Vol 89, No 6 (2019)

The review presents the evolution of the static tensimetric method from Mendeleev to the present day. A description of a new-generation automatic tensimetric apparatus is given. The specific examples show application of the static method with a membrane null-manometer to the study of various processes involving inorganic and coordination compounds: homogeneous gas phase equilibria, heterogeneous condensed phase-vapor equilibria, and kinetics of amidoboranes decomposition.

Principles and examples of assembling heteroleptic supramolecular cluster compounds of copper subgroup metals based on polydentate phosphine ligands of various topologies are considered. The choice of an organic linker between phosphorus atoms allows one to control the formation of three-dimensional aggregates with a regular architecture, whereas the choice of alkynyl ligands determines their luminescent properties.

The coexistence of two crystal modifications of lanthanum gallate, orthorhombic and rhombohedral, was revealed for the first time in two series of solutions: LaNi_xMg_0.2xGa_1–1.2xO_3−δ ([Ni]: [Mg] = 5: 1) and LaNi_xMg_0.5xGa_1–15xO_3−δ ([Ni]: [Mg] = 2: 1), x = 0.01–0.10. The unit cell parameters in the both series of solid solutions were refined by the Rietveld method. The magnetic susceptibility measurements point to the presence of clusters of Ni(III) atoms with strong antiferromagnetic interactions. The conductivity measurements point to high conductivity values for the system with the ratio [Ni]: [Mg] = 5 : 1.

The results of the study of ternary systems containing copper, cobalt, nickel, and cadmium halides and sulfates in binary water-organic and mixed organic solvents are summarized. The influence of the donor-acceptor properties of the ternary system components, the relative dielectric permittivity, and the intermolecular association in the mixed solvent on the solubility of salts and the crystalline structure of solvates is analyzed.

The crystal structure of the new polymorphic modification of B(C₆F₅)₃·Py complex was determined. It was shown by a static tensimetric method using a membrane null manometer that in the condensed phase in an excess of pyridine, B(C₆F₅)₃·Py complex is stable up to 220°C. When temperature rises to 230°C, the complex undergoes irreversible thermal decomposition, with the release of pentafluorobenzene and the polymerization of pyridine. The sublimation enthalpy of B(C₆F₅)₃·Py was determined for the first time by the calorimetric method. The results of quantum chemical calculations using the M06-2X method provide qualitative agreement with the experiment, in contrast to the B3LYP method.

A method was developed for the synthesis of pyrano[4,3-b]thieno[3,2-e]pyridine derivatives based on the reaction of 3-amino-7-ethyl-7-methyl-7,8-dihydro-5H-pyrano[4,3-b]thieno[3,2-e]pyridine-2-carboxylic acid ethyl ester with chloroacetic acid chloride, triethyl orthoformate, hydrazine hydrate, and also phenyl chloroformate. The synthesis of various new representatives of pyrano[2″,3″:5′,6′]pyrido[3′,2′:4,5]thieno[3,2-dl-pyrimidine series was carried out.

Novel α-aminophosphonates based on a non-ionic surfactant (ethoxylated alcohol syntanol) with varied length of the oxyethyl moiety have been synthesized. The obtained phosphonates have been characterized by ¹H, ³¹P, and ¹³C NMR spectroscopy, IR spectroscopy, and mass spectrometry. Investigation of their anticorrosive activity by gravimetry method revealed fairly strong effect of the metal protection against corrosion in the presence of phosphonates (up to 94%) and decrease of the corrosion rate (to 0.030 mm/year).

The title compounds are synthesized by condensation of 2-[4-(arylidene)-5-oxo-4, 5-dihydrooxazol-2-yl]phenylacetate with aromatic amines in presence of the Vilsemeier Haack reagent. Structures of all compounds are elucidated from ¹H and ¹³C NMR, IR, and mass spectra. The compounds are tested for their antibacterial activity. Molecular docking study is focused on the relative orientation and nature of bonding between imidazoles and bacterial protein.

A new imidazolium-based poly(ionic liquid) has been synthesized and used as a robust heterogeneous catalyst for the preparation of phenacyl derivatives by an S_N2 reaction of different phenacyl bromides with a broad range of nucleophiles. The products are obtained in high yields under mild conditions. The catalyst can be recycled efficiently.

Synthesis, structure, properties, and reactivity of verdazyls based on formazans, as well as of metalverdazyl complexes, formazanate BR₂-complexes (R = F, H, Ph), and other Group 13 and 14 formazanate complexes, were considered. Special attention was focused on the study of redox-active formazanate ligands.

