Atmospheric chemistry of 1,1,1,2-tetrachloroethane (CCl3CH2Cl): spectrokinetic investigation of the CCl3CClHO2 radical, its reactions with NO and NO2, and atmospheric fate of the CCl3CClHO radical

Publikation: Bidrag til tidsskriftTidsskriftartikelForskningfagfællebedømt

A pulse radiolysis technique was used to study the ultraviolet absorption spectra of CCl3CClH and CCl3-CClHO2 radicals, the kinetics of the self-reaction of CCl3CClHO2 radicals, and the kinetics of the reactions of CCl3CClHO2 with NO and NO2 in the gas phase at 296 K. At 240 nm, σ(CCl3CClH) = (303 ± 35) × 10-20, and at 250 nm, σ(CCl3CClHO2) = (288 ± 48) × 10-20 cm2 molecule-1. The observed rate constant for the self-reaction of CCl3CClHO2 radicals was (5.0 ± 1.2) × 10-12 cm3 molecule-1 s-1. The rate constants for reactions of CCl3CClHO2 radicals with NO and NO2 were k3 > 9.0 × 10-12 and k4 = (8.9 ± 2.6) × 10-12 cm3 molecule-1 s-1, respectively. A long path length Fourier transform infrared technique was used to show that at 295 K in 700 Torr total pressure of air 76 ± 3% of CCl3CClHO radicals decornpose via C-C bond scission and 24 ± 3% undergo three-center intramolecular HCl elimination. As part of this work rate constants for the reaction of F and Cl atoms with CCl3CH2Cl were determined to be (6.4 ± 1.2) × 10-12 and (5.7 ± 1.0) × 10-14 cm3 molecule-1 s-1, respectively. The results are discussed with respect to the atmospheric chemistry of tetrachloroethane.

OriginalsprogEngelsk
TidsskriftJournal of Physical Chemistry
Vol/bind100
Udgave nummer47
Sider (fra-til)18399-18407
Antal sider9
ISSN0022-3654
StatusUdgivet - 21 nov. 1996

ID: 227487916