Line-width alternation by methoxy group rotation in the electron spin resonance spectra of a phenoxy radical

Abstract

ESR spectra of the 2,6-dimethyl-4-methoxyphenoxy radical show line-width alternation at temperatures from 0 to −80°C. The effect is ascribed to the rotation of the methoxy group. The line-width analysis is given in terms of the relaxation matrix theory. From the spectra a value of 7.8 kcal/mole is estimated for the experimental energy of activation. This value is compared with dielectric relaxation data.