SUBSTITUENT EFFECTS ON REDOX POTENTIALS OF NOVEL AMPHOTERIC TERPHENOQUINONE ANALOGS - UNSYMMETRICALLY SUBSTITUTED 2,5-BIS(4-OXO-2,5-CYCLOHEXADIEN-1-YLIDENE)-2,5-DIHYDROTHIOPHENES

The unsymmetrically substituted derivatives of the title heterocycle-extended quinone have been synthesized and the substituents effects on their electrochemical properties have been investigated. The first reduction potentials and the first oxidation potentials correlate well with the Hammett SIGMAsigmap and SIGMAsigmap+ constants of the substituents, respectively.