Electrosynthesis of Poly(3,4-ethylenedioxythiophene) and Its Composite with a Polymer Perfluorinated Sulfo-Cationite from Water–Acetonitrile Solutions

Films of poly(3,4-ethylenedioxythiophene) (PEDT) are synthesized during anodic polarization from a water-acetonitrile mixture containing sulfo-cationite MF-4SK and without it. A comparison of electrochemical and spectroelectrochemical characteristics of the films and an elemental analysis evidence the formation of composite PEDT–MF-4SK. The immobilization of the polymer anion in the PEDT matrix is shown to alter its oxidation mechanism. For a neutral composite film, this mechanism includes the exit of sulfo-cationite cations and the entering of supporting anions.     

Anodic Polymerization of Aluminum Tetraaminophthalocyanine and Electrocatalysis of This Process by Polymer Perfluorinated Cation Exchanger MF4-SK

Anodic polymerization of aluminum tetraaminophthalocyanine chloride on conducting glasses in dimethyl formamide containing Bu₄NBF₄and the effect of cation exchanger MF4-SK on this process are studied. The polymer accumulation, monitored from optical absorption spectra, shows that introducing MF4-SK into solution or depositing it as a solid layer on the electrode accelerates the polymerization by a factor of four to six.     

Real energies of ferricinium cation transfer from water to organo-aqueous solvents

The redox potentials of ferrocene-ferricinium couple are determined for five organo-aqueous systems with respect to a reversible chloride electrode in the same solvent. Combined with the literature data on real (and some chemical) transfer energies of chloride ion, the effective real energies of ferricinium transfer from water into organo-aqueous mixtures are determined. These values do not obey the Born equation. Most probably, this is due to the selective solvation of cation by water and of neutral ferrocene molecule by an organic component.     

Polybithiophene Heterogeneity: A Differential Cyclic Voltabsorptometry Study

The redox behavior of polybithiophene in 0.1 M Bu₄NBF₄ solutions in acetonitrile is studied using cyclic voltammetry, potentiostatic spectroelectrochemical measurements, and differential cyclic voltabsorptometry. Comparing differential cyclic voltabsorptograms, obtained at wavelengths of 420, 475, and 520 nm for the undoped state and 720, 850, and 1050 nm for the doped state, with the cyclic voltammetry data reveals the polymer heterogeneity. The heterogeneity of the undoped polymer is ascribed to the formation of polymer chains of different lengths during the polybithiophene synthesis. The heterogeneity of the doped polymer is attributed to the existence of two types of an oxidized state. Both states presumably form as the result of the occurrence of two parallel processes. The first oxidized state is probably connected with the formation of a strong complex (associate) of positively charged fragments of a polymer chain with the dopant anion, while the second oxidized state is caused by a weak interaction between the dopant and the doped polymer.     

Poly(3,4-ethylenedioxythiophene) Heterogeneity: A Differential Cyclic Voltabsorptometry Study

A voltabsorptometry study of the redox behavior of poly(3,4-ethylenedioxythiophene) films in tetrabutylammonium tetrafluoroborate solutions in acetonitrile shows the polymer to exhibit heterogeneous properties when both reduced and oxidized. The measurements are taken at characteristic wavelengths selected on the basis of stationary absorption spectra. The reduced polymer's heterogeneity is explained under the assumption that the polymer contains simultaneously linear ( = 530 nm) and spiral ( = 660 nm) structures. The formation of two oxidized polymer states is proved experimentally. Both states presumably result from strong ( = 880 nm) and weak ( = 1050 nm) interactions between the anion and the positively charged polymer chain. The oxidized 880-nm state is shown to arise from the 660-nm state, whereas the 1050-nm state forms of the 530-nm state.