molecular reaction mechanisms. The mode-specific nuclear dynamics that occur immediately after excitation of a photochemically active system will be determined by measuring and analyzing absolute laser resonance Raman vibrational scattering intensities. Picosecond time-resolved resonance Raman and absorption spectroscopy will be used to study the kinetics of ground-state photoproduct formation and the structures and relaxation of ground-state photochemical intermediates. The following studies will be pursued. 1) Photochemical ring-opening, ring-closing and 1,7 hydrogen shift reactions of cyclic polyenes; 2) the response of protein environment in bacteriorhodopsin and in phycobiliproteins to the electronic excitation/photoisomerization of their bound chromophoric prosthetic groups will be studied; 3) the photoexcitation of visual pigment rhodopsin will be investigated; 4) the photochemical electron transfer reaction in bacterial photosynthetic reaction centers, and 5) the mechanism of photochemical excitation of tetrapyrrole chromophore in phytochrome, the light sensing pigment in plants, will be examined. These investigations probe the basics of the interaction between light and photo-biologically active materials and will contribute to our understanding of the fundamental processes which take place in animate and inanimate living systems. The overall goal of this research is to find general principles about how chemical reactions occur in condensed phase photochemical systems at room temperature.

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 a . Mathies教授将进行一系列的研究，以确定凝聚态光化学和光生物反应中发生的基态和激发态核动力学和结构变化，从而了解它们的分子反应机制。光化学活性体系激发后立即发生的特定模式核动力学将通过测量和分析绝对激光共振拉曼振动散射强度来确定。皮秒时间分辨共振拉曼光谱和吸收光谱将用于研究基态光产物形成动力学和基态光化学中间体的结构和弛豫。将进行下列研究。1)环多烯的光化学开环、闭环和1,7氢移反应；2)研究细菌视紫红质和藻胆蛋白中蛋白质环境对其结合的发色基团的电子激发/光异构化的响应；3)研究视色素视紫红质的光激发；4)细菌光合反应中心的光化学电子转移反应；5)植物光敏色素光敏色素中四吡咯发色团的光化学激发机制。这些研究探索了光和光生物活性材料之间相互作用的基础，并将有助于我们理解发生在有生命和无生命生命系统中的基本过程。本研究的总体目标是找到在室温下凝聚态光化学系统中化学反应发生的一般原理。