ABSTRACT The mass spectrometric discharge-flow method has been used to investigate the reactions of Cl atoms and ClO radicals with different naturally emitted sulphur compounds, dimethyl sulphide (CH3SCH3), dimethylsulphoxide (CH3SOCH3) and different thiols (CH3CH2SH, CH3CH2CH2SH and (CH3)2CHSH). The absolute rate constants have been measured at different temperatures and at low total pressure. The mechanism and products of the reactions have been studied and discussed in order to establish the possible channels. At one Torr of total pressure, reactions of DMS and thiols with Cl have been found to undergo abstraction while the reaction of Cl atoms with DMSO proceeds through addition. The results obtained are related to previous studies of sulphur compounds, and the atmospheric implications are also discussed in relation to the homogeneous sinks of these sulphur compounds. All the reactions of Cl atoms may significantly contribute to the tropospheric chemistry of the studied reduced sulphur compounds.
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