French-Ukrainian Journal of Chemistry
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The quasi-perpetual electricity generating device based on ceramic fuel cell for closed systems
Get PDFThe features of ceramic fuel cells developed in Ukraine are discussed and their application for production of hydrogen and oxygen in a closed loop device combining ceramic fuel cells (CFC) and ceramic electrolyser cells (CEC) is considered. High-temperature electrolysis is profitable for production of hydrogen and oxygen from hot water steam, that is outcoming gas of CFC’s reactions and released traditionally in environment, as it is demonstrated theoretically
Reaction of 1-aminoisoindole with 1,4-naphthoquinone and study of the product by spectroscopic methods.
Get PDFIn our previous researches we have shown, that 1-aminoisoindole, which exists predominantly in isoindoline tautomeric form, can undergo [4+2]-cycloaddition reactions with maleimides according to the Curtin-Hammet principle. We continued to study this reaction, but with another dienophile – 1,4-naphtoquinone. In this case, the reaction does not stop when the bis-Michael adduct is obtained, but continues with the formation of a more complex compound, the structure of which we have studied by two-dimensional NMR spectroscopic methods
New Ferrocenyl Phenol Thiophosphines
Get PDFTwo new enantiomerically pure ferrocenyl phenol-thiophosphine compounds have been efficiently synthesized by a one pot procedure from enantiomerically pure alcohol (R)-(diphenylthiophosphinoferrocenyl)methanol 1 by a fully regioselective Friedel-Crafts reaction on phenols after strong acid activation. A mechanistic proposal through O-alkylation followed by rearrangement of the formed oxonium is proposed. All compounds have been and fully characterized by NMR(1H, 31P and 13C) and High Resolution Mass Spectroscopy. The molecular structure of one of these ferrocene derivatives have been determined by X ray diffraction analysis on monocrystal
Influence of Indifferent Electrolytes on Formation of Coagulative Structures in Aqueous Silica Dispersions
Get PDFEffects of indifferent electrolytes (NaCl, KCl, LiCl, NaI, NaNO3, CaCl2, and MgCl2) on the electrical double layer (EDL), aggregation, gelling, and rheological properties of aqueous dispersions of nanosilica were investigated. All examined indifferent electrolytes enhance interactions between nanoparticles of fumed silica through the coagulation mechanism. The critical concentration of gelation and gelling time decrease in the presence of the electrolytes, while the effective viscosity of the dispersions and average size of aggregates (Def) increase in series of chlorides: Li+ < Na+ < K+ < Ca2+ < Mg2+. That corresponds to an increase in the cation radius and reduction of the hydration shell. The nature of anions and cations significantly affects the values of Def and viscosity. For sodium salts, the viscosity increases in series I- < NO3- < Cl- corresponding to an increase in the hydration shell
Sulfonyl-bridged Calix[4]arene as an Inhibitor of Protein Tyrosine Phosphatases
Get PDFPreviously, phosphonic acid derivatives of calix[4]arene and thiacalix[4]arene were found to be potential inhibitors of protein tyrosine phosphatase 1B. In the present paper, the inhibitory activity of unsubstituted sulfonyl-bridget calix[4]arene towards some of the therapeutically important protein tyrosine phosphatases has been established. The obtained results showed that the sulfonylcalix[4]arene is able to inhibit protein tyrosine phosphatase MEG2 with IC50 value in the micromolar range. At the same time, the inhibitor demonstrated lower activity in case of other protein tyrosine phosphatases such as PTP1B, MEG1, TC-PTP, SHP2, and PTPβ. The performed molecular docking indicated that the inhibitor binds to the active site region of MEG2 and PTP1B with WPD-loop in the open conformation
Thermochemical properties of liquid alloys along xCu/xSb= 0.2/08 section of the ternary Cu-Sb-Ce system
Get PDFThe enthalpies of mixing of liquid alloys of the ternary Cu–Sb–Ce system were studied by high-temperature calorimetry along the cross-section = 0.2/0.8. The composition dependence of these values were modelled using four "geometric" models and also the analytical method of Redlich–Kister–Muggianu. A comparison of the experimental data for the cross section = 0.2/0.8 and simulated values of the enthalpies of mixing showed that the most suitable for describing the properties of liquid alloys of ternary Cu–Sb–Ce system is the Toop model
Electrooxidation of Se on nanodispersed films of titanium dioxide modified with ZnO and Au
Get PDFSelenium electrooxidation process on TiO2 and TiO2/ZnO electrodes, modified by gold nanoparticles, was investigated in solutions of sulfuric, chloric and citric acids. It is shown that TiO2/ZnO/Au electrodes can be used as indicator electrodes at the determination of selenium by anodic stripping voltammetry method. Optimum conditions of selenium (IV) determination are: supporting solution 0,001М H2SO4, electroconcentrating potential -(1,3¸1,5) V; time of electrolysis 120 s, scanning speed of potential 20 mV/s
Сitric acid influence on electroreduction processes in low concentrated Cu(NO3)2 solutions
Get PDFPhysico-chemical regularities citric acid influence on processes of copper and nitrate-ions reduction in low concentrated nitrate solutions were established. An influence of pH value on inhibitor action of low concentrations of the additive according to cathode reduction reaction of nitrate-ions, on kinetics of copper electrodeposition, on structure of the precipitates obtained was shown. Polarization measurements show us changes of copper electrodeposition at introduction of citric acid in Cu(NO3)2 solution. By the methods of traced elements and extraction into aqueous phase the reversible inclusion complexes into electrolytic copper, was established that proves participation of complexes in cathode process
The synthesis of angular heteroarenochromones based on 7-hydroxy-8-carbonylchromones
Get PDFThe present review highlights advanced strategies to the synthesis of the chromones annulated with O- and N-containing heterocycles at C(7)-C(8) bond. Due to the prevalence of such motives in different kinds of natural flavonoids and some alkaloids, fused chromones have attracted a great deal of attention so far. On the other hand a wide range of biological activities is displayed by the compounds of this type both among naturally occurring flavonoids and their synthetic analogues. 8-Carbonyl-7-hydroxychromones proved to be versatile synthones for the synthesis of angular hetarenochromones via approach of annulation of a heterocycle to the chromone core. It also addresses the question of the biological activity of naturally occurring and fused synthetic hetarenochromones
Structure and electronic absorption spectra of cyanine dyes – derivatives of tetrazolo- and triazoloisoindole
Get PDFThe electronic structure and absorption spectra of cyanine dyes – tetrazoloisoindole derivatives and triazoloisoindole were calculated. It was shown that these dyes, in terms of their electronic structure, are trimethine cyanine, although formally they are monomethine cyanine. The electron donation of the tetrazoloisoindole and triazoloisoindole residues was determined on the Ilchenko scale, which allows them to quantitatively quantify their Bruker basicity in comparison with the most known heterocyclic end groups of cyanine dyes