Kinetic study of the reactions of Br2 with OH and OD

The kinetics of the reactions OH + Br₂ → HOBr + Br (1) and OD + Br₂ → DOBr + Br (3) have been studied in the temperature range 230–360 K and at total pressure of 1 Torr of helium using the discharge‐flow mass spectrometric method. The following Arrhenius expressions were obtained either from the kinetics of product formation (HOBr, DOBr) in excess of Br₂ over OH and OD or from the kinetics of Br₂ consumption in excess of OH and OD: k₁ = (1.8 ± 0.3) × 10^?11 exp (235 ± 50)/T] and k₃ = (1.9 ± 0.2) × 10^?11 exp (220 ± 25)/T] cm³ molecule^?1 s^?1. For the reaction channels of the title reactions: OH + Br₂ → BrO + HBr and OD + Br₂ → BrO + DBr, the upper limits of the branching ratios were found to be 0.03 and 0.02 at T = 320 K, respectively. © 1999 John Wiley & Sons, Inc. Int J Chem Kinet 31: 698–704, 1999