Solvent and Temperature Effects on the Proton hfs in the ESR Spectra of the Organic Radical

Abstract

Abstract A theoretical investigation is made into the solvent and temperature effects on the proton hfs in the ESR spectra of such organic radicals as: (Remark: Graphics omitted.) where X stands for the CH3 group, in several solvents. Both effects are explained on the assumption that a molecular complex is formed between radical and solvent, so that the charge-transfer occurs from radical to solvent: The solvent effect is caused by the fact that, in various solvent molecules, slight changes take place in their lowest vacant levels, which are occupied by the electron transferred from the radical; on the other hand, the temperature effect is explained by the thermal motion of the molecules, which changes the probabilities of the radical being in the solvated state and in the free state.