A temperature-dependent kinetics study of the reaction of O(3PJ) with (CH3)2SO

✍ Scribed by F. D. Pope; J. M. Nicovich; P. H. Wine

• Publisher: John Wiley and Sons
• Year: 2002
• Tongue: English
• Weight: 155 KB
• Volume: 34
• Category: Article
• ISSN: 0538-8066
• DOI: 10.1002/kin.10040

✦ Synopsis

Abstract

A laser flash photolysis–resonance fluorescence technique has been employed to investigate the kinetics of the reaction of ground state oxygen atoms, O(^3^P~J~), with (CH~3~)~2~SO (dimethylsulfoxide) as a function of temperature (266–383 K) and pressure (20–100 Torr N~2~). The rate coefficient (k~R1~) for the O(^3^P~J~) + (CH~3~)~2~SO reaction is found to be independent of pressure and to increase with decreasing temperature. The following Arrhenius expression adequately describes the observed temperature dependence: k~R1~(T) = (1.68 ± 0.76) × 10~−12~ exp[(445 ± 141)/T] cm^3^ molecule^−1^ s^−1^, where the uncertainties in Arrhenius parameters are 2σ and represent precision only. The absolute accuracy of each measured rate coefficient is estimated to be ±30%, and is limited predominantly by the uncertainties in measured (CH~3~)~2~SO concentrations. The observed temperature and pressure dependencies suggest that, as in the case of O(^3^P~J~) reactions with CH~3~SH and (CH~3~)~2~S, reaction occurs by addition of O(^3^P~J~) to the sulfur atom followed by rapid fragmentation of the energized adduct to products. The O(^3^P~J~) + (CH~3~)~2~SO reaction is fast enough so that it could be a useful laboratory source of the CH~3~SO~2~ radical if this species is produced in significant yield. © 2002 Wiley Periodicals, Inc. Int J Chem Kinet 34: 156–161, 2002; DOI 10.1002/kin.10040