Primary Radical Cations in Irradiated Ethylene Carbonate

Abstract

To search for and elucidate the nature of radical cations arising in irradiated liquid ethylene carbonate (EC), the effect of the external magnetic field on the radiation-induced fluorescence of fluorophore solutions in EC has been studied. Using quantum-chemical calculations, it has been shown for the first time that primary EC radical cations are rapidly transformed into ion–molecular complexes containing, in addition to the initial radical cation, one or more solvent molecules. In the complexes, two particles are oriented to each other by carbonyl groups, on which almost all of the spin density is localized. This result shows that the prevailing concepts describing the primary stages of liquid carbonate radiolysis should be revised, and the possibility of the formation of such ion–molecular complexes should be taken into account when studying the oxidative decomposition of carbonates used in organic electrolytes.