H-1 AND 2D ELECTRON NUCLEAR DOUBLE-RESONANCE (ENDOR) AND ELECTRON-SPIN ECHO ENVELOPE MODULATION (ESEEM) INVESTIGATIONS ON GAMMA-IRRADIATED BETAINE ARSENATE

Electron spin resonance, electron nuclear double resonance and electron spin echo envelope modulation measurements were performed on gamma-irradiated betaine arsenate single crystals. The investigations revealed that two radicals, N(CH3)3 and (CH3)3N+CHCOO-, are formed by the gamma-irradiation at room temperature. The concentration of both radicals decays in time with a time constant of a few days. In deuterated betaine arsenate the protons of the CH2 group are partially replaced by deuterons. The N-14 hyperfine coupling tensor of the N(CH3)3 radical as well as the H-1, 2D hyperfine coupling tensor and the 2D quadrupole tensor of the (CH3)3N+CHCOO- ((CH3)3N+CDCOO-) radicals were determined.