Rate constants for the reactions of OH radicals with CH{sub 3}OCF{sub 2}CHF{sub 2}, CHF{sub 2}OCH{sub 2}CF{sub 2}CHF{sub 2}, CHF{sub 2}OCH{sub 2}CF{sub 2}CF{sub 3}, and CF{sub 3}CH{sub 2}OCF{sub 2}CHF{sub 2} over the temperature range 250--430 K
The OH reaction rate constants have been measured for CH{sub 3}OCF{sub 2}CHF{sub 2}, CHF{sub 2}OCH{sub 2}CF{sub 2}CHF{sub 2}, CHF{sub 2}OCH{sub 2}CF{sub 2}CF{sub 3}, and CF{sub 3}CH{sub 2}OCF{sub 2}CHF{sub 2} over the temperature range 250--430 K. Kinetic measurements have been carried out using the flash photolysis, laser photolysis, and discharge flow methods, combined respectively with the laser-induced fluorescence technique to monitor the OH radical concentrations. The influence of impurities contained in the samples of fluorinated ethers has been investigated by means of sample purification using gas chromatography. No sizable effect of impurities was found on the measured rate constants of these fluorinated ethers, if the purified samples were used in the kinetic measurements. The Arrhenius rate constants have been determined from the respective kinetic data as k(CH{sub 3}OCF{sub 2}CHF{sub 2}) = 2.60 x 10{sup {minus}12} exp[-(1420 {+-} 170)/T], k(CHF{sub 2}OCH{sub 2}CF{sub 2}CHF{sub 2}) = 2.49 x 10{sup {minus}12} exp[-(1500 {+-} 170)/T], k(CHF{sub 2}OCH{sub 2}CF{sub 2}CF{sub 3}) = 2.14 x 10{sup {minus}12} exp[-(1580 {+-} 170)/T], and k(CF{sub 3}CH{sub 2}OCF{sub 2}CHF{sub 2}) = 1.49 x 10{sup {minus}12} exp[-(1520 {+-} 170)/T] cm{sup 3} molecule{sup {minus}1} s{sup {minus}1}, where the quoted errors represent the 95% confidence level and included systematic errors. Uncertainty factors at 298 K (with the formulation of the NASA panel for data evaluation{sup 14}) for these fluorinated ethers were 1.1.
- Research Organization:
- National Inst. of Materials and Chemical Research, Tsukuba, Ibaraki (JP)
- OSTI ID:
- 20017548
- Journal Information:
- Journal of Physical Chemistry A: Molecules, Spectroscopy, Kinetics, Environment, amp General Theory, Vol. 104, Issue 6; Other Information: PBD: 17 Feb 2000; ISSN 1089-5639
- Country of Publication:
- United States
- Language:
- English
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