Rate Coefficients for the Reactions of Cl Atoms with a Series of C3−C6 Hydroxyalkyl Nitrates at 296 ± 2 K

Abstract

Rate coefficients for the gas-phase reactions of chlorine atoms with a series of C3−C6 hydroxyalkyl nitrates of atmospheric interest have been determined at 296 ± 2 K and atmospheric pressure. The experiments were conducted using the relative rate technique combined with solid-phase microextraction (SPME) sampling followed by gas chromatography (GC) analysis with an electron capture detector (ECD). The experiments were performed in a collapsible 100 L PVF-film (Tedlar) reaction chamber. It is shown that the presence of the hydroxy group enhances the reactivity of the hydroxyalkyl nitrates toward the Cl atom as compared to the corresponding alkyl nitrates and alkyl dinitrates. The Cl atom reactivity toward the hydroxyalkyl nitrates increases with the length of the alkyl chain and with increasing separation between the hydroxy and the nitrooxy groups. Tropospheric lifetimes are calculated using the determined rate coefficients and the atmospheric implications are briefly discussed.