Radiation Damage Centers in Cholesteryl Heptanoate

Abstract

Cholesterol takes part signi cantly in many biological mechanisms and as important component for manufacture of bile acids, steroid hormones, and several fat-soluble vitamins. To determine magnetic properties of cholesteryl heptanoate (C34H58O2) which is an important cholesteryl ester in human life and new technology, the single crystals of cholesteryl heptanoate were grown by slow evaporation of concentrated ethyl acetate solution and the grown single crystals were irradiated at room temperature with Co γ ray. The radical produced by gamma irradiation has been investigated in the range of temperatures 123 330 K for di erent orientations of the crystal in a magnetic eld by EPR. Radiation damage center was attributed to radical ĊHαCH2β . The g factor and hyper ne coupling constants have slight dependence on temperature and evident dependence on the orientation of the magnetic eld. Determined g factor and hyper ne coupling constants for the radical ĊHαCH2β were found to be anisotropic with the average values gav = 2.0036, (aCHα)av = 14.52 G, (aCH2β )av = 25.78 G.