A coordination compound of copper(II) with succinic acid was obtained by electrochemical synthesis in media of various compositions. The samples were characterized by methods of quantitative analysis, ESR and IR spectroscopy, synchronous thermal analysis. The vibrational frequencies of copper(II) succinate were calculated by using DFT and the experimental IR spectra were interpreted on the basis of the results. Micro-sized copper(II) oxide fibers were obtained by thermal decomposition of synthesized samples. It was shown that the use of the water–dimethyl sulfoxide system with a volume ratio 1:1 is optimal to achieve the formation of moderately aggregated particles with a distinct filamentous morphology.

An inclusion complex of gadolinium(III) with L-tryptophan (Trp) and β-cyclodextrin (β-CD) with the composition Gd(Trp)3Cl3∙3β-CD∙nH2O was synthesized. It was established that the complex is formed due to the entry of the aromatic part of the L-Trp molecule into the β-CD cavity, and the Gd3+ ions are located in the outer sphere.

The effects are described of the influence of the particle size of a sulfonic cation exchanger in nickel form introduced into the epoxy binder on the sensory characteristics of the resulting moisture-sensitive system. The introduced filler was crushed on a planetary mill by changing the speed of the glass (300, 400, and 500 rpm). It is shown that differences in the conditions of mechanical processing of the filler cause changes in the permeability of the resulting systems, while the moisture-sensitive characteristics of the obtained films also depend on the fractional composition. The obtained values of the flow parameters (percolation) are consistent with the theoretical values for spherically overlapping particles, while the critical fraction of the conducting phase is smaller for systems with larger particles due to the early formation of transport paths. These data indicate that varying the particle size of the active filler in the sensor system creates the possibility of a directed change in its performance. The size factor can be used to create self-adjusting protective coatings with improved weather resistance and a high protective resource.

Meconic, comenic, chelidonic, and kojic acids are the main representatives of gamma-pyronic acids. It was found that comenic acid has a neuroprotective effect, and chelidonic acid has a pronounced anti-inflammatory effect. The neuroprotective effect of meconic acid has not been explored. The aim of this study was to investigate the neuroprotective potential of meconic acid on an in vitro ischemic stroke model, as well as on the basis of its physicochemical properties. A primary neuro-glial culture was obtained from the cerebellum of 7- to 8-day-old Wistar rats by mechanical dissociation. The protective effect of meconic acid on the culture of cerebellar neurons was studied using a model of glutamate toxicity and oxygen–glucose deprivation. The antioxidant activity of meconic acid was studied by quantum mechanical calculations and experimentally in the citrate-phosphate-luminol model system by chemiluminescence analysis. The chelating properties of meconic acid with respect to Fe3+ in solutions were studied by the Job’s method. Meconic acid has been found to have a protective effect on in vitro models of ischemia. It caused a decrease in the level of intracellular calcium and restoration of the membrane potential of mitochondria in the culture of cerebellar neurons under glutamate exposure and an increase in the percentage of living cells under oxygen–glucose deprivation. Meconic acid had a high calculated antioxidant potential, as was confirmed experimentally. With an increase in pH of the medium, a stepwise binding of meconic acid with Fe3+ occurred with the formation of complexes of different ligand/metal ratios. At physiological pH, the resulting complex had a composition with the ratio 1 : 3. The revealed antioxidant, chelating, and cytoprotective effects of meconic acid provide a basis for further study of the possible neuroprotective properties of this compound in experiments in vivo; the data on its physicochemical properties can be useful for the synthesis and study of new coordination compounds based on this acid.

Приведены результаты влияния размера частиц сульфокатионита в никелевой форме, введенного в эпоксидное связующее, на сенсорные характеристики получаемой влагочувствительной системы. Вводимый наполнитель измельчали на планетарной мельнице при изменении частоты вращения стакана (300, 400 и 500 об./мин). Показано, что различия в условиях механообработки наполнителя обуславливают изменения в проницаемости полученных систем, а влагочувствительные характеристики полученных пленок также зависят от фракционного состава. Полученные значения параметров протекания (перколяции) согласуются с теоретическими для сферически перекрывающихся частиц, при этом для систем с более крупными частицами критическая доля проводящей фазы меньше, вследствие раннего формирования путей переноса. Приведенные данные указывают на то, что варьирование размера частиц активного наполнителя в сенсорной системе создает возможность направленного изменения его эксплуатационных характеристик. Размерный фактор может быть использован при создании саморегулируемых защитных покрытий с улучшенной погодозащищенностью и высоким защитным ресурсом.

Dissociation constants of 2-furancarboxylic and 2-furylacrylic acids and stability constants of their complexes with Pr3+, Nd3+, Sm3+, Eu3+, Gd3+, Tb3+, Ho3+, Er3+, and Yb3+ ions were determined in aqueous ethanol solution (5 : 1 by volume) by pH-potentiometric titration. It was found that the complex formation occurs in the pH range of 3.0–6.5, the stability constants of complex compounds increasing with increasing values of the protonation constant of the ligands. Solid complex compounds with 2-furancarboxylic and 2-furylacrylic acids of the compositions (С5Н3О3)3Ln·nH2O and (С7Н5О3)3Ln·nH2O (n = 2–4), respectively, have been synthesized. According to IR spectra, Ln3+ ions are coordinated to acids bidentately by the carboxyl groups. The range of thermal stability of the complex compounds has been determined by the TG/DTG/DSC methods. Spectral-luminescent properties of the complex compounds of 2-furancarboxylic acid with Eu3+ and Tb3+ ions have been studied.

A study was preformed of complex systems containing a biocide (isothiozolone-3) introduced into a carrier, thermally expanded graphite. It is shown that when thermally expanded graphite is introduced into the binder, the kinetics of biocide release from the system varies, therewith the maximum biocide release rate increase and a decay rate of the release rate is reduced. The antifouling properties of the compositions obtained were evaluated. It was demonstrated that the effective protection time of samples by coatings containing thermally expanded graphite increases.

The influence of AV-17-8, a strong basic anion-exchange resin introduced in various ionic forms as an active filler on the adhesive resistance of bitumen–anionite protective systems during their cathodic polarization has been studied. The following ionic forms of the anionite were selected for study: the initial chloride form and the nitrate, hydroxo, sulfate, chromate, carbonate, silicate, phosphate, and hydroxoaluminate forms. A significant effect of the ionic form of the introduced anion exchange resin on the cathodic disbondment and, as a result, the adhesive durability of bitumen–anion exchange protective anticorrosion coatings is shown. The effect of disbandment inhibition was found, explained by the nature of the interaction of the mobile anion of the microreservoir (AV-17-8 particles) with iron (2+) cations formed in the anode zone on a steel surface in the “disbandment cell.” This effect can be used to create protective anticorrosion coatings with increased durability and protective capacity.

The effect that diatomite in various ion-modified forms, introduced as active filler, exerts on the adhesion durability of bitumen–inorganic protective systems at their cathodic polarization was studied. The cathodic disbondment and, as a consequence, the adhesion durability of bitumen–polymer protective coatings depend on the ionic composition of modified diatomite clay. According to the results of the 10-day polarization, introduction of Na+ increases the disbondment by 33% relative to the initial bitumen, whereas metal ions forming insoluble hydroxides are ranked in the following order with respect to the degree of suppression of the “disbondment cell”: Сo2+ ˂ Ca2+, Zn2+ ˂ Mg2+ ˂ Cu2+ ˂ Ni2+. Physicochemical mechanisms responsible for the promotion or inhibition of the disbondment in the systems under consideration are discussed. The results obtained can serve as a basis for the further development of durable protective coatings.

Complex compounds of 3-hydroxy-4-oxo-4H-pyran-2,6-dicarboxylic (meconic) acid (H3Mec) with europium(III), gadolinium(III), terbium(III), dysprosium(III), erbium(III), thulium(III) and ytterbium(III) ions were synthesized by the ion exchange method in aqueous solution. The hydrates of the complex compounds [Ln(HMec)(H2O)]·nH2O (n = 0‒4) are solid amorphous substances (Sm3+, Eu3+, Gd3+, and Tm3+ complexes) and fine crystalline substances (Tb3+, Dy3+, Er3+, and Yb3+ complexes) with colors characteristic of lanthanide ions. The region of thermal stability of the complexes was determined by the TG/DTG/DSC methods. The Ln3+ ions are coordinated monodentately to the ionized carboxyl groups and the oxygen atom O1 of the pyrone ring. The coordination of Ln3+ to the С3‒OH group and the С4=О ketogroup of the second ligand molecule leads to the formation of a polymer chain. The triplet level of the ligand (3T*) was determined from the phosphorescence spectrum of the Gd3+ complex compound (77 K). The spectral-luminescent properties of Sm3+, Eu3+, Tb3+, Dy3+, and Tm3+ complexes were studied.

New methods for the electrochemical synthesis of copper(II) and zinc(II) coordination compounds with pyridinecarboxylic acids (nicotinic and picolinic) have been developed. The resulting compounds were characterized by quantitative analysis and IR spectroscopy. The vibrational frequencies of the synthesized compounds were calculated by a DFT quantum-chemical method, and the experimental IR spectra were interpreted on this basis. It was found that pyridinecarboxylate ions in all cases are coordinated both at the nitrogen atom and at the carboxylate group, however, in the case of nicotinic acid, this leads to the formation of coordination polymers, whereas for picolinic acid, the formation of mononuclear complexes is typical.

Microparticles of CuO were obtained by thermal decomposition of copper(II) oxalate synthesized by pulse electrolysis of an oxalic acid solution with a sacrificial copper anode. Scanning electron microscopy showed that the particles are rectangular hexagon-shaped with a size of 0.2–5 µm and form complex irregular aggregates with a porous structure. The use of the water–dimethylformamide solvents with a volume ratio 1 : 1 is optimal to achieve the desired morphology of the product.

Синтезировано комплексное соединение Eu(III) с глицином (Gly) состава EuCl3·3Gly·3H2O. Методом РСА установлено, что в комплексном соединении реализуется бидентатная координация глицина по карбоксильной группе без участия аминогруппы. Структура представляет собой полимерные цепи, в которых две из трех координирующих карбоксильных групп — мостиковые, соединяющие соседние атомы европия(III). Полимерные цепи располагаются параллельными слоями, между которыми находятся атомы хлора внешней сферы. По данным РСА, согласующимся с полученными методами ИК спектроскопии, элементного и термического анализа и люминесцентной спектроскопии, определена структурная формула комплекса: [Eu(Gly)3(H2O)3]Cl3.

Coordination compound of Eu(III) with glycine (Gly) with the composition EuCl3·3Gly·3H2O is synthesized. The obtained XRD data testify that the coordination compound is characterized by a bidentate coordination of glycine via the carboxyl group without the participation of the amino group. The structure is composed of polymer chains where two of three coordinating carboxyl groups are bridging groups connecting neighboring europium(III) atoms. The polymer chains are arranged in the form of parallel layers containing outer-sphere chlorine atoms between them. The structural formula [Eu(Gly)3(H2O)3]Cl3 of the complex is determined from XRD data which agree with IR spectroscopy, elemental and thermal analysis, and luminescence spectroscopy data.

The effect of diatomite introduced as an active filler in nickel 2(+) and sodium (+) ionic forms on the adhesion resistance of bitumen–diatomite protective systems during their cathodic polarization is studied. A significant effect of the introduced diatomite clay, the method of its activation, its ionic form on the cathodic exfoliation, and, as a result, the adhesive durability of bitumen–polymer protective coatings during their cathodic polarization are shown. This effect can be used to create protective anticorrosion coatings with increased durability.