“Autoxidation of Organic Compounds in the Atmosphere”
Paul Wennberg, R. Stanton Avery Professor of Atmospheric Chemistry and Environmental Science and Engineering
Caltech
MONDAY, May 7
3:30pm / Olin 149
Gas-phase autoxidation — regenerative peroxy radical formation following intramolecular hydrogen shifts — is known to be important in the combustion of organic materials. The relevance of this chemistry for atmospheric oxidation has received less attention due, in part, to the lack of kinetic data at relevant temperatures. I describe computational and experimental approaches to investigate the rate of autoxidation for organic peroxy radicals (RO2) produced in the oxidation of typical organic compounds found in the atmosphere. We find that autoxidation pathways are competitive against bimolecular reactions for a broad range of substrates, including many that result from urban emissions. This chemistry can efficiently generate highly oxidized organic molecules known to contribute to particle formation and growth. The formation of organic hydroperoxides from atmospheric autoxidation has unknown implications for air quality.