Atmospheric Chemistry of HFE-7100 (C 4 F 9 OCH 3 ): Reaction with OH Radicals, UV Spectra and Kinetic Data for C 4 F 9 OCH 2 · and C 4 F 9 OCH 2 O 2 · Radicals, and the Atmospheric Fate of C 4 F 9 OCH 2 O· Radicals

Relative rate techniques were used to estimate k (OH+HFE-7100) ≈ 1.2 × 10 -14 cm 3 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 C 4 F 9 OCH 2 and C 4 F 9 OCH 2 O 2 radicals at 296 K. At 300 nm σ(C 4 F 9 OCH 2 ) = (5.80 ± 0.76) × 10 -19 and at 250 nm σ(C 4 F 9 OCH 2 O 2 ) = (2.24 ± 0.24) × 10 -18 cm 2 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 C 4 F 9 OCH 2 and C 4 F 9 OCH 2 O 2 radicals, the reaction of C 4 F 9 OCH 2 radicals with O 2, and the reactions of C 4 F 9 OCH 2 O 2 radicals with NO and NO 2 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 cm 3 molecule -1 s -1, respectively. Using a pulse radiolysis method we measured k (F+HFE-7100) = (1.6 ± 0.6) × 10 -11 cm 3 molecule -1 s -1 . Using a Fourier transform infrared spectroscopic technique rate, constants for the reaction of F and Cl atoms with HFE-7100 and Cl atoms with C 4 F 9 OC(O)H were determined to be (1.3 ± 0.3) × 10 -11, (9.7 ± 1.4) × 10 -14, and (1.6 ± 0.7) × 10 -14 cm 3 molecule -1 s -1, respectively. Finally, it was determined that the sole atmospheric fate of C 4 F 9 OCH 2 O· radicals is reaction with O 2 to give C 4 F 9 OC(O)H (perfluorobutyl formate). The results are discussed with respect to the atmospheric chemistry of HFE-7100.