Reactions of alkoxy radicals under atmospheric conditions: The relative importance of decomposition versus reaction with O2

✍ Scribed by Roger Atkinson; William P. L. Carter

• Book ID: 104626555
• Publisher: Springer Netherlands
• Year: 1991
• Tongue: English
• Weight: 890 KB
• Volume: 13
• Category: Article
• ISSN: 0167-7764
• DOI: 10.1007/bf00115973

✦ Synopsis

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 O 2 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 02 versus decomposition was derived. This estimation method utilizes the differences in the heats of reaction, A(AH) = (AH d .... position -AHo,,,actioo), between these two reactions pathways. For A(AH)~ [22-0.5(AHo ...... io,)], alkoxy radical decomposition dominates over the reaction with 02 at room temperature and atmospheric pressure of air, while for A(AH) -> [25 --0.5(AH O .... tion)], the 02 reaction dominates over decomposition (where the units of AH are in kcal mol-t). The utility and shortcomings of this approach are discussed. It is concluded that further studies concerning the reactions of alkoxy radicals are needed.