Rate Coefficients for the Gas‐Phase Reactions of Chlorine Atoms with Cyclic Ethers at 298 K

Abstract

Rate coefficients of reactions of Cl atoms with cyclic ethers, tetrahydropyran (THP), tetrahydrofuran (THF), and dihydrofurans (2,5-DHF and 2,3-DHF) have been measured at 298 K using a relative rate method. The relative rate ratios for THP and THF are 0.80 ± 0.05 and 0.80 ± 0.08, respectively, with n-hexane as the reference molecule. The relative rate ratios for THF and 2,5-DHF with n-pentane as the reference molecule are 0.95 ± 0.07 and 1.73 ± 0.06, respectively, and for 2,5-DHF with 1-butene as reference is 1.38 ± 0.05. The average values of the rate coefficients are (2.52 ± 0.36), (2.50 ± 0.39), and (4.48 ± 0.59) × 10 −10 cm 3 molecule −1 s −1 for THP, THF, and 2,5-DHF, respectively. The errors quoted here for relative rate ratios are 2σ of the statistical variation in different sets of experiments. These errors, combined with the reported errors of the reference rate coefficients using the statistical error propagation equation, are the quoted errors for the rate coefficients. In the case of 2,3-DHF, after correcting for the dark reaction with CH 3 COCl and assuming no interference from other radical reactions, a relative rate ratio of 0.85 ± 0.16 is obtained with respect to cycloheptene, corresponding to a rate coefficient of (4.52 ± 0.99) × 10 −10 cm 3 molecule −1 s −1 . Unlike cyclic hydrocarbons, there is no increase with increasing number of CH 2 groups in these cyclic ethers whereas there is an increase in the rate coefficient with unsaturation in the ring. An attempt is also made to correlate the rate coefficients of cyclic hydrocarbons and ethers with the molecular size as well as HOMO energy. C 2013 Wiley Periodicals, Inc. Int J Chem Kinet 45: [295][296][297][298][299][300][301][302][303][304][305] 2013

Experimental study of the kinetics of reaction of chlorine atoms with tetrahydrofuran and fully deuterated tetrahydrofuran

“…5,6 The kinetics of the reaction of THF with chlorine atoms, for which the overall rate constant for H atoms abstraction, is designated as k H THF + Cl → Product (1) was the subject of two experimental studies. 7,8 Giri and Roscoe 7 studied the reaction of Cl + THF in the temperature range of 298.4-362.3 K and in the pressure range of 403-760 Torr. The authors showed that the overall rate constant for this reaction is temperature and pressure independent, with the average value of the overall rate constant of (2.71 ± 0.34) × 10 −10 cm 3 molecule −1 s −1 .…”

“…They determined that the average value of the overall rate constant equaled to (2.50 ± 0.39) ×10 −10 cm 3 molecule −1 s −1 . 8 In this paper, we present the experimental kinetic studies of the Cl reaction with THF in the temperature range of 298-547 K, using the relative rate method. The kinetic studies of fully deuterated tetrahydrofuran TDF (where "TDF" denotes fully deuterated THF) with atomic chlorine have also been performed.…”

“…The kinetics of the reaction of THF with chlorine atoms, for which the overall rate constant for H atoms abstraction, is designated as k H was the subject of two experimental studies 7,8 . Giri and Roscoe 7 studied the reaction of Cl + THF in the temperature range of 298.4‐362.3 K and in the pressure range of 403‐760 Torr.…”

“…The authors showed that the overall rate constant for this reaction is temperature and pressure independent, with the average value of the overall rate constant of (2.71 ± 0.34) × 10 −10 cm 3 molecule −1 s −1 . Alwe et al 8 studied this reaction at the temperature of 298 K and at pressure of 800 Torr. They determined that the average value of the overall rate constant equaled to (2.50 ± 0.39) ×10 −10 cm 3 molecule −1 s −1 8 …”

“…Alwe et al 8 studied this reaction at the temperature of 298 K and at pressure of 800 Torr. They determined that the average value of the overall rate constant equaled to (2.50 ± 0.39) ×10 −10 cm 3 molecule −1 s −1 8 …”