ELECTRON SPIN RESONANCE SPECTRA OF RADICALS IN GAMMA IRRADIATED DICYANDIAMIDE

Abstract

The ESR spectra of three radical species have been observed near g = 2 in powder and single crystal samples of dicyandiamide (cyanoguanidine). ($NH_{2})_{2} C_{2}NCN$. One of the spectra is a broad line of width 8 G. The other spectra each show interaction of an unpaired electron with one proton and one $N^{14}$ nucleus. One radical, with $a_{H}$ = 29 G and $a_{N}$ = 16 G is a $\pi$-electron radical whereas the other, with $a_{H}$ = 72.5 G and $a_{N}$ = 6 G appears to be a $\pi$-electron radical. The origin of the radicals in relation to the atom positions in the undamaged dicyandiamide crystal will be discussed.