Heterogeneous Chemistry of Halogen-, Nitrogen- and Sulfur-Containing Acids and Salts

9711970卡斯特尔曼该项目是对含有卤素、氮和硫分子的电解液系统进行研究，这些分子对大气很重要。本工作的重点是通过分子簇方法研究电解质在水体系中的吸收/溶解以及相关的气粒转化过程。对于与大气现象高度相关的一组较小的电解液体系，也将研究电解液体系的热化学和反应机理。重点将主要放在卤素(作为酸的形式)、卤素含氧酸和盐，以及由氮和硫酸盐化合物组成的一些相关的电解液种类。两种光谱方法将被用来研究与电解液溶解有关的过程：(1)溶剂化时的共振电子态能量变化；(2)光耗尽。这项研究将使用配备适当可调谐激光的飞行时间质谱仪系统。该项目的结果将提供关于通过分子聚集发生的相互竞争的化学和物理过程的相对重要性的新信息。这些非均匀过程对于理解极地平流层冰晶对大气分子的吸收，以及对于阐明发生在对流层低层的气体到粒子的转化机制具有潜在的重要意义。

9711970 Castleman The project is a study of electrolyte systems that contain halogens, nitrogen and sulfur molecules which are important to the atmosphere. The main focus of the work is to study the uptake/dissolution of electrolytes in aqueous systems and related gas-to-particle processes via a molecular cluster approach. The thermochemistry and reaction mechanisms of electrolyte systems will also be investigated for a smaller set of electrolyte systems which have high relevance to atmospheric phenomena. The main emphasis will be on halogens (as the acid forms), halogen oxyacids and salts, and on some related electrolyte species composed of nitrogen and sulfate compounds. Two spectroscopic approaches will be employed to study the processes associated with electrolyte dissolution: (1) resonant electronic state energy change upon solvation; and (2) photodepletion. A time-of-flight mass spectrometer system configured with appropriate tunable lasers will be used for the research. Results from the project will provide new information on the relative importance of competing chemical and physical processes that occur via molecular aggregation. These heterogeneous processes have potential importance for understanding the uptake of atmospheric molecules by polar stratospheric ice crystals, and for elucidating gas-to-particle conversion mechanisms that occur in the lower troposphere.