Vol 62, No 10 (2017)

Two alternative chemical synthesis methods—cryotechnological coprecipitation of hydroxides and cocrystallization of salts—were used for preparing (CeO₂)_1–x(Y₂O₃)_x nanopowders (x = 0.10, 0.15, 0.20) with a mean coherent scattering domain size of ~7–11 nm and S_sp = 2.1–97.5 m²/g. From these nanopowders, ceramic nanomaterials with mean coherent scattering domain sizes of ~61–85 nm were synthesized. It was studied how the phase composition, microstructure, and electrical transport properties of the produced samples depend on the Y₂O₃ content of a CeO₂-based solid solution and on the synthesis method. It was shown that, in the series (CeO₂)_1–x(Y₂O₃)_x (x = 0.10, 0.15, 0.20), the solid solution (CeO₂)_0.90(Y₂O₃)_0.10 has the highest ionic conductivity with the ion transport number t_i = 0.73 (600°C). In its physicochemical characteristics, this ceramic can be used as a solid electrolyte of intermediate-temperature fuel cells.

A coordination polymer, catena((μ₂-4,4,10,10-tetramethyl-1,3,7,9-tetraazaspiro[5.5]undecane- 2,8-dione-O,O')-aquadinitratocadmium(II) {[Cd(C₁₁H₂₀N₄O₂)(H₂O)(NO₃)₂]}_n} (I), has been prepared for the first time from cadmium(II) nitrate and the bicyclic bisurea 4,4,10,10-tetramethyl-1,3,7,9-tetraazaspiro[5.5]undecane-2,8-dione (TTSU). Its molecular structure has been determined (CIF file CCDC no. 903387). Triclinic crystals: space group P1̅, a = 8.9967(4) Å, b = 9.6011(4) Å, c = 12.5131(7) Å, α = 76.307(4)°, β = 73.465(5)°, γ = 63.310(5)°, V = 918.26(8) ų, ρ_calc = 1.789 g/cm³, Z = 2. The Rietveld refinement was carried out at 293 K to confirm the single-phase constitution of the obtained powder sample of I: a = 8.9972(4) Å, b = 9.6104(4) Å, c = 12.5203(4) Å, α = 76.373(3)°, β = 73.485(3)°, γ = 73.485(3)°, V = 919.80(6) ų. A number of lines not corresponding to the main phase and not identified from PDF-2 database are observed on the powder X-ray diffraction pattern. The Rietveld refinement showed that the sample contains 91.4 wt % of the main compound I and 8.6 wt % of the TTSU nitrate admixture. The cadmium atom is coordinated by the O(1) and O(1)ⁱ atoms of two molecules of the organic ligand (L) generated by the symmetry operation (ⁱ1–x,–y,–z), the O(2)ⁱⁱ atom of the third ligand L molecule bound with the supporting one with the symmetry operation (ⁱⁱ–x,–y,–z), a water molecule, and a bidentate and a monodentate nitrate anions. The coordination number of the cadmium atom is 7, the coordination polyhedron is a distorted pentagonal bipyramid. The Cd···Cd distance is 4.0208 (3) Å.

Dichloro(ethylenediamine-N,N-di-3-propionato)zinc (I) has been synthesized for the first time by the reaction between acrylic acid and ethylenediamine coordinated with ZnCl₂ in an aqueous medium. Complex I has been characterized by IR, Raman, and ¹H,¹³C NMR spectroscopy, mass spectrometry, and elemental analysis. The X-ray diffraction analysis of complex I has also been performed. Crystals are monoclinic, а = 9.7792(4) Å, b = 9.9805(4) Å, c = 13.1130(5) Å, β = 101.5620(10)°, space group Р2₁/c, Z = 4, V = 1253.88(9) ų, ρ_calc = 1.804 g/cm³. The coordination polyhedra of Zn atoms in complex I are slightly distorted {ZnCl₂O₂} tetrahedra, each of which are built of two chlorine atoms and the carboxyl oxygen atoms of the two propionic groups of two ligand molecules and form a polymeric layer parallel to crystallographic plant (100). Bond lengths are Zn–О 1.970(1) and 1.976(1); Zn–Cl 2.2600(4) and 2.2693(4) Å. The ligand molecule in complex I has a double betaine structure.