The paper considers directions for the development of waste-free, large-scale industrial technologies by setting up new technological routs, including wide use of electrical technologies of a new generation and excluding formation of any industrial waste as a matter of principle. The electrical technologies of a new generation are technologies based on the use of generators and flows of technological plasmas in chemical and metallurgical industries, electromagnetic fields of various frequency ranges for the synthesis and processing of metal and ceramic materials, and technological lasers for, for instance, separation of isotopes and for making micro articles for nanotechnology and micrometallurgy applications. All these technologies have become theoretically and technically feasible in combination with purification technologies for liquid and gaseous raw material preparation for the nuclear fuel cycle (NFC), specifically, ion-exchange sorption on synthetic organic ion-exchange resins, fluid extraction, rectification, or sorption on granular fluoride sorbents, which all provide a tool for attaining any level of purification of raw materials. In many processes discussed in the paper, extraction, sorption and rectification can be directly incorporated in electrical technologies, i.e. this means combined technologies for the synthesis, separation, and purification of the products, such as plasma rectification, plasma sorption, etc.

The paper considers a series of such scientifically and technically advanced but still uncommercialized electrical technologies which should form the basis for new environmentally friendly, waste-free industries of a new technological structure. As examples, we focus on several plasma, electromagnetic, and laser technologies, operating on raw materials refined by the above-mentioned purification technologies, including the new technology for the purification of gaseous industrial emissions. These waste-free electrical technologies for the production and processing of inorganic materials were developed for the nuclear industry in the USSR. These are mostly physical technologies insensitive to the chemical formula of the produced or processed materials, and, therefore, they can be used without any problems in other branches of industry.

Modified adsorbents for gas chromatography were prepared using a Cu(II) complex of a camphorsabstituted tetrapyrasinoporphyrazine. The thermal stability of phthalocyanines and modified adsorbents was studied by thermogravimetry. The adsorption of a series of organic compounds from the gas phase on the surface of the modified sorbents was studied by gas chromatography. Electron-donor methylpyridine and dimethylpyridine isomers and low-polar xylene and alcohol isomers were used as sorbates. Specific retention volumes of sorbates and separation factors of close-boiling hydrocarbons were calculated. The sorbents on the basis of Cu(II) tetra(1′,7′,7′-trimethylbicyclo[2.2.1]heptano[2′,3′-b]pyrazino)porphyrazine exhibit a high selectivity to closely boiling organic compounds of different classes and a high efficiency in their separation.

Phthalonitriles substituted with o-hydroxybenzoic, o-aminobenzoic, and o-mercaptobenzoic acids moieties were synthesized by nucleophilic substitution of bromine in 4-bromophthalonitrile and of nitro group in 4-nitrophthalonitrile. Template condensation of these phthalonitriles with metal acetates gave the corresponding phthalocyanines. Metal-free phthalocyanines were synthesized by dissociation of the magnesium complexes of the substituted phthalocyanines in a sulfuric acid medium. Treatment of the resultant phthalocyanines with sodium ethoxide in ethanol yielded sodium salts of the carboxylic acids. The spectral properties of the compounds synthesized were examined.

Temperature effect on the kinetics of plasticization of cellulose nitrate/plasticizer compositions is studied. The obtained experimental data are used to construct a mathematical model of the dissolution of cellulose nitrate in plasticizer. The mathematical model describes the dependence of the optical density of 1 % cellulose nitrate/plasticizer compositions on time, temperature, and type of the plasticizer, as well as the rate of change of the optical density as a function of temperature and type of the plasticizer.

The effect of the composition of mixed dilute solutions of chitosan and sodium alginate on the size, ζ-potential, and weight yield of the submicron particles of the insoluble interpolymer polyelectrolyte complex, formed in these solutions, was examined. By the example of ionic dyes used as model sorbates it was shown that the composition of the initial solutions is a major factor in tuning the sorption properties of chitosanalginate carriers with respect to charged organic compounds.

Natural and anthropogenic sources of nitrous oxide were considered, and their contribution to environmental pollution was determined. The effect of N₂O on Earth’s ozone layer was described. The commercial method of production of technical and medical nitrous oxide, based on decomposition of a hot solution of ammonia nitrate, was considered. Application areas of nitrous oxide were described, and examples of its use in organic and inorganic synthesis reactions, as well as in medicine, food industry, and technology were given. Methods employed for neutralizing process gases containing nitrogen oxides, in particular absorption and adsorption methods, were reviewed. Particular attention was paid to catalytic tail gas purification in various industries; high- and low-temperature reduction of N₂O by natural gas and ammonia were described; analytical review of the literature dedicated to catalytic systems and individual compounds that show activity in the decomposition and reduction of nitrous oxide was provided; and mechanisms of nitrous oxide decomposition over various catalysts were considered.