Electron paramagnetic resonance study of γ-irradiated [(CH3)4N]H2F3 single crystals

Abstract γ -Irradiated [(CH 3 ) 4 N]H 2 F 3 single crystals and powders were investigated by electron paramagnetic resonance (EPR) technique at ambient temperature. It has been found that this compound indicates the existence of ( CH 3 ) 3 N + radicals after γ -irradiation. The isotropic g factor and the isotropic hyperfine constant for H atoms were measured as 2.0031 and 28.8 G, respectively. The hyperfine coupling constant of the N nucleus, observed in ( CH 3 ) 3 N + radical was found to be anisotropic with A z =15.9 G, A y =21.9 G and A x =22.1 G values. These results indicate that each methyl group rotates around its C 3v axis and three methyl groups also rotate around the C 3v axis of ( CH 3 ) 3 N + radical. In addition to these motions, the C 3v axis of the radical seem to rotate around the c- axis of the crystal. These results were compared with the literature data for similar compounds and the EPR properties of the ( CH 3 ) 3 N + radical were discussed.