OH reaction kinetics and atmospheric lifetimes of CF[sub 3]CFHCF[sub 3] and CF[sub 3]CH[sub 2]Br

Journal Article · Fri Feb 05 04:00:00 EST 1993 · Geophysical Research Letters (American Geophysical Union); (United States)

DOI:https://doi.org/10.1029/93GL00239· OSTI ID:6660326

Nelson, Jr, D D; Zahniser, M S; Kolb, C E ^[1]

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1. Aerodyne Research, Inc., Billerica, MA (United States)

The rate constants for the reaction of the OH radical with CF[sub 3]CFHCF[sub 3] and with CF[sub 3]CH[sub 2]Br have been measured as a function of temperature using the discharge flow technique with laser induced fluorescence detection of the OH radicals. The temperature dependent rate coefficients are well described by a simple Arrhenius expression, k(T) = A exp[-E/(RT)]. For the reaction of OH with CF[sub 3]CFHCF[sub 3] the authors find A = 3.7 [times] 10[sup [minus]13] cm[sup 3] molecule[sup [minus]1] s[sup [minus]1] and E/R = 1615K; for the reaction of OH with CF[sub 3]CH[sub 2]Br they report A = 1.4 [times] 10[sup [minus]12] cm[sup 3] molecule[sup [minus]1] s[sup [minus]1] and E/R = 1350 K. These Arrhenius parameters imply rate coefficients at 277 K of 1.09 [times] 10[sup [minus]15] cm[sup 3] molecule[sup [minus]1] s[sup [minus]1] for CF[sub 3]CFHCF[sub 3] and 1.06 [times] 10[sup [minus]14] cm[sup 3] molecule[sup [minus]1] s[sup [minus]1] for CF[sub 3]CH[sub 2]Br. The authors find atmospheric lifetimes for CF[sub 3]CFHCF[sub 3] and CF[sub 3]CH[sub 2]Br of 42 years and 4.1 years, respectively. They also estimate the steady state ozone depletion potential (ODP) of the brominated species relative to CFCl[sub 3] as [approximately]0.84 using a semi-empirical model. 22 refs., 1 fig., 1 tab.

• OSTI ID: 6660326
• Journal Information: Geophysical Research Letters (American Geophysical Union); (United States), Journal Name: Geophysical Research Letters (American Geophysical Union); (United States) Vol. 20:3; ISSN GPRLAJ; ISSN 0094-8276
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
540110*
ATMOSPHERIC CHEMISTRY
BROMINATED ALIPHATIC HYDROCARBONS
CHEMICAL REACTION KINETICS
CHEMISTRY
DETECTION
FLUORESCENCE
FLUORINATED ALIPHATIC HYDROCARBONS
HALOGENATED ALIPHATIC HYDROCARBONS
HYDROXYL RADICALS
KINETICS
LUMINESCENCE
ORGANIC BROMINE COMPOUNDS
ORGANIC COMPOUNDS
ORGANIC FLUORINE COMPOUNDS
ORGANIC HALOGEN COMPOUNDS
OZONE
RADICALS
REACTION KINETICS