The pyrolysis of CF3OOCF3 (BTMP) was studied in the gas phase from 1 to 200 Torr pressure and between 236 and 272 °C in a nickel reactor by the static method. Decomposition was limited to 5% to avoid complications. The reaction proceeds according to the overall stoichiometry BTMP CF3OF + COF2, as determined by analysis of the products. The reaction is self-inhibited by COF2 and accelerated by the addition of inert gases N2, CO2, and C2F6. Addition of 1-400 Torr of C2F6 was studied at 232 and 260 °C. A mechanism is proposed that accounts for the initial rate. Its main features are: (1) steady-state concentration of CF3O radicals maintained by the equilibrium BTMP 2CF3O;(2) the rate-determining step is the unimolecular decomposition of the CF3O radical which is pressure dependent and reversible: CF3O (+M) 4n COF2 + F (+M); this also accounts for the inhibition by COF2. The expression for initial rate is = 2! (A 1 /A 5) [BTMP])1/2, with ko pressure dependent. The observed experimental activation energy of 49.7 kcal/mol therefore corresponds to E2 + %(Ei -E5).

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BERNARD DESCAMPS and WENDELL FORST. Can. J. Chem. 53,1442(1975). The pyrolyosis of CF300CF3 (BTMP) was studied in the gas phase from 5 to 100 Torr BTMP pressure and between 197 and 244 O C in a clean nickel reactor by the static method. C F 3 0 [1 I radicals, due to the initial split CF300CF3 + 2CF30, were scavenged by S 0 3 F radicals produced in situ by the thermal decomposition of their dimer S206F2. Under these conditions, C F 3 0 0 S 0 2 F 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 C F 3 0 0 S 0 2 F is a measure of kl. The rate constant kl turns out to be pressure-insensitive under the experimental conditions, from which it is inferred that k1 is actually klw. the limiting high-pressure unimolecular rate constant for reaction 1. Its temperature dependence yields the result klw (s-l) = 1015.9f0. L'expression experimentale pour klw est ensuite utilisee pour la reconstitution de la courbe de la chute de k1 avec la pression, suivant la prockdure de Forst. Ce calcul confirme que k1 ne chute qu'au dessous de 10 Torr.

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