Atmospheric Chemistry of HFE-7100 (C4F9OCH3): Reaction with OH Radicals, UV Spectra and Kinetic Data for C4F9OCH2· and C4F9OCH2O2· Radicals, and the Atmospheric Fate of C4F9OCH2O· Radicals

Relative rate techniques were used to estimate k(OH+HFE-7100) ≈ 1.2 × 10-14 cm3 molecule-1 s-1 at 295 K leading to an estimate of ≈5 years for the atmospheric lifetime of HFE-7100 (HFE = hydrofluoroether). Pulse radiolysis transient UV absorption spectroscopy was used to study the ultraviolet absorption spectra and kinetics of C4F9OCH2 and C4F9OCH2O2 radicals at 296 K. At 300 nm σ(C4F9OCH2) = (5.80 ± 0.76) × 10-19 and at 250 nm σ(C4F9OCH2O2) = (2.24 ± 0.24) × 10-18 cm2 molecule-1. Both UV spectra showed two absorption maxima, one below 230 nm and one at 290 nm. Rate constants for the self-reactions of C4F9OCH2 and C4F9OCH2O2 radicals, the reaction of C4F9OCH2 radicals with O2, and the reactions of C4F9OCH2O2 radicals with NO and NO2 were (3.5 ± 0.8) × 10-11, (1.35 ± 0.17) × 10-11 (uncorrected for possible secondary chemistry), (2.5 ± 0.5) × 10-12, (8.5 ± 2.5) × 10-12, and (8.8 ± 1.8) × 10-12 cm3 molecule-1 s-1, respectively. Using a pulse radiolysis method we measured k(F+HFE-7100) = (1.6 ± 0.6) × 10-11 c...