Kinetics of the Fully Inhibited Thermal Decomposition of Bistrifluoromethyl Peroxide, CF3OOCF3

Abstract

The pyrolyosis of CF3OOCF3 (BTMP) was studied in the gas phase from 5 to 100 Torr BTMP pressure and between 197 and 244 °C in a clean nickel reactor by the static method. CF3O radicals, due to the initial split[Formula: see text] were scavenged by SO3F radicals produced in situ by the thermal decomposition of their dimer S2O6F2. Under these conditions, CF3OOSO2F is the only product of BTMP pyrolysis, as shown by gas chromatographic analysis. Thus the BTMP pyrolysis becomes fully inhibited and the rate of accumulation of CF3OOSO2F is a measure of k1. The rate constant k1 turns out to be pressure-insensitive under the experimental conditions, from which it is inferred that k1 is actually k1∞, the limiting high-pressure unimolecular rate constant for reaction 1. Its temperature dependence yields the result[Formula: see text]This result is compared with other values of the O—O bond dissociation energy in BTMP. The experimental expression for k1 ∞ is used to construct the pressure falloff of k1 following the procedure of Forst. The calculation confirms that falloff begins only below 10 Torr.