Preparation of fullerene С<Subscript>60</Subscript> dispersions in water

Stable colloidal dispersions of fullerene С₆₀ in water free of organic solvents have been obtained. The addition of a С₆₀ solution to a water–acetone mixture has been shown to cause a solvatochromic effect.     

Crystal structure of α-Ag<Subscript>8</Subscript>S<Subscript>3</Subscript>SO<Subscript>4</Subscript>

The crystal structure of silver sulfide-sulfate α-Ag₈S₃SO₄ was determined by X-ray powder diffraction data. The substance crystallizes in the tetragonal system and the space group P-4 with the unit cell parameters of α = 7.2032(4) Å, c = 5.1043(5) Å, Z = 1, R _f = 5.55%, χ² = 3.45. The layers in the structure of the compound formed by trigonal prisms of Ag₆S connected to each other through the vertices are connected by the additional atoms of sulfur into a three-dimensional framework. Distorted tetrahedral anions of SO ₄ ^2? are located in the cavities of the framework, the symmetry (D _2d ) of which was confirmed by the data of IR spectroscopy.     

Crystal structure of Bi<Subscript>36</Subscript>MgP<Subscript>2</Subscript>O<Subscript>60 − δ</Subscript>

A compound with the general formula Bi₃₆MgP₂O_{60 ? δ} was obtained by a solid-state reaction method. Its composition was confirmed using EDAX. The compound belongs to the cubic crystal system (space group I23, no. 197) and has a sillenite-type structure. The lattice parameter a _o is 10.15704(12) Å. The Rietveld refinement of the crystallographic data revealed mixed tetrahedral sites (2a) occupied by Mg, P, and Bi in a ratio of 32: 63: 5. The resulting lattice strains are compensated by vacancies in the cationic (2a) and anionic sites (24f) and by distortion of the Bi-O framework detected by IR and Raman spectroscopy.     

Hydroethoxycarbonylation of α-olefins at low pressure of carbon(II) oxide in the presence of the PdCl<Subscript>2</Subscript>(PPh<Subscript>3</Subscript>)<Subscript>2</Subscript>–PPh<Subscript>3</Subscript>–AlCl<Subscript>3</Subscript> system

High catalytic activity of the PdCl₂(PPh₃)₂–PPh₃–AlCl₃ system containing AlCl3 as promotor has been demonstrated in the reaction of hydroethoxycarbonylation of hexene-1 and octene-1 at low pressure of carbon(II) oxide (≤25 atm). The reaction yields linear and branched products. The optimal conditions of the process have been elaborated. The target products yield is 84.6–93.8%.     

The characterization and property of polystyrene compounding of α-Fe<Subscript>2</Subscript>O<Subscript>3 </Subscript>in the nano-scale

-Fe₂O₃/polystyrene composite nanoparticles were synthesized in an oil/water microemulsion. Their structure was characterized by transmission electron microscopy, X-ray diffraction and Fourier transform-infrared spectrometry. An Ubbelonde viscometer, a Gouy balance and a model 283 potentiostat/galvanostat measured the molecular weight of the composite nanoparticles and their magnetic and electrical characteristics respectively.     

Effect of Fe-zeolite on formation of N<Subscript>2</Subscript>O in selective reduction of NO by NH<Subscript>3</Subscript> over V<Subscript>2</Subscript>O<Subscript>5</Subscript>–WO<Subscript>3</Subscript>/TiO<Subscript>2</Subscript> catalyst

An approach for significantly suppressing N₂O formation in reduction of NO by NH₃ over V₂O₅–WO₃/TiO₂ (VWT) catalyst has been studied by coating different amounts of a Fe-exchanged zeolite (FeZ) onto the catalyst. FeZ-promoted VWT samples were characterized using N₂ sorption, X-ray diffraction (XRD) analysis, and NH₃ adsorption/desorption techniques to understand the primary role of FeZ in lowering N₂O production levels. At high temperatures (≥450 °C), VWT gave N₂O production with high concentrations, while N₂O formation was noticeably reduced when using FeZ-promoted catalysts, which also showed somewhat lower NO removal activities (<5 %) at all temperatures. N₂ sorption and XRD measurements revealed no perceptible physical or chemical alterations of each constituent, even in VWT catalysts after FeZ coating following high-temperature calcination. Adsorption of NH₃ on unpromoted and FeZ-promoted catalysts and subsequent desorption yielded very complicated spectra for N₂O that might primarily come from NH₃ oxidation, and the interaction between V–NO species at temperatures >580 °C. NO on neighboring sites seems to be produced via decomposition of N₂O generated at lower temperatures. The FeZ in the promoted VWT catalysts could be responsible for N₂O decomposition and N₂O reduction with unreacted NH₃ at temperatures >400 °C, thereby significantly lowering N₂O emission levels. This promotional effect bodes well for use in many industrial deNO _x applications.     

