Electron spin resonance investigation of the reduction of o-diaroylbenzenes by main group II metals

Abstract

Paramagnetic species obtained by reducing o-diaroylbenzenes electrolytically or with Main Group II metals have been studied by e.s.r. Ion-pairs, whose concentration decreases with decrease in temperature, are observed in fluid solutions. In rigid solutions triplet-state species, believed to comprise two radical anions complexed with one metal cation, are observed. Estimates of the out-of-plane rotation of the carbonyl groups in the radical-anions have been made on the basis of McLachlan calculations of the spin densities.