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.
