Abstract

The redox behavior and the interaction with OH-​ of juglone in DMSO has been studied by cyclic voltammetry, controlled-​potential electrolysis, UV, and magnetic susceptibility measurements. The interaction of the semiquinone with mol. oxygen generates the quinone and superoxide ion. The latter is a very strong base in DMSO and causes the dissocn. of the proton corresponding to the OH group in position 5. The resulting anion presents a redn. peak at -​1.12 V vs. SCE, generating the dianion of protonated juglone.