Atmospheric chemistry of HFC-143a: Spectrokinetic investigation of the CF[sub 3]CH[sub 2]O[sub 2][center dot] radical, its reactions with NO and NO[sub 2], and the fate of CF[sub 3]CH[sub 2]O

Journal Article · Thu Sep 22 00:00:00 EDT 1994 · Journal of Physical Chemistry; (United States)

DOI:https://doi.org/10.1021/j100089a026· OSTI ID:7070982

Nielsen, O J; Gamborg, E; Sehested, J ^[1]; Wallington, T J; Hurley, M D ^[2]

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1. Riso National Lab., Roskilde (Denmark)
2. Ford Motor Company, Dearborn, MI (United States)

The ultraviolet absorption spectrum of CF[sub 3]CH[sub 2]O[sub 2] radicals, the kinetics of their self-reaction, and their reactions with NO and NO[sub 2] have been studied in the gas phase at 296 K using a pulse radiolysis technique. A long path-length Fourier transform infrared technique was used to study the fate of CF[sub 3]CH[sub 2]O radicals. Absorption cross sections were quantified over the wavelength range 220-300 nm. At 250 nm, [sigma](CF[sub 3]CH[sub 2]O[sub 2]) = (2.73 [+-] 0.31) [times] 10[sup [minus]18] molecule[sup [minus]1]. By monitoring the rate of NO[sub 2] formation, k[sub 4] = (1.2 [+-] 0.3) [times] 10[sup [minus]11] cm[sup 3] molecule[sup [minus]1] s[sup [minus]1] was found for the reaction of CF[sub 3]CH[sub 2]O[sub 2] radical with NO. The reaction of CF[sub 3]CH[sub 2]O[sub 2] radicals with NO gives CF[sub 3]CH[sub 2]O radicals. In the atmosphere, >99.33% of the CF[sub 3]CH[sub 2]O radicals react with O[sub 2] to give CF[sub 3]CHO. By monitoring the rate of NO[sub 2] decay, k[sub 5] = (5.8 [+-] 1.1) [times] 10[sup [minus]12] cm[sup 3] molecule[sup [minus]1] s[sup [minus]1] was found for the reaction of CF[sub 3]CH[sub 2]O[sub 2] radical with NO[sub 2]. The results are discussed with respect to the atmospheric chemistry of CF[sub 3]CH[sub 3] (HFC-143a). 34 refs., 12 figs., 1 tab.

• OSTI ID: 7070982
• Journal Information: Journal of Physical Chemistry; (United States), Vol. 98:38; ISSN 0022-3654
• Country of Publication: United States
• Language: English

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37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
54 ENVIRONMENTAL SCIENCES
CHLORINE
CHEMICAL REACTIONS
FLUORINE
NITRIC OXIDE
NITROGEN DIOXIDE
ORGANIC FLUORINE COMPOUNDS
OXYGEN
RADICALS
ATMOSPHERIC CHEMISTRY
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RADIOLYSIS
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CHEMICAL RADIATION EFFECTS
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DECOMPOSITION
ELEMENTS
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NITROGEN OXIDES
NONMETALS
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ORGANIC HALOGEN COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
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400201* - Chemical & Physicochemical Properties
400102 - Chemical & Spectral Procedures
540110