Rate Coefficient Measurements for the CH₃SCH₂OO Radical + NO Reaction Between 313 and 413 K

ABSTRACT The CH 3 SCH 2 OO radical is a key intermediate formed in the gas‐phase oxidation of dimethyl sulfide (CH 3 SCH 3 , DMS). In this study, the rate coefficient, k 1 ( T ), for the gas‐phase CH 3 SCH 2 OO + NO reaction was measured using a pulsed laser photolysis–iodide chemical ionization mass spectrometry (CIMS) detection competitive reaction method over the temperature range 313–413 K. Hydroperoxymethyl thioformate (HOOCH 2 SCHO, HPMTF) formed following a H‐shift reaction of the CH 3 SCH 2 OO radical was monitored using CIMS as a function of added NO concentration. The k 1 ( T ) results are described by the Arrhenius expression k 1 (313–413 K) = (1.43 ± 0.29) × 10 −12 exp((510 ± 160)/ T ) cm 3 molecule −1 s −1 , where the quoted uncertainties are 2 σ and the pre‐exponential coefficient uncertainty includes estimated systematic errors. An extrapolation to room temperature yields k 1 (298 K) = 7.9 × 10 −12 cm 3 molecule −1 s −1 . Results from this study are compared with previous room temperature and temperature dependent (261–400 K) studies. The reaction rate coefficient obtained in this work is recommended for use in atmospheric chemistry and climate models.