Spectrum and mutual kinetics of .beta.-hydroxyethylperoxo radicals

Evaluated kinetic and photochemical data for atmospheric chemistry: Volume II – gas phase reactions of organic species

“…Increasing σ 230 (HOCH 2 CH 2 O 2 ) by a factor of two in a re-interpretation of the data of Jenkin and Cox (1991) yielded a revised value of k=(8.4±3.0)×10 −12 cm 3 molecule −1 s −1 at 13 mbar pressure, in fair agreement with the current recommendation. The approximate value of k derived by Anastasi et al (1991) from pulsed radiolysis experiments is almost a factor of two higher than our recommended value. We have not taken this value of Anastasi et al (1991) into account, because of the differences in the absorption spectrum of the radical observed compared with the consistent spectra shapes reported by Jenkin and Cox (1991) and …”

“…The approximate value of k derived by Anastasi et al (1991) from pulsed radiolysis experiments is almost a factor of two higher than our recommended value. We have not taken this value of Anastasi et al (1991) into account, because of the differences in the absorption spectrum of the radical observed compared with the consistent spectra shapes reported by Jenkin and Cox (1991) and …”

“…The earlier determinations of Jenkin and Cox (1991) and Anastasi et al (1991) were subject to errors in the magnitude and shape of the HOCH 2 CH 2 O 2 absorption spectrum, respectively, which influenced the derived values of k. Murrells et al (2001) demonstrated that cross-sections reported by Jenkin and Cox (1991), from molecular modulation studies of the photolysis of HOCH 2 CH 2 I, are low by a factor of approximately two. Jenkin and Cox (1991) made the assumption that the photolysis of HOCH 2 CH 2 I in their system yielded entirely HOCH 2 CH 2 O 2 radicals, which was apparently not the case.…”

The temperature dependence of the rate coefficients for ?-hydroxyperoxy radical self reactions

“…A study of reaction (1) has also been reported by Anastasi et al [8], who found a value for k 1 of 7.7 ϫ 10 Ϫ12 cm 3 molecule Ϫ1 s Ϫ1 , the difference between their value and the preferred value of Jenkin and Hayman having been previously explained [9]. For reaction (2), no branching ratio measurement had been carried out and this is reflected in the large uncertainty range for k 2 at room temperature (corresponding to the branching ratio extremes of 0 and 1 and hence a k 2 range given by k obs /(1 ϩ ␣ 2 ) where k obs is the measured global second-order rate coefficient for HOCH 2 CH 2 O 2 loss).…”

Spectroscopic studies of the $\tilde{A}$Ö$\tilde{X}$X̃ electronic spectrum of the β-hydroxyethylperoxy radical: Structure and dynamics

“…2 It is a very intense transition leading to it being used in kinetic studies of β-HEP. [16][17][18] TheÃ-X origin band of two conformers(G 1 G 2 G 3 and G 1 G 2 G 3 ) of β-HEP have been identified via vibronic analysis of the ambient temperature CRDS spectrum. 19 However, a jet-cooled spectrum is required to confirm the conformational assignment explicitly since the rotational contour in the ambient temperature CRDS cannot be resolved because of congestion.…”