Electron Spin Resonance of γ-Irradiated, Substituted Toluenes

Abstract

THE results reported here were obtained during an attempt to study the energy transfer efficiency from low-temperature, rigid glass solvent to dissolved solute molecules on γ-irradiation. This has recently been studied by Porter et al. ¹, who recorded the ultraviolet absorption spectra of both γ-irradiated and ultra-violet illuminated side-chain substituted aromatic hydrocarbons dissolved in hydrocarbon glasses at 77° K. and, using comparative methods previously reported^2,3, assigned the various spectra to benzyl-type radicals. It was thought that using the electron spin resonance technique instead of ultra-violet spectroscopy, additional information might be obtained ; but preliminary experiments soon showed that, while a radical signal characteristic of the solute could be detected, the fine structure of the electron spin resonance spectrum of the glass solvent made quantitative estimations impossible. However, the electron spin resonance spectra of the various radicals produced by γ-irradiation of the pure, degassed, frozen solutes alone were determined.