Ketorolac tromethamine or 1,3-dihy-droxy-2-(hy-droxy-meth-yl)propan-2-am-inium 5-benzoyl-2,3-di-hydro-1H-pyrrolizine-1-carboxyl-ate, C15H12NO3 +·C4H12NO3 -, was studied by single-crystal and powder X-ray diffraction methods. One cation and one anion are present in the asymmetric unit. In the crystal, N-H⋯O and O-H⋯O hy-dro-gen bonds link the cation and anion. All the hy-dro-gen-bond inter-actions result in the formation of a di-periodic layer in the (100) crystallographic plane.

YAG:Sm3+ (5 at.%) transparent ceramics have been obtained by reactive sintering using different starting Al2O3 powders. Effect of particle size in the 100–400 nm range, morphology and dispersity of starting alumina powders on the properties of YAG:Sm3+ powder mixtures, their densification and resulted optical ceramics have been studied. It was shown that YAG:Sm3+ powder mixtures prepared with BMA15 and AKP-50 powders possess significant reduction of a fraction of micron-sized agglomerates. The particles within the range of 100–300 nm presented in BMA15 and AKP-50 powders, act as proppant, enabling collapse of the Y2O3 agglomerates. As a result, ceramics prepared from these powder mixtures show improved densification behavior. Reactively-sintered YAG:Sm3+ transparent ceramics prepared using AKP-50 powder are characterized by optical transmittance of 83% and low concentration of residual pores.

Investigated are mechanical characteristics of alkaline dihydrogen phosphate single crystals KH2PO4 and LiH2PO4 with different cation sizes. There are established those features of the internal structure that define the character of damage in the crystals under the mechanical stresses. It is shown that the mechanical strength of the studied crystals depends, first of all, on the number and direction of the hydrogen bonds in the crystal lattice. The longer hydrogen bonds (similar to 2.684 angstrom) in alkaline dihydrogen phosphate with a small four-coordinated cation R-Li(+) = 0.68 angstrom are weaker than the hydrogen bonds which belong to a strong type (similar to 2.564 angstrom) in alkaline dihydrogen phosphate with a large eight-coordinated cation R-K(+) = 1.33 angstrom. The value of fracture toughness of LiH2PO4 single crystals is approximately 2-2.5 times lower than that of KH2PO4 single crystals. The plasticity of potassium dihydrophosphate is higher in comparison with the one of lithium dihydrophosphate. This is due to the fact that the contribution of the small Li+ cation to the formation of the framework is lower than that of the large K+ cation. The values of LiH2PO4 microhardness are 1.2-1.3 higher than the corresponding values of KH2PO4.

The reaction products formed in the SO2 – ROH – (HOCH2)3CNH2 (where R – CH3, C2H5, n-C3H7, i-C3H7, n-C4H9 and n-C5H11) systems were isolated and identified as: binary salt – ammonium O-methylsulfite [(HOCH2)3CNH3]+ [CH3OSO2]− (1); 1/1 charge transfer complex between diethyl sulfite (2) and tris(hydroxymethyl)aminomethane by S-N binding; polymorhps of zwitterionic internal salt – O-sulfite tris(hydroxymethyl)methylammonium (at R – n-C4H9 and n-C5H11); and its solvates with n-propanol 1/1 (3) and isopropanol 2/1. The structures of all synthesized products were confirmed by FT-IR, Raman, 1H NMR and 13C NMR spectrometry, and the structure of 1 and 3 was characterized by crystal X-ray diffraction studies as well.

The reaction of methallyl thioethers of a polysubstituted 5-amino-1,2,4-triazole-3-thiones with hex-abromotelluric acid leads to the formation of a new hybrid hexabromotellurates containing the [1,3]thiazolo [3,2-b][1,2,4]triazol-7-ium cations. The annulation of the thiazoline ring undergoes through the proton-induced electrophilic cyclization of the methallyl thioether fragment. The structure analysis indicates that the newly synthesized 6,6-dimethyl-3-phenyl-2-(phenylamino)-5,6-dihydro-3H-[1,3]thiazolo[3,2-b][1,2,4]triazol-7-ium hexabromotellurate has a zero-dimensional perovskite-type structure. Theoretical quantum chemical modeling of the proposed mechanisms explains the preferable formation of the five-membered thiazoline ring. Bioactivity of the [1,3]thiazolo[3,2-b][1,2,4]triazol-7-ium cation was investigated using molecular docking.

