Atmospheric chemistry of CH2BrCl, CHBrCl2, CHBr2Cl, CF3CHBrCl, and CBr2Cl2

Relative-rate methods were used to measure the following rate constants at 296 K in 700 Torr of N-2, O-2, or air diluent (all cm(3) molecule(-1) s(-1)): K(OH + CHBrCl2) = (1.2 +/- 0.3) x 10(-13), k(OH + CH2BrCl) = (1.2 +/- 0.3) x 10(-13), k(Cl + CHBr2Cl) = (2.2 +/- 0.6) x 10(-13), k(Cl + CBr2Cl2) = (1.8 +/- 0.4) x 10(-13), k(CI + CBrCl3) = (7.1 +/- 0.9) x 10(-14), and k(Cl + CF3CHBrCl) = (2.0 +/- 0.3) x 10(-14). Over the temperature range 217-296 k(Cl + CHBrCl2) = (2.6 +/- 0.4) x 10(-12) exp(-852 +/- 76/T) and k(Cl + CH2BrCl) = (1.2 +/- 0.2) x 10(-11) exp(-1000 +/- 82/T) cm(3) molecule(-1) s(-1) were found. The UV absorption spectra of CHBrCl2, CF3CHBrCl, and CHBr2Cl were measured at temperatures between 223 and 298 K over the range 210-320 nm, The products of Cl-atom-initiated oxidation of CHBrCl2, CBr2Cl2 CHBr2Cl, and CF3CHBrCl were determined using FTIR smog-chamber techniques. Reaction of Cl atoms with CHBrCl2, CHBr2Cl, and CF3CHBrCl proceeds via hydrogen abstraction. Reaction of Cl atoms with CHBr2Cl2 and CBrCl3 occurs via bromine abstraction. Product studies of the Cl-initiated oxidation of CHBrCl2 and CBr2Cl2 conducted with, and without, added NO showed strong evidence for the production of chemically activated alkoxy radicals in the reaction of CBrCl2O2 radicals with NO. These results are discussed with respect to the atmospheric chemistry of CH2BrCl, CHBrCl2, CHBr2Cl, CBr2Cl2, CF3CHBrCl, and other brominated organic compounds.