Electrochemical redox reactions of poly( 1,8-diaminocarbazole) (PDACz) films in aqueous (0.1 M HClO4) and nonaqueous(0.1 M LiClO4 in acetonitrile) solutions were studied by cyclic voltammetry, in situ vis/NIR and Raman spectroscopy. It has been demonstrated that spectroelectrochemical behavior of the polymer is strongly dependent on the nature of the solution used for doping-uncloping but not on the medium used for electropolymerization. A redox couples Fe2+/Fe3+, Fe(CN)(6)(4-/3-) and tertrathiafulvalene were used as the probes for the studies of electroactivity of the oxidized polymer films. The results were discussed in terms of different mechanism of deprotonation process of the polymer in aqueous solution of 0.1 M HClO4 and in 0.1 M LiClO4 solution in aprotic acetonitrile and the reaction schemes in the two media are proposed. (C) 2009 Elsevier Ltd. All rights reserved.