Atmospheric Chemistry of (E)- and (Z)-CF3CF2CH═CHCF2CF3 (HFO-153-10mczz): Kinetics and Mechanisms of the Reactions with Cl Atoms, OH Radicals, and O3

Smog chamber experiments were conducted to establish the atmospheric chemistry of (E)- and (Z)-CF3CF2CH & boxH;CHCF2CF3. Kinetics of the reactions of the two compounds with Cl atoms and OH radicals were measured using relative rate techniques, giving k(Cl + (E)-CF3CF2CH & boxH;CHCF2CF3) = (5.63 +/- 0.84) x 10(-12), k(Cl + (Z)-CF3CF2CH & boxH;CHCF2CF3) = (1.17 +/- 0.20) x 10(-11), k(OH + (E)-CF3CF2CH & boxH;CHCF2CF3) = (1.64 +/- 0.21) x 10(-13), and k(OH + (Z)-CF3CF2CH & boxH;CHCF2CF3) = (3.13 +/- 0.38) x 10(-13) cm(3) molecule(-1) s(-1) in 680 Torr air/N-2/O-2 diluents at 296 +/- 2 K. Rate coefficients for the reactions with O-3, k(O-3 + (E)-CF3CF2CH & boxH;CHCF2CF3) similar to 1 x 10(-22) and k(O-3 + (Z)-CF3CF2CH & boxH;CHCF2CF3) <= 5x 10(-24) cm(3) molecule(-1) s(-1), were established using absolute techniques in a 680 Torr air diluent and 296 +/- 2 K. The Cl reaction with (E)-CF3CF2CH & boxH;CHCF2CF3 gives CF3CF2CHClC(O)CF2CF3 as the sole oxidation product, whereas the reaction with (Z)-CF3CF2CH & boxH;CHCF2CF3 also gives rise to the formation of the (E)-isomer in minor yields. The reaction of OH radicals with CF3CF2CH & boxH;CHCF2CF3 gives CF3CF2CHO in a yield of 177 +/- 17%. The main atmospheric fate of (E)- and (Z)-CF3CF2CH & boxH;CHCF2CF3 is the reaction with OH radicals, resulting in overall atmospheric lifetime estimates of 71 and 37 days, for (E)- and (Z)-CF3CF2CH & boxH;CHCF2CF3, respectively. The IR absorption cross sections are reported, and the global warming potentials of (E)- and (Z)-CF3CF2CH & boxH;CHCF2CF3 for the 20-, 100-, and 500-year time horizons are calculated to be 36, 10, and 3 for the (E)-isomer and 11, 3, and 1 for the (Z)-isomer, respectively. Atmospheric processing of (E)- and (Z)-CF3CF2CH & boxH;CHCF2CF3 is expected to yield CF3CF2COOH and CF3COOH in yields of <10%. This study provides a comprehensive description of the atmospheric chemistry and fate of (E)- and (Z)-CF3CF2CH & boxH;CHCF2CF3.