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Quantum dots (QDs) of zinc sulfide are synthesized by a microwave method in an aqueous medium using sodium dioctyl sulfosuccinate (DS) or 4,4¢-bipyridine (BP). Based on the analysis of X-ray diffraction profiles the conclusion is drawn that QDs obtained have a structure of cubic zinc blende with an average particle size of 5.6 nm for the ZnS_DS sample and 4.8 nm for ZnS_BP. Transmission electron microscopy images show the presence of spherical aggregates of particles only for ZnS_DS. IR data indicate the presence of sulfate ions in both samples; DS remains in the sample, facilitating the QD agglomeration, while BP is effectively washed out. From the optical diffusion scattering spectra the band gap is estimated, which turns out to be larger than the expected one due to the presence of elemental sulfur in the samples and partial oxidation of the QD surface. The QD structure based on ZnS particles is also modeled in the work. The possibility to employ X-ray absorption near-edge spectroscopy for the verification of atomic structural parameters around zinc sites in QDs based on zinc sulfide is demonstrated.

A new numerical method to determine the chirality of water configurations is developed. It consists in the comparison of matrices composed for both initial configuration and its mirror image based on the information of four bound water molecules. The method developed enables the rapid and unambiguous determination of the chirality of an aqueous system.

In a recent work by Zelikman et al.(J. Struct. Chem., 2015, 56(1)), the molecular dynamics simulation of dimers of glycyrrhizic acid (GA), which arise from the spontaneous collision of two GA molecules in water, is performed. Several relatively stable dimer structures are found, and when a cholesterol molecule is inserted, associates are observed that constitute a GA dimer with a cholesterol molecule "stuck" to it. Here, we simulate the associates consisting of three and four GA molecules and a cholesterol molecule. It appears that the cholesterol molecule, as a rule, is also located at the surface of the GA associate. Therewith, trimers do not form any clear characteristic structures, as dimers do, and tetramers can be two stuck dimers.

With an increase in the concentration of additives the hydration numbers of compounds decrease. Thus, in the saturated 54.6 % solution, urea loses approximately 3/4 of the initial amount of water, forming an aquacomplex of the composition (NH₂)₂COxH₂O. In a supersaturated 44% solution, the sodium chloride aquacomplex is dehydrated by 2/3, and in a supersaturated 67% solution, sodium sulfate is dehydrated by 5/6. The density of these solutions is 1.354¸1.360 g/cm³ (44 % NaCl) and 1.800¸1.849 g/cm³ (67 % Na₂SO₄). In the saturated urea solution, NaNO₃, NaCl, and Na₂SO₄ complexes lose 53¸55 % of hydrate water. It is shown here that in the binary water-urea system, interactions somewhat increase the hydration number of the salts (structural hydration). The characteristic important in the structural aspect (density of hydration water) increases in a series of solutions of compounds: urea, NaNO₃, NaCl, and Na₂SO₄. In the same series of additives, an excess volume of binary water-urea and water-salt systems becomes more negative.

Interest in the reduction of NiMoО₄-SiO₂ is related to its promising use as catalysts in hydrodeoxygenation and hydrodesulfurization processes. By means of in situ X-ray diffraction phase transformations occurring during the hydrogen reduction of NiMoO₄-SiO₂ in the temperature range 30-700 °C are studied in this work. It is shown that the reduction of a-NiMoО₄ proceeds in two stages. At the first stage, at 400-500 °C an intermediate state forms, which is a mixed oxide (Ni,Mo,□)O and Ni_{1- x} Mo _x . At the second stage, above 650 °C, two solid solutions form based on Mo and Ni structures. By the Rietveld method the structure of the intermediate state is refined. It is shown that the mixed Ni-Mo oxide forms based on the NiO structure, which contains some amount of cation vacancies.

The reaction of [W₃S₄(H₂O)₉]⁴⁺ with thiourea (tu) in hydrochloric acid produces a new cluster complex [W₃S₄(tu)₈(H₂O)]Cl₄×2H₂O containing coordinated thiourea. The complex is characterized by elemental analysis, thermogravimetry, IR, NMR, UV-Vis spectroscopy, and mass spectrometry. The crystal structure is determined by X-ray analysis. The thermal decomposition of [W₃S₄(tu)₈(H₂O)]Cl₄×2H₂O on heating from 20 °С to 700 °С in He gives WS₂, identified by the X-ray diffraction pattern. DFT calculations for [W₃S₄(tu)₈(H₂O)]⁴⁺ show that HOMO has a comparable contribution from metal- and ligand-centered atomic orbitals.

The new mixed-ligand complex of [Tl(Ph₂phen)Cl₃(DMSO)] (1) is obtained from the reaction of TlCl₃×4H₂O with 4,7-diphenyl-1,10-phenanthroline (Ph₂phen) in a methanol solution. Suitable crystals of 1 are obtained for the X-ray diffraction measurement by methanol diffusion into a DMSO solution. This complex is characterized by spectral methods (IR, UV-Vis, ¹H NMR, and luminescence), elemental analysis, thermal analysis (TG, DTA), and single crystal X-ray diffraction.

As a new precursor to prepare nano molybdenum trioxide, methanol {2-[(2-hydroxy-1, 1-dimethyl-ethylimino)-methyl]phenolato}dioxidomolybdenum(VI) complex (1) with the Schiff base ligand (H₂L) is synthesized by two different methods: solvothermal and sonochemical. Nanoparticles of 1 are obtained by one-pot solvothermal treatment of methanolic solutions of the ligand and di-oxomolybdenyl acetylacetonate at 150 °C for 24 h and for improving the quality of nanostructures by sonochemical method with two types of solvents, different concentrations of initial reagents and also different sonication times. The thermal stability of nanosized compound 1 is studied by thermal gravimetric (TG) analysis and differential scanning calorimetry (DSC). Nanoparticles of orthorhombic a-MoO₃ are obtained by calcination of nanostructures of compound 1 at 700 °C. All compounds and the obtained molybdenum trioxide nanostructures are characterized by elemental analysis, FT-IR, UV-Vis spectroscopy, X-ray powder diffraction (XRD), and scanning electron microscopy (SEM).

The titled complex is synthesized from the ethanolic solutions of 1-chloro-2,4-dinitrobenzene, 2-thiobarbituric acid, and 2-methylpyridine and characterized by spectral and elemental analyses. The single crystal X-ray diffraction results for the complex are compatible with the spectral observations. The titled complex exhibits anticonvulsant activity and reduces all phases of convulsion even at a low dosage. Acute toxicity studies of the complex are performed to understand the safer dose concentration for clinical trials.

A new copper(II) complex of 1,10-phenanthroline (C₁₂H₈N₂) and the meta -aminobenzoate ion ( m -amb; ), having the formula Cu(C₁₂H₈N₂)(C₇H₆NO₂)Cl×0.5H₂O, is prepared and characterized by elemental analysis, IR spectroscopy, and single crystal X-ray diffraction. The structure is built up from monomeric units in which the coordination environment around the metal ion is a square plane arising from a bidentate 1,10-phenanthroline molecule, a monodentate m -amb anion, and a chloride ion. A very long (Cu-N = 2.856(5) Å) bond to the nitrogen atom of an adjacent m -amb ion generates [101] polymeric chains in the crystal. The crystal structure is consolidated by N-H⋯O and O-H⋯O hydrogen bonds and C-H⋯O, C-H⋯Cl, and aromatic p-p stacking interactions. Crystal data: C₁₉H₁₅ClCuN₃O_2.5, M _r = 424.33, monoclinic, P 2₁/ n (No. 14), a = 9.8200(5), b = 10.9291(7), c = 16.3803(9) Å, b = 105.293(3)°, V = 1695.74(17) ų, Z = 4, R ( F ) = 0.043, wR ( F ²) = 0.122.