ÉTUDE DES SPECTRES DE RÉSONANCE PARAMAGNÉTIQUE ÉLECTRONIQUE DE RADICAUX ALLYLIQUES POLYORIENTÉS

Abstract

The effect of the hyperfine coupling anisotropy on the shape of the electron spin resonance spectra of randomly oriented allyl radicals has been studied by means of electronic computer calculation. The line shape has been shown to be strongly dependent on the relative orientation of the tensor axes, and it can be used, therefore, to characterize the structural isomerism of the radical. The comparison of the computed spectra, taking account of the ġ tensor anisotropy, with the spectra recorded after γ irradiation of several monoethylenic compounds, allowed the identification of the produced allyl radicals and showed that, in most cases, these radicals keep the geometrical configuration of the corresponding undamaged molecules.