Atmospheric Chemistry of ()- and ()-CFCFCH═CHCFCF (HFO-153-10mczz): Kinetics and Mechanisms of the Reactions with Cl Atoms, OH Radicals, and O.

Smog chamber experiments were conducted to establish the atmospheric chemistry of ()- and ()-CFCFCH═CHCFCF. Kinetics of the reactions of the two compounds with Cl atoms and OH radicals were measured using relative rate techniques, giving (Cl + ()-CFCFCH═CHCFCF) = (5.63 ± 0.84) × 10, (Cl + ()-CFCFCH═CHCFCF) = (1.17 ± 0.20) × 10, (OH + ()-CFCFCH═CHCFCF) = (1.64 ± 0.21) × 10, and (OH + ()-CFCFCH═CHCFCF) = (3.13 ± 0.38) × 10 cm molecule s in 680 Torr air/N/O diluents at 296 ± 2 K. Rate coefficients for the reactions with O, (O + ()-CFCFCH═CHCFCF) ∼ 1 × 10 and (O + ()-CFCFCH═CHCFCF) ≤ 5× 10 cm molecule s, were established using absolute techniques in a 680 Torr air diluent and 296 ± 2 K. The Cl reaction with ()-CFCFCH═CHCFCF gives CFCFCHClC(O)CFCF as the sole oxidation product, whereas the reaction with ()-CFCFCH═CHCFCF also gives rise to the formation of the ()-isomer in minor yields. The reaction of OH radicals with CFCFCH═CHCFCF gives CFCFCHO in a yield of 177 ± 17%. The main atmospheric fate of () and ()-CFCFCH═CHCFCF is the reaction with OH radicals, resulting in overall atmospheric lifetime estimates of 71 and 37 days, for ()- and ()-CFCFCH═CHCFCF, respectively. The IR absorption cross sections are reported, and the global warming potentials of ()- and ()-CFCFCH═CHCFCF for the 20-, 100-, and 500-year time horizons are calculated to be 36, 10, and 3 for the ()isomer and 11, 3, and 1 for the ()-isomer, respectively. Atmospheric processing of ()- and ()-CFCFCH═CHCFCF is expected to yield CFCFCOOH and CFCOOH in yields of <10%. This study provides a comprehensive description of the atmospheric chemistry and fate of ()- and ()-CFCFCH═CHCFCF.