Formation of solid solutions of multiferroics in the Bi<Subscript>2</Subscript>O<Subscript>3</Subscript>–Nd<Subscript>2</Subscript>O<Subscript>3</Subscript>–Fe<Subscript>2</Subscript>O<Subscript>3</Subscript> system

The sequence of phases appearance during the formation of Bi_1–xNd_xFeO₃ solid solutions in powder oxides mixtures of bismuth, neodymium, and iron has been determined. It has been shown that the closeness of the reaction mixture composition to that of the individual compound (BiFeO₃ or NdFeO₃) is essential for the realization of the series of phase transformations yielding solid solutions of multiferroics Bi_1–xNd_xFeO₃ as the final product, due to the prevalence of various interphase contacts in the starting reaction zone.     

Motif of the three-layered close packing of cluster anions in [RhPy<Subscript>4</Subscript>Cl<Subscript>2</Subscript>]<Subscript>4</Subscript>[Re<Subscript>6</Subscript>S<Subscript>8</Subscript>(CN)<Subscript>6</Subscript>]·1.5H<Subscript>2</Subscript>O

[RhPy₄Cl₂]₄[Re₆S₈(CN)₆]·1.5H₂O (Py is pyridine) was investigated by X-ray analysis. In the cluster anion, the Re-Re distances vary from 2.6063(2) Å to 2.6125(2) Å. For two crystallographically independent complex cations, the distances are 〈Rh-N〉 2.060 Å and 〈Rh-Cl〉 2.336 Å. The motif of the three-layered close packing was found; the [Re₆S₈(CN)₆]^4? anions follow the vertices of a rhombohedron with the parameters a _c ≈ 15.5 Å and α_c ≈ 61°.     

Oxidation of Adamantane with H<Subscript>2</Subscript>O<Subscript>2</Subscript>–CF<Subscript>3</Subscript>COCF<Subscript>3</Subscript> · 1.5 H<Subscript>2</Subscript>O in the Presence of VO(acac)<Subscript>2</Subscript>

The system hydrogen peroxide–hexafluoroacetone sesquihydrate effectively oxidizes adamantane in the presence of VO(acac)₂ to afford 64% of adamantan-1-ol in tert-butyl alcohol or 76% of adamantan-2-one in a mixture of acetic acid with pyridine.     

Crystal structure of Na<Subscript>3</Subscript>(NH<Subscript>4</Subscript>)<Subscript>2</Subscript>[Ir(SO<Subscript>3</Subscript>)<Subscript>2</Subscript>Cl<Subscript>4</Subscript>]·4H<Subscript>2</Subscript>O

The complex Na₃(NH₄)₂[Ir(SO₃)₂Cl₄]·4H₂O was examined with single crystal X-ray diffraction and IR spectroscopy. Crystal data: a = 7.3144(4) Å, b = 10.0698(5) Å, c = 12.3748(6) Å, β = 106.203(1)°, V = 875.26(8) ų, space group P2₁/c, Z = 2, d _calc = 2.547 g/cm³. In the complex anion two trans SO ₃ ^2? groups are coordinated to iridium through the S atom. The splitting of O-H bending vibrations of crystallization water molecules and N-H ones of the ammonium cation is considered in the context of different types of interactions with the closest neighbors in the structure.     

High-temperature heat capacity of Pb<Subscript>8</Subscript>La<Subscript>2</Subscript>(GeO<Subscript>4</Subscript>)<Subscript>4</Subscript>(VO<Subscript>4</Subscript>)<Subscript>2</Subscript> in the range 320–1000 K

The oxide compound Pb₈La₂(GeO₄)₄(VO₄)₂ with an apatite structure has been synthesized by a ceramic method. The effect of temperature on the molar hear capacity of polycrystalline samples in the temperature range 320–1000 K has been studied by differential scanning calorimetry. The results have been used to calculate the thermodynamic functions of the synthesized compound.     

