SVNIHI.SIS OF ORGANIC COMPOUNDS BY IOM/I\(, RADIATION 



addition, half-lioui irradiations were made using an X-ray machine, but the 

 absorbed dose was ratlier low. However, the range was considered wide 

 enough to test the claim of the synthesis with u.v. light and X-rays. 



The method of jjrecipitation given by Loiselcur gave negative results and 

 the behaviour of the reagent was found unreliable. The chromatographic 

 method of identifying urea was found to be more sensitive, and was limited 

 however, by the final concentration of the diamine added to the paper. The 

 'tailing' effect increased with the concentration of diamine. Again, negative 

 results were obtained. 



It seems that the formation of a blue colour in the Loiseleur solution was 

 considered by him to be a measure of irradiation beyond the optimum for 

 maximum urea yield. Our observations showed that the colour was obtained 

 shortly after the preparation of the solution and increased markedly during 

 the course of several days. It is assumed that this is not a simple oxidative 

 phenomenon because of its occurrence in various polar solvents. Complete 

 oxidation of w-phenylencdiamine produces yellow-brown cjuinoid substances. 

 The intensity of this blue colour increased sharply after two hours irradiation 

 with the y-ray source. Although no attempt was made to identify the blue 

 compound, from its chromatographic behaviour, separation and purification 

 for this purpose appears feasible. 



In postulating a reaction mechanism for this complex system, under the 

 conditions of aeration, the action of OH radicals must be considerable, 

 suggesting the formation of phenolic (or even polyhydidc) intermediates. 

 Reaction may then follow with ?«-phenylenediamine present or \vith latter 

 and further oxidized phenolic bodies. The catalytic behaviour of the phenyl- 

 enediamine would also need mass-balance studies. Unfortunately no energy 

 absorption measurements were reported by Loiseleur, although a high X-ray 

 flux at the liquid surface was used (200,000 roentgen per min). It is possible 

 that this fact may be significant for successful synthesis. 



REFERENCES 



^CoLLiNsoN, E. and Swallow, A.J. Chem. Rev. 56 (1956) 471 



^United Kingdom Atomic Energy Authority Reports A.E.R.E. CjR 1575 (/), (2), {3) et seq. 



^Oparin, a. I. The Origin of Life : Dover Publications, Inc., New York, 1953 



*Urey, H. C. The Planets: Yale University Press, New Haven, 1952 



^LiND, S. C. The Chemical Effects of Alpha Particles and Electrons: Chemical Catalog 



Company, New York, 1928 

 «Stevenson, D. p. J.phys. Chem. 61 (1957) 1453 



^Meisels, G. C, Hamill, W. H. and Williams, R. R. /. Phys. Chem. 61 (1957) 1456 



* Napier. K. H. and Green. J. H. unpublished work 1958; Proceedings of the Second 



Australasian Corference on Radiation Biology: Buttcrworths, London, 1959 p. 87; 



Proceedings of the Symposium on Atomic Energy in Australia Sydney, 1958 



^ Field, F. H. and Franklin, J. L. Electron Impact Phenomena: Academic Press Inc., 



New York, 1957 

 loScHULER, R. H. f.phys. Chem. 62 (1958) 37 

 i^Magee, J. L. and Ganguly, A. K. /. phys. Chem. 25 (1956) 129 

 12MAGEE, J. L. Ann. Rev. nucl. Sci. 3 (1953) 171 

 inViLZBACH. K. R. ./. Amer. chem. Soc. 79 (1957) 1013 

 "Keller, M. and Weiss, J. J. chem. Soc. (1951) 1247 



114 