2,3,4,5,6-Pentafluorophenoxytetraphenylantimony (I), 2,3,4,5,6-pentachlorophenoxytetraphenylantimony (_II), 2,3,4,5,6-pentafluorophenoxytetra-p-tolylantimony (III), and 2,3,4,5,6-pentachlorophenoxytetra-p-tolylantimony (IV) were synthesized by the reaction of pentaarylantimony (Ar = Ph, p-Tol) with pentafluoro- and pentachlorophenol in toluene. Compounds I–IV were also synthesized with yields of up to 95% from pentaarylantimony and triarylantimony diaroxides. Triarylantimony diaroxides Ph₃Sb(OC₆F₅)₂ (V), Ph₃Sb(OC₆Cl₅)₂ (VI), p-Tol₃Sb(OC₆F₅)₂ (VII), p-Tol₃Sb(OC₆Cl₅)₂ (VIII) were synthesized from triarylantimony, tert-butylhydroperoxide, and phenol in ether. The Sb atoms in compounds I–VIII had a distorted trigonal bipyramidal coordination with electronegative ligands in axial positions.

Computations for the possible structures of SnCl₄–ortho-dimethoxybenzene complexes and initial components have been performed by MP2/LANL2DZ method. Computation results have been compared with experimental data of ³⁵Cl nuclear quadrupole resonance. cis-Octahedral structure of the complex through the coordination of both oxygen atoms has been confirmed. This complex differs considerably from the majority of studied tetrachlorostannane complexes of cis-octahedral structure in terms of the ratios of axial and equatorial Sn–Cl bond distances, p_σ electron density, and ³⁵Cl NQR frequencies for axial and equatorial chlorine atoms.

In the framework of the search for promising electrodes and membranes for lithium-ion batteries, quantum-chemical modeling of the contact area of the solid (Li₁₀GeP₂S₁₂) and polymeric LiNafion · nDMSO-based electrolytes with an anode as carbon fibers coated with silicon nanoclusters (Si_nC_m) has been performed by the density functional theory method with inclusion of gradient correction and periodic conditions (PBE/PAW). It has been found that the polymeric electrolytes form a better contact with the electrode surface than the solid electrolytes. The barriers to lithium transport in the polymeric LiNafion · nDMSO-based electrolyte have been estimated at 0.3 eV, and those to Li migration from the electrolyte into the electrode have been estimated at 0.4 eV.

In this investigation, quantum chemical calculations using MPW1PW91 method were applied to analyze of the solvent effect on the structural, vibrational analysis, thermochemical parameters and first hyperpolarizability for CpMe₂Ta(benzyne) complex. The solvent effects on the structure and properties were examined by the self-consistent reaction field theory (SCRF) based on Polarizable Continuum Model (PCM). Good correlations exist between these parameters and dielectric constants of solvents. The wavenumbers of the IR-active symmetric stretching vibrations of Ta-Me in different solvents were correlated with the Kirkwood–Bauer–Magat equation (KBM). In addition, Monte Carlo simulations using standard procedure of Metropolis sampling were applied to investigate of the solvation of CpMe₂Ta(benzyne) complex. In addition, the bonding interaction between the CpTaMe₂ and benzyne fragments was analyzed by means of the energy decomposition analysis (EDA).

Manganese and cobalt oxopivalates and lead pivalate have been synthesized, mass spectral and thermogravimetric analysis have been performed. Sublimation enthalpies of cobalt and manganese oxopivalates have been determined for the first time, while the sublimation enthalpy of lead pivalate has been found to agree well with literature data. Low sublimation enthalpy, high volatility, and monomolecular composition of gas phase allow one to use these complexes as precursors for preparing oxide films and materials by MOCVD method.

The differentiation of the quaternary reciprocal system Li, K, Ca, Ba||F, WO₄ was performed based on the graph theory using special software. Stable and metastable complexes of the system were found using a matrix of reciprocal pairs of salts. For the first time, by a set of physicochemical analysis methods (differential thermal, visual polythermal, and X-ray powder diffraction analyses), based on the method of thermal analysis of successive projections of the composition polytope, the quaternary system LiF–K₂WO₄–CaF₂–BaF₂–BaWO₄, which is a stable complex of the quaternary reciprocal system Li, K, Ca, Ba||F, WO₄, was studied and the coordinates of invariant points were determined.

The scientific basis of the development of liquid cleaning compositions is physicochemical analysis of multicomponent systems that comprise the major components of detergents. The method was implemented in Optimum software for the sulfirol-8–isobutanol–turpentine–water four-component system. After solubility in the system was studied, homogeneous mixtures were optimized by their physicochemical and functional properties (viscosity, density, refractive index, pH, detergency, and corrosion activity). The compositions having the highest detergency and neutral pH and not causing corrosion on titanium and aluminum alloys were selected and recommended for use as technical detergents.