Synthesis and Properties of Film Electrodes from N-Substituted Carbazoles in Acid Medium

Electroactive films were deposited on Au and glassy carbon electrodes by anodic oxidation of ethyl, phenyl and vinyl N-substituted carbazoles and were identified as C-C coupled polyetherocyclic sequences. In aqueous HClO4 the polyethylcarbazole filmed electrode exhibits two reversible oxidations which correspond respectively to 50 and 100% conversion into (cationic) polyiminic structures. An ac impedance investigation of the system outlined a behaviour typical of redox polymers. Polyphenylcarbazole films have similar characteristics. Conversely, oxidation of the N-viayl derivative leads to polycarbazole structures which have lost the pendant vinyl group owing to hydrolytic reactions.