Competitive Reaction Pathways

实验物理化学项目支持南加州大学的Curt Wittig继续进行光诱导反应的研究。他将着重于两组实验：(a)二聚体受限几何结构下的反应和(b)阈值下的单分子反应速率。在前者中，他将使用双共振技术来选择簇大小。将选择团簇的旋转分辨状态，并询问它们的光化学性质。Wittig将研究HF-HCl、HCl- hf和HCl二聚体及其氘化类似物中的氢交换反应和非弹性散射。第二组研究将集中于二氧化氮、高碳水化合物、水和氟化氢。这些研究的一个潜在主题是通过提供基准数据来挑战理论建模。因此，在某些情况下，需要重新考虑伴生气相过程的现有模型。在其他情况下，研究系统的动力学被认为是已知的伴生气相过程。在这里进行的聚类实验将显示归因于受限入口通道的影响，即由于聚类几何形状的影响。这样的工作开始以高精度弥合气相和凝聚相之间的差距，同样是在实验基准上，尽管是在既不是凝聚相也不是气相的微观世界中。因此，这些研究结果将对提高我们对反应动力学的认识和理解产生非常重要的影响。

The Experimental Physical Chemistry Program supports Curt Wittig of the University of Southern California in his continuing studies of photoinduced reactions. He will focus on two sets of experiments: (a) reactions in the restricted geometries of dimers and (b) unimolecular reaction rates at threshold. In the former, he will use double resonance techniques for cluster size selection. Rotationally resolved states of clusters will be selected and their photochemistries interrogated. Wittig will study the hydrogen exchange reaction and inelastic scattering in HF-HCl, HCl-HF and HCl dimer and its deuterated analogs. The second set of studies will focus on nitrogen dioxide, HNCO, water and HF. An underlying theme of these studies is to challenge theoretical modeling by providing benchmark data. Thus, in some cases, existing models of the associated gas phase phase processes will need to be reconsidered. In other cases, systems are studied for which the dynamics are believed to be known for the associated gas phase processes. The cluster experiments to be carried out here will then display effects attributable to the restricted entrance channel, i.e., effects due to the geometry of the cluster. Such work starts to bridge the gap between the gaseous and condensed phases at a high level of precision, again with experimental benchmarks, albeit in a microcosm that is neither the condensed nor gas phase. Results from these investigations will thus have a very significant impact in advancing our knowledge and understanding in reaction dynamics.