The Radiolysis of Ethanol: Iii. Liquid Phase

Abstract

The G values of the major products of the r-radiolysis of liquid ethanol a t a dose of 2 X 1020 eV/g are: hydrogen, 4.2; acetaldehyde, 1.9; 2,s-butanediol, 2.2; G(-CzHsOH) = 7.5. At progressively lower doses G(Hz),increases to a ~naximum of 5.0. The yield of water, G(Hz0) = 0.5, is equal to the sum of the y~elds of the Ce fragments found in the other products.The approximate yields of three kinetically distinguishable sources of hydrogen were found to be G(e& free ion) = 0.9, G(H) = 2.7 and G(unscavengeab1e Hz) = 1.5. The half,life of solvated electrons with respect to reactions such as e,,, + CeH50-+ H is 3 ps.Both l,3-pentadiene and benzene inhibit hydrogen and glycol formation but neither affect the high dose yield of acetaldehyde. Pentadiene reacts with H atoms and other radicals and possibly also with eklV. Benzene appears to inhibit hydrogen and glycol formation mainly by an unidentified activation transfer process.

The radiolysis of ethanol. VI. Hydrogen precursors at −196°C

“…This is consistent with the proposed mechanism because the same radical is formed by reactions [2] and [5]. Butanediol is formed by reaction [17] (2).…”

“…-+ 2H + CO, and a chain reaction ensues. In the present work, the yields of methane and carbon monoxide were unaffected by p~otolysis, so light of wavelength > 5 200 A does not cause reactions [8] and [9] (2), because the concentration of acetaldehyde formed a t the dose used would not be high enough to capture electrons that undergo geminate recombination when the sample is warmed. The sum of these results supports the suggestion that the mechanisms of the liquid phase (2) and solid phase radiolyses are similar.…”

“…[I] e~l , + CH3CHO --t CH3CHO-Reactions [I] and [2] occur when the samples are warming up, in the present instance.…”

“…3 ps a t 25 O C (2). If this difference in rate a t the two temperatures is due only to the activation energy of reaction [6], then…”

“…Benzene-free absolute ethanol from Reliance Chemical Company was purified by the method of Myron and Freeman (2).…”