A relative rate study of the reaction of bromine atoms with a variety of organic compounds at 295 K

The relative rate technique has been used to determine rate constants for the reaction of bromine atoms with a variety of organic compounds. Decay rates of the organic species were measured relative to i ‐butane or acetaldehyde or both. Using rate constants of 1.74 × 10 −15 and 3.5 × 10 −12 cm 3 molecule −1 s −1 for the reaction of Br with i −butane and acetaldehyde respectively, the following rate constants were derived, in units of cm 3 molecule −1 s −1 : 2, 3−dimethylbutane, (6.40 ± 0.77) × 10 −15 ; cyclopentane, (1.16 ± 0.18) × 10 −15 , ethene, (≤2.3 × 10 −13 ); propene, (3.85 ± 0.41) × 10 −12 ; trans ‐2‐butene, (9.50 ± 0.76) × 10 −12 , acetylene, (5.15 ± 0.19) × 10 −15 ; and propionaldehyde, (9.73 ± 0.91) × 10 −12 . Quoted errors represent 2σ and do not include possible systematic errors due to errors in the reference rate constants. Experiments were performed at 295 ± 2 K and atmospheric pressure of synthetic air or nitrogen. The results are discussed with respect to the mechanisms of these reactions and their utility in serving as a laboratory source of alkyl and alkyl peroxy radicals.