Water Vapor Dependence of the Reaction Kinetics of the Methylperoxyl Radical with Hydroperoxyl and Itself

实验研究了甲基过氧基+过氧化氢(CH3O2+HO2)的反应动力学和甲基过氧基自反应随压力和水蒸气的变化。激光闪光光解/紫外时间分辨/近红外波长调制二极管激光光谱分析将被用来测量在一系列与大气相关的条件下(220-298K，50-760Torr)标题反应的动力学和产物。生成CH3O2-H2O络合物的平衡常数将在220-298K和50-760Torr的压力范围内测量。水对反应的依赖结果将被用来解决对流层上层HOx(OH、HO2和H2O2)和有机过氧化物的模型值和实测值之间的差异。此外，这项建议中的工作将产生关于水在大气中重要反应的动力学中所起作用的数据。对于理解水合CH3O2对大气的影响，关键是测量其在大气中的丰度；关于平衡常数的数据将有助于预测这种丰度。该项目将为研究生和本科生提供研究和培训机会。设计了气相动力学实验，并将其引入本科物理化学课程。

Experimental investigation of the kinetics of the methylperoxyl + hydoperoxyl (CH3O2 + HO2) and methylperoxyl self-reaction as a function of pressure and water vapor will be conducted. Laser Flash Photolysis/UV Time-Resolved/Near-IR Wavelength Modulated Diode Laser Spectroscopy will be utilized to measure the kinetics and products of the title reactions over a range of atmospherically relevant conditions (220-298 K, 50-760 Torr). The equilibrium constant for the formation of a CH3O2-H2O complex will be measured between 220 and 298 K and at pressures ranging between 50 and 760 Torr. Results of the water dependence on the reactions will be used to address discrepancies between modeled and measured values of HOx (OH, HO2 and H2O2) and organic peroxides in the upper troposphere. In addition, the work in this proposal will generate data about the role of water in the kinetics of atmospherically important reactions. Critical to the understanding of the atmospheric implications of hydrated CH3O2 is a measurement of its abundance in the atmosphere; data on the equilibrium constant will help to predict this abundance.This project will provide research and training opportunities for both graduate and undergraduate students. A gas phase kinetics experiment will be designed and introduced into the undergraduate physical chemistry curriculum.