AAAR 32nd Annual Conference
September 30 - October 4, 2013
Oregon Convention Center
Portland, Oregon, USA
Abstract View
Aerosol Phase Chemistry of Isoprene Derived Epoxides Evaluated Using Density Functional Theory
IVAN PILETIC, Edward Edney, Libero Bartolotti, U.S. Environmental Protection Agency
Abstract Number: 534 Working Group: Aerosol Chemistry
Abstract Epoxides have been detected as important intermediates during atmospheric isoprene oxidation. Their subsequent reactions in the particle phase lead to the production of low volatility compounds detected in ambient aerosols. In this work, we apply density functional theory to computationally assess the reactivity of isoprene derived epoxides in the condensed phase. The M062x density functional and 6-311++G** basis set are applied to reacting molecular clusters in a dielectric continuum model to simulate the aerosol condensed phase. The relative barriers and energies of epoxide reactions such as hydrolysis, organosulfate formation, organonitrate formation and oligomerization are determined. In particular, the relative rates of 2-methyl-2,3-epoxybutane-1,4-diol (isoprene epoxide – IEPOX) and 2-methyl-2,3-epoxypropanoic acid (methacrylic acid epoxide - MAE) are discussed. Both epoxides are important in organic aerosol formation under low and high NOx conditions respectively.