Determination of D[C6F5-I] by the toluene carrier method

The pyrolysis of C₆F₅I has been studied by the toluene carrier method over the temperature range of 900–978°K with contact times of 0.4–2.0 seconds and total pressures of 11.2–19.5 torr. Percent decomposition ranged from 8.6 to 97.7%. With toluene-to-C₆F₅I molar ratios of greater than 150, 85–100% of the C₆F₅ released abstracts a hydrogen atom from toluene to produce C₆F₅H. No significant quantities of I₂ were observed and the only major gaseous product was HI. Within the limits of the experimental method the decomposition of C₆F₅I was first order and homogeneous. Least squares analysis of log k₁ and 10³/T(C₆F₅I → C₆F₅ + I) values gives while a weighted line of best fit yields. Based on this latter equation DC₆F₅? I] at 298°K is estimated as 66.2 kcal/mole.