Atmospheric Chemistry of Dimethyl Sulfide: UV Spectra and Self-Reaction Kinetics of CH3SCH2 + O2 -> CH3SCH2O2 and CH3SCH2O2 + NO -> CH3SCH2O + NO2

Article abstract of DOI:10.1021/j100134a013

A pulse radiolysis technique has been used to measure the UV spectra of CH3SCH2 and CH3SCH2O2 radicals over the range 225-350 nm.At 285 nm, ?(CH3SCH2) = (9.8 +/- 1.7) X 10^-18; at 250 nm, ?(CH3SCH2O2) = (4.3 +/- 0.7) X 10^-18 cm² molecule^-1.Observed self-reaction rate constants, defined as -d/dt = 2k₆² and -d/dt = 2k_7obs², were k₆ = (3.0 +/- 0.6) X 10^-11 and k_7obs = (7.9 +/- 1.4) X 10^-12 cm³ molecule^-1 s^-1.Errors are statistical (2 standard deviations) plus our estimate of potential systematic uncertainty (15percent).A rate constant, k₂ = (5.7 +/- 0.4) X 10^-12 cm^-3 molecule^-1 s^-1, was derived for the addition reaction CH3SCH2 + O2 -> CH3SCH2O2.A rate constant, k₃ = (1.9 +/- 0.6) X 10^-11 cm³ molecule^-1 s^-1, is reported for the reaction of CH3SCH2O2 radicals with NO, producing NO2.Errors for k₂ and k₃ are 2 standard deviations.Results are discussed with respect to the atnospheric chemistry of dimethyl sulfide.