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

Related Subjects

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