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.

Kinetic study of 2‐furanaldehyde, 3‐furanaldehyde, and 5‐methyl‐2‐furanaldehyde reactions initiated by Cl atoms

“…SPME has been applied in studies of atmospheric reactivity in two ways. It has been used as a preconcentration method during reaction product identification work 16, 21–23 and as a sampling tool in the kinetic studies in which the reactants have a low vapor pressures 24–28.…”

The Atmospheric Fate of C3−C6 Hydroxyalkyl Nitrates

“…The hydroxyalkyl nitrates, including double-bond hydroxyalkyl nitrates, were all (except 1OH6C 6 ) synthesized by selective nitration of the parent diols or epoxides. They were purified (>98%) and characterized according to the previously developed procedures. ,, 1OH6C 6 was synthesized by nitration of (iodohexoxy)- tert -butyldimethylsilane by silver nitrate . This reaction occurs via two steps: a replacement of the halogen atom by a nitrooxy group, while the tert -butyldimethylsilane tail blocks the hydroxy group.…”

“…Reactions with Cl Atoms. Reactions of hydroxyalkyl nitrates with Cl atoms, although fast, may not be globally important …”

“…To our knowledge, only the reaction of the OH radical with a β-type hydroxy cyclopentyl nitrate has so far been studied . In addition, the gas-phase kinetics of β-, γ-, and δ-hydroxyalkyl nitrates with Cl atoms have been reported …”

Reactivity of 2-ethyl-1-hexanol in the atmosphere

“…17 The application of SPME in the study of atmospheric reactivity has two uses: firstly, as a preconcentration method during identification of the reaction products [18][19][20][21] and secondly, to a lesser extent as a tool for sampling during the kinetic study of certain reactions. [22][23][24][25][26] The reaction sample was collected from the reactor by inserting the fiber (polymer mixture of divinylbenzene, carboxen and poly(dimethylsiloxane) (DVB/CAR/ PDMS), 50/30 mm SPME, SUPELCO) in the reactor, through a septum positioned at its centre. After optimization of the time, the fiber was exposed to the gas mixture for 15 min.…”