Charge Scavenging vs Hydrogen Atom Scavenging in the Radiolysis of Liquid Saturated Hydrocarbons

Abstract

The nitrogen and hydrogen yields from the γ radiolysis of solutions of nitrous oxide in various saturated hydrocarbons were measured. The nitrogen yields were nearly the same in all hydrocarbons, but the amounts of decrease in the hydrogen yields caused by the nitrous oxide varied markedly. The results support the suggestion that nitrous oxide reacts with electrons rather than hydrogen atoms in liquid hydrocarbons, but indicate that some nitrogen is also formed by another reaction and that all electrons do not eventually lead to hydrogen formation during the radiolysis of the pure hydrocarbon. The gaseous product yields from binary cyclohexane solutions of nitrous oxide and of propylene were subjected to kinetic analysis according to several models. It was concluded that the decrease in hydrogen yield caused by nitrous oxide and by propylene can be quantitatively interpreted in terms of interactions between the solutes and the charged intermediates. This offers an alternative to the hydrogen atom scavenging mechanism that has usually been assumed in the past for propylene. Although carbon dioxide and propylene do not attach electrons in the gas phase, they appear to do so in liquid alkanes. Propylene is a somewhat less efficient scavenger than is nitrous oxide.