Cinética de ozonólisis de una serie de aldehidos biogénicos en fase gaseosa a 298K y presión atmosférica

ELIZABETH GAONA COLMÁN, MARÍA B. BLANCO, IAN BARNES AND MARIANO A. TERUEL

Valparaiso

Jornada; XXII Jornadas de Jóvenes Investigadores de AUGM; 2014

Asociacion de Universidades del Grupo Montevideo

Rate coefficients for the reactions of ozone with the biogenic aldehydes trans-2-heptenal, trans-2-octenal and trans-2-nonenal have been determined at 298 K and (990  10) mbar of pressure in air in an environmental chamber using in situ FTIR spectroscopy to monitor the reactants. The following rate coefficients in units of kO3  1018 (cm3/molecule-1 s-1) were obtained: (2.47 ± 0.73) for trans-2-heptenal, (2.37 ± 0.68) for trans-2-octenal and (2.05 ± 0.20) for trans-2-nonenal. It is shown that rate coefficients for the addition of O3 molecules and OH radicals to the double bond of alkenes and unsaturated and oxygenated volatile organic compounds (OVOCs) at 298 K are related to a good approximation by the expression: log kOH = 0.16 log kO3 - 7.55. Furthermore, a correlation between the reactivity of unsaturated VOCs toward O3 molecules and the energies of the Highest Occupied Molecular Orbit (HOMO) of the unsaturated VOCs is presented and potential atmospheric implications of the results are discussed.