Electron spin resonance (ESR) spectroscopy of both experimental and theoretical aspects revealed the gamma irradiated radicals in two glucose polymers, cellulose and starch. Prior to the irradiation, ESR signals are silent in both the glucose polymers. After the irradiation, however, a singlet signal at
g = 2.0 was appeared in both the glucose polymers. The twin peaks were induced at the symmetric fields in the both sides of the singlet peak in cellulose sample. Conversely, the twin peaks were invisible in starch sample. We identified the twin peaks to be a part of triplet signal and determined the molecular structure of the cellulose radical. By the theoretical simulation method, we revealed, for the first time, that the triplet signal was attributed to the hyperfine interactions with two protons in the radical. The third peak within the triplet is overlapped by the organic radical at
g = 2.0. We found that the cellulose radical does not remain in the rigid limit or the static state, but rather undergoes axial rotations around both C-C and C-H bonds. Thus the triplet may be used as a dosimeter for the irradiated plant foods.
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