Flash Photolysis-Time-Resolved UV Spectroscopy of the CF3CFHO2 Self-Reaction

Article abstract of DOI:10.1021/j100205a048

The self-reaction of CF3CFHO2 has been studied via time-resolved ultraviolet spectroscopy over the temperature range 211-372 K.The absorption spectrum of CF3CFHO2 extends from 190 to 275 nm with a maximum cross section of (5.2 +/- 0.3) * 10^-18 cm² molecule^-1 at 213 nm.The UV absorbance of the reaction mixture decreases and shifts to the blue as the reaction progresses.This is consistent with the CF3CFHO2 self-reaction producing CF3CFHO, the alkoxy radical then decomposing to yield CF3, which adds molecular oxygen to form CF3O2.The CF3CFHO2 self-reaction has a negative temperature dependence with rate constant given by k₁ = (7.8 +/- 1.3) * 10^-13 e^(605+/-40)/T cm³ s^-1.The rate of alkoxy radical dissociation, at 230 Torr of total pressure, is k_2a = (3.7 +/- 0.7) * 10⁷ e^{-(2200+/-150)/T} s^-1.The rate constants for CF3O2 reaction with CF3CFHO2 and itself are determined to be k₈ = (8 +/- 3) * 10^-12 and k₉ = (1.8 +/- 0.5) * 10^-12 cm³ s^-1, respectively, at 297 K.