Single crystals of Co-doped magnesium-aluminum spinel (MALO:Co) are used for Q-switching of laser radiation at & lambda; = 1.54 & mu;m. Usually, they are grown by the Czochralski method from iridium crucibles that are too expensive. This investigation demonstrates the possibility of obtaining MALO:Co single crystals by the horizontal directional crystallization method using a molybdenum crucible in Ar + (CO, H2) protective reducing medium. The obtained MALO:Co crystals have the spinel structure of MgO ‧xAl2O3 with 1 & LE; x < 1.15, and the impurity of molybdenum in them does not exceed 0.019 wt%. Co2+ ions replace Mg2+ ions in the [MgO4] tetrahedral environment. This is confirmed by the broad absorption bands (& lambda;max & AP;600 nm and & lambda;max & AP; 1400 nm) in Vis-IR spectra. The absorption bands in the UV region of the spectrum are shown to originate from the complexes of point defects that can be eliminated by subsequent annealing in oxidizing/reducing environment. Experimentally shown is the possibility to obtain monoimpulses with the energy of -1-2 mJ and-10-15 ns duration at a wavelength of-1.54 & mu;m in passive Q-switches based on MALO:Co crystals.

An easy to handle high-efficient approach to 5-polyfluoroalkyl-1,2,4-triazole-3-thiones (11 examples, up to 91% yield) is reported. The tautomerism of thione and thiol forms for the obtained products is discussed. A one step procedure for 6,6-dimethyl-3-(trifluoromethyl)-5,6-dihydro[1,3]thiazolo[2,3-c][1,2,4]triazole formation from trifluoroacetic acid and 4-methallylthiosemicarbazide has been developed. The structures of the products were unambiguously determined by complex NMR investigation and by single crystal X-ray diffraction.

YAG:Sm3+ (3-15 at.%) transparent ceramics, a promising cladding material for suppressors of parasitic oscillations at 1064 nm of YAG:Nd3+ lasers, have been prepared by solid-state reactive sintering at 1725 degrees C. The effect of samarium ions concentration on the microstructure and optical properties of YAG:Sm3+ sintered ceramics was studied for the first time. The solubility limit of samarium ions in the garnet matrix was found to lie within the range of 9-11 at.%. The spectroscopic characterization of YAG:Sm3+ (3-15 at.%) ceramic samples showed that the absorption coefficients corresponding to Sm3+ ions transitions increased linearly with increasing Sm3+ doping. Also, the increase in the concentration of Sm3+ ions contributes to the increase in the intensities of the satellites, leading to the broadening of the main spectral lines and implicitly to the increase of the absorption coefficient around 1064 nm. It was shown that YAG:Sm3+ ceramics doped with 9 at.% Sm3+ ions possess optical losses of 0.07 cm(-1) at 808 nm and an optical absorption coefficient of 4.45 cm(-1) at 1064 nm. The concentration dependence of the (4)G(5/2) level decay confirmed that the luminescence extinction is due to the energy transfer between the Sm3+ ions through cross-relaxation processes. All these results show that highly-doped YAG:Sm3+ (9 at.%) ceramics could be the best candidate for parasitic oscillation suppression in high-power YAG:Nd3+ lasers at 1064 nm.

A polymorphic transition as a result of grinding was found for 3-[1-( tert -butoxycarbonyl)azetidin-3-yl]-1,2-oxazole-4-carboxylic acid. The thorough study of polymorphic structures before and after crystal structure transformation has revealed some pre-conditions for a polymorphic transition and regularities of changes in molecular and crystal structure. In metastable polymorph 1a , the conformationally flexible molecule adopts a conformation with the higher energy and forms a less preferable linear supramolecular synthon. Additional energy imparted to a crystal structure during the grinding process proved to be enough to overcome low energy barriers for the nitrogen inversion and rotation of the oxazole ring around the sp 3 – sp 2 single bond. As a result, polymorph 1b with a molecule adopting conformation with lower energy and forming a more preferable centrosymmetric supramolecular synthon was obtained. The study of pairwise interaction energies in the two polymorphs has shown that metastable polymorph 1a is organized by molecular building units and has a columnar-layered structure. A centrosymmetric dimer should be recognized as a complex building unit in more stable polymorph 1b , which has a layered structure.

