State-to-State Reaction Dynamics

在这个由化学系实验物理化学计划支持的项目中，斯坦福大学的Richard Zare将利用分子束和激光光谱方法获得关于基本气相和气体表面化学反应动力学的量子态特定信息。 实验将给出基本反应H + D2生成HD（v，J）+ D和Cl + HD（v=1）生成HCl（v，J）+ D或DCl（v，J）+ H产物的完整三维速度分布，测量分子光解离产生碎片的排列和取向;以及表征由气体-表面反应产生的产物的速度、散射角、内部量子态和偏振。 在这项工作中获得的信息使化学家能够更好地了解化学转化是如何发生的，通过提供详细的观察结果，可以与最佳理论计算的预测进行比较。 有了这样一个更好的理解，应该有可能设计化学反应，以得到更高产率的所需产品，从而减少分离和纯化反应产物所花费的时间，并减少整个过程中消耗的能量。 化学反应的详细知识对于理解大气过程也很重要，例如温室气体与光，其他气体和表面的相互作用。

In this project supported by the Experimental Physical Chemistry Program of the Chemistry Division, Richard Zare of Stanford University will obtain quantum-state-specific information on the dynamics of elementary gas-phase and gas-surface chemical reactions using molecular beam and laser spectroscopic methods. Experiments will povide the complete three-dimensional velocity distribution of products from the fundamental reactions H + D2 yield HD(v,J) + D and Cl + HD(v=1) yield HCl(v,J) + D or DCl(v,J) + H; measurement of alignment and orientation of fragments produced by molecular photodissociation; and characterization of speed, scattering angle, internal quantum state, and polarization of products produced by gas-surface reactions. The information obtained in this work enables chemists to understand better how chemical transformations occur by providing detailed observations that can be compared against the predictions of the best theoretical calculations. With such a better understanding it should be possible to engineer chemical reactions to give higher yields of desired products, resulting in less time spent separating and purifying reactions products and less energy expended in the entire process. A detailed knowledge of chemical reactions is also important in understanding atmospheric processes such as the interactions of greenhouse gases with light, other gases, and surfaces.