Work

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

Year: 2025

Type: article

Abstract: ABSTRACT The CH3SCH2OO radical is a key intermediate formed in the gas‐phase oxidation of dimethyl sulfide (CH3SCH3, DMS). In this study, the rate coefficient, k1(T), for the gas‐phase CH3SCH2OO + 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 (HOOCH2SCHO, HPMTF) formed following a H‐shift reaction of the CH3SCH2OO radical was monitored using CIMS as a function of added NO concentration. The k1(T) results are described by the Arrhenius expression k1(313–413 K) = (1.43 ± 0.29) × 10−12 exp((510 ± 160)/T) cm3 molecule−1 s−1, where the quoted uncertainties are 2σ and the pre‐exponential coefficient uncertainty includes estimated systematic errors. An extrapolation to room temperature yields k1(298 K) = 7.9 × 10−12 cm3 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.

Source: International Journal of Chemical Kinetics

DOI: 10.1002/kin.21784

Authors: Zachary Finewax, Emmanuel Assaf, Andrew W. Rollins, James B. Burkholder

Institutions: National Oceanic and Atmospheric Administration, Cooperative Institute for Research in Environmental Sciences, University of Colorado Boulder, NOAA Chemical Sciences Laboratory

Language: English

Topic: Atmospheric chemistry and aerosols

Subfield: Atmospheric Science

Field: Earth and Planetary Sciences

Domain: Physical Sciences

Open Access status: hybrid

Estimated APC paid: $3,700

Funder: National Oceanic and Atmospheric Administration