TY - JOUR

T1 - Atmospheric chemistry of HFC-152

T2 - UV absorption spectrum of CH2FCFHO2 radicals, kinetics of the reaction CH2FCFHO2 + NO → CH2FCHFO + NO2, and fate of the alkoxy radical CH2FCFHO

AU - Wallington, Timothy J.

AU - Hurley, Michael D.

AU - Ball, James C.

AU - Ellermann, Thomas

AU - Nielsen, Ole J.

AU - Sehested, Jens

PY - 1994/12/1

Y1 - 1994/12/1

N2 - The ultraviolet absorption spectrum of CH2FCFHO2 radicals and the kinetics and mechanism of their reaction with NO 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 atmospheric fate of CH2FCFHO radicals. Absorption cross sections were quantified over the wavelength range 220-300 nm. At 240 nm, σCH2FCFHO2 = (3.28 ± 0.40) × 10-18 cm2 molecule-1. Errors are statistical (2 standard deviations) plus our estimate of potential systematic uncertainty (10%). Monitoring the rate of NO2 formation using a monitoring wavelength of 400 nm allowed a lower limit of k3 > 8.7 × 10-12 cm3 molecule-1 s-1 to be derived for the reaction of CH2FCFHO2 radicals with NO. The alkoxy radical CH2FCFHO was found to undergo C-C bond scission rapidly with a rate greater than 6 × 104 s-1. The Cl-atom-initiated oxidation of HFC-152 in air in the presence of NOx gave HC(O)F as the sole carbon-containing product. The carbon balance was 91 ± 10%. Results are discussed with respect to the atmospheric chemistry of HFC-152. As part of the present work, a relative rate technique was used to measure rate constants of (6.7 ± 0.8) × 10-13 and (3.8 ± 1.1) × 10-11 cm3 molecule-1 s-1 for the reaction of CH2FCH2F with Cl and F atoms, respectively.

AB - The ultraviolet absorption spectrum of CH2FCFHO2 radicals and the kinetics and mechanism of their reaction with NO 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 atmospheric fate of CH2FCFHO radicals. Absorption cross sections were quantified over the wavelength range 220-300 nm. At 240 nm, σCH2FCFHO2 = (3.28 ± 0.40) × 10-18 cm2 molecule-1. Errors are statistical (2 standard deviations) plus our estimate of potential systematic uncertainty (10%). Monitoring the rate of NO2 formation using a monitoring wavelength of 400 nm allowed a lower limit of k3 > 8.7 × 10-12 cm3 molecule-1 s-1 to be derived for the reaction of CH2FCFHO2 radicals with NO. The alkoxy radical CH2FCFHO was found to undergo C-C bond scission rapidly with a rate greater than 6 × 104 s-1. The Cl-atom-initiated oxidation of HFC-152 in air in the presence of NOx gave HC(O)F as the sole carbon-containing product. The carbon balance was 91 ± 10%. Results are discussed with respect to the atmospheric chemistry of HFC-152. As part of the present work, a relative rate technique was used to measure rate constants of (6.7 ± 0.8) × 10-13 and (3.8 ± 1.1) × 10-11 cm3 molecule-1 s-1 for the reaction of CH2FCH2F with Cl and F atoms, respectively.

UR - http://www.scopus.com/inward/record.url?scp=0008896387&partnerID=8YFLogxK

M3 - Journal article

AN - SCOPUS:0008896387

VL - 98

SP - 5435

EP - 5440

JO - Journal of Physical Chemistry

JF - Journal of Physical Chemistry

SN - 0022-3654

IS - 21

ER -