Author(s)

E. Bolzacchini, M. Bruschi, J. Hjorth, S. Meinardi, M. Orlandi, G. Restelli & B. Rindone

Abstract

Tropospheric chemistry of aromatic compounds: Evidence for a rate-determining addition of NOg and OH to substituted toluenes E. Bolzacchini*, M. Bruschi*, J. Hjorth\ S. Meinardi\ M. Orlandi*, G. Restelli*, B. Rindone* ^Dipartimento di Scienze dell'Ambiente e del Territorio, Universita' di Milano, Via Emanueli, 15, 1-20126 Milano, Italy, e-mail: rindone@alpha.disat.unimi.it; ^Commission of the European Communities, Joint Research Centre, Environment Institute, 21020 Ispra (VA), Italy, e-mail: jens.hjorth@jrc.it. Abstract The OH- and the NOs-initiated oxidation of aromatic hydrocarbons are major sinks for these species, observed in high concentrations in urban areas. This demands a better knowledge of mechanisms and reaction products. The plot of log k (six compounds) for para-substituted toluenes vs Hammett's p for the reaction with OH has a p = - 2.3 ± 0.2; r% = 0.96. This is in line with the known rate-determining addition of OH involving a polar transition state.

Keywords