ELECTRON SPIN RESONANCE ABSORPTION OF DIPHENYLPICRYLHYDRAZYL–ZINC OXIDE MIXTURES

Electron spin resonance measurements on mixtures of αα-diphenyl-β-picrylhydrazyl (DPPH) and zinc oxide when compared with corresponding determinations on DPPH itself, and with DPPH–potassium chloride mixtures, indicate that there is a transfer of electrons between the DPPH and the zinc oxide. These observations support earlier published views of Harrison and McDowell, who found that the above mixture was able to enhance the catalysis of the ortho–para hydrogen conversion, and the hydrogen–deuterium exchange reaction.