Irradiated Single Crystal of Glycylglycine

Katayama and Gordy31 studied ESR spectra of y-irradiated single crystals of glycylglycine. The data were analyzed as described above to yield the 

The conclusion was that the radical produced by y-irradiation was that pictured in Table 4.6. This conclusion was based on the larger coupling to H than to N, but nonetheless there is a significant coupling to N. 

2 X-irradiated Single Crystal of Methylene Diphosphonic Acid 

Lucken and co-workers32 subjected a single crystal of methylene diphosphonic acid to X-irradiation. The ESR spectrum indicated that the radicals produced were those pictured in Tables 4.7 and 4.8. The spectra were analyzed as described above and the results are also summarized in the tables. The species shown in Table 4.7 is the more abundant of the two. The methylene group freely rotates at room temperature but is stationary at 77 K, where splitting from two non-equivalent protons is observed for some orientations of the crystal. 

Restrictions on diagonal elements None None None. v.v = Syy 

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