Rare-Gas Sensitized Radiolysis of Propane

Abstract

The radiolysis of mixtures of C₃H₈ and nitric oxide containing excess amounts of the rare gases Xe, Kr, Ar, and He, and of equimolar amounts of C₃H₈–C₃D₈ in the same mixtures has been investigated. The product yields are compared with those expected assuming that the primary process leading to decomposition of the hydrocarbon is charge exchange with the appropriate noble gas, followed by ion—molecule reactions of the hydride‐transfer type. The experiments with deuterated propane demonstrate the formation of ethane and acetylene in bimolecular processes, and the production of methane, ethylene, and propylene chiefly by unimolecular decomposition. If it is assumed that neutralization of propyl ions results in the formation of ethylene and propylene as molecular products, the observations are consistent with the reaction sequence charge transfer, ion—molecule reactions, and neutralization leading to the production of unscavengeable species.