Crystal structure of Ba<Subscript>3</Subscript>[UO<Subscript>2</Subscript>(C<Subscript>2</Subscript>O<Subscript>4</Subscript>)<Subscript>2</Subscript>(NCS)]<Subscript>2</Subscript> · 9H<Subscript>2</Subscript>O

Single crystals of Ba₃[UO₂(C₂O₄)₂(NCS)]₂ · 9H₂O are synthesized and studied by X-ray diffraction. The crystals are orthorhombic, space group Fddd, Z = 16, and the unit cell parameters are a = 16.253(3) Å, b = 22.245(3) Å, c = 39.031(6) Å. The main crystal structural units are mononuclear complex groups [UO₂(C₂O₄)₂NCS]^3? of the crystal-chemical family (AB ₂ ⁰¹ M¹ (A = UO ₂ ²⁺ , B⁰¹ = C₂O ₄ ^2? , M¹ = NCS^?) of the uranyl complexes linked into a three-dimensional framework by electrostatic interactions and hydrogen bonds involving oxalate ions and water molecules.     

High-temperature reactions in the Co<Subscript>3</Subscript>Cr<Subscript>4</Subscript>(PO<Subscript>4</Subscript>)<Subscript>6</Subscript>–Cr(PO<Subscript>3</Subscript>)<Subscript>3</Subscript> system

A new dichromium(III) cobalt(II) diphosphate(V) of the formula CoCr₂(P₂O₇)₂ was detected in the Co₃Cr₄(PO₄)₆–Cr(PO₃)₃ system. The new compound was obtained as a result of high-temperature solid-state reactions between CoCO₃, Cr₂O₃ and (NH₄)₂HPO₄ as well as between Cr(PO₃)₃ and Co₃Cr₄(PO₄)₆. CoCr₂(P₂O₇)₂ was characterized using XRD, DTA and IR methods. Results demonstrated that CoCr₂(P₂O₇)₂ crystallizes in the triclinic system and its unit cell parameters were calculated. Its infrared spectrum was presented. CoCr₂(P₂O₇)₂ melts incongruently at 1270±10 °C with a formation of solid α-CrPO₄. The compound Co₃Cr₄(PO₄)₆, component of the system under study, was obtained for the first time as a pure phase. Its thermal stability was also investigated. Co₃Cr₄(PO₄)₆ is stable in air up to 1410 ± 20 °C.     

Crystal structure of Cs[(UO<Subscript>2</Subscript>)<Subscript>2</Subscript>(C<Subscript>2</Subscript>O<Subscript>4</Subscript>)<Subscript>2</Subscript>(OH)] · H<Subscript>2</Subscript>O

Single crystals of Cs[(UO₂)₂(C₂O₄)₂(OH)] · H₂O were synthesized and structurally studied using X-ray diffraction. The compound crystallizes in monoclinic space group P2₁/m, Z = 2, with the unit cell parameters a = 5.5032(4) Å, b = 13.5577(8) Å, c = 9.5859(8) Å, β = 97.012(3)°, V = 709.86(9) ų, R = 0.0444. The main building units of crystals are [(UO₂)₂(C₂O₄)₂(OH)]^? layers of the A₂K ₂ ⁰² M² (A = UO ₂ ²⁺ , K⁰² = C₂O ₄ ^2? , and M² = OH^?) crystal-chemical family. Uranium-containing layers are linked into a three-dimensional framework via electrostatic interactions with outer-sphere cations and hydrogen bonds with water molecules.     

Transformations of CO<Subscript>2</Subscript> in Two-Phase Systems C<Subscript>8</Subscript>F<Subscript>18</Subscript>–H<Subscript>2</Subscript>O and C<Subscript>6</Subscript>F<Subscript>6</Subscript>–H<Subscript>2</Subscript>O

The transformation of carbon dioxide in aqueous emulsions of perfluorons in the presence of oxygen in the air results in the formation of a mixture of oxalic acid and a minor set of organic compounds C₄–C₈. The maximum CO₂ consumption occurs in the emulsion with the C₈F₁₈: H₂O vol/vol ratio of 1: 0.42 at pH 2.4; the H₂C₂O₄ yield is 11 mol %.     

