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Electron paramagnetic resonance study of the paramagnetic center in gamma-irradiated tetrahydrophthalic anhydride single crystal

Electron Paramagnetic Resonance (EPR) analysis of gamma-irradiated tetrahydrophthalic anhydride (C8H8O3) single crystals was performed at 120 K. The single crystals were exposed to 60Co-gamma source at room temperature. The EPR spectra of gamma-irradiated single crystals of tetrahydrophthalic anhydride (THPA) were recorded at 10-degree intervals for different orientations of crystals in a magnetic field. Detailed examination of THPA single crystals by EPR spectroscopy method showed the presence of two carbon-centered THPA anion radicals. Both radicals were determined to have the same structure. The anion radicals observed in gamma-irradiated THPA single crystal were created by the scission of the carbon–oxygen double bond. The g values of the radiation damage centers observed in the THPA single crystal and the hyperfine structure constants of the free electron with nearby protons were obtained. Highlights Single crystals of tetrahydrophthalic anhydride were exposed to gamma radiation. Radiation damage centers in single crystals of tetrahydrophthalic anhydride were determined by EPR spectroscopy method. The presence of two anion radicals in single crystals of tetrahydrophthalic anhydride was determined. The formation mechanism of the paramagnetic centers in the tetrahydrophthalic anhydride is similar to that of succinic anhydride.