ISSN:
0538-8066
Keywords:
Chemistry
;
Physical Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
The kinetics of four gas-phase reactions involving halogenated methyl radicals (R = CF3, CF2Cl, CFCI2, and CCI3) with molecular chlorine have been studied using a tubular reactor coupled to a photoionization mass spectrometer. The radicals were homogeneously generated by the pulsed photolysis of precursor molecules at 193 nm. The subsequent decays of the radical concentration were monitored in real-time experiments as a function of Cl2 concentration to obtain the rate constants of these R + Cl2 reactions. Where possible, the rate constants were measured as a function of temperature to determine Arrhenius parameters. Apparent discrepancies between these measured rate constants for CF3 and CCl3 with Cl2 and ones obtained in prior indirect studies are explained. The higher activation energies for these R + Cl2 reactions compared to that of the CH3 + Cl2 reaction are attributed in part to the different polarities of the transition states formed.
Additional Material:
2 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/kin.550181008
