Gas-phase rate constants for the reaction of NO3 radicals with selected oxiranes

The gas-phase reaction of NO3 radicals with selected oxiranes has been studied in a flow system at T = 295 +/- 2 K in the pressure range 3.4-50 mbar using N-2 as carrier gas. The analysis of the organics was performed by means of on-line connected GC-FID. Rate constants were obtained with the relative rate method: 3,4-epoxy-cyclohexene: (2.70 +/- 0.18) x 10(-13): 2,2-dimethyl-3-(2,2-dimethyl-vinyl)-oxirane: (4.74 +/- 0.54) x 10(-12); 2-methyl-2-(1-methyl-vinyl)-oxirane: (1.55 +/- 0.12) x 10(-13); 2-methyl-2-vinyloxirane: (9.40 +/- 2.62) x 10(-15); vinyloxirane: (6.15 +/- 1.94) x 10(-15); tetramethyloxirane: < 5 x 10(-15); and cis-2,3-dimethyloxirane: < 5 x 10(-15) cm(-3) molecule(-1) s(-1).