State Resolved Dynamics of Metal Atom-H2/CH4 Reactive Collisions

在化学系实验物理化学计划的这个项目中，爱荷华大学的P.Kleiber教授和K.Sando教授将继续他们使用半碰撞方法对状态分辨分子动力学的研究。为了研究非弹性(包括化学反应)碰撞，他们率先应用了被称为散射态光谱的技术。在这个项目中，他们将把这些实验扩展到金属原子与分子H2和CH4的碰撞。另一种新技术涉及“分数碰撞”，即使用轨道跟踪模型检测金属-离子/分子碰撞复合体中的散射共振。这些在某种程度上是互补的技术，有助于描述碰撞过程的不同方面。存在着碱性双原子分子光解的理论模型，但这些理论往往不能服从简单的物理解释，也不容易应用于复杂的解离过程。在目前感兴趣的一些情况下，例如超冷原子之间的碰撞，基本的物理学还没有被很好地理解，以至于无法自信地应用理论方法。这些关于激发态金属原子和分子在相对简单的体系中反应的实验结果将使理论动力学模型在应用于碰撞和光解动力学领域中更复杂的问题之前得到检验。实际应用包括更好地理解化学气相沉积过程。

In this project in the Experimental Physical Chemistry Program of the Chemistry Division, Professors P. Kleiber and K. Sando of the University of Iowa will continue their investigations of state-resolved molecular dynamics using `half-collision` methods. They pioneered the application of the technique known as scattering state spectroscopy in order to study inelastic (including chemically reactive) collisions. In this project they will extend these experiments to collisions of metal atoms with the molecules H2 and CH4. Another, new technique involves `fractional collisions,` in which scattering resonances in a metal-ion/molecule collision complex are detected using orbital-following models. These are somewhat complementary techniques which help describe different aspects of the collision process. %%% Theoretical models exist for the photodissociation of alkali diatomic molecules, but such theories are often not amenable to simple physical interpretation and can not easily be applied to complex dissociation processes. In some cases of current interest, such as collisions between ultra-cold atoms, the underlying physics is not understood well enough to allow application of theoretical methods with confidence. The results of these experiments on reactions between excited metal atoms and molecules in relatively simple systems will allow theoretical dynamical models to be tested before applying them to more complicated problems in the domain of collision and photodissociation dynamics. Practical applications include a better understanding of chemical vapor deposition processes