Electron spin resonance studies. Part XXXVI. Formation of ion-pairs by semidiones and related radicals in aqueous solution

Abstract

The one-electron oxidation of some α-hydroxy-acids or the one-electron reduction of α-keto-acids or α-diketones, in aqueous solution, yields hydroxysemidiones or semidiones which, in the presence of an appropriate di- or tripositive metal ion, give metal complexes; in some cases metal-ion splittings can be observed. Data relating to the structures of the complexes are reported and discussed.