ISSN:
1573-0662
Keywords:
Alkoxy radicals
;
atmospheric chemistry
;
isomerization
;
decomposition
;
reaction with O2
Source:
Springer Online Journal Archives 1860-2000
Topics:
Chemistry and Pharmacology
,
Geosciences
Notes:
Abstract The reactions of alkoxy radicals determine to a large extent the products formed during the atmospheric degradations of emitted organic compounds. Experimental data concerning the decompositions, 1,5-H shift isomerizations and reactions with O2 of several classes of alkoxy radicals are inconsistent with literature estimations of their absolute or relative rate constants. An alternative, although empirical, method for assessing the relative importance under atmospheric conditions of the reactions of alkoxy radicals with O2 versus decomposition was derived. This estimation method utilizes the differences in the heats of reaction, Δ(ΔH)=(ΔHdecomposition−ΔHO 2 reaction), between these two reactions pathways. For Δ(ΔH)≲[22−0.5(ΔHO 2 reaction)], alkoxy radical decomposition dominates over the reaction with O2 at room temperature and atmospheric pressure of air, while for Δ(ΔH)≳[25-0.5(ΔHO 2 reaction)], the O2 reaction dominates over decomposition (where the units of ΔH are in kcal mol−1). The utility and shortcomings of this approach are discussed. It is concluded that further studies concerning the reactions of alkoxy radicals are needed.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00115973
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