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

Abstract

gamma-Irradiated [(CH3)(4)N]H2F3 single crystals and powders were investigated by electron paramagpetic resonance (EPR) technique at ambient temperature. It has been found that this compound indicates the existence of (CH3)(3) N+ radicals after gamma-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 (CH3)(3) ($) over circleN(+) radical was found to be anisotropic with A(z) = 15.9 G, A(y) = 21.9 G and A(x) = 22.1 G values. These results indicate that each methyl group rotates around its C-3v axis and three methyl groups also rotate around the C-3v axis of (CH3)(3) ($) over circleN(+) 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 (CH3)(3) ($) over circleN(+) radical were discussed. (c) 2007 Elsevier Ltd. All rights reserved.