Temperature-dependent kinetics study of the gas-phase reactions of atomic chlorine with acetone, 2-butanone, and 3-pentanone

✍ Scribed by Z. Zhao; D. T. Huskey; J. M. Nicovich; P. H. Wine

• Publisher: John Wiley and Sons
• Year: 2008
• Tongue: English
• Weight: 223 KB
• Volume: 40
• Category: Article
• ISSN: 0538-8066
• DOI: 10.1002/kin.20321

✦ Synopsis

Abstract

A laser flash photolysis–resonance fluorescence technique has been employed to study the kinetics of the reactions of atomic chlorine with acetone (CH~3~C(O)CH~3~; k~1~), 2‐butanone (C~2~H~5~C(O)CH~3~; k~2~), and 3‐pentanone (C~2~H~5~C(O)C~2~H~5~; k~3~) as a function of temperature (210–440 K) and pressure (30–300 Torr N~2~). No significant pressure dependence is observed for any of the reactions studied. Arrhenius expressions (units are 10^−11^ cm^3^ molecule^−1^ s^−1^) obtained from the data are k~1~(T) = (1.53 ± 0.19) exp[(−594 ± 33)/T], k~2~(T) = (2.77 ± 0.33) exp[(+76 ± 33)/T], and k~3~(T) = (5.66 ± 0.41) exp[(+87 ± 22)/T], where uncertainties are 2σ and represent precision only. The accuracy of reported rate coefficients is estimated to be ±15% over the entire range of pressure and temperature investigated. The room temperature rate coefficients reported in this study are in good agreement with a majority of literature values. However, the activation energies reported in this study are in poor agreement with the literature values, particularly for 2‐butanone and 3‐pentanone. Possible explanations for discrepancies in published kinetic parameters are proposed, and the potential role of Cl + ketone reactions in atmospheric chemistry is discussed. © 2008 Wiley Periodicals, Inc. Int J Chem Kinet 40: 259–267, 2008