The paper is devoted to studying of Si4++Mg2+ complex additive for obtaining transparent YAG ceramics for laser applications. Ceramics were fabricated by reactive vacuum sintering of commercial Y2O3, Al2O3 powders taken in a stoichiometric mixture with TEOS and MgO as sintering aids. Microstructure and optical properties of YAG:Si4+,Mg2+ ceramics were investigated as a function of the Si4+/Mg2+ ratio. It was found that the influence of complex additive does not correspond to the direct superposition of known Si4+- and Mg2+-induced sintering mechanisms and involves interaction between Si4+ and Mg2+ ions during sintering. It was shown that CSi/CMg> 1 provides more effective pore elimination and uniform microstructure when CSi/CMg< 1 gives more intense inhibition of grain grown which may be important for scaling the size of ceramics.

A polymorphic transition as a result of grinding was found for 3-[1-(tert-butoxycarbonyl)azetidin-3-yl]-1,2-oxazole-4-carboxylic acid. The thorough study of polymorphic structures before and after crystal structure transformation has revealed some pre-conditions for a polymorphic transition and regularities of changes in molecular and crystal structure. In metastable polymorph 1a, the conformationally flexible molecule adopts a conformation with the higher energy and forms a less preferable linear supramolecular synthon. Additional energy imparted to a crystal structure during the grinding process proved to be enough to overcome low energy barriers for the nitrogen inversion and rotation of the oxazole ring around the sp3-sp2 single bond. As a result, polymorph 1b with a molecule adopting conformation with lower energy and forming a more preferable centrosymmetric supramolecular synthon was obtained. The study of pairwise interaction energies in the two polymorphs has shown that metastable polymorph 1a is organized by molecular building units and has a columnar-layered structure. A centrosymmetric dimer should be recognized as a complex building unit in more stable polymorph 1b, which has a layered structure.

YAG:Sm3+ (5 аt.%) optical ceramics were obtained by the solid-state reactive sintering in the 1700–1800°C temperature range. The effect of the sintering temperature on the microstructure, phase composition and optical properties of YAG:Sm3+ ceramics has been studied. It has been shown that the optimal sintering temperature in order to produce YAG:Sm3+ transparent ceramics is 1725°С. The sintered ceramics are characterized by high optical transmittance (>82% at 808 nm), low residual porosity and the average grain size of 21 μm. It has been shown that the sintering temperature has a little effect on the average grain size of synthesized ceramics. Microstructure of YAG:Sm3+ ceramics consolidated at 1800°C is characterized by the presence of large grains up to 90 μm surrounded by the main fraction with an average grain size of 19 μm, which could be evidence of starting bimodal grain size distribution.

A study of two polymorphic forms of 1-allyl-4-hydroxy-2,2-dioxo-N-(4-methoxyphenyl)-1-2λ6,1-benzothiazine-3-carboxamide (a structural analogue of piroxicam) has revealed some regularities in the crystal structure formation due to different evaporation rates from the tested solvents. The monoclinic polymorph crystallized from ethyl acetate is formed due to a large number of very weak C-H...O and C-H...π interactions as well as one strong stacking interaction. The triclinic polymorph crystallized from N,N-dimethylformamide is formed due to a small number of weak specific interactions and a maximal number of strong stacking interactions. The stacked dimer is a complex building unit in both polymorphic structures. Further analysis showed that the monoclinic structure is layered while the triclinic one is columnar. The two polymorphic structures also differ in their biological activity (antidiuretic and analgesic). The monoclinic polymorph possesses very high biological activity while the triclinic polymorph is almost inactive. The polymorphic transition of the biologically active metastable monoclinic structure into the inactive stable triclinic one within four weeks of grinding is caused by orientational factors rather than conformational ones and is accompanied by a change in the redistribution of interaction energies in the crystal from anisotropic to more isotropic. Thus, a slow polymorphic transition after grinding results in a loss of the biological activity.

Ce-doped lanthanum gadolinium pyrosilicates are among the most efficient oxide scintillation crystals with a light yield of ca. 40 000 ph MeV −1 and a high energy resolution.

In the paper, synthesis process of the TiO2 particles was discussed, from the fluoride solution, through TiO2·nH2O gel thermal precipitation and decomposition, and its impact on the further sintering of the obtained powders. It was demonstrated that the main phase of the obtained titania was anatase. Morphology of the obtained TiO2 can be controlled through variations of the precipitation temperature and the emulsifier concentration. It was found that the addition of the chloride ions during gel formation caused crystallization of the (NH4)2TiOF4 phase. When it underwent decomposition under heating, agglomerated particles in form of rods several micrometers long were synthesized. Obtained powders were sintered, and both the sintering process and the final bulk structures were examined. The results indicated the lowest microhardness of 540 kg/mm2 in the specimens prepared out of the powders synthesized without emulsifier, while the highest hardness of 1450 kg/mm2 was reached when the TiO2 particles had been precipitated at room temperature with emulsifier proportion С(Ti):C(OР9) = 1:0.5. However, further increase of the emulsifier concentration led to the decrease of hardness.

