Photochemical Properties of CH<sub>2</sub>CH-CFCl-CF<sub>2</sub>Br (4-Bromo-3-chloro-3,4,4-trifluoro-1-butene) and CH<sub>3</sub>‑O-CH(CF<sub>3</sub>)<sub>2</sub> (Methyl Hexafluoroisopropyl Ether): OH Reaction Rate Constants and UV and IR Absorption Spectra OrkinVladimir L. MartynovaLarissa E. KuryloMichael J. 2017 Rate constants for the reactions of hydroxyl radicals (OH) with 1,1,1,3,3,3-hexafluoroisopropyl methyl ether (CH<sub>3</sub>-O-CH­(CF<sub>3</sub>)<sub>2</sub>) and 4-bromo-3-chloro-3,4,4-trifluoro-1-butene (CH<sub>2</sub>CH-CFCl-CF<sub>2</sub>Br) have been measured over the temperature range 230–370 K to give the following Arrhenius expressions: <i>k</i><sub>CH3OCH(CF3)2</sub>(<i>T</i>) = 7.69 × 10<sup>–14</sup> × (<i>T</i>/298)<sup>2.99</sup> × exp­(+342/<i>T</i>), cm<sup>3</sup> molecule<sup>–1</sup> s<sup>–1</sup>, and <i>k</i><sub>CH2CHCFClCF2Br</sub>(<i>T</i>) = (6.45 ± 0.72) × 10<sup>–13</sup> × exp­{+(424 ± 32)/<i>T</i>}, cm<sup>3</sup> molecule<sup>–1</sup> s<sup>–1</sup>. Atmospheric lifetimes of compounds were estimated to be 67 days and 4.5 days, respectively. UV absorption spectrum of CH<sub>2</sub>CH-CFCl-CF<sub>2</sub>Br between 164 and 260 nm and IR absorption spectra of both compounds between 450 and 1600 cm<sup>–1</sup> were measured at room temperature.