Kinetic study of CCl2 radical recombination reaction by laser induced fluorescence technique

Abstract

An experimental set-up which coupled IR multiple-photon dissociation (IRMPD) and laser induced fluorescence (LIF) techniques was implemented to study the kinetics of the recombination reaction of dichlorocarbene radicals, CCl2, in an Ar bath. The CCl2 radicals were generated by IR multiple-photon dissociation of CDCl3. The time dependence of the CCl2 radicals´ concentration in the presence of Ar was determined by laser induced fluorescence. The experimental conditions achieved allowed us to associate the decrease in the concentration of radicals to the self-recombination reaction to form C2Cl4. The rate constant for this reaction was determined in both the fall-off and the high-pressure regimes at room temperature. The values obtained were k0 = (2.23 ± 0.89) x 10-29 cm6 molec-2 s-1 and kinf = (6.73 ± 0.23) x 10-13 cm3 molec-1 s-1, respectively.