Kinetics of the CCl2 + Br2 and CCl2 + NO2 reactions in the temperature range 266−365 K and reactivity of the CCl2 biradical

The kinetics of the CCl2 + Br2 and CCl2 + NO2 reactions have been studied at temperatures between 266 and 365 K using laser photolysis/photoionization mass spectrometry. Dichloromethylene biradicals were produced by the pulsed laser photolysis of CCl4. The bimolecular rate coefficients of the CCl2 + Br2 reaction can be described by the Arrhenius expression k1 = (7.05 ± 1.75) × 10−12 exp[(3.52 ± 0.63) kJ mol−1/RT] cm3 molecule−1 s−1. CCl2Br was observed as a primary product of this reaction. Interestingly, the bimolecular rate coefficients of the CCl2 + NO2 reaction were observed to depend weakly on the bath gas density and to possess a negative temperature dependence.