Toward a Molecular Understanding of Quantum Chemical Dynamics in Solution

溶液中量子化学动力学的分子理解

基本信息

批准号：
9908772
负责人：
Paul Barbara
金额：
$ 28万
依托单位：
University of Texas at Austin
依托单位国家：
美国
项目类别：
Continuing Grant
财政年份：
1999
资助国家：
美国
起止时间：
1999-08-01 至 2001-07-31
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=9908772&HistoricalAwards=false
关键词：
Toward Molecular Understanding Quantum Chemical

项目摘要

Paul Barbara of the University of Texas is supported by a grant from the Theoretical and Computational Chemistry Program to continue his theoretical and experimental research directed at understanding quantum chemical dynamics in solution. Using femtosecond pump-probe optical spectroscopy as an experimental tool Barbara will study: 1) electronically nonadiabatic transitions in symmetric and asymmetric metal-metal intervalence compounds; 2) electronically nonadiabatic transitions in the one and two photon ionization of aqueous iodide solution and the two photon ionization of water; 3) vibrationally nonadiabatic transitions in the photodissociation, recombination, and the vibrational relaxation of small strongly solvated radicals with high frequency vibrations; and 4) the putative long-range coherent electron transfer between metallointercalators in DNA. Theoretical studies are also proposed of current quantum theoretical models for electron transfer and vibrational relaxation.Since many commercially important chemical reactions take place in polar solvents such as water, it is important to understand the influence which such solvents have on the reaction dynamics. A number of effects, such as solvent cage effects, vibrational relaxation and quantum mechanical tunneling, which are not present in the gas phase completely dominate condensed phase chemical reactions. It is important to develop reliable theories for model chemical systems which can then be applied to improving the efficiency of commercially important chemical reactions. The work which is being performed by Barbara provides an important experimental basis for the development of such theories.

德克萨斯大学的保罗·芭芭拉 (Paul Barbara) 得到了理论和计算化学项目的资助，继续他的理论和实验研究，旨在理解溶液中的量子化学动力学。使用飞秒泵浦探针光谱作为实验工具，芭芭拉将研究：1）对称和不对称金属-金属间隔化合物中的电子非绝热跃迁； 2)碘化物水溶液的一光子电离和二光子电离以及水的二光子电离中的电子非绝热跃迁； 3) 高频振动的小强溶剂化自由基的光解离、重组和振动弛豫中的振动非绝热跃迁； 4) DNA 中金属嵌入剂之间假定的长程相干电子转移。还提出了当前电子转移和振动弛豫量子理论模型的理论研究。由于许多商业上重要的化学反应发生在极性溶剂（例如水）中，因此了解此类溶剂对反应动力学的影响非常重要。许多在气相中不存在的效应，如溶剂笼效应、振动弛豫和量子力学隧道效应，完全主导了凝聚相化学反应。为模型化学系统开发可靠的理论非常重要，然后可以将其应用于提高商业上重要的化学反应的效率。芭芭拉正在进行的工作为此类理论的发展提供了重要的实验基础。