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By cation exchange for clinoptilolite tuff from the Khonguruu deposit (Yakutia) the Mg-, Ca-, Sr-, Ba-modified heulandite-clinoptilolite zeolites are obtained. Based on the data of powder X-ray diffraction and thermal analyses, the properties of these modifications are characterized. Using nitrogen cryosorption, the specific surface areas are determined. Found that the specific surface areas of the cationic modifications obtained increase with the ion charge.

An analysis is performed of the crystal structures of complex salts [RhL₄Cl₂]X (L=Py, γ- and β-picolines; X are different anions) in light of the effect induced by the nature of the anion X. It is shown that the intermolecular interactions between the anions play a key role in creating the general motif of the structure.

At a temperature of 20 K the crystal structures of two paracetamol polymorphs (monoclinic, form I, SPG P2₁/n and orthorhombic, form II, SPG Pbcа) are solved by single crystal X-ray diffraction and a comparative analysis of the geometric characteristics of intra- and intermolecular interactions is performed. Polymorphous transformations were not observed until cooling to this temperature. It is shown that in form II hydrogen bonds remain longer than those in form I up to a temperature of 20 K, and the density of metastable form II remains higher than that of stable form I. At the same time, in form II, thermal parameters of nitrogen and oxygen atoms remain higher than those in form I. The features observed in the behavior of the heat capacity of both forms at temperatures below 100 K are not directly related to a change in the geometry of hydrogen bonds. The methyl group orientation determined from the electron density maps does not alter as compared to higher temperatures in both modifications. Thus, changes in the Raman spectra observed in the orthorhombic paracetamol form below 100 K are explained by the features of its dynamics rather than a change in the overall average orientation of the methyl group determined by X-ray diffraction.

The results of the study of statistical copolymers of 3,3-bis(azidomethyl)oxetane (BAMO) and 3-azidomethyl-3-methyloxetane (AMMO) with a different molecular weight of monomer units, where А is the non-crystallizable "soft" block of AMMO and B is the “hard” block of BAMO, are reported. By wide angle X-ray diffractometry and IR spectroscopy, the amorphous-crystalline structure of AMMO BAMO copolymers is studied; the degree of crystallinity, crystallite size, and their defects are determined. The domain structure of the statistical copolymers is determined using small angle X-ray diffractometry.

Using methods of molecular mechanics and quantum chemistry in the DFT approximation, a conformational analysis of one of the most biologically active compounds of the class of brassinosteroids, natural brassinolide, and less active natural 24-epibrassinolide and synthetic (22S,23S)-24-epibrassinolide is performed with a subsequent comparison of their side chain structures. Found that the 22R,23R,24S-configuration of two hydroxyl and one methyl groups of brassinolide provides the side chain structures in which its diol system forms an O6…H(O5) intramolecular hydrogen bond. Therewith, the O6H hydroxyl group is free and can participate in the formation of intermolecular hydrogen bonds with a receptor. On the contrary, the 22S,23S,24R-configuration of (22S,23S)-24-epibrassinolide corresponds to the side chain structures in which the O6H hydroxyl group is shielded by the 21-methyl group, which determines a lower biological activity of this hormone.

Flavonoid-metal complexes have anticancer activities. However, the quantitative structure-activity relationship (QSAR) of flavonoid-metal complexes and their anticancer activities has not been known so far. Based on the 14 structures of flavonoid-metal complexes and their anticancer activities for HepG2 from the references, we optimised their structures using the density functional theory (DFT) method, and subsequently calculated 19 quantum chemical descriptors, such as dipole, charge, and energy. Then, we chose several quantum chemical descriptors that are very important for IC₅₀ which represents the anticancer activities of flavornoid-metal complexes for HepG2 through the stepwise linear regression method. Meanwhile, we obtained six new variables through the principal component analysis. Finally, we built QSAR models based on those important quantum chemical descriptors, six new variables as independent variables, and IC₅₀ as a dependent variable using an artificial neural network (ANN). At last, we validated the models using the experimental data from the references. The results show that models presented in this paper are accurate and predictive.

Three (E)-5-bromo-2-methoxy-4-((phenylimino)methyl)phenol derivatives (1-3) are synthesized and characterized by elemental analysis and single-crystal X-ray diffraction. The antibacterial activities of compounds 1-3 against Escherichia coli , Pseudomonas aeruginosa , Bacillus subtilis , and Staphylococcus aureus are evaluated by the MTT method.

The crystal structure of [Pt(En)₂](ReO₄)₂ (En is ethylenediamine) is studied. The crystal chemical analysis is performed and the main factors affecting the packing of moieties in this structure are determined. Shown that thermal decomposition in the He atmosphere at 880 °C results in the formation of the Pt_0.33Re_0.67 solid solution with the hexagonal close packed lattice parameters а = 2.765 Å, c = 4.422 Å and the size of the coherent scattering regions of 42 nm.

Spherical gold nanoparticles with the metal core of 5nm in diameter (according to the data of the transmission electron-microscopy) are prepared by the reduction of chloroauric acid with hydrazine monohydrate in reverse micelles of sodium bis-(2-ethylhexyl sulfosuccinate) (AOT). The photon correlation spectroscopy (PCS) method is used to determine the structure of the gold nanoparticle adsorption layer after their concentration and redispersion in AOT solutions in organic solvents with different polarity (in a series of decane, toluene, and chloroform). It is shown that in case of the abovementioned solvents at low AOT concentrations a gold nanoparticle is surrounded by a monolayer consisting of AOT molecules. When the concentration increases up to 1 M, the absorption layer thickness sharply increases; an increase in the organic solvent polarity enhances this increase. An increase in the temperature (from 20°C to 55 °C) leads to a partial and reversible decrease in the absorption layer thickness.

The X-ray diffraction and conformational study of bis(4-chloroquinoline-N-oxide)hydrogen tribromide is performed. Two conformations corresponding to the minima on the energy curve are found by DFT using the ABINIT software. The model of one of the conformers generally matches with the structure determined experimentally for this compound using X-ray diffraction. In both instances, the structure with the dihedral angle (quinoline - N-O-H) close to 90° is most favorable, which is explained in terms of resonance theory and steric factors. It is concluded that oxygen atoms in the complex are in the sp³ hybridization state and the sp² hybrid state of the oxygen atom is not possible here due to steric factors.