Vol 63, No 9 (2018)

Protocols for sputtering stoichiometric aluminum antimonide thin films were developed by calculating aluminum and antimony vapor condensation flux densities. Aluminum and antimony were sputtered separately. The high chemical reactivity of nanosized aluminum and antimony films made it possible to reduce the synthesis temperature considerably (far below the melting point of the compound). The synthesis involved thermal annealing. The reaction between aluminum and antimony films started at 470°С. Optimal AlSb formation parameters comprise annealing at 540°С for at least 10 h. Film synthesis steps were studied by X-ray powder diffraction, optical, electron, and atomic force microscopy. The composition was monitored by energy dispersive X-ray spectra. The films were found to have hole conductivity; the 300-K charge density and charge mobility in the films are 1 × 10¹⁹ cm^–3 and 1 × 10² cm²/(V s), respectively.

The paper reports the results of using polymer-colloid complexes in solutions in order to control textural properties of mesoporous aluminium oxide in the sol–gel synthesis process. Polyethyleneimine, cetyltrimethylammonium chloride, as well as a polymer-colloid complex formed by their interaction in the solution were used as pore-forming templates. The mesoporous aluminium oxides synthesized in this work had a narrow pore size distribution and a large surface area. The application of different templates made it possible to affect the mechanism of supramolecular self–assembly of materials, namely by controlling the pore sizes. When the polymer-colloid complex was used as the template for the formation of aluminium oxide nanostructures, 6 nm cylindrical pores were formed, while using individual templates led to the formation of 8–13 nm mesopores. Identifying the formation mechanism of a certain pore type will make it possible to use these materials in specific reactions.

Relationships between synthesis conditions, phase composition, and ion-exchange properties have been analyzed on the basis of results of physicochemical study for reaction products in the (NH₄)₂TiO(SO₄)₂–H₃PO₄–H₂O system. Mechanisms have been suggested for the formation of final titanium phosphate phase in different synthesis methods.

Cesium-containing complex oxides Cs[MgR_0.5P_1.5O₆] (R = B, Al, Fe) are prepared from solutions containing H₃BO₃, metal chlorides, and H₃PO₄/NH₄H₂PO₄. The chemical and phase transformations that occur during the synthesis are elucidated by differential thermal analysis (DTA) and X-ray powder diffraction (XRD). Optimal synthesis parameters are determined. The oxides where R = B or Fe are formed at 800°C, those where R = Al are formed at 1100°C. All compounds crystallize in the pollucite-type structure (cubic system, space group I4₁32).

The reactions of μ-nitridodimeric iron(IV) tetra-4-tert-butylphthalocyaninate with tert-butylhydroperoxide and tert-butylperoxide are studied using spectroscopic methods. The kinetic parameters of the reaction are determined, and the mechanism of the process is suggested. Activation of organic peroxide is preceded by its coordination with the dimeric iron complex. The coordinated and activated substrate oxidizes μ-nitridodimeric iron(IV) tetra-4-tert-butylphthalocyaninate at the macrocycle to yield the radical cation form. The oxidized species can be easily reduced to the neutral species in the presence of a nitrogen-containing base.

Complexes \(\rm[{Ph_{3}PR]_2^+[RuCl_6]^{2-}}\), where R = C₂H₅ (I), CH=CHCH₃ (II), CH₂CH=CHCH₃ (III), and CH₂OCH₃ (IV), have been prepared by the reaction between ruthenium(III) chloride hydrate and triphenylorganylphosphonium chlorides in dimethylsulfoxide in the presence of hydrochloric acid. A hydrochloric acid solution of ruthenium(III) chloride hydrate when mixed with an aqueous solution of 2-butylene-1,4- bis(triphenylphosphonium dichloride) followed by recrystallization from dimethylsulfoxide results in complex \(\rm[{Ph_{3}PCH_2CH=CHCH_2{PPh_3}]_2^{2+}[Ru_2Cl_{10}O]^{4-}}\)· 4H₂O (V). According to X-ray diffraction data, phosphorus atoms in mono- and binuclear cations have slightly distorted tetrahedral coordination (CPC 105.54(13)°−113.00(8)°, P−C 1.758(9)−1.839(7) Å). In slightly distorted octahedral anions [RuCl₆]²⁻ of complexes I–IV, the Ru−Cl bond lengths vary in the range 2.3222(6)−2.340(2) Å; the cis-ClRuCl and trans-ClRuCl angles are 89.133(18)°–90.867(18)° and 179.53(13)°–180°, respectively. In the binuclear [(RuCl₅)₂O]⁴⁻ anion of complex V, RuCl₅ fragments are bonded by a bridging oxygen atom. The Ru–Cl bond lengths fall in the range 2.3375(8)−2.3957(8) Å; the Ru–O bond length is 1.7832(2) Å. The cis-ClRuCl, trans-ClRuCl, cis-ORuCl, and trans-ORuCl angles are 86.67(3)°−91.28(3)°, 174.60(3)°−174.83(3)°, 91.49(2)°−93.65(2)°, and 178.39(2)°, respectively. In crystals I–V, interionic hydrogen bonds Cl···H_cation (2.63−2.95 Å), Cl··· \({\rm{H}_{{H_2}O}}\) (2.35−2.79 Å), and H_cation···\({\rm{O}_{{H_2}O}}\) (1.72−1.93 Å) (for V) are found.

