Infrared Multiphoton Absorption and Reaction of 2-Chloro-1,1,1-trifluoroethane

Article abstract of DOI:10.1021/j100272a045

The infrared multiphoton absorption and dissociation of CF3CH2Cl has been studied by measuring the dependence of the reaction probability and product distribution on the laser fluence and bath gas pressure.Absorption measurements were performed at two laser frequencies to estabilish the absorbed laser energy: the absorption measurements displayed Beer's law behavior except at very low laser fluence.Sensitized reactions with SiF4 were conducted for comparison to the direct laser-induced process: the effective temperature within the irradiated volume for the SiF4 experiments was determined as a function of incident laser energy.The three main reaction channels are four centered HF elimination, three-centered HCl elimination, and C-Cl homolysis: the product ratios were very dependent on the incident laser fluence.Addition of toluene as a bath gas significantly lowered the reaction probability, especially at lower laser fluence, but had only a minor influence on the product distribution.The infrared laser-induced energy absorption and reaction processes of CF3CH3, CF3CH2Cl, and CF3CH2Br are compared.The data provide evidence for a fluence-dependent fractionation of absorbed laser energy producing a two-component energy distribution for the former two compounds.