A study of complexation of chloral hydrate with heteropoly anions having various structures

¹H NMR was applied to study the interaction of chloral hydrate in deuterionitrobenzene solution with tetrabutylammonium salts of the heteropoly acids (HPA) belonging to five structural types: Keggin (H₃PW₁₂O₄₀, H₃PMo₁₂O₄₀, H₄SiW₁₂O₄₀), Dawson (-H₆P₂W₁₈O₆₂, -H₆P₂Mo₁₈O₆₂, -H₄S₂Mo₁₈O₆₂), H₆P₂W₂₁O₇₁(H₂O)₃, H₆As₂W₂₁O₆₉(H₂O), and H₂₁B₃W₃₉O₁₃₂. The surface of the HPA anions is nonuniform in acid-base properties. A general rule for all HPA was found, namely, that the HPA acidity increases with a decrease in the specific anion charge (per W or Mo atom).     

Dimethyl- and Diethyltin(IV) Compounds with Perfluorobiphenyl-4-Thiolate and Perfluoronaphthalene-2-Thiolate Anions: The Crystal Structure of (CH3)2Sn(C12F9S)2

Compounds (CH₃)₂Sn(C₁₂F₉S)₂ (I), (CH₃)₂Sn(C₁₀F₇S)₂ (II), and (C₂H₅)₂Sn(C₁₀F₇S)₂ (III) were synthesized. Single crystals of Iwere grown and structurally characterized using X-ray diffraction analysis (1590 reflections, R = 0.0209). The crystals are orthorhombic, a = 40.848(8) Å, b = 6.058(1) Å, c = 11.183(2) Å, V = 2767(1) ų, (calcd.) = 2.024 g/cm³, space group Pbcn, Z = 4. The structure is built from monomeric molecules. The coordination polyhedron of the Sn atom (the SnC₂S₂ core) is a distorted tetrahedron. Compounds I–III are volatile when heated in vacuo. Thermolysis of these compounds results in SnO₂ (in air) or SnS₂ (in argon).     

Plasma-assisted oxidative degradation of organic dyes in solution by the joint action of underwater discharge and ozone

Data on the degradation kinetics of two organic dyes in a mixture by the action of electrical underwater discharges and ozone are presented. It has been found that the rate of degradation by the to combined treatment of the both dyes with face discharge and ozone is five times the sum of degradation rates expected on the assumption of the additive effect of each of these factors.     

Natural convection in a closed parallelepiped with a local energy source

An experimental and numerical analysis was performed to investigate the laminar regimes of conjugate thermogravitational convection in a closed parallelepiped with heat-conducting walls of finite thickness in the presence of a local energy source with convective heat exchange with the environment. The numerical studies were performed using the Fluent software. The experimental data and numerical results agree well each other.     

Simulation of the processes of polarization switching in ferro- and antiferroelectric polymer systems

The ordering of ferroelectric and antiferroelectric polymer systems in an external electric field is studied by the Monte Carlo method. The threshold value of electric field strength at which the antiparallel packing of chains is converted into parallel is calculated. The hysteresis curves are studied and compared to experimental data.     

Specific features of the unsteady combustion of planar Ti–2B–αCu samples

The modes of spin gasless combustion of plate- and disk-shaped Ti–2B–Cu samples are investigated using frame-by-frame filming. The combustion process takes place under unsteady conditions. An increase in the diameter of the reaction sample makes the pattern of movement of the reaction front more complicated.     

Development of Ni–Mo Sorption-Catalytic Materials for Removing Arsenic Compounds from Middle Distillates

Possibility of using mesoporous materials for obtaining Ni–Mo sorption-catalytic materials for purification of medium-distillate fractions to remove arsenic-containing compounds was examined. It was shown that, in the course of hydropurification, the acidity of the mesoporous material does not directly affect the extent to which the amount of arsenic in hydrocarbons is diminished. It was found that mesoporous supports of the SBA-15, TUD, and MCF types reduce the content of arsenic to less than 0.5 ppm at 360°C and 50 atm of H₂.