An electron spin resonance investigation of the reduction of o-diaroylbenzenes by Group III metals

Abstract

The e.s.r. spectra obtained when various o-diaroylbenzenes are reduced with Group III metals have been studied. Fluid solutions have spectra which show large metal hyperfine splittings and which are believed to arise from triple ions comprising a radical-anion, a dianion, and a metal ion. The temperature dependence of the intensity of the spectra of these species indicates that they are in equilibrium with species which do not have S½. In two cases where reduction was effected with aluminium the frozen solution spectra indicate the presence of triplet-state species, presumed to be triple ions containing two radical anions.