Formation of Electrons and of Atomic Hydrogen in γ-irradiated Ice

Abstract

IN ice at 77° K containing acids such as sulphuric, perchloric and orthophosphoric, irradiated with γ-rays, hydrogen atoms were first detected by electron spin resonance by Livingston, Zeldes and Taylor¹. In neutral ice, however, no hydrogen atoms were observed at 77° K although some were detected at 4° K². It has been suggested³ that radiation-produced electrons, (H₂O)⁻, which have been shown⁴ to occur in the radiolysis of aqueous solutions, may react with a hydrogen ion in the acidic ice to produce a (stable) hydrogen atom: In an analogous manner we may expect that a Brønsted acid such as H₂PO⁻₄ may react to form a hydrogen atom, by a proton transfer, according to the equation: Such reactions have been suggested to occur in aqueous solution⁵. In the case of bisulphate, one would have the analogous reaction: although there are reasons to suggest that here, as in the other cases, the reaction goes to a greater or lesser extent through an unstable intermediate, namely (HSO₄)2⁻, which may break up according to: and possibly also to some extent: