Study of Triple System Calcium Iodide-HMTA-Water

Research relevance: synthesis, physicochemical studies of complexes bioactivity with salts of biometals and organic ligands are of great interest for bio-coordination chemistry. Materials and research methods: isothermal method was used to study heterogeneous equilibria at 25 °C. The concentration limits of compounds existence and the types of their solubility have been established. Research objectives: to investigate compounds of hexamethylenetetramine with salts of biometals with organic ligands in order to reduce toxicity, increase the bioactivity and bioavailability of coordination compounds. Research results: concentration limits of compounds existence and types of their solubility have been established. Conclusions: in obtained complexes, HMTA ligand contains four equivalent electron donor nitrogen atoms.

EVALUATION OF EFFECTIVENESS OF COMPREHENSIVE TREATMENT OF DUODENAL ULCER IN CHILDREN

In the structure of pathology of the digestive organs 1.7–16% constitute peptic ulcerdisease, which in 90% of cases is associated with H.pylori infection.The aim is to evaluate the effectiveness of comprehensive treatment of duodenal ulcer inchildren.Material and methods: The study included 60 children at the age of 10 -18 years withHelicobacter pylori-associated duodenal ulcer (DU), who were divided into three groupsof 20 people depending on the treatment regimen (protocol, including the donor of nitrogen monoxide and capillary stabilizing preparation).Results. Complex therapy of the disease in children provides faster positive dynamics ofclinical and endoscopic symptoms, increases the frequency of eradication of Helicobacterpylori, the relative risk of recurrence will decrease by 0.57 times when included in thetreatment regimen of nitrogen oxide donor and 0.66 times when used along with theprotocol scheme of the donor nitrogen oxide and capillarotropic drug.Conclusion. Comprehensive treatment of DU provides more stable results of treatmentand decreases the disease recurrences both in the early and late stages of observation.

DFT Quantum-Chemical Modeling Molecular Structures of Cobalt Macrocyclic Complexes with Porphyrazine or Its Benzo-Derivatives and Two Oxygen Acido Ligands

Based on the results of a quantum chemical calculation using the DFT method with the OPBE/TZVP and B3PW91/TZVP levels, the possibility of the existence of three cobalt heteroligand complexes containing in the inner coordination sphere porphyrazine, di[benzo]- and tetra[benzo]porphyrazine, and two oxygen (O2−) ions with probable oxidation state VI of Co, which is unknown for this element at the present time, was shown. Data on the structural parameters are presented. It was shown that CoN4 chelate nodes as well as all metal-chelate and non-chelate cycles in each of these complexes, were strictly planar. Besides, the bond angles formed by two donor nitrogen atoms and a Co atom were close or equal to 90°, while the bond angles formed by donor atoms N, Co, and O, in most cases, albeit insignificantly, differed from this value. Good agreement between the calculated data obtained using the above two versions of the DFT method was found. Standard thermodynamic parameters of formation (standard enthalpy ΔH0f, 298, entropy S0f, 298 and Gibbs’s energy ΔG0f, 298) for the indicated complexes were presented too.

New Silver(I) Coordination Polymer with Fe4 Single-Molecule Magnets as Long Spacer

In continuation of our work on supramolecular architectures of single-molecule magnets (SMMs) as a promising strategy in developing their magnetic performance, in this paper we report the synthesis and single crystal X-ray structure of the centered triangular tetrairon(III) SMM, [Fe4(PhpPy)2(dpm)6], Fe4 (Hdpm = dipivaloylmethane, H3PhpPy = 2-(hydroxymethyl)-2-(4-(pyridine-4-yl)phenyl)propane-1,3-diol), and its assembly in the coordination polymer {[Fe4(PhpPy)2(dpm)6Ag](ClO4)}n, Fe4Ag, upon reaction with silver(I) perchlorate. Thanks to the presence of the pyridyl rings on the two tripodal ligands, Fe4 behaves as divergent ditopic linker, and due to the Fe4:AgClO4 1:1 ratio, Fe4Ag probably possesses a linear arrangement in which silver(I) ions are linearly coordinated by two nitrogen atoms, forming 1D chains whose positive charge is balanced by the perchlorate anions. The stabilization of such a polymeric structure can be ascribed to the long distance between the two donor nitrogen atoms (23.4 Å) and their donor power. Fe4Ag shows slow relaxation of the magnetization which follows a thermally activated process with Ueff/kB = 11.17(18) K, τ0 = 2.24(17) 10−7 s in zero field, and Ueff/kB = 14.49(5) K, τ0 = 3.88(8) 10−7 s in 1-kOe applied field, in line with what reported for tetrairon(III) SMMs acting as building blocks in polymeric structures.

Defect Control in Zinc Oxynitride Semiconductor for High-Performance and High-Stability Thin-Film Transistors

The fabrication of thin-film transistor devices incorporating active semiconductors based on zinc oxynitride (ZnON) compound is presented. It is demonstrated that the addition of appropriate dopant, gallium, in ZnON, suppresses the formation of shallow donor, nitrogen vacancies, and significantly improves electrical characteristics of the resulting TFT. The Ga:ZnON devices with field-effect mobility values exceeding 50 cm2/Vs are achieved, which makes them suitable as switching or driving elements in next-generation flat-panel displays.

Impact of n-Type versus p-Type Doping on Mechanical Properties and Dislocation Evolution during SiC Crystal Growth

The origin of dislocation evolution during SiC crystal growth is usually related to lattice relaxation mechanisms caused by thermal stress. In this paper we discuss dislocation generation and dislocation propagation related to doping and suppression of basal plane dislocations, the latter being of particular interest for bipolar electronic devices. We have prepared alternating p-/n-/pdoped SiC crystals using the donor nitrogen and the acceptors aluminum or boron. In addition we determined the mechanical properties of n-type and p-type SiC; in particular we measured the critical shear stress by nano-indentation on c-plane and a-plane 6H-SiC surfaces. A considerably lower basal plane dislocation density is found in aluminum as well as in boron doped p-type SiC compared to nitrogen doped n-type SiC. It is concluded that the explanation of the reduced basal plane dislocation density in p-type SiC needs the consideration of electronic as well as mechanical effects.

The Structure of a Methylpalladium(II) Complex of Pyridine-2-carboxylato (N - O) and Triphenylphosphine (PPh3), [Pd(CH3)(N - O)(PPh3)]

The compound [Pd(CH3)(PPh3)(N–O)] (N–O represents pyridine-2-carboxylato (pyca)) has been synthesized and the structure determined. The compound crystallized in the monoclinic space group P21/c, a 8.4844(9), b 12.845(2), c 19.690(3) Å, b 92.09(1)˚, V 2144.4(5) Å 3 , Z 4, and was refined to an R value of 0.022 on 3551 F. The structure had a distorted square-planar geometry in which the donor nitrogen and phosphine ligands are trans.