Kinetics and mechanisms of the gas phase reactions of the NO3 radical with a series of reduced sulfur compounds

Abstract

The gas phase reactions of the NO3 radical, a ubiquitous constituent of nighttime atmospheres with the reduced sulfur compounds COS, CS2, CH3SH, C2H5SH, and CH3SSCH3 have been investigated. Using a relative rate technique and long path length Fourier transform infrared (FT‐IR) absorption spectroscopy, rate constants for these reactions have been determined at 297 ± 2 K in one atmosphere of air. The resulting rate constants (in units of 10−13 cm3 molecule−1 s−1) are: COS, <0.0004; CS2, <0.008; CH3SH, 10 ± 3; C2H5SH, 12 ± 3; and CH3SSCH3, 0.42 ± 0.09. A number of products from these reactions were determined using FT‐IR absorption spectroscopy and combined gas chromatography/mass spectrometry. Atmospheric implications of these kinetic and product data are discussed.