Water-soluble fullerene С<Subscript>60</Subscript> derivative obtained by radiation polymerization of <Emphasis Type="Italic">N</Emphasis>-vinylpyrrolidone in the presence of С<Subscript>60</Subscript>

Method of radiation polymerization of N-vinylpirrolidone (NVP) in the presence of fullerene C₆₀ has been used to obtain water soluble compound containing fullerene C₆₀. The yield of resulted product was ~10% in the case of low-temperature radiation polymerization of NVP—C₆₀ mixture in ethanol and ~40% at 300 K. The content of C₆₀ in obtained product was ~0.5 wt.%.     

Graphitized carbon materials for electrosynthesis of Н<Subscript>2</Subscript>О<Subscript>2</Subscript> from О<Subscript>2</Subscript> in gas-diffusion electrodes

New graphitized carbon materials: technical carbon N220, С140, and СН85 (Omsktekhuglerod) were studied as catalysts of electrosynthesis of alkaline solutions of hydrogen peroxide from oxygen in gasdiffusion electrodes (GDEs). The kinetic parameters of oxygen reduction in alkaline solution and the capacity of gas-diffusion electrodes based on technical carbon N220, С140, and СН85 were determined. Data on the kinetics of hydrogen peroxide accumulation were obtained at different current densities. The fraction of current γ spent on the reduction of oxygen to hydrogen peroxide was determined. The rate constants of hydrogen peroxide decomposition under the given conditions were calculated.     

Phase formation in the system Li<Subscript>2</Subscript>MoO<Subscript>4</Subscript>–MgMoO<Subscript>4</Subscript>–Sc<Subscript>2</Subscript>(MoO<Subscript>4</Subscript>)<Subscript>3</Subscript>

Phase formation in the system Li₂MoO₄–MgMoO₄–Sc₂(MoO₄)₃ was studied by X-ray powder diffraction analysis and differential thermal analysis. Ternary molybdate LiMgSc(MoO₄)₃ was synthesized, which crystallizes in the triclinic system (space group P\(\bar 1\)). In the Li₂Mg₂(MoO₄)₃–Li₃Sc(MoO₄)₃ section, a continuous solid solution in the rhombic system was found to form (space group Pnma).     

Phase formation in Li<Subscript>2</Subscript>MoO<Subscript>4</Subscript>-K<Subscript>2</Subscript>MoO<Subscript>4</Subscript>-MMoO<Subscript>4</Subscript> (M = Ca,Pb, Ba) systems and the crystal structure of α-KLiMoO<Subscript>4</Subscript>

Solid-phase interactions in Li₂MoO₄-K₂MoO₄-MMoO₄ (M = Ca, Pb, Ba) systems were studied, and the subsolidus regions of these systems were triangulated. The lead and barium systems were studied in a more detailed way to discover that, along KLiMoO₄-K₂M(MoO₄)₂ (M = Pb, Ba), KLiMoO₄-PbMoO₄, and Li₂MoO₄-K₂Ba(MoO₄)₂ quasi-binary sections, there are homogeneity regions reaching 6–11 mol % based on K₂M(MoO₄)₂ and lead molybdate. Triple molybdates are formed in none of the systems, which is verified by experiments on spontaneous crystallization from solution in melt. Crystallization experiments yielded crystals of potassium dimolybdate and simple and double molybdates from the boundary systems. The crystal structure was solved for a hexagonal KLiMoO₄ phase: (Na,K){ZnPO4}, a = 18.8838(7) Å, c = 8.9911(6)Å, Z = 24, space group P6₃, R = 0.065. The structure comprises a three-dimensional tridymite framework built by an alternation of corner-sharing LiO₄- and MoO₄ tetrahedra wherein voids are occupied by potassium cations.     

Synthesis and structure of the complex [Mo<Subscript>3</Subscript>(μ<Subscript>3</Subscript>-S)(μ<Subscript>2</Subscript>-S<Subscript>2</Subscript>)<Subscript>3</Subscript>(Et<Subscript>2</Subscript>NCS<Subscript>2</Subscript>)<Subscript>3</Subscript>]I

The structure of tri-μ₂-disulfido-μ₃-thiotris(diethyldithiocarbamato)-S,S′-triangle-trimolybdenum iodide [Mo₃(μ₃-S)(μ₂-S₂)₃(Et₂NCS₂)₃]I was determined. The compound was characterized by differential thermal analysis and IR, Raman, and X-ray electronic spectroscopy.