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I. MCALPINEAND H. SUTCLIFFE
The Radiolysis of Liquid Trifluoroiodomethane by I. McAlpine and H. Sutcliffe Chemistry Department, University of Salford, Salford 6 , Lancashire, England
(Received J u l y $1, 1969)
The radiolysis of trifluoroiodomethane in the liquid phase at room temperature has been examined. The products and 100-eV yields are tetrafluoromethane (0.37), hesafluoroethane (1.03), and iodine (1.36) Experiments in the presence of oxygen and nitric oxide as radical scavengers indicate that the reaction proceeds mainly by a radical process. I
The radiolysis of trifluoroiodomethane in the gas phase has been studied and shown to give the following products and 100-eV yields : tetrafluoromethane (1.08), iodine (0.13), and difluorodiiodomethane (0.82) . l Surprisingly, hexafluoroethane was absent in this gas phase work. This work was interpreted mainly in terms of radical abstraction of fluorine and radical combination reactions. It is of interest therefore to study the reaction in the liquid phase where spur reactions may be expected to give an increase in those products arising from radical-radical recombination reactions. We report here the results on the liquid phase radiolysis of trifluoroiodomethane, both alone and in the presence of the radical scavengers oxygen and nitric oxide.
Experimental Section The preparation of trifluoroiodomethane and the analysis of products was carried out as described previously.'I2 Samples for irradiation were sealed in Pyrex tubes 20 cm long X 5-mm id., having a wall thickness of 3 mm for all experiments except those involving oxygen. When oxygen was used, the tube was closed with a Hoke needle valve which was fastened to the glass by means of Araldite. The tubes were heated to 400" and evacuated before any reactants were introduced. Irradiations were carried out on a 10,000-Ci cobalt-60 source. The dose was measured using a modified Fricke dosimeter3 (G(Fe3+) = 0.66), and the usual corrections were made for electron density. The density of liquid trifluoroiodomethane at 25" was determined by sealing a known amount of the compound in a glass tube and measuring the volume occupied by the liquid at 25". A correction was made for the amount of trifluoroiodomethane in the gas phase. In this way a value of 2.115 g/ml was obtained. All sample volumes were in the range 2.3 0.1 ml in tubes of total volume 4 ml. The amount of sample in the gas phase was thus maintained at
