K. H. NAPIER AND J. H. GREEN 



This probably applies to more complex compounds with correspondingly 

 more bonds to break. 



Thus by studying the effects of radiation on simple organic compounds, 

 it is possible to observe their behaviour. From these results it should be 

 possible to estimate the breakdown products from more complex compounds, 

 especially when we wish to look at biologically active compounds, which 

 could have as breakdown products, products that are active in a different 

 way from the original. 



One of lis {K. H. N.) wishes to acknowledge the grant of a Research Studentship 

 from the Australian Atomic Energy Commission, which made it possible for him to 

 undertake this work. 



REFERENCES 



^LiND, S. C. and Bardwell, D. C. /. Amer. chem. Soc. 48 (1926) 1575 



2DEWHURST, H. A. /. chem. Phys. 24 (1956) 1254 



3 Durham, R., Martin, G. and Sutton, H. Nature, Land. 164 (1949) 1052 



^Williams, R. R. and Gevantman, L. H. /. phys. Chem. 56 (1952) 569 



^Dewhurst, H. a. /. phys. Chem. 62 (1958) 15 



® Napier, K. H. and Green, J. H. Proceedings of the Symposium on Atomic Energy in 

 Australia Sydney, 1958 



'Green, J. H. and Napier, K. H. — in the press 



sSchuler, R. H. J. phys. Chem. 62 (1958) 37 



sDewhurst, H. a. J. phys. Chem. 61 (1957) 1466 

 lODoRFMAN, L. M. J. phys. Chem. 62 (1958) 29 

 "Stevenson, D. P. Trans. Faraday Soc. 49 (1953) 867 

 12CAFFREY, J. M., Jr., and Allen, A. D. /. phys. Chem. 63 (1958) 33 

 i^BuRTON, N., Chang, J., Lipsky, S. and Reddy, M. P. Radiation Res. 8 (1958) 203 



DISCUSSION 



Dr. Gray : I was wondering whether out of your observations you can reach any 

 idea of the relative probability of breaking a carbon-carbon bond thus liberating 

 one of the hydrogens ? That is one question. The second is whether by any chance 

 you have tried the two radical scavengers, namely oxygen or nitric oxide ? 



Mr. Napier: I will answer the second question first. I have not tried oxygen or nitric 

 oxide; as a matter of fact I am not too sure what effect oxygen has, but I have been 

 removing it by de-gassing under high vacuum, to reduce complications. The other 

 question regarding the breakage of carbon-carbon bonds to carbon-hydrogen bond — 

 I do not know of any mathematical calculations here, but I think it must be pointed 

 out that it is usually considered that the carbon-hydrogen bond is the stronger. Yet 

 from these results one appears to get a lot more breakage of the carbon-hydrogen bond. 



Dr. Gray: There is a great deal of energy to spare if one ionizes it, so that the fact 

 is that it is a stronger bond. It is interesting to know whether it breaks or does not 

 break. 



Mr. Napier: There is so much excess energy that the difference of a few calories in 

 the bond energy should not make any difference. 



Dr. Duncan : What you are really saying is that the bond energy in the excited state 

 is making the different order. 



93 



