Vol 63, No 2 (2018)

New solid solutions La_1.8Sr_0.2Ni_0.8M_0.2O₄ (M = Fe, Co, or Cu) have been prepared, and their crystal- chemical characteristics and electric properties studied. The studied materials have been shown to have activation-time conductivity. Structural distortions have been found to affect the dielectric properties of ceramic samples. La_1.8Sr_0.2Ni_0.8M_0.2O₄ is observed to have the greatest distortion of АО₉ coordination polyhedra and a higher dielectric constant.

Subsolidus phase ratios in K₂MoO_4–CaMoO₄–Ln₂(MoO₄)₃ systems where Ln = Nd, Sm, Eu, and Gd, have been studied by vibrational spectroscopy, X-ray powder diffraction, and differential thermal analysis. Triple molybdates KCaLn(MoO₄)₃ (Ln = Nd, Sm, Eu, and Gd) have been synthesized; they have a scheelite-derivative structure, monoclinic crystal system (space group P21/n). Their unit cell parameters have been determined, and IR and Raman spectra characterized.

The solubilities of aluminum oxide (Al₂O₃) and zirconium oxide (ZrO₂) in fluoride-containing salt melts is discussed. Metal oxides are shown to be highly soluble due to chemical interaction involving complex ions within the temperature range of 450–800°C.

Tris(3-fluorophenyl)antimony bis(2,4-dibromophenoxide) (I), tris(3-fluorophenyl)antimony bis(pentachlorophenoxide) (II), and tris(3-fluorophenyl)antimony bis(2-nitrobenzoate) (III) have been synthesized by the reaction of tris(3-fluorophenyl)antimony with 2,4-dibromo- and 2,3,4,5,6-pentacholophenols and 2-nitrobenzoic acid in the presence of tert-butylperoxide. The antimony atoms in complexes I–III have a distorted trigonal bipyramidal coordination with aroxides (carboxyl) groups in axial positions (OSbO angles, 176.0(2)° (I), 174.89(7)° (II), 173.04(8)° (III); Sb–O distances, 2.057(5), 2.048(5) Å (I); 2.098(2), 2.106(2) Å (II); 2.120(6), 2.090(6) Å (III)).

The heteromolecular insertion of carbon dioxide in combination with heterocumulenes, iso(thio)cyanates or N,N′-dicyclohexylcarbodiimide, into rhenium–alkoxy group bond was accomplished for the first time in relation to reactivity of rhenium oxoalkoxides. The ease of combined insertion of iso(thio)cyanate and carbon dioxide into Re–O(Me) bond is determined by the nature of the heterocumulene organic group. Indeed, if ethyl iso(thio)cyanate is used in the reaction, the insertion is reversible, whereas the reaction with PhNCS (unlike PhNCO) together with carbon dioxide leads to complete insertion into two Re–O(R) bonds to give the insertion product (OMe)₁₀O₆Re₄[OC(O){N(Ph)C(S)}₂-OMe]₂. In similar reactions carried out with N,N′-dicyclohexylcarbodiimide, a dependence of the number of bonds participating in the inner-sphere condensation of the inserted moieties on the duration of the experiment was found for the first time. An increase in the time of synthesis from 3 to 5 h results in insertion involving six rather than three bonds, the heteromolecular insertion products being (OMe),O₆Re₄{OC(O)[(Hex)N=C=N(Hex)]₂}₃ and (OMe)₆O₆Re₄{OC(O)[(Hex)N=C=N(Hex)]₂}₆, respectively.

The optimal geometry and wave functions of the complexes [M(Solv)]⁺ (M = Li, Na, K; Solv is an aprotic solvent molecule) were calculated and the topological characteristics of the electron density distribution at the (3,–1) critical points (CP) of ion–molecule bonds were analyzed by the density functional theory in the B3LYP/6-31+G(d, p) approximation. The parametric dependences for the energy of ion–molecule bonds in terms of the local kinetic and potential electron energy densities at the bond CTs were proposed.

A new approach to the preparation of boron-containing siloxanes based on cluster boron anions has been suggested. This approach consists in the reaction of hydroxy derivatives of closo-decaborate anion [B₁₀H_10–n(OH)_n]^2– (n = 1, 2) with dihalosilanes SiR₂Cl₂ (R = CH₃, _t-C₄H₉, C₆H₅). The obtained compounds have been characterized by IR, ESI/MS, and NMR (1H, 11B, 13C) spectroscopy.

We have studied the usefulness of alcoholic dispersions of Au nanoparticles (NPs) stabilized by isonicotinic acid (INA) and tris(2-aminoethyl)amine (TAEA) for manufacturing colloidal films on glass substrates and composites with nanosized carbon materials (based on nanotubes (NTs) and a porous carbon material (PCM)) and oxide powders (Al₂O₃, SiO₂, and CeO₂).

The solvothermal decomposition of a hybrid organic–inorganic material based on α-Со(ОН)₂ and sodium dodecyl sulfate has been studied in n-octanol at 190°C and the atmospheric pressure. It has been found that the process includes two stages: in the first stage, anhydrous CoCO₃ is formed, followed by its topochemical decomposition to form Co₃O₄. It has been found that products consist of rhombic-shaped particles about 250 nm in size.

The rates and factors influencing the rates of liquid-phase oxidation of inorganic sulfides by oxygen in aqueous media in the presence of a homogeneous catalyst based on 3,3′,5,5′-tetra-tert-butyl-4,4′-stilbenequinone dissolved in the kerosene fraction have been studied.

The ternary system Tl–Gd–Te within the composition range Tl₂Te–T_l5Te₃–T_l9GdTe₆ was studied by a set of physicochemical analysis methods. Some internal polythermal sections and the isothermal section at 300 K of the phase diagram were built, projections of the liquidus and solidus surfaces were constructed, and the graphs of the concentration dependences of the parameters and microhardness were plotted. It was shown that much (more than 90%) of the area of the concentration triangle is occupied by the homogeneity region of solid solutions with the Tl₅Te₃ structure (δ-phase). Solid solutions based on Tl₂Te (α-phase) form within a narrow region. The regions of the α- and δ-phases are separated by two-phase region α + δ.

The mutual effect of the components in four aqueous systems consisting of sodium dicarbamidochlorate, monoethanolamine acetate, ethanol, and acetamiprid are studied. No new compounds are formed in these systems. The components of the systems upon joint presence retain their individuality. The results for the systems under study demonstrate that a liquid defoliant exhibiting insecticide activity can be produced.

Extraction of Sc, Zr, Th, Fe, and Eu with triisoamyl phosphate from aqueous solutions containing HNO₃ and LiCl has been studied. Extraction system efficient for scandium purification from concomitant admixture elements has been revealed. Prevalent Sc, Zr, Th, Fe, and Eu species that transfer to organic phase have been determined.