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PubMed | University of Kharkiv, SSI Institute for Single Crystals NAS of Ukraine, University of Konstanz and Heinrich Heine University Düsseldorf
Type: | Journal: Beilstein journal of organic chemistry | Year: 2015

The switchable three-component reactions of 5-amino-3-methylisoxazole, salicylaldehyde and N-aryl-3-oxobutanamides under different conditions were studied and discussed. The unexpected influence of the aryl substituent in N-aryl-3-oxobutanamides on the behavior of the reaction was discovered. The key influence of ultrasonication and Lewis acid catalysts led to an established protocol to selectively obtain two or three types of heterocyclic scaffolds depending on the substituent in the N-aryl moiety.


PubMed | National University of Pharmacy, SSI `Institute for Single Crystals NAS of Ukraine and Far Eastern State Medical University
Type: Journal Article | Journal: Acta crystallographica. Section C, Structural chemistry | Year: 2016

The fact that molecular crystals exist as different polymorphic modifications and the identification of as many polymorphs as possible are important considerations for the pharmaceutic industry. The molecule of N-benzyl-4-hydroxy-1-methyl-2,2-dioxo-1H-2(6),1-benzothiazine-3-carboxamide, C17H16N2O4S, does not contain a stereogenic atom, but intramolecular hydrogen-bonding interactions engender enantiomeric chiral conformations as a labile racemic mixture. The title compound crystallized in a solvent-dependent single chiral conformation within one of two conformationally polymorphic P212121 orthorhombic chiral crystals (denoted forms A and B). Each of these pseudo-enantiomorphic crystals contains one of two pseudo-enantiomeric diastereomers. Form A was obtained from methylene chloride and form B can be crystallized from N,N-dimethylformamide, ethanol, ethyl acetate or xylene. Pharmacological studies with solid-particulate suspensions have shown that crystalline form A exhibits an almost fourfold higher antinociceptive activity compared to form B.


PubMed | Taras Shevchenko National University and SSI Institute for Single Crystals NAS of Ukraine
Type: Journal Article | Journal: Acta crystallographica. Section E, Crystallographic communications | Year: 2016

The title compound, [Fe


PubMed | Taras Shevchenko National University and SSI Institute for Single Crystals NAS of Ukraine
Type: Journal Article | Journal: Acta crystallographica. Section E, Crystallographic communications | Year: 2015

In the title salt, C26H40N3O2 (+)ClO4 (-), the positive charge of the organic cation is delocalized between the two N atoms of the imidazole ring. The CN bond distances are 1.338(2) and 1.327(3). The substituents on the benzene ring are rotated almost orthogonal with respect to this ring due to the presence of the bulky isopropyl substituents. The dihedral angle between the benzene and imidazole rings is 75.15(12). Three of the O atoms of the anion are disordered over two sets of sites due to rotation around one of the O-Cl bonds. The ratio of the refined occupancies is 0.591(14):0.409(14). In the crystal, the cation and perchlorate anion are bound by an N-HO hydrogen bond. In addition, the cation-anion pairs are linked into layers parallel to (001) by multiple weak C-HO hydrogen bonds.


PubMed | University of Kharkiv, Ukrainian State University of Chemical Technology, Polish Academy of Sciences, SSI Institute for Single Crystals NAS of Ukraine and Jan Kochanowski University
Type: Journal Article | Journal: Acta crystallographica. Section E, Crystallographic communications | Year: 2016

The asymmetric unit of the title salt, (C10H8S8)[Re2Br6(CH3COO)]0.5C2H3Cl3, contains one bis-(ethyl-enedi-thio)-tetra-thia-fulvalene (ET) radical cation, one 2-acetato-bis-[tri-bromido-rhenate(III)] anion and a 1,1,2-tri-chloro-ethane mol-ecule with half-occupancy disordered about a twofold rotation axis. The tetra-thia-fulvalene fragment adopts an almost planar configuration typical of the ET radical cation. The C atoms of both ethyl-enedi-thio fragments in the cation are disordered over two orientations with occupancy factors 0.65:0.35 and 0.77:0.23. In the anion, six Br atoms and a 2-acetate ligand form a strongly distorted cubic O2Br6 coordination polyhedron around the Re2 dinuclear centre. In the crystal, centrosymmetrically related ET cations and Re2O2Br6 anions are linked into dimers by - stacking inter-actions [centroid-to-centroid distance = 3.826(8)] and by pairs of additional ReBr contacts [3.131(3)], respectively. The dimers are further packed into a three-dimensional network by non-directional inter-ionic electrostatic forces and by C-HBr and C-HS hydrogen bonds. The disordered 1,1,2-tri-chloro-ethane mol-ecules occupy solvent-accessible channels along the b axis.


Voloshyna O.,Institute for Scintillation Materials of Ukraine | Neicheva S.V.,Institute for Scintillation Materials of Ukraine | Starzhinskiy N.G.,Institute for Scintillation Materials of Ukraine | Zenya I.M.,Institute for Scintillation Materials of Ukraine | And 3 more authors.
Materials Science and Engineering B: Solid-State Materials for Advanced Technology | Year: 2013

Samples of undoped and Ce-, Eu- and Pr-doped orthotantalates with common formulae RETaO4 (RE = Y, Sc, La, Lu and Gd) have been obtained by solid-state reaction. Optical and luminescent characteristics in visible and UV bands have been explored. The most intense light output is determined for GdTaO4, YTaO4, and LuTaO4 (for GdTaO 4 it is 111% compared to BGO). Among lanthanide-doped samples, the highest light output is achieved with Eu-doped YTaO4, GdTaO 4 and LuTaO4 (up to 136% compared to BGO). Undoped rare-earth tantalates may be considered as promising materials for high energy physics due to extremely high density, substantial light output, and fast decay. Eu3+-doped orthotantalates are the brightest among the studied samples for X-ray radiography, or other application where slow decay is acceptable. © 2013 Published by Elsevier B.V.


Voloshina O.V.,Institute for Scintillation Materials of Ukraine | Baumer V.N.,SSI Institute for Single Crystals NAS of Ukraine | Bondar V.G.,Institute for Scintillation Materials of Ukraine | Kurtsev D.A.,Institute for Scintillation Materials of Ukraine | And 4 more authors.
Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment | Year: 2012

Aiming to explore the possibility of using the undoped rare-earth orthovanadates as scintillation materials, we developed the procedure for growth of gadolinium (GdVO 4) and yttrium (YVO 4) orthovanadate single crystals by Czochralski method, and determined the optimal conditions of their after-growth annealing. Optical, luminescent, and scintillation properties of YVO 4 and GdVO 4 were discussed versus known literature data. Scintillation characteristics of GdVO 4 were determined for the first time. © 2011 Elsevier B.V. All rights reserved.


Gerasymov I.,Institute for Scintillation Materials of Ukraine | Sidletskiy O.,Institute for Scintillation Materials of Ukraine | Neicheva S.,Institute for Scintillation Materials of Ukraine | Grinyov B.,Institute for Scintillation Materials of Ukraine | And 6 more authors.
Journal of Crystal Growth | Year: 2011

Ce, Pr, and La-doped gadolinium pyrosilicate Gd2Si 2O7 (GPS) single crystals were grown by the Czochralski and Top Seeded Solution Growth (TSSG) techniques for the first time. Formation conditions of different pyrosilicate phases were determined. X-ray luminescence integral intensity of Ce-doped GPS is about one order of magnitude higher in comparison with gadolinium oxyorthosilicate Gd2SiO5:Ce (GSO:Ce). All samples demonstrate temperature stability of luminescence yield up to 400 K. © 2010 Elsevier B.V. All rights reserved.


Chebanov V.A.,SSI Institute for Single Crystals NAS of Ukraine | Sakhno Y.I.,SSI Institute for Single Crystals NAS of Ukraine | Desenko S.M.,SSI Institute for Single Crystals NAS of Ukraine | Desenko S.M.,University of Kharkiv
Ultrasonics Sonochemistry | Year: 2012

New and high regioselective method of the synthesis of 2,7-diaryl-4,7- dihydropyrazolo[1,5-a]pyrimidine-5-carboxylic acids by reaction of 3-aryl-5-aminopyrazoles with arylidenpyruvic acid at room temperature under ultrasonication was developed and discussed. © 2011 Elsevier B.V. All rights reserved.


Chebanov V.A.,SSI Institute for Single Crystals NAS of Ukraine | Chebanov V.A.,University of Kharkiv | Saraev V.E.,SSI Institute for Single Crystals NAS of Ukraine | Shishkina S.V.,SSI Institute for Single Crystals NAS of Ukraine | And 5 more authors.
European Journal of Organic Chemistry | Year: 2012

Multicomponent heterocyclization of 5-amino-N-arylpyrazole-4-carboxamides, 1,3-cyclohexanediones, and aromatic aldehydes was studied, and reaction conditions allowing selective switching between two directions were found. When the reaction was carried out under thermal heating or ultrasonication at room temperature, formation of linear pyrazoloquinoline-3-carboxamides was observed. Isomeric angular heterocycles were obtained by ultrasonic-assisted synthesis at ambient temperature in the presence of HCl catalyst. Treatment with 2 equiv. of 1,3-diketone in boiling N,N-dimethylformamide/HCl gave a mixture of pyrazoloquinoline-3-carboxamides and unusual acridin-10-yl-pyrazole-4- carboxamides, which showed hindered rotation of the pyrazole fragment around the C-N bond. © 2012 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

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