The growth conditions to produce a high quality ZnWO4:Sm single crystals by the Czochralski method were determined in this work. The role of the Sm impurity in the formation of bubbles in a ZnWO4 single crystal is discussed. The Sm3+ ions segregation coefficient in the ZnWO4 single crystal was estimated to be 0.023. The effect of non-isomorphic substitution of Sm3 + for Zn2 + ions on the ZnWO4 crystal lattice parameters has been investigated. The X-ray luminescence spectra of ZnWO4:Sm3+ crystals are discussed. Two ZnWO4 crystals doped with samarium enriched in Sm-148 and Sm-149 isotopes were obtained following the established growth technique, which demonstrates its feasibility and reliability for production of detector for rare nuclear processes studies.

Cubic crystals of tripotassium aluminium (or gallium) nitridotriphosphate, K3MIII (PO3)(3)N (M-III = Al, Ga), were grown by application of the self-flux method. In their isostructural crystal structures, all metal cations and the N atom occupy special positions with site symmetry 3, while the P and O atoms are situated in general positions. The three-dimensional framework of these oxidonitridophosphates is built up from [ (MO6)-O-III] octahedra linked together via (PO3)(3)N groups. The latter are formed from three PO3N tetrahedra sharing a common N atom. The coordination environments of the three potassium cations are represented by two types of polyhedra, viz. KO9 for one and KO9N for the other two cations. An unusual tetradentate type of coordination for the latter potassium cations by the (PO3)(3)N-6(-) anion is observed. These K3MIII(PO3)(3)N (M-III = Al, Ga) compounds are isostructural with the Na3MIII (PO3)(3)N (M-III = Al, V, Ti) compounds.

The synthesis of a new hexabromotellurate of triazole ring-containing amino acid is described. XRD, NMR and DFT analysis of the structure of protonated [(5-amino-4-phenyl-4H-1,2,4-triazol-3-yl)sulfanyl]acetic acid testifies the protonation of the first nitrogen atom of the triazole ring. Hirshfeld surface analysis identifies numerous intermolecular interactions in the newly synthesized organic-inorganic hybrid hexabromotellurate. The DFT based comprehensive analysis of the structures of possible conformers also testifies the higher thermodynamic stability of the 1-protonated triazole cation, whereas the starting [(5-amino-4-phenyl-4H-1,2,4-triazol-3-yl)sulfanyl]acetic acid exists in solution in neutral form with the intermolecular hydrogen bond between the carboxylic acid OH group and the second nitrogen of the triazole ring. The experimentally observed NMR upfield shift of the signal of the exocyclic amino group was studied via GIAO computations and was explained through the analysis of the HOMOs of the neutral and protonated forms of the triazole compound.

The work is devoted to obtaining of transparent nanocomposite materials as low loss, highly thermally conductive materials for potential laser applications. We report Ho3+:Y2O3–MgO nanocomposite ceramics with excellent mechanical and optical properties by combining glycine-nitrate process and spark plasma sintering. Morphology, structural-phase state, infrared transmittance and luminescence depending on the holmium concentration (0…12 at.%) were studied for the first time. It was found that optical transmittance reaches 75% at 6000 nm for 3 at.% Ho3+:Y2O3–MgO ceramics.

Cubic crystals of tripotassium aluminium (or gallium) nitridotriphosphate, K3 M III(PO3)3N (M III = Al, Ga), were grown by application of the self-flux method. In their isostructural crystal structures, all metal cations and the N atom occupy special positions with site symmetry 3, while the P and O atoms are situated in general positions. The three-dimensional framework of these oxidonitridophosphates is built up from [M IIIO6] octahedra linked together via (PO3)3N groups. The latter are formed from three PO3N tetrahedra sharing a common N atom. The coordination environments of the three potassium cations are represented by two types of polyhedra, viz. KO9 for one and KO9N for the other two cations. An unusual tetradentate type of coordination for the latter potassium cations by the (PO3)3N6– anion is observed. These K3 M III(PO3)3N (M III = Al, Ga) compounds are isostructural with the Na3 M III(PO3)3N (M III = Al, V, Ti) compounds.