The intramolecular isotope effect in the pyrolysis of 1– 14 C propane

Abstract

1- 14 C propane has been synthesized from active barium carbonate in 50 % yield. This propane has been pyrolyzed at temperatures from 550 to 603°C, both in the presence and in the absence of added nitric oxide. The methane formed by this thermal decomposition was converted into carbon dioxide, the specific activity of which was determined. By comparison of this with the specific activity of the carbon dioxide obtained by the complete oxidation of the original propane it has been possible to determine the relative rates of rupture of the bonds 12 C— 12 C and 12 C— 14 C. The former is found to break about 8 % more frequently than the latter, in both the normal and in the inhibited reaction. The results obtained are discussed in relation to the mechanism of the decomposition.