The ultraviolet absorption spectrum and the self reaction kinetics of CF302 radicals have been studied in the gas phase at 298 K using the pulse radiolysis technique. Long pathlength Fourier transform infrared (FTIR) spectroscopy was used to identify and quantify reaction products. Absorption cross sections were quantified over the wavelength range 215-270 nm. The measured cross section at 230 nm was; a,-no2(230 nm) = (2.06 2 0.40) X lo-'* cm2 molecule-' Errors represent statistical (2a) together with our estimate of potential systematic errors. The absorption cross section data were then used to derive the observed self reaction rate constant for reaction (I), defined as -d[CF302]/dt = 2ko~s[CF302]2 (1) CF302 + CF3O2 -products kj& = (3.6 2 0.9) X lo-'' cm3 molecule-' 5-l. The only carbon containing product observed by FTIR spectroscopy was CF3000CF3. Consideration of the loss of CF302 radicals to form the trioxide CF3000CF3 allows derivation of the true bimolecular rate constant for reaction (1); k l = (1.8 2 0.5) X cm3 molecule-' s-l. These results are discussed with respect to previous studies of the absorption spectra of peroxy radicals, the kinetics, and mechanisms of their self reaction. 0 1992 John Wiley & Sons, Inc.

The ultraviolet absorption spectrum of CH2FOZ radicals and the kinetics and mechanism of their self-reaction have been studied in the gas phase at 298 K. Two techniques have been used: pulse radiolysis UV absorption to measure the spectrum and kinetics and long path length Fourier transform infrared spectroscopy (FTIR) to identify and quantify the reaction products.Absorption cross sections were quantified over the wavelength range 220-300 nm. The measured cross section near the absorption maximum is ~~~~~( 2 4 0 nm) = (4.1 1 f 0.67) X cm2 molecule:' Errors are statistical ( 2 4 plus our estimate of potential systematic uncertainty (10%). This absorption cross section was then used to derive the observed self-reaction rate constant for reaction 1, defined as -d[CH2F02]/dt = 2kob[CH2F02]2, CH2F02 + CHZFO2 -products (1). klob = (4.01 f 0.52) X (errors are 2 4 . The only carbon-containing products observed by FTIR spectroscopy were HC(0)F and CH2FOOH, indicating that the majority (>77%) of the self-reaction proceeds via the channel CH2F02 + CH2F02 -CH2F0 + CH2F0 + Oz (la). As part of this work, a rate constant of (3.24 f 0.51) X cm3 molecule-I s-' was measured for the reaction of C1 atoms with CH3F and a lower limit of 1.2 X 10-

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