The substitutions of water molecules in the bisaqua axial complex of carboxy-substituted Co(III)-tetraphenylporphyrin by drug molecules based on amines and nitrogen-containing heterocycles are studied. The strongest bonded Co(III)-porphyrin complexes are formed with imidazole and pyridine derivatives. Depending on the nature and positions of functional groups in the heterocyclic moiety, imidazole- and pyridine- containing compounds can form either mono- or bis-axial complexes with Co(III) porphyrinate, these complexes having various stabilities. Aniline and quinuclidine drugs were found to react with Co(III) porphyrinate in aqueous media to produce only unstable monoaxial complexes.

The molecular structures of (5454)macrotetracyclic M(II) chelates with a tetradentate (NNNN)- donor ligand formed through template reactions in the ternary systems M(II)–1,2-ethandiamine (H₂N–CH₂–CH₂–NH₂)–trioxosulfidosulfate(VI) anion (SO₃S(2)^–), where M = Mn, Fe, Co, Ni, Cu, and Zn, have been calculated by the density functional theory OPBE/TZVP method. The bond lengths and selected bond and nonbonded angles in these complexes have been determined. Standard enthalpies, entropies, and Gibbs energies of formation of these compounds have been calculated.

The separation of lanthanides from calcium compounds in the form of oxalates from hot nitric acid solutions of Ln(NO₃)₃ and Ca(NO₃)₂ with the insertion of oxalic acid and a Ln₂(C₂O₄)₃ · nH₂O crystal seed was studied by mass-spectrometric, atomic emission, microscopic, X-ray diffraction, and fluorescence analyses. The produced single-phase precipitate was found to contain an isomorphic impurity of La–Sm oxalates, while calcium oxalate remained in the hot nitric acid solution (95°С) saturated with oxalic acid. This facile and efficient method provides Ln₂(C₂O₄)₃ · nH₂O (n = 9.5 mol) in one step in a 80.1 rel. % yield, with the major phase being at least 99.4 wt %. The unit cell parameters were determined for the crystals of the isomorphic lanthanide oxalate mixture: a = 11.243(2) Å, b = 9.591(2) Å, c = 10.306(2) Å; α = γ = 90°, β = 114.12(1)°; Z = 2; V = 1013.7(5) ų.

According to powder X-ray diffraction data, the crystal structures of compounds SrLnCuS₃ (Ln = Er, Yb) have been refined by minimizing the derivative difference in the anisotropic approximation for all atoms. Crystals are orthorhombic, space group Cmcm, structure type KZrCuS₃: a = 3.93128(3) Å, b = 12.9709(1) Å, c = 10.1161(1) Å, V = 515.843(9) ų, ρ_calc = 5.337 g/cm³, Z = 4, R_DDM = 3.73%, R_F = 2.06% (SrErCuS₃); a = 3.91448(4) Å, b = 12.9554(1) Å, c = 10.0332(1) Å, V = 508.842(8) Å3, ρ_calc = 5.487 g/cm³, Z = 4, R_DDM = 3.56%, R_F = 1.48% (SrYbCuS₃). The structure of SrLnCuS₃ is described by [LnCuS₃] twodimensional layers formed by distorted CuS₄ tetrahedra and LnS₆ octahedra with Sr²⁺ ions residing between the layers. The compounds are transparent for IR radiation in the range 3200–1800 cm^–1.

The quaternary reciprocal system Li, Na, Cs∥F, I was partitioned into simplexes, and the tree of phases was constructed. By differential thermal analysis, the stable triangle LiF–NaF–CsI was studied, and the characteristics of a ternary eutectic were determined.

A model of the chemical interaction of Si with the (HF₂)^– ion was propsoed to explain some experimental data on the formation of porous silicon.

Aqueous solutions of aluminum chloride in a wide range of concentrations have been studied by X-ray diffraction under standard conditions. It has been demonstrated that aluminum speciation in highly concentrated solutions is dominated by ionic associates involving two chloride ions. As the concentration decreases, the associates first converts to ion pairs and then to independently hydrated ions. The coordination number of the Al³⁺ ion increases to 6 when the solution is diluted and with an increase in the Al³⁺–OH₂ distance from 0.190 to 0.207 nm. The second coordination sphere of the cation is formed at an average distance of 0.400 nm. The number of solvent molecules in it naturally increases as the solution is diluted. The anion in highly concentrated solutions does not form its own coordination sphere. It begins to form at a distance of 0.315 nm only in solutions of average concentrations.