Vol 54, No 7 (2018)

In this work novel bisheterocyclic derivatives of alkylcarbazole with A–CZ–A architecture are investigated (CZ stands for alkylcarbazole). The study presents their opto-electronic and electrochemical properties which influence on the possibility of their prospective application. Monomers undergo electropolymerisation with formation of conducting layer of polythiophene derivatives, while presence of chalcone moiety hampers the process. Two-step oxidation processes of polymers results in generation of polaron and bipolaron types of charge carriers on the macromoleculs’ chains. The charge is delocalized over center and side subunits (bithiophene or bithiazole one) in first stage of oxidation. It is possible to influence on the properties of the polymers and their composition by variation of synthesis condition like solvent polarity and applied potential boundaries. Obtained conducting polymers show high stability under ambient conditions. Their energy gap values are estimated with electrochemical and spectroscopic methods.

The anodic oxidation of serine anion on smooth (Pt) and platinized (Pt(Pt)) platinum electrodes is studied by the methods of cyclic and linear voltammetry, rotating disk electrode, coulometry, and reflectance IR spectroscopy. On both electrodes, the potential regions of electrochemical transformation of this amino acid are determined. It is shown that electrooxidation of serine proceeds with abstraction of 4 and 2 electrons on Pt and Pt(Pt) electrodes, respectively. It is found that the anodic oxidation of serine anions proceeds from the adsorbed state; a possible kinetic scheme of this process is proposed.

The fundamentally new model describes the initial current transients during the growth of clusters in the diffusion mode after instantaneous nucleation. The specific feature of the model is that it is based on the initial hemispherical diffusion of ions from bulk solution to the surface of growing clusters rather than on the period of Cottrell current decay. The subsequent overlapping of diffusion zones is taken into account by multiplying the current by a factor smaller than unity. The factor is equal to the ratio of true diffusion volume to the “extended” volume, which is equal to the overall volume of all diffusion hemispheres ignoring their overlapping. The results calculated by the model appeared to be rather close to those obtained using the conventional Scharifker–Hills–Mostany model, and, thus, confirm the correctness of this model. In this connection, the reasons for its inconsistency with the experimental data on the number of growing clusters remain unclear.