NMR and inelastic incoherent neutron scattering (IINS) studies of monohydroxy-17 and -21-substituted derivatives of progesterone.

Internal dynamics of 17- and 21-substituted progesterone derivatives was studied by the methods NMR, inelastic incoherent neutron scattering (IINS) and quantum chemical calculations. Comparison of the computer simulation of the phonon density of states (PDS) spectrum performed by the density functional theory (DFT) method with the spectrum obtained after a transformation of the experimental results permits an interpretation of subsequent modes. Only for 17OH prg the second moment of NMR line decreases to 10 G2 near room temperature, most probably because of the oscillations about direction of inter-molecular hydrogen bond.

ENDOR study of gamma-irradiated hydrated testosterone orthorhombic single crystals.

The molecular structure of free radicals formed in gamma-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 C(5), with one alpha-proton in position 4 and with four unequivalent beta-protons connected with the carbon atoms C(2) and C(6).

EPR/ENDOR investigations of gamma-irradiated steroid hormone single crystals.

The molecular structure of free radicals formed in certain gamma-irradiated steroid hormones and cholesterol determined by electron spin resonance (ESR) and electron nuclear double resonance studies has been reviewed. The influence of intermolecular interactions and hydrogen bonds on the structure of the radicals formed, as well as the effect of substitution of hydroxyl group on the alpha-hyperfine splitting tensor have also been analyzed.

EPR study of hydrated testosterone monoclinic and orthorhombic single crystals gamma-irradiated at 295 K.

The molecular structure of free radicals formed in gamma-irradiated monoclinic and orthorhombic single crystals of hydrated testosterone were investigated by EPR spectroscopy. Two different types of radical were observed. In the monoclinic form, the radical arises by the loss of a hydrogen atom from the carbon atom C(2), whereas, in the orthorhombic form, it arises by addition of a hydrogen atom to the oxygen atom O(3).