Spin trapping of radicals formed during radiolysis of aqueous solutions. Direct electron spin resonance observations

It is shown that hydrated electrons, hydrogen radicals and hydroxyl radicals formed by the radiolysis of water by 3 MeV electrons are trapped by nitroso and nitrone compounds to give nitroxides with well defined esr spectra. Three spin trapping agents were used, nitroso-t-butane, phenyl-t-butyl nitrone, and 5,5'-dimethyl pyrroline-1-oxide. The latter was shown to be an excellent compound for these studies. Complications due to the instability of some of the nitroxides were overcome by coupling the electron accelerator to the esr spectrometer to permit direct observation of the spectra. (author)