Journal ArticleDOI
A temperature dependent kinetics study of the reaction of OH with CH3Cl, CH2Cl2, CHCl3, and CH3Br
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In this article, temperature dependent rate data for the reaction of OH with the partially halogenated methane species CH3Cl, CH2Cl2, CHCl3, and CH3Br were reported.Abstract:
Reported in this study are temperature dependent rate data for the reaction of OH with the partially halogenated methane species CH3Cl, CH2Cl2, CHCl3, and CH3Br. The nominal temperature range covered was 245–375 K. The appropriate Arrhenius expressions are kA= (1.84±0.18) ×10−12 exp[−(2181±70/RT)], kB= (4.27±0.63) ×10−12 exp[−(2174±161/RT)], kC= (4.69±0.71) ×10−12 exp[(2254±214/RT)], kD= (7.93±0.79) ×10−13 exp[−(1766±116/RT)]. Units are cm3 molecule−1⋅s−1. No simple correlations between Eact and C–H bond strengths were found. The impact of these halogenated species on stratospheric ozone is also discussed.read more
Citations
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The stratosphere: Present and future
R. D. Hudson,E. I. Reed +1 more
TL;DR: In this paper, the three basic elements of stratospheric science-laboratory measurements, atmospheric observations, and theoretical studies are presented along with an attempt to predict, with reasonable confidence, the effect on ozone of particular anthropogenic sources of pollution.
Journal ArticleDOI
Atmospheric lifetimes and ozone depletion potentials of methyl bromide (CH3Br) and dibromomethane (CH2Br2)
Abdelwahid Mellouki,Ranajit K. Talukdar,A. M. Schmoltner,Tomasz Gierczak,Michael J. Mills,Susan Solomon,A. R. Ravishankara +6 more
TL;DR: In this article, the rate coefficients for the reactions of OH radical with CH3Br and CH2Br2 were measured as functions of temperature using the laser photolysis - laser induced fluorescence method.
Journal ArticleDOI
Predicting gas phase organic molecule reaction rates using linear free-energy correlations. I. O(3P) and OH addition and abstraction reactions
J. S. Gaffney,S. Z. Levine +1 more
TL;DR: In this article, linear free energy (LFE) correlations for gas phase O(3P) and abstraction reactions with a number of organic compounds have been established using existing room-temperature rate constants evaluated from the literature.
Journal ArticleDOI
Methyl chloride in the stratosphere
TL;DR: The only natural chlorine containing compound which is likely to enter the stratosphere at significant concentrations is methyl chloride and it is therefore important that its profile be measured and compared with a computed profile to ascertain the likely impact on the ozone layer of naturally occurring chlorine.
References
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Journal ArticleDOI
The chemistry of atmospheric bromine
TL;DR: The lower atmosphere contains small concentrations of gaseous bromine produced in part by marine activity and volatilization of particulate material released during the combustion of leaded gasoline, with an additional contribution due to the use of methyl bromide as an agricultural fumigant as mentioned in this paper.
Journal ArticleDOI
Rate constants for the reactions of OH with CH4 and fluorine, chlorine, and bromine substituted methanes at 296 K
Carleton J. Howard,K. M. Evenson +1 more
TL;DR: The absolute rate constants for the reactions of OH radicals with CH4 and fifteen fluorine, chlorine, and bromine substituted methane molecules have been measured using a discharge flow system and laser magnetic resonance detection of OH as mentioned in this paper.
Journal ArticleDOI
Flash photolysis‐resonance fluorescence kinetics study: Temperature dependence of the reactions OH + CO → CO2 + H and OH + CH4 → H2O + CH3
TL;DR: In this paper, the activation energies reported for both processes, virtually zero for Reaction (1) and 3400 cal mol−1 for Reaction(2), are incompatible with those same quantities previously reported at elevated temperatures and indicate either nonlinear Arrhenius behavior for these reactions or possibly errors in experimental measurements.
Journal ArticleDOI
Absolute rate constants for elementary reactions in the chlorination of CH4, CD4, CH3Cl, CH2Cl2, CHCl3, CDCl3 and CBrCl3
TL;DR: In this article, the rates of reactions of Cl2P atoms with methane, and with a series of substituted methanes, have been measured using mass spectrometric analysis of molecular reactant consumption in the presence of excess Cl atoms, with pseudo first order kinetic analysis; this approach minimizes secondary reactions and the problem of reaction stoichiometries.
Journal ArticleDOI
Estimate of late 1974 stratospheric concentration of gaseous chlorine compounds (ClX)
TL;DR: In this article, the predicted present stratospheric concentrations are due to photolysis near 30 km of man-made CF2Cl2 and CFCl3, and CCl4 from a ground-level source, either manmade or natural.
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Rate constants for the reactions of OH with CH4 and fluorine, chlorine, and bromine substituted methanes at 296 K
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