The mechanism of cyclohexane ring scission in radiolysis

Publisher Website
Google Scholar
Abstract
The processes of cyclohexane radiolysis in the liquid and solid state have been studied. The formation of unsaturated and saturated products of cyclohexane C–C bond scission have been studied as a function of dose, dose rate, temperature, the amount of scavenger (O2, NH3, CO2, N2O, C6H6) and the concentration of cyclohexane-benzene mixtures. It was found that the yields of all the products of cyclohexane ring scission display a pronounced phase effect at the change of aggregate state from liquid to solid. It has been shown that the formation of saturated and unsaturated products proceeds by entirely different mechanisms. It has been concluded that in the condensed phase the major mechanism of low molecular weight unsaturated product formation involves the decomposition of superexcited electronic states of cyclohexane molecules with further decomposition and/or stabilization of fragments. Radiation chemical yields of processes resulting in product formation and involving both charged and neutral species have been calculated. The comparison of radiation chemical data with the data of analysis of labelled products, formed by recoil tritium atoms in cyclohexane, leads to the conclusion that the mechanism of saturated product formation in radiolysis involves as a primary stage the scission of cyclohexane molecule C–C bonds by hot H atoms, produced in the system under irradiation.