Kinetics and Mechanism of Elementary Chemical Processes of Importance in Combustion. Periodic Report 2 for the Period October 1986 - April 1987. Spectrokinetics Studies of Vinyl and Propargyl Radicals

摘要

UV-spectra of vinyl and propargyl radicals have been recorded employing the technique of pulse radiolysis combined with time resolved UV-absorption spectroscoppy. The kinetics of vinyl radiocals was studied by monitoring the transient absorption signals in the range of 215-230 nm. In the presence of oxygen we observed the build-up of strong transient absorption signals at 230nm. Based on analysis of the spectral and kinetic features we have tentatively assigned the new absorption band to the vinyl peroxy radical. Propargyl radicals were produced by the argon sensitized radiolysis of propargyl bromide. In addition to the well-known absorption band at 332 nm we have observed a much stronger band with a maximum at 250 nm. The observed second order decay kinetics is accounted for by the combination reactions 2 C(sub x)H(sub x) -> products and C3H3 + Br -> C3H3 Br. (ERA citation 13:045482)