SYNTHESIS, CHARACTERIZATION, AND ELECTROCHEMISTRY OF SOME ACRIDINE-1,8-DIONE DYES

The synthesis, characterization, and electrochemical behavior of some acridinedione derivatives are reported. Cyclic voltammetric studies sh ow that all the dyes undergo irreversible oxidation irrespective of th e substitution on the nitrogen. The product formed on oxidation is the aromatic derivative in the case of N-H compounds and the acridinium s alt in the case of the N-substituted compounds, which have been isolat ed and characterized. Formation of an intermediate carbon-centered rad ical is observed as evidenced by ESR spin-trapping experiments. A mech anistic scheme for the electrochemical oxidation is proposed. On carry ing out reduction after oxidation, different products are formed depen ding on the substitution on the nitrogen. There is no reduction of the oxidized product in the case of N-H compounds, and compounds with sub stitution on nitrogen undergo reduction consistent with the observatio n in N-alkylpyridinium salts.