Reaction between CH3O2 and BrO radicals: a new source of upper troposphere lower stratosphere hydroxyl radicals.

Over the last two decades it has emerged that measured hydroxyl radical levels in the upper troposphere are often underestimated by models, leading to the assertion that there are missing sources. Here we report laboratory studies of the kinetics and products of the reaction between CH3O2 and BrO radicals that shows that this could be an important new source of hydroxyl radicals:BrO + CH3O2 → products (1). The temperature dependent value in Arrhenius form of k(T) is k1 = (2.

Temperature and pressure dependence of the rate coefficient for the reaction between ClO and CH3O2 in the gas-phase.

A temperature and pressure kinetic study for the CH(3)O(2) + ClO reaction has been performed using the turbulent flow technique with a chemical ionisation mass spectrometry detection system. An Arrhenius expression was obtained for the overall rate coefficient of CH(3)O(2) + ClO reaction: k(10)(T) = (1.96(−0.

Structure-activity relationship (SAR) for the prediction of gas-phase ozonolysis rate coefficients: an extension towards heteroatomic unsaturated species.

Heteroatomic unsaturated volatile organic compounds (HUVOCs) are common trace components of the atmosphere, yet their diverse chemical behaviour presents difficulties for predicting their oxidation kinetics using structure-activity relationships (SARs). An existing SAR is adapted to help meet this challenge, enabling the prediction of ozonolysis rates with unprecedented accuracy. The new SAR index, x(H), correlates strongly with available literature measurements of ozonolysis rate coefficients (R(2) = 0.

Temperature-dependent ozonolysis kinetics of selected alkenes in the gas phase: an experimental and structure-activity relationship (SAR) study.

The kinetics of the reactions of ozone with several alkenes have been measured at atmospheric pressure between 217 and 301 K using EXTRA (EXTreme RAnge chamber). This work represents the first kinetic determinations of the system and focuses on the temperature-dependence of alkene ozonolysis, which is an important tropospheric process impacting upon climate and human health, yet few studies have investigated these reactions as a function of temperature. Temperature-dependent rate coefficients have been established for 3,3-dimethyl-1-butene, 2,4,4-trimethyl-1-pentene and 4-methyl-1-pentene at 217-301 K and atmospheric pressure.