Radiation mechanisms. Part I. Inorganic salts in aqueous solutions: electron spin resonance studies of γ-irradiated aqueous glasses containing oxyanions

Abstract

Acidic, neutral, and alkaline aqueous glasses containing the anions perchlorate, chlorate, chlorite, perbromate, bromate, sulphate, sulphite, selenate, selenite, phosphate, hydrogen phosphite, and arsenate have been exposed to ⁶⁰Co γ-rays at 77 K and their e.s.r. spectra recorded. Primary products detected include e_t^–, ȮH(ȮD), ·H(D), ·O^–, and in certain instances species formed from the oxyanions by electron-capture (e.g. ṠeO₄^3–, ȦsO₄^4–), or hole-capture (e.g. PO·₄^2–, AsO·₄^2–).

On annealing above 77 K, reactions between the primary species from water and the oxyanions were observed (e.g. ·OH + HPO₃^2–→H₂O + ṖO₃^2–; ·OH + SeO₃^2–→HOSėO₃^2–). These results of ‘temperature resolved’ processes are compared with those from pulse-radiolysis optical studies, and steady-state e.s.r. studies.