REACTION OF NO3 RADICALS WITH 2,3-DIMETHYLBUT-2-ENE, BUTA-1,3-DIENE AND 2,3-DIMETHYLBUTA-1,3-DIENE

The reactions of the NO3 radical with alkenes have been studied at 298K in a flow reactor coupled to a mass spectrometer. The reaction F + HNO3 was used as the source of NO3. The absolute determination of the rate constants yielded the following values: (4.5 +/- 0.4) x 10(-11), (9.7 +/- 0.4) x 10(-14), (1.96 +/- 0.20) x 10(-12) (cm3 molecule-1 s-1) for 2,3-dimethyl 2-butene, 1,3-butadiene and 2,3-dimethyl 1,3-butadiene, respectively. These data are compared with the literature values and show a reactivity trend which can be related to the structure of the molecules. Furthermore, the detection of primary products contributes to interprete the mechanisms of the nighttime atmospheric oxidation of the studied alkenes.