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Hydroperoxyl radical (HO 2 • ) oxidizes dibromide radical anion ( • Br 2 − ) to bromine (Br 2 ) in aqueous solution: Implications for the formation of Br 2 in the marine boundary layer
Author(s) -
Matthew Brendan M.,
George Ingrid,
Anastasio Cort
Publication year - 2003
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2003gl018572
Subject(s) - bromine , bromide , hydroperoxyl , chemistry , aqueous solution , hydroxyl radical , inorganic chemistry , halogen , radical , photochemistry , organic chemistry , alkyl
The release of photoactive halogen species such as Br 2 from sea‐salt particles, snowpack, and sea‐ice can have significant effects on chemistry in the marine boundary layer (MBL). Although the reaction of hydroperoxyl radical (HO 2 • ) with dibromide radical anion ( • Br 2 − ) might be a key step in the formation and release of Br 2 , there is currently no consensus on whether this reaction produces bromide (Br − ) or molecular bromine (Br 2 ). To address this question, we measured the formation of gaseous and aqueous oxidized bromide (primarily Br 2 ) in illuminated bromide solutions as a function of pH. Results from these two sets of experimental data are best explained by kinetic models where HO 2 • oxidizes • Br 2 − to Br 2 . Using this reaction in a simple aerosol model reveals that the hydroxyl radical‐induced oxidation of particulate bromide, followed by reaction of • Br 2 − with HO 2 • , could be an important source of Br 2 in the MBL.