ISSN:
0538-8066
Keywords:
Chemistry
;
Physical Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
The UV absorption spectrum and kinetics of CH2I and CH2IO2 radicals have been studied in the gasphase at 295 K using a pulse radiolysis UV absorption spectroscopic technique. UV absorption spectra of CH2I and CH2IO2 radicals were quantified in the range 220-400 nm. The spectrum of CH2I has absorption maxima at 280 nm and 337.5 nm. The absorption cross-section for the CH2I radicals at 337.5 nm was (4.1 ± 0.9) × 10-18 cm2 molecule-1. The UV spectrum of CH2IO2 radicals is broad. The absorption cross-section at 370 nm was (2.1 ± 0.5) × 10-18 cm2 molecule-1. The rate constant for the self reaction of CH2I radicals, k = 4 × 10-11 cm3 molecule-1 s-1 at 1000 mbar total pressure of SF6, was derived by kinetic modelling of experimental absorbance transients. The observed self-reaction rate constant for CH2IO2 radicals was estimated also by modelling to k = 9 × 10-11 cm3 molecule-1 s-1. As part of this work a rate constant of (2.0 ± 0.3) × 10-10 cm3 molecule-1 s-1 was measured for the reaction of F atoms with CH3I. The branching ratios of this reaction for abstraction of an I atom and a H atom were determined to (64 ± 6)% and (36 ± 6)%, respectively. © 1994 John Wiley & Sons, Inc.
Additional Material:
8 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/kin.550260204
