ELECTROCHEMICAL STUDY OF INTRAMOLECULAR CHARGE-TRANSFER COMPLEXES DERIVED FROM 1,4-NAPHTHOQUINONE .2. ELECTROOXIDATION OF 2-SUBSTITUTED 3-ARYLAMINO-1,4-NAPHTHOQUINONE AUTOCOMPLEXES

Electrochemical oxidation of intramolecular charge transfer complexes (ICTs) derived from 1,4-naphthoquinone has been studied in acetonitril e using cyclic voltammetry and RRDE. The anodic oxidation of 2-substit uted 3-arylamino-1,4-naphthoquinone autocomplexes AC I proceeds in one quasi-reversible stage. The ICT conformation is preserved not only du ring the electron transfer, but also in the cation radicals formed. Th e results, obtained from electro-oxidation of AC, confirm the marked e lectron acceptor properties of the arylamino moiety, at the same time acting as an electron donor in the intramolecular donor-acceptor (D-A) bond. A relationship between redox potentials and ICT electron transf er energy has been found in the case of AC I reversible electrochemica l redox reactions.