RADICAL CATIONS FROM NITRONE SPIN-TRAPS - REACTION WITH WATER TO GIVEOH ADDUCTS

Exposure of dilute solutions of three widely used nitrone spin-traps i n dry Freon matrices (CFCl3) at 77 K to ionising radiation gave corres ponding radical cations, characterised by their EPR spectra. On meltin g, these radical-cations were stable and good liquid-phase EPR spectra were obtained, together with spectra for chloride ion adducts. When s olutions containing water were used, the same cations were detected at 77 K. However, on melting, isotropic spectra characteristic of the (O H)-O-. radical adducts were obtained in high yield. These results are discussed in terms of the use of nitrone spin-traps to detect (OH)-O-. radicals, especially in biological systems.