Contents of Volume 81 №7 (2015)

Summary: The present Review aims to summarize and systematize published data devoted to (1) fundamental methods of fluoroalkoxy groups introduction in aromatic compounds and (2) methods of synthesis of five-membered heterocycles with poly- and perfluoroalkoxy substituents attached to heterocyclic ring or to annelated benzene ring. In this Review we analyzed the ability of fluoroalkoxy substituted five-membered heterocyclic compounds modification in order to obtain biologically active organic molecules and compounds for materials science.

Summary: Based on nanoparticles of lithium-lanthanum titanate and lithium-titanium-aluminum phosphate the thick films had been obtained by "tape casting" method. The microstructure and electrical properties of thick films was investigated. Established that thick film of lithium- titanium-aluminium phosphate characterized by conductivity 6^.10^–5 S/cm, which is similar to the conductivity of ceramics samples with a the same chemical composition.

Summary: The organic-inorganic ion exchange membranes based on polymer heterogeneous matrices containing nanoparticles of zirconium hydrophosphate (or nanoparticles of hydrated zirconiumdioxide) were synthesized. Interconnection between porous structure and functional properties of these materials was studied by methods of electron scanning microscopy, impedance spectroscopy, reference contact porosimetry, and potentiometry. It was determined that the nanoparticles promote intensification of ion transport through the membrane and aggregates serve as a barrier for penetration of non-exchange sorbed ectrolyte and organics which poison polymer, into the membranes. This barrier eliminates concentration polarization at prelimit current conditions and it, as a result, prevents sedimentation in the volume of membranes. Obtained materials were used for the electrodialysis of whey.

Summary: New complexone bis(phosphonometyl) aminosuccinic acid (H₆BPMAS) was synthesized for the first time by interaction of DL-aspartic and phosphoric acids with paraformaldehyde in acidic medium. Acid dissociation constants were identified by pH-potentiometric titration and spectroscopic and thermal characteristics of H₆BPMAS were also obtained. Equimolar complexes of Cu(II) with bis(phosphonometyl)aminosuccinic acid were studied in aqueous solutions (pH 1— 10). Formation of complexes with different proton composition was determined, their stability constants were calculated and distribution diagram depending on pH was drawn. Solid complex having composition of Na₄ [Cu- BPMAS(H₂O)₂]6H₂O was synthesized and its hydrated composition was established, the thermal characteristics were obtained and the coordination mode of Cu(II) with donor groups of bis(phosphonometyl)aminosuccinic acid was suggest.

Summary: 3-Arylpropanethiols-1: 3-naphthalene- 1-yl-propane-1-thiol (T1) and new 3-phenanthrene-9- yl-propane-1-thiol (T2), which was not described earlier, have been synthesized. It has been found that the adsorption of T1 and T2 on activated carbon in CH3OH solution takes place by themolecular mode of interaction and is described by the Langmuir equation. The structure of T1 and T2 films, adsorbed on atomically smooth surfaces of Au(III) and highly oriented pyrolytic graphite, has been investigated by scanning tunnel microscopy (STM). It has been found for the Au(III) substrate that T1 and T2 molecules form a disordered film, whereas 2-naphthalenethiol films consist of ordered islands of two types. In the case of graphite, there is no ordering. The oxidation of 3-arylpropanethiols-1 has been performed by the method of cyclic voltammetry (CV) with linear potential scan. In the CH3CN solution, the oxidation potential of T1 is 1.46 and 1.57 V for glassy carbon (GC) and platinum (Pt) electrode, respectively, and that of T2 is 1.43 and 1.49 V for GC and Pt electrode respectively.

Summary: The photoelectrochemical properties of nanocomposite films CdSe—reduced graphene oxide deposited on Ti-substrate with a crafted layer TiO₂ nanotubes (NT-TiO₂), the possibility of their use in photoelectrochemical system with the accumulation of hydrogen were studied. It is shown that the introduction of graphene oxide in semiconductor electrodes increases their photosensitivity, which is associated with a decrease in the surface recombination velocity. It is shown that the basic material of the cathode can be nanocomposites based on the reduced graphene oxide, whose characteristics in the hydrogen evolution reaction close to the platinum metals.

Summary: The optimal composition of a polyligand ammonium-chloride-fluoride electrolyte and electrolysis conditions for the deposition of functional tinnickel coatings are proposed. Tin-nickel alloy with tin content of 65 wt % and nickel content of 35 wt % has the greatest promise in microellectronics. It has been shown that the obtained coatings are suitable for soldering using low-temperature solders and acid-free fluxes and for ultrasonic spot welding.

Summary: Electrochemical processes on the gold cathode involving cysteine and acetylcysteine were investigated by electrochemical impedance spectroscopy, differential pulse voltammetry, and cyclic voltammetry. The differences in themechanism of electrochemical reduction of cysteine and acetylcysteine sulfhydryl groups are determined. Cathodic reduction of S–H bond with the formation and adsorption of RS– anion is shown to be the primary process for cysteine, while a specific adsorption is the primary process for acetylcysteine which accompanioned by splitting of S–H bond of sulfhydryl group and reducing of formed proton. The calculated free adsorption energies characterizing interaction of acetylcysteine with the substrate have lower values in comparison with the energies obtained for cysteine. The energies of lateral interactions of the adsorbed molecules calculated for these amino acids have opposite signs. The discovered features of the electrochemical behavior of the studied amino acids are due to the presence of uncompensated negative charge on the carboxyl group of acetylcysteine.

Summary: The samples of titanium dioxide (TiO₂) modified by β-cyclodextrin-containing polymers were synthesized. The obtained polymers were studied by UV- and IR-spectroscopy. The research results indicate that the TiO₂ modification has a significant positive impact on the methyl orange photodegradation. It was established that the modified TiO₂ samples containing β-cyclodextrin in binder layer are more effective than the other for the dye sorption and photodestruction. It should be noted that the obtained modified photocatalyst is promising for its using in the water treatment process from organic pollutants.

Summary: The influence of phenalenone dyes on the mobility of macrochains of crosslinked polyurethanes based on oligo(oxyprolylenglycol) (MM1000) and various diisocyanates: aliphatic diisocyanate (hexamethylene diisocyanate) and aromatic (toluene diisocyanate) was studied using EPR method with nitroxyl paramagnetic probe .It was found that introduction of phenalenone dyes into the polyurethane based on hexamethylene diisocyanate leads to increasing of mobility of macrochains as well as to increasing of the polymer permeability for probe. In polyurethane based on toluene diisocyanate macrochains mobility suppression is observed in the presence of phenalenone dyes and in most cases the polymer permeability decreases. This may be due to --interaction between dyes condensed rings and diisocyanate aromatic rings.