Ашық рұқсат
Рұқсат берілді
Тек жазылушылар үшін
Том 471, № 2 (2016)
- Жылы: 2016
- Мақалалар: 10
- URL: https://journal-vniispk.ru/0012-5008/issue/view/9240
Chemistry
Solid-phase synthesis of intermetallic compounds Al13Co4, Al13Fe4, and Al13Co2Fe2
Аннотация
Intermetallic compounds Al13Co4, Al13Fe4, and Al13Co2Fe2 were obtained by solid-phase synthesis in air at temperatures below 600°C using precursor metals subjected to mechanochemical preactivation. The phase composition of the synthesized aluminides and composites Al13Co4/SiO2 and Al13Fe4/SiO2 was analyzed.
347-349
Sigmatropic hydrogen shifts in aryltetraphenylcyclopentadienes
Аннотация
Dynamic NMR has revealed intramolecular migrations of hydrogen atom over the periphery of the five-membered ring in 5-(p-tolyl)-1,2,3,4-tetraphenylcyclopentadiene in a deuteronitrobenzene solution with energy barrier ΔG180≠ = 24.8 kcal/mol. Quantum-chemical DFT calculations B3LYP/6-311++G** have shown that such migrations in 1,2,3,4,5-pentaphenylcyclopentadiene in the gas phase occur in a chiral conformation of propeller type by the mechanism of 1,5-sigmatropic hydrogen shifts with retention of configuration through asymmetric transition state with energy barrier ΔEZPE≠ = 25.9 kcal/mol. Enantiomers P and M can readily interconvert into each other (ΔEZPE≠ = 3.9 kcal/mol) owing to synchronous flip rotations of the phenyl groups.
350-355
The role of pre-nucleus states in formation of nanocrystalline yttrium orthoferrite
Аннотация
Formation of hexagonal and orthorhombic YFeO3 nanocrystals from an amorphous phase upon heat treatment of glycine–nitrate combustion products has been studied. The initial X-ray amorphous precursor has been shown to have pre-nucleus species of two types. Rapid formation of h-YFeO3 nanocrystals is explained by the presence of structurally similar pre-nucleus species in the precursor, while o-YFeO3 nanocrystals are formed much more slowly through recrystallization of the hexagonal and amorphous yttrium orthoferrite phases.
356-359
Environmentally benign (Green) synthesis of Cobazole, an efficient erythropoiesis-stimulating agent
Аннотация
A practicable and environmentally benign process for the synthesis of Cobazole, an erythropoiesisstimulating agent, has been developed. The process is based on the reaction of N-vinylimidazole with cobalt chloride in water and requires no toxic organic solvents, which ensures the preparation of high-purity product.
360-361
362-364
Interaction of indium antimonide with saturated sulfur vapor
Аннотация
The chemical reaction of single-crystal indium antimonide with saturated elemental sulfur vapor is diffusion-limited and leads to the formation of the triple layer In2S3–(xIn2S3 + (1–x)Sb2S3)–Sb on the surface of the samples. A model explaining the experimental facts is proposed.
365-367
Photodynamic chromogenic system based on photo- and ionochromic 8-(1,3-benzoxazol-2-yl)-substituted spirobenzopyran
Аннотация
8-(1,3-Benzoxazol-2-yl)-substituted spirobenzopyran is a new chromogenic system in which complexation with metal ions accompanied by a change in color can be controlled by photoirradiation. According to X-ray crystallography, the merocyanine ligand in the zinc complex has the TTT conformation.
368-372
New narrow-band-gap thiazoloquinoxaline-containing polymers and their use in solar cells with bulk heterojunction
Аннотация
Two new regioregular polymers P1 and P2 with structure of type D–A1–D–A2 have been prepared. The polymers exhibit strong light absorption in the range 300–1100 nm and have band gaps of 1.09 and 1.11 eV, respectively. The HOMO and LUMO energies for P1 and P2 are–5.08/–3.81 and–5.16/–3.85 eV, respectively. Polymer solar cells (PSC) based on P1: PC71BM (1: 2, v/v) and P2: PC71BM (1: 1, v/v) have open-circuit voltage Voc, short circuit current Jsc, and efficiency of 0.79 and 0.84 V, 8.32 and 9.54 mA/cm2, 3.5 and 4.7%, respectively. The PSC based on P2 exhibits higher characteristics due to the presence of fluorine atoms in the structure: their strong electron-withdrawing properties decrease the HOMO level of polymer P2 as compared with that of P1, which increases the Voc value. Moreover, the formation of additional S∙∙∙F contacts leads to the growth of ordering and crystallinity of polymer P2 as compared with P1, which favors an increase in the values of Jsc and filling factor.
373-377
Synthesis and study of photochromic asymmetric bis-spiropyran
Аннотация
Asymmetric indoline-benzoxazine bis-spiropyran showing improved photochromic properties due to the electron-donating methoxy group has been prepared by multistage synthesis. The molecular structure of 8-methoxy-3-methyl-4-oxo-2H-1,3-benzoxazine-2-spiro-2′H,8′H-pyrano-[2,3-f]chromene-8′-spiro-2″-1″,3″,3″-trimethylindoline has been studied by X-ray diffraction. After exposure to UV light, the absorption spectra display several long-wavelength maxima, which can correspond to different merocyanine isomers of the bis-spiro compound.
378-383
Chemical Technology
Copper-substituted tricalcium phosphates
Аннотация
Copper-substituted tricalcium phosphates (CuTCP) with different copper contents were developed using precipitation of copper-containing amorphous calcium phosphates (ACP) from salt solutions followed by heat treatment. Porous CuTCP ceramic was obtained using negative replicas. Using a set of investigation methods (powder X-ray diffraction, IR spectroscopy, ESR spectroscopy, and scanning electron microscopy), all copper-substituted tricalcium phosphates were found to have the whitlockite structure with copper incorporated in TCP in the 2+ oxidation state. The resulting material is promising for the use in regenerative medicine owing to higher solubility in body fluids compared with TCP and combination of bactericidal properties and the lack of cytotoxicity.
384-387