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.

No abstract

The value of G (-ethanol) in the vapor phase is nearly double that in the liquid phase. Part of the difference appears to be due to the recombination of radicals in liquid cages. Ethanol molecules, on the average, break into s~llaller fragments in the gas than in the liquid phase radiolysis. The isotopic con~positions of the hydroge? produced from various deuterated ethanols are consistent with the suggestion that the reactlon CH,CH?OH+ + CH3CH,OH + CH3CHzOH?+ + CH3CH?O occurs t o a significant extent in the liquid but not in the gas phase. This reaction probably involves the shift of a hydrogen atom along a hydrogen bond. The reaction C?HjOH?+ + e,,~; + C?H50 + H 2 does not occur to an appreciable extent in the liquid phase. I n the liquid phase the relative contributions of the three different groups in the ethanol molecule to hydrogen production are in the order CN2 > OH >> CH3. H similar trend occurs in the gas, although the contributions of the three groups are more nearly equal in this phase. Isotope effects, in the range kn/ku = 2.2-3.9 per bond, occur in the methane formation mechanism. The isotope effects are some\vhat srllaller in the liquid than in the vapor phase and somewhat smaller in the inhibited than in the uninhibited systems. H comparison of product distributions in the liquid and gas radiolyses of several compounds by y-rays and by a-particles indicates that L.E.T. effects can also occur in the gas phase. ISTRODUCTIONI t has been suggested that the reaction [I] CH,CH?OH+ + CHJCM~OH + CH3CH20Me+ + CH3CH20 occurs in the liquid phase radiolysis of ethanol (I). Since this reaction merely involves the shift of a hydrogen atom along a hydrogen bond, it should occur to a smaller extent in the vapor than in the liquid phase. This hypothesis can be tested by irradiating C 2 H 5 0 D and CzD5013 in the liquid and vapor states to determine the contributions of the hydroxyl hydrogen to the product hydrogen in the two phases. I t is expected that the contribution of the hydroxyl hydrogen will be greater in the liquid phase. The present paper reports the results of this test. TO increase the confidence that inay be placed in the results and their interpretation, the isotopic colnposition of the product hydrogen froin CHsCDnOH, CD3CH20H, and CzDBOD is also reported.Ryan et al. (2) have recently observed that reaction [I] does not occur to an appreciable extent in a mass spectrometer, but that the reaction occurs very readily. However, all of the reactions [3]-[5] occurred readily under the salne conditions as those used for the ethanol study, so the situation is not clear.

The ultraviolet absorption spectra and infrared carbonyl bands of a number of s~~b s t i t~l t e d benzoyl chlorides are determined. It is found that as a first approximation the B-bands of the ultraviolet spectra are similar for benzoyl chlorides and for the corresponding be~~zalde-hydes and acetophenones. T h e spectra are discussed in terms of previo~~sly stated hypotheses.In this wav the order of the aDDarent nerative mesomeric effect is deduced t o be -NO. > -COCI >--CHO > -COCI~;, and theYeffective size of these substituents is confir~nid t o be in the order -NO2

With an initial microbial level of ca. 107 microorganisms per g of Ivory Coast cacao beans, 5 kGy of gamma radiation Linder an atmosphere of air reduced the microflora per g by 2.49 and 3.03 logs at temperatures of 35 and 50°C, respectively. Bahia cacao beans were artificially contaminated with dried spores of Aspergilliusflaias and Penicillium citrinurm, giving initial fungal levels of 1.9 x 104 and 1.4 x 103 spores per g of whole Bahia cacao beans, respectively. The average D (values for A. flaiw'is and P. citrinum spores on Bahia cacao beans were 0.64 and 0.88 kGy. respectively.