Yields of dimeric products in. gamma. -irradiated C/sub 10/H/sub 22//C/sub 10/D/sub 22/ mixtures at 77/sup 0/K. Evidence of an H/D isotope effect

The dimer products formed by ..gamma..-irradiation at 77/sup 0/K of frozen solution of n-decane-d/sub 22/ containing n-decane-h-/sub 22/ have been measured as a function of sample composition by means of capillary gas-liquid chromatography and mass spectrometry. The results have been analyzed to estimate the relative initial (prompt) yields of C/sub 10/D/sub 21/ and C/sub 10/H/sub 21/ radicals produced for each C/sub 10/D/sub 22//C/sub 10/H/sub 22/ concentration. Consistent with previous electron spin resonance examination of trapped radicals, the C/sub 10/H/sub 21/ yields effect. The data are consistent with the data obtained from an analysis of the isotopic composition of the hydrogen gas evolved in the same mixtures. Mechanisms are briefly discussed.