THERMAL EFFECTS IN THE IR MULTIPHOTON PHOTOLYSIS OF CF3I IN THE PRESENCE OF ISOBUTANE

The IR multiphoton photolysis of CF3I was studied in the presence of i sobutane by room temperature irradiation with a TEA CO2 laser. The CF3 radicals produced react with isobutane to yield CF3H at a rate higher than expected. This enhancement is moderated by increasing the pressu re of the substrate, but the addition of up to 40 Torr of Ar has no no ticeable effect on the product distribution. Calculations of the speci fic rate constant for hydrogen abstraction from isobutane by CF3, toge ther with the known Arrhenius parameters for this reaction, allowed th e temperature of the gas mixture to be calculated as a function of pre ssure.