Discharge flow-chemiluminescence study of the rate coefficients for O(3P) + CF2?CCl2 and O(3P) + CF3CF?CF2 reactions at 298 K

Abstract

The kinetics of the reactions O( 3 P) ϩ CF 2 "CCl 2 and O( 3 P) ϩ CF 3 CF "CF 2 were studied at room temperature in a discharge flow tube system. The overall rate constants based on the measured afterglow reactions were (3.10 Ϯ 0.40) ϫ 10 Ϫ13 and (3.00 Ϯ 0.60) ϫ 10 Ϫ14 cm 3 molecule Ϫ1 s Ϫ1 , respectively. The experiments were carried out under pseudo-first-order conditions with [O( 3 P)] 0 Ͻ Ͻ [alkene] 0 . These results are compared with previous relative measurements using different experimental techniques. The effect of substituent atoms or groups on the overall rate constants is analyzed in comparison with other alkenes in the literature.

Kinetics of the Reactions of O(3P) with CCl2CH2, (Z)-CHClCHCl, and CCl2CCl2: A Temperature Dependence Study

“…Detailed descriptions of the apparatus and the experimental methods used to measure the rate coefficients for the reactions of chloroethenes with O( 3 P) are given in previous papers; , therefore, only a brief description is presented here.…”

Absolute rate constants for the gas‐phase reactions of O(3P) atoms with CF2CFCl and (E/Z)‐CFClCFCl at 298 K. Reactivity trends of the halogen‐substituted ethenes series

“…As part of a systematic study of O( 3 P) atom reactivity and a prototype system for the addition reactions to the CC bond, we report in this work absolute rate constants for the reactions of O( 3 P) with the two title perhaloalkenes, measured in a conventional discharge flow tube apparatus at 298 K, as an extension of our earlier measurements of the rate coefficients for the reactions of O( 3 P) with CF 2 CCl 2 and CF 3 CFCF 2 10.…”

“…While there are many studies of O atom reactions with a variety of unsaturated hydrocarbons, only limited information is available for halogenated alkenes, most of which has been reviewed by Cvetanovic 1. The database for perhaloalkenes is even more scarce 2–7, and fluoroalkene reactivity studies toward O atoms are still less 8–11. Most of these studies have been relative measurements of the rate coefficients.…”

Transition-state-theory calculations for reactions of O(3P) with halogenated olefins

“…The absolute rate coefficients for the reactions of O( 3 P) with CF 2 QCCl 2 and CF 2 QCF-CF 3 , have been determined at 298 K using a discharge flow system. 8 The aim of the present paper is to assess, using a theoretical approach the effect of the substitution on the activation of the olefinic bond in the addition reaction. To this purpose we have investigated in detail the potential energy surfaces associated with these reactions using second-order Møller-Plesset perturbation theory (MP2), and the QCISD level of theory.…”

“…Finally the derived rate constants of this study are compared with the experimental values recommended by Cvetanovic 2 and those obtained in our laboratory. 8…”