Gas-Phase Reactions of Brominated Diphenyl Ethers with OH Radicals
- 24 August 2006
- journal article
- research article
- Published by American Chemical Society (ACS) in The Journal of Physical Chemistry A
- Vol. 110 (37), 10783-10792
- https://doi.org/10.1021/jp0630222
Abstract
A small volume reaction chamber coupled to a mass spectrometer was used to study the gas-phase kinetics and mechanism of the reaction of OH radicals with diphenyl ether and seven polybrominated diphenyl ethers (PBDEs) with 1−2 bromines. Relative rate constants for these reactions were determined using isopropyl nitrite photolysis in He−air mixtures at ∼740 Torr between the temperatures of 326−388 K. The Arrhenius expression for each compound was used to extrapolate the following OH rate constants at 298 K (in units of 10-12 cm3 molecule-1 s-1, with 95% confidence intervals): diphenyl ether, 7.45 ± 0.13; 2-bromodiphenyl ether, 4.7 ; 3-bromodiphenyl ether, 4.6 ; 4-bromodiphenyl ether, 5.7 ; 2,2‘-dibromodiphenyl ether, 1.3 ; 2,4-dibromodiphenyl ether, 3.8 ; 3,3-dibromodiphenyl ether, 3.2 ; and 4,4‘-bromodiphenyl ether, 5.1 . The measured OH rate constants are in reasonable agreement with those predicted by structure activity relationships. Positive temperature dependences of these OH rate constants are observed for all compounds measured except for diphenyl ether and 4,4‘-dibromodiphenyl ether. Bromophenols (in yields up to 20% relative to the amount of PBDE consumed) and Br2 were characterized as products of these reactions, suggesting that OH addition to ipso positions of these brominated aryls may be an important reaction pathway.Keywords
This publication has 29 references indexed in Scilit:
- Gas-Phase Molecular Halogen Formation from NaCl and NaBr Aerosols: When Are Interface Reactions Important?The Journal of Physical Chemistry A, 2006
- UV absorption spectra of methyl-substituted hydroxy-cyclohexadienyl radicals in the gas phaseJournal of Photochemistry and Photobiology A: Chemistry, 2005
- Kinetic Studies on the Reactions of Hydroxyl Radicals with Cyclic Ethers and Aliphatic DiethersThe Journal of Physical Chemistry A, 2003
- Gas-phase reaction of OH radicals with phenolPhysical Chemistry Chemical Physics, 2003
- The heterogeneous hydrolysis of NO2 in laboratory systems and in outdoor and indoor atmospheres: An integrated mechanismPhysical Chemistry Chemical Physics, 2002
- On the Addition of •OH Radicals to the Ipso Positions of Alkyl-Substituted Aromatics: Production of 4-Hydroxy-4-methyl-2,5-cyclohexadien-1-one in the Radiolytic Oxidation of p-CresolThe Journal of Physical Chemistry A, 2002
- Kinetic study of hydroxyl reactions with perfluoropropene and perfluorobenzeneThe Journal of Physical Chemistry, 1993
- Rate constants for the addition of hydroxyl to aromatics (benzene, p-chloroaniline, and o-, m-, and p-dichlorobenzene and the unimolecular decay of the adduct. Kinetics into a quasi-equilibrium. Part 1The Journal of Physical Chemistry, 1983
- Model reactions for the metabolism of thyroxine. II. Reaction of thyropropionic acid with hydroxyl radicalThe Journal of Organic Chemistry, 1971
- Solvent Effects in the Reactions of Free Radicals and Atoms. II. Effects of Solvents on the Position of Attack of Chlorine Atoms upon 2,3-Dimethylbutane, Isobutane and 2-Deuterio-2-methylpropane1Journal of the American Chemical Society, 1958