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A number of physicochemical characteristics of ten 1,2,3,4-tetrahydroquinoline derivatives synthesized for the first time, along with their third order Wiener and Randič indices are calculated by quantum chemical methods. Correlations between the topological indices, physicochemical parameters, and retention factors of the mentioned compounds are obtained for conditions of reversed-phase high performance liquid chromatography on porous graphitized carbon.

Novel Pd(0) nanocomposites using polycaprolactam as a reducing and stabilizing matrix are synthesized. Data on the nanoparticle formation mechanism in a polycaprolactam matrix under the conditions of changing pH of the medium and reagent concentration ratios are obtained. The nanocomposite structure is studied by electron and infrared spectroscopy, X-ray diffraction analysis, atomic force and transmission electron microscopy. The size of metal-containing particles in the composite composition and their size distribution are determined. The obtained nanocomposites can serve as heterogeneous catalysts.

A quantitative topological analysis of supramolecular structures in ethanol solutions with methanol, propanol, water, benzene, and hexane is performed by the MDGT method previously proposed by the authors. The method is based on a combination of molecular dynamics calculations and the graph theory, which enables the recognition and memorization of supramolecular structures observed in each snapshot of the molecular dynamic trajectory, the averaging of data for any number of these snapshots. Thus, the averaged concentrations of associates (dimers, trimers, etc.) are represented and then the concentrations and characteristics of isomers (e.g., chains, branched chains, rings, etc.), bond lengths, angles, etc. are determined in each group of associates.

The reaction between 1,3,6,8-tetraazatricyclo[4.4.1.1^3,8]dodecane (TATD) and 4-nitrophenol (4-NP) under solvent-free conditions results in the formation of a proton transfer (PT) complex, (TATD)⁺(4-NP)^-x4-NP, (3). This is the first crystal structure of a PT complex of TATD, whose structure is stabilized by N⁺-H⋯O and O^-⋯H-O hydrogen bonds. The characterization was performed using FTIR and ¹H NMR spectroscopy, and X-ray crystallography. From X-ray diffraction data collected at 173(2) K, it is concluded that it crystallizes in the monoclinic system (C2/c space group) containing one 4-nitrophenolate anion and one neutral 4-nitrophenol molecule. The stoichiometry of the proton transfer species in DMSO- d ₆ solution is in agreement with the structural data. A combined theoretical and experimental correlation of the structural parameters of free and protonated TATD are in good agreement. The discrepancies in the C-C bond distances between the experimental and calculated results can be attributed to hyper-conjugative interactions and electron delocalization.

A new caffeic acid derivative ((E)-3-(2,3-dihydrobenzo[b][1,4]dioxin-6-yl)acrylic acid, HL¹)) is synthesized from caffeic acid, followed by the preparation of a Cu(II) complex, [Cu₂(L¹)₄DMSO₂]x2DMSO. The structure is determined by single crystal X-ray diffraction, and the urease inhibitory activity of the complex is studied. The results show that IC₅₀ of the complex is 0.56 μmol/L, which is superior to positive control acetohydroxamic acid (AHA, IC₅₀ was 10.95 μmol/l), i.e., the complex has strong inhibitory activity towards urease.

Piperidine is one of the basic skeletons in many of pharmacological active compounds derived from natural or synthetic medicaments. Substitution of various groups in the piperidine ring regulates conformational flexibility due to the nature of the substituent on the nitrogen atom. One of the N-substituted piperidine derivatives, PMDPM, phenyl(3-methyl-2,6-diphenylpiperidin-1-yl)methanone, was crystallized and analysed by X-ray crystallography. The crystallographic data are: C₂₃H₂₅NO, M = 355.46, triclinic, space group Pī, a = 8.2543(7), b = 10.5543(8), c = 12.6184(6) Å, α = 77.901(7), β = 71.270(2)°, γ = 70.390(5)°; V = 974.3(1) ų, Z = 2, d_cal = 1.212 Mg/m³, λ(MoK_α) = 0.71073 Å. The core piperidine ring of PMDPM shows a positional disorder and adopts dual conformations as chair and twisted boat. The phenyl rings are oriented axially to the piperidine ring with the dihedral angle of 22.0(1)° between them. The packing is stabilized by C-H⋯O intra molecular interactions including few C-H⋯π and π⋯π weak interactions.

The crystallographic analysis of the tourmaline structure type with the general formula XY₃Z₆(T₆O₁₈)(BO₃)₃V₃W (R3m, Z = 3, a ≈ 16 Å, c ≈ 7.2 Å) shows that tetrahedrally coordinated T (Si, Al, …) cations, octahedrally coordinated Z (Al, Fe, Mg), and Y (Fe, Mg, Mn, …) form a joint cation framework with a sublattice whose geometry is close to F_cub (a_k ≈ 4.40 Å, a_k ≈ 93°) with 40% vacant positions in it. The anion ordering is less regular.

The crystal structures of isostructural fluoride complexes of indium(III) M[InF₄(H₂O)₂] (M = Rb, Cs) crystallizing in the monoclinic system, space group I2/a, are studied. The structures of M[InF₄(H₂O)₂] (M = Rb, Cs) are formed of isolated centrosymmetric complex [InF₄(H₂O)₂]^- anions with the trans -position of coordinated H₂O molecules and Rb⁺, respectively Cs⁺, cations. The In atom in the complex [InF₄(H₂O)₂]^- anion is surrounded by four F atoms and two oxygen atoms of coordinated H₂O molecules, forming the coordination polyhedron as a slightly distorted octahedron. Via a system of hydrogen O-H⋯F bonds the polyhedra of In atoms are arranged in a three-dimensional framework with the cations located in its channels.

The slow diffusion of ethanol vapor into a Na₈[Ta₆O₁₉]x24.5H₂O solution in 30% hydrogen peroxide leads to the formation of colorless Na₃[TaO₈]x14H₂O crystals (1) whose structure and composition are determined by single crystal XRD.

The crystal structure of a hexanuclear Na(I) complex based on 3,5-dimethyl-1H-pyrazole (C₅H₈N₂) and its anion is determined (space group P2₁/c, a = 12.2194(5) Å, b = 24.1554(9) Å, c = 11.3311(4) Å, β = 109.942(1)°, V = 3143.99(8) ų, Z = 2). The crystal structure is formed by Na₆(C₅H₈N₂)₄(C₅H₇N₂)₆ molecules. Thermogravimetric studies show that the compound exhibits volatility at elevated temperatures. The compound can be used in chemical gas-phase deposition processes.