A Theoretical Study of Dynamics at the Transition State of Gas Phase Chemical Reactions

气相化学反应过渡态动力学的理论研究

• 批准号: 9321543
• 负责人: Rex Skodje
• 金额: $ 19万
• 依托单位: University of Colorado at Boulder
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1994
• 资助国家: 美国
• 起止时间: 1994-04-01 至 1997-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9321543&HistoricalAwards=false
• 关键词: Theoretical; Study; Dynamics; Transition; State

This research, funded by the NSF Theoretical and Computational Chemistry Program, treats two topics in the theory of state-to-state reaction dynamics. First, hydrogen atom exchange in heavy-light-heavy-atom systems is treated by quantum or semi-classical (phase space) dynamics. Second, scattering resonances will be computed by Fourier analysis of high energy quantum wavepackets evolving in the transition state region. A complex gas phase reaction consists of many elementary steps such as O+HCl = OH+Cl occurring sequentially or in parallel. The first research topic is the development of mathematical methods for predicting the rate of such an elementary reaction, in particular, one involving the transfer of a hydrogen atom from one heavy atom to another. The theory treats the dependence of the reaction rate upon the initial relative translational energy of the reactants and the vibrational and rotational quantum states of the reactants and products. In the course of a chemical reaction the molecular system usually passes through a high energy configuration known as the transition state. The second research topic attempts to follow the behavior of a molecular system which starts out in the transition state region. One way to prepare molecules in this initial condition in the laboratory is to first generate a stable negative complex ion having (approximately) the appropriate geometry, and then suddenly remove one electron by laser excitation (photodetachment). One goal of this research project is to develop the theory of these photodetachment experiments.

这项研究由美国国家科学基金会理论和计算化学项目资助，研究了态间反应动力学理论中的两个主题。 首先，重-轻-重原子系统中的氢原子交换是通过量子或半经典（相空间）动力学来处理的。 其次，将通过对过渡态区域中演化的高能量子波包进行傅立叶分析来计算散射共振。 复杂的气相反应由许多基本步骤组成，例如依次或并行发生的 O+HCl = OH+Cl。第一个研究课题是开发预测此类基元反应速率的数学方法，特别是涉及氢原子从一个重原子转移到另一个重原子的反应。 该理论讨论了反应速率对反应物初始相对平移能量以及反应物和产物的振动和旋转量子态的依赖性。 在化学反应过程中，分子系统通常会经历称为过渡态的高能构型。 第二个研究课题试图追踪从过渡态区域开始的分子系统的行为。 在实验室中在此初始条件下制备分子的一种方法是首先生成具有（大约）适当几何形状的稳定负配离子，然后通过激光激发（光分离）突然去除一个电子。 该研究项目的目标之一是发展这些光脱离实验的理论。