Estimation of Rate Constants for Gas-Phase Reactions of Chrysene, Benz[a]anthracene, and Benzanthrone with OH and NO3 Radicals via a Relative Rate Method in CCl4 Liquid Phase-System

CCl4 liquid-phase reaction kinetics of polycyclic aromatic compounds (PACs), including chrysene (CHRY), benz[a]anthracene (BaA), and benzanthrone (BA), with NO3 radicals were investigated at 273K using a relative rate method with naphthalene (NA) as the reference compound. The obtained relative reaction rates of CHRY, BaA, and BA to NA were 1.76 +/- 0.08, 2.27 +/- 0.20, 0.75 +/- 0.01, respectively. CHRY, BaA, and BA are semi-volatile PACs with four aromatic rings. They are chemically modified into mutagenic nitropolycyclic aromatic compounds via gas-phase OH or NO3 radical-initiated reactions. Based on the PACs relative reactivity in the CCl4 liquid phase-system, the rate constants at 298K for the gas-phase reaction of CHRY, BaA, and BA with OH radicals and those of CHRY, BaA, and BA with NO3 radicals were estimated to be (in cm(3)molecule(-1)s(-1)): CHRY, (4.4 +/- 0.3) x 10(-11) and (9.2 +/- 3.2) x 10(-28) [NO2]; BaA, (5.3 +/- 0.5) x 10(-11) and (1.3 +/- 0.5) x 10(-27) [NO2]; BA, (2.3 +/- 0.1) x 10(-11) and (3.1 +/- 1.1) x 10(-28) [NO2].