ENDOR study of γ-irradiated hydrated testosterone orthorhombic single crystals

The molecular structure of free radicals formed in γ-irradiated orthorhombic single crystals of hydrated testosterone was investigated by Electron Nuclear Double Resonance (ENDOR) spectroscopy. Only one kind of radical was observed, which is formed by addition of hydrogen atom to oxygen atom O(3). We observed interaction of the unpaired electron, which is delocalized on the carbons C(3), C(4) and C95), with one α-proton in position 4 and with four unequivalent β-protons connected with the carbon atoms C(2) and C(6). The matrices of the hyperfine couplings and the g-factor of the radical are given.