The Radiolysis of Organic Solutions. I. Acetone as a Trap for Hydrogen Atoms1

Autor: J. D. Strong, J. G. Burr
Rok vydání: 1959
Předmět:
Zdroj: Journal of the American Chemical Society. 81:775-779
ISSN: 1520-5126
0002-7863
DOI: 10.1021/ja01513a003
Popis: The irradiation with cobalt-60 gamma rays of mixtures of acetone and propanol-2 has shown that addition of acetone is highly effective in reducing the yield of hydrogen from propanol-2, whereas the yields of methane and carbon monoxide are almost unaltered. Irradiation of mixtures of propanol-2 with 5% acetone-d/sub 6/ produced mefthane, 3.2% of which derived from the acetone and hydrogen containing 3.7 atom% deuterium. From these datas from the failure to find biacetyl among the radiolysis products and from the lack of disproportionate increase in the yield of carbon monoxide with addition of acetone, it is concluded that the function of the added acetone is that of a trap for hydrogen atoms rather than that of an energy sink. Comparison of the radiolyses of pure acetone and acetone-d/sub 6/ shows that the ratio G(H/sub 2/)/ G(D/sub 2/i) is 2.66, the ratio G(CH/sub 4/)/G(CD/sub 4/) is 1.4 and the ratio G(CO)sub h/G(CO)/ sub D/ is 2.1. Irradiation of equimolar mixtures of acetone and acetone-d/sub 6/ gave hydrogen with H/sub 2/HD/D/sub 2/ ratios, suggesting that about 80% of the hydrogen was formed via processes other than unimolecular ones, and a CD/sub 3/H/ CD/sub 4/ ratio of 5.9 (suggesting a thermal radical mechanismmore » for the formation of methane). Evidence for the presence of hot'' hydrogen atoms in the radiolyses of acetone is discussed. (auth)« less
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