Primary step in the mercury photosensitization of propane and deuterated propanes

The primary processes in the mercury-photosensitized decomposition of propane and three deuterated propanes have been studied at low pressures. The primary radicals were trapped by methyl radicals, from the in situ decomposition of dimethyl mercury, and the products measured by gas chromatography. The trapping technique was checked by using 1-chloropropane, 2-chloropropane, and their mixtures. The butane yields were representative of the primary radical yields.The ratio of i-butane to n-butane from the propane reaction was found to be dependent on light intensity, which fact, not having been recognized before, vitiates earlier results. The ratio varied between 0.3 (at high intensity) and 8.5 (at low intensity). The i-propyl to n-propyl split in the primary step of propane is 9.1 to 1.0, as found earlier by Holroyd and Klein.