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Kinetic and mechanistic study of the X and XO (X = Cl, Br) reactions with dimethyl sulfoxide

“…The value of the rate constant measured with three different references (ethene, toluene, p-xylene) varied between 1.4 and 4.5 Â 10 À14 cm 3 molecule À1 s À1 and the mean value of k 2 ¼ (2.4 AE 1.6) Â 10 À14 cm 3 molecule À1 s À1 was finally recommended. This latter value is a factor two higher than that measured in the present study, although the two measurements agree if the rather high uncertainty reported in 17 is considered. Among the final sulfur containing products of the Br initiated oxidation of DMSO Ballesteros et al 17 identified CH 3 SO 2 Br as the main product and DMSO 2 with a yield of 4%.…”

“…In the unique previous study 17 the rate constant of reaction (2) was measured in a photoreactor at 740 Torr of synthetic air and T ¼ 296 K, using a relative rate method. The value of the rate constant measured with three different references (ethene, toluene, p-xylene) varied between 1.4 and 4.5 Â 10 À14 cm 3 molecule À1 s À1 and the mean value of k 2 ¼ (2.4 AE 1.6) Â 10 À14 cm 3 molecule À1 s À1 was finally recommended.…”

“…[14][15][16] The values of the reaction rate constant obtained in two smog chamber studies 14,15 at one atmosphere pressure of air are in good agreement, whereas a value lower by a factor four at P ¼ 0.5-3.0 Torr was recently reported by Martı ´nez et al 16 Barnes et al 14 and Falbe-Hansen et al 15 have quantified the final reaction products, SO 2 and DMSO 2 , while Martı ´nez et al 16 report qualitative detection of the reaction adduct CH 3 SO(Cl)CH 3 and the absence of HCl among the reaction products. The reactions of Br atoms and BrO radicals with DMSO have been investigated only in one work, 17 where the rate constants have been determined at P ¼ 740 Torr by the relative rate method. For the reaction of ClO radicals with DMSO the only study 16 reports an upper limit of 6 Â 10 À14 cm 3 molecule À1 s À1 .…”

A systematic computational study on the reactions of dimethyl sulfoxide with XO (X=NO2, Cl, Br and I)

“…Martí-nez et al [14] and Riffault et al [15] recommended a upper rate constant of k ClO+DMSO < 6 Â 10 À14 and 1.6 Â 10 À14 cm 3 molecule À1 s À1 . Ballesteros et al [16] found a close unity yield of DMSO 2 in the reaction of DMSO + BrO, which suggested the reaction mechanism is similar to that of DMS + Br reaction. There is no information is available in the literature on the reaction DMSO + IO.…”

Theoretical study on the Br + CH3SCH3 reaction

“…A few experimental kinetic studies have been performed on reaction of DMS with Br atom at the 298 K and in the temperature range of 386–604 K. In a mechanism view, three channels are available for the title reaction, i.e., At 298 K, the relative overall rate constants are obtained by Ballesteros et al13 and Maurer et al14 However, only upper limit value, k ≤ 1 × 10 −13 cm 3 /(molecule s), was presented by Maurer et al14 The total rate–temperature expression of k = (9.0 ± 2.9) × 10 −11 exp[(−2386 ± 151)/ T ] cm 3 /(molecule s) over the temperature range 386–604 K was presented by Jefferson et al15 These experimental values agree well with each other in the common temperature.…”