Direct probing of low frequency motions in solution phase chemical dynamics

直接探测溶液相化学动力学中的低频运动

• 批准号: 0211894
• 负责人: David Blank
• 金额: $ 33.88万
• 依托单位: University of Minnesota-Twin Cities
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-08-15 至 2006-02-28
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0211894&HistoricalAwards=false
• 关键词: Direct; probing; low; frequency; motions

In this project funded by the Experimental Physical Chemistry Program of the Chemistry Division, David Blank will develop and apply novel experimental methods designed to address the role of intermolecular and low frequency intramolecular nuclear motions in condensed-phase reactive and nonreactive chemical dynamics. The experiments utilize multidimensional femtosecond spectroscopic techniques, and can be divided into two types, based on the complementary information each will provide. First, the response of low frequency motions in response to the progress of a dynamic event in solution will be probed by photo-initiating that event with an ultrafast laser pulse, and monitoring the response using third-order time domain Raman spectroscopy. Second, the coupling between low frequency motions in condensed systems will be directly measured using a new resonance enhanced version of coherent two-dimensional time domain Raman spectroscopy. These studies are expected to enable new insights into low frequency motions in solution phase chemical reactions.The significant proportion of chemistry, from industrial reactions to the chemistry of biology, takes place in the solution phase. This project aims at providing a microscopic description of chemical reactivity in solution, one of the central issues in physical chemistry today. The proposed methods are direct and generally applicable techniques that will aid in understanding the scientific issues involved. This work has applications ranging from modern optics and metrology to advanced materials characterization and fundamental research in condensed matter. As part of this research effort, students from the undergraduate through the postdoctoral level are trained with state-of-the-art instrumentation in ultrafast laser technology, an emerging field in the physical sciences.

在该项目由化学部实验化学计划资助的项目中，David Blank将开发和应用新型的实验方法，旨在解决分子间和低频分子内核运动在凝结相反应性和非反应化学动力学中的作用。 这些实验利用多维飞秒光谱技术，可以根据每种互补信息分为两种类型。 首先，低频运动对解决方案中动态事件的进展的响应将通过使用超快激光脉冲进行照片来探测该事件，并使用三阶时域拉曼光谱法监测响应。 其次，将使用新的共振增强版本的相干二维时域拉曼光谱仪直接测量凝结系统中低频运动之间的耦合。 预计这些研究将使在溶液相化学反应中对低频运动的新见解。化学的显着比例（从工业反应到化学生物学的化学反应）发生在溶液阶段。 该项目旨在提供对溶液中化学反应性的微观描述，这是当今物理化学中的核心问题之一。 所提出的方法是直接的，通常适用的技术，将有助于理解所涉及的科学问题。 这项工作具有从现代光学和计量学到高级材料表征和冷凝物质的基础研究不等的应用。 作为这项研究工作的一部分，本科生到博士后一级的学生接受了超快激光技术的最新仪器，这是物理科学的新兴领域。