Formation of a novel electroactive film by electropolymerization of ortho-aminophenol (original) (raw)

The anodic oxidation of ortho-aminophenol (oAP) in acid aqueous media on different electrode materials, leads to the formation of an electroactive polymer, poly(oAP). Cyclic voltammetric studies allow the inference of a quite complex mechanism for the formation of this film. These studies and the spectroscopic data suggest that the structure of poly( oAP) is mainly a polymer of phenoxazine rings. To confirm these studies the electroactive polymer was also prepared by chemical oxidation of oAP and its properties were compared with those of the electrochemically produced poly( oAP). Moreover, a film was obtained by electrooxidation of the cyclic dimer of oAP, the 3-aminophenoxazone (3APZ). The differences between these films are discussed, leading to the conclusion that the actual monomer in the formation of poly( oAP) is 3APZ. However, the fact that the film obtained from pure 3APZ has an ideal nemstian behavior while the one obtained from oAP does not, gives evidence that side reactions and consequently a "side" polymer make the real structure of poly(oAP) more complex. Then the conditions for obtaining reproducible poly( oAP) modified electrodes are proposed.