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Journal of Structural Chemistry

2010 year, number 1

1.
Electronic structure of Pu3+ and Pu4+ impurity centers in zircon

M. V. Ryzhkov, A. L. Ivanovskii, A. V. Porotnikov, Y. V. Shchapova, S. L. Votyakov
Keywords: cluster calculation, relativistic effects, chemical bond of a Pu impurity with the ZrSiO4 matrix
Pages: 7-14

Abstract >>
Using a fully relativistic DV cluster method, we study the electronic structure of a large fragment of the crystal lattice of zircon ZrSiO4 with a plutonium dopant atom replacing a Zr4+ zirconium atom. Three possible states of the impurity center are considered: Pu4+ (isovalent substitution), Pu3+ (non-isovalent substitution), and Pu3+ with an oxygen vacancy in the nearest environment that provides charge compensation. Relaxation of the ZrSiO4 crystal lattice near a defect is simulated using a semi-empirical method of atomic pair potentials (GULP program). An analysis of overlap populations and effective charges on atoms shows that the chemical bonding of plutonium with a matrix is covalent, while isovalent substitution yields a more stable system than a Pu3+ impurity. In the presence of vacancies the structure of chemical bonding is intermediate with respect to substitutions Pu4+ → Zr4+ and Pu3+ → Zr4+.



2.
INTERACTION OF L-CYSTEINE WITH SELENIOUS AND SELENIC ACIDS: A STUDY BY THE DENSITY FUNCTIONAL THEORY METHOD

A. N. Pankratov, N. A. Bychkov, O. M. Tsivileva
Keywords: density functional theory, hydrogen bond, complexes, L-cysteine, selenious acid, selenic acid
Pages: 15-21

Abstract >>
Using the density functional theory method at the B3LYP/6-31G(d,p) theory level, the formation of hydrogen bonded complexes of L-cysteine with selenious and selenic acids is studied. In both cases, complexes formed through the carboxyl group of cysteine mostly arise, their enthalpy of formation being of -19 kcal/mol to -21 kcal/mol and the free energy of -6 kcal/mol to -9 kcal/mol. The primary act of interaction in the system of hydroxyl-containing selenium compound - α-aminoacid, including the mutual orientation of reactant molecules and the formation of intermolecular hydrogen bonds is likely to a serve as prerequisite for the thiol group to be able to participate in the next stages (including deeper chemical transformations) of biologically significant reactions.



3.
APPLICATION OF TOPOLOGICAL INDICES IN CORRELATION ANALYSIS OF N-ALKYLCARBOXYL-IMIDES OF CYCLIC 1,2-DICARBONIC ACIDS

M. S. Salakhov, O. T. Grechkina, B. T. Bagmanov
Keywords: N-alkylarboxylimides of cyclic 1, 2-dicarbone acids, theoretical-information indices, constant of acid ionization, chemical shift of protons of carboxyl groups, chemical shift of olefinic protons
Pages: 22-28

Abstract >>
Correlations of topological indices with physicochemical parameters of N-alkylcarboxylimides of cyclic dicarboxylic acids are investigated and a comparative analysis of the obtained results with the correlations binding these parameters is carried out.



4.
Structure of A zinc(II) N,N′-ethylene-bis(acetylacetoniminate) molecule, ZnO2N2C12H18, according to gas electron diffraction data and quantum chemical calculations

G. V. Girichev, N. I. Giricheva, E. D. Pelevina, N. V. Tverdova, N. P. Kuz'mina, O. V. Kotova
Keywords: geometric structure, Schiff bases, ZnO2N2C12H18, Zn(acacen), electron diffraction, mass spectrum
Pages: 29-37

Abstract >>
Gas electron diffraction is used to study the structure of a zinc(II) N,N′-ethylene-bis(acetylacetoniminate) molecule, ZnO2N2C12H18, at a temperature T = 503(5) K. It is found that the molecule has the symmetry of the 2 equilibrium configuration with a nonplanar structure of the ZnN2O2 coordination fragment and internuclear distances rh1(Zn-O) of 1.958(13) Å and rh1(Zn-N) of 2.012(16) Å. Quantum chemical calculations by the DFT/3LYP/,TZV method gives the molecular structure consistent with that found in the experiment.



5.
CALCULATION AND ANALYSIS OF THE STRUCTURE AND VIBRATIONAL SPECTRA OF URACIL TAUTOMERS

G. N. Ten, V. V. Nechaev, R. S. Shcherbakov, V. I. Baranov
Keywords: uracil, tautomers