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Captopril disulphide is obtained under hydrothermal conditions. The IR and Raman spectra data are in agreement with the X-ray diffraction results. The disappearance of the band at 2566 cm^-1 (n(SH)) in both spectra of captopril disulphide is consistent with the formation of the S-S bond. The degradation of the captopril drug is investigated by Raman spectroscopy and the results indicate that after 6 weeks of air exposure, a band at 512 cm^-1, assigned as n(SS), is observed, suggesting the formation of captopril disulphide. DFT calculations in the solid state are performed for captopril and captopril disulphide. The results indicate that captopril disulphide is approximately 30 kcal×mol^-1 more stable than captopril. The analysis of the total density of states (DOS) reveals that the captopril valence band contains a significant contribution from the S atom, whereas for captopril disulphide, the O atom is the most important for the valence band.

The electronic structure of free radicals and Cu(II) complexes with the nitronylnitroxyl radical and amino nitron is studied by X-ray photoelectron spectroscopy (XPS). N1 s XPS spectra of nitrogen atoms of Cu(II) complexes with amino nitrons confirm the diamagnetic nature of the ligands. The binding energies of the main peak and the intense satellite structure in the Cu2p_3/2,1/2 spectra of the complexes under study correspond to the Cu(II) state. The structure of the satellite in the Cu2p_3/2,1/2 spectrum depends on the environment of the metal ion.

By the single crystal X-ray diffraction analysis in combination with quantum chemical calculations the molecular and crystal structures of energy-intensive 2,4,6-triazipyridine and 2,4,6-triazido-3,5-dibromopyridine are studied; the dependence of structural parameters of their azido groups on the size of substituents in b-positions of the pyridine ring is analyzed. The effect of the intramolecular contact involving the central nitrogen atom of -azido groups in substituted triazides on their structure and properties is revealed.

Silver nanoparticles are synthesized in the medium of an aqueous cysteine-silver solution at different рН values using sodium borohydride as a reductant. By means of dynamic light scattering, electron spectroscopy, and transmission electron microscopy it is found that the size and stability of nanoparticles in this system depend on the рН value that is regulated by alkali and on the concentration of the cysteine-silver solution. Under certain conditions the unimodal distribution of silver nanoparticles with an average size of 40 nm are obtained.

Films of hydrogenated SiC _x N _y O _z :H obtained by plasma-enhanced chemical vapor deposition from a mixture of 1,1,3,3-tetramethyldisilazane with oxygen and nitrogen (TMDS+O₂+ x N₂) in the temperature range 373-973 K are nanocomposites in whose amorphous part nanocrystals belonging to phases of the Si-C-N: -Si_3-x C _x N₄ system and graphite are distributed. A change in the chemical composition of gas mixtures enables the preparation of SiC _x N _y O _z :H films with a broad variation range of the functional properties, such as the 1.45-2.15 variation of the refractive index; the controlled transparency ( T 92-99.7 %) in UV, visible, and IR spectral ranges; tunable characteristics of the band gap (3.5-5.4 eV), and dielectric constants (5.2-5.8).

In order to obtain crystalline photochromic materials combining the advantages of photochroms in liquid and polymeric solutions (high quantum yields) and in the solid state (enhanced resistance to photodegradation) a photochromic adduct consisting of a metal-organic framework [Zn₄(dmf)(ur)₂(ndc)₄] (ndc^2- is 2,6-naphthalenedicarboxylate, ur is urotropine, dmf is N,N-dimethylformamide) and 2,3-bis-(2,5-dimethylthiophen-3-yl-cyclopent-2-en-1-one) is synthesized (compound 1). The photochemistry of the adduct is studied. Solid 2,3-diarylcyclopentenone exhibits photochromism typical of diarylethenes. Quantum yields of the adduct photocoloration and photobleaching turn out to be 1.5 and 3 times higher respectively than those for solid compound 1 and lower than those of solution 1 in acetonitrile by an order of magnitude. The number of photochemical cycles for compound 1 in the solution, the solid state, and the adduct composition is limited by the monomolecular side reaction.

A motif of the supramolecular architecture of соcrystals of 18-crown-6 and polychloropolyfluoro-1,3-phenylenediamines or partially fluorinated 1,3-phenylenediamines (1:1 stoichiometry) is infinite 1D ensembles of alternating components. Mutual coordination of molecules in the ensembles is due to the hydrogen bond between crown ether oxygen atoms and hydrogen atoms of polyfluoroarene amino groups. Parameters of the architecture of соcrystals are determined by the effect of the number and positions of substituents (chlorine and fluorine atoms) in the polyhalogenated aromatic ring.

Carboxylate ligands are very versatile because they can adopt different coordination modes towards metal cations, such as monodentate, bidentate-chelate, bidentate bridging and monoatomic bridging. Because of this versatility, these ligands have been widely used in coordination chemistry. In this study the three dimensional structure of the crystal arrangement of 2,5-thiophenedicarboxylic (H₂TPD), trans-3-(3-pyridyl)acrylic (HPYA), and 4,4¢-sulfonyldibenzoic (H₂SFD) acids are determined in order to investigate their supramolecular properties for coordination polymers and metal-organic framework (MOF) constructions.

Mechanisms of radiation damages in minerals promising for the utilization of highly active radioactive waste (zircon ZrSiO₄, monazite LaPO₄, orthophosphate YbPO₄, lakargiite CaZr_0,8Sn_0,1Ti_0,1O, and Gd₂Zr₂O₇ and Gd₂Ti₂O₇ compounds with the pyrochlore structure) are studied by the computer simulation using the molecular dynamics method. The formation of a damaged region in the structures under study is considered along with the reduction (relaxation) processes in these structures. The number of Frenkel pairs and antistructural defects that form in the structure of these minerals after the pass of the knocked out thorium atom is calculated by the molecular dynamics method. A parameter is proposed that characterizes the mineral tendency to amorphization under the effect of the radiation damage. The obtained results show that one of the main factors determining the radiation stability of minerals is the crystal structure type, compounds with the monazite structure being more radiationally stable than compounds with the zircon structure. It is found that the Gd₂Zr₂O₇ compound and lakargiite have a weaker tendency to amorphization than other minerals such as zircon, monazite, and orthophosphate YbPO₄. A high radiation stability of the studied Gd₂Zr₂O₇ compound as well as a solid solution of the composition CaZr_0.8Sn_0.1Ti_0.1O₃ makes it possible to propose them as a possible matrix for the utilization of highly active radioactive waste.

A new Cu(II) coordination polymer, namely {[Cu₂(btb)₂(sip)(OH)]×(H₂O)_0.25} _n (btb = 4,4¢-bis(1,2,4-triazolyl-1-yl)-biphenyl, H₃sip = 5-sulfoisophthalic acid), is hydrothermally synthesized and characterized by elemental analyses, infrared (IR) spectroscopy, and single crystal X-ray diffraction. It crystallizes in the monoclinic space group P 2₁/ c , a = 14.9676(3) Å, b = 14.3478(3) Å, c = 21.2719(5) Å, b = 125.325(2)°, V = 3727.11(14) ų, Z = 4, C₄₀H_28.50Cu₂N₁₂O_8.25S, M _r = 968.39, D _c = 1.726 g/cm³, m = 1.274 mm^-1. The structural analyses reveal that the compound displays a 2D binodal rarely (4,5)-connected network with 4,5L50 topology. Moreover, the thermal and catalytic properties of the complex for the degradation of the congo red azo dye in a Fenton-like process are investigated.