Electrochemical study on calix [4]quinone and calix[4]hydroquinone in N,N-dimethylformamide

Abstract

The voltammograms of calix[4]quinone (C[4]Q) and calix[4]hydroquinone (C[4]HQ) were measured in N,N-dimethylformamide (DMF) solutions containing tetraethylammonium perchlorate (TEAP). The cyclic voltammogram of C[4]Q had four reversible or quasi-reversible small waves and a more negative quasi-reversible large wave. Comparison between the oxidation–reduction potentials of C[4]Q and those of linear polymeric quinones cited in the literature shows that the oxidation–reduction potentials of these compounds are mainly determined by the intrinsic oxidation–reduction potentials of each quinone moiety in the molecule and the coulomb interaction energies between the newly entering electron and the unpaired electrons in the ready-reduced quinone moieties. However, the cyclic voltammogram of C[4]HQ had only one large anodic peak and one cathodic peak showing that the oxidation products have no positive charge.