Reaction of hydrogen atoms with solid unsaturated hydrocarbons at 77 K

Abstract

The reactions of thermal hydrogen atoms with solid unsaturated hydrocarbons at 77 K were investigated. The H atoms were found to penetrate deep into the organic films and the unsaturated hydrocarbons were hydrogenated to fully saturated compounds with high yields. The yields of the hydrogenated compounds are highly dependent on the rates of the H atom addition reactions to the reactant molecules, i.e. the smaller the rate of the H-atom addition reactions, the higher the yield of the hydrogenated compounds due to the longer distance of the H-atom migration in solids. The relative yields of the hydrogenated products in the solid-phase reactions are in the order isobutene>benzene>tetramethylethylene>toluene≈1,4-cyclohexadiene>1,3-cyclohexadiene>cyclohexene>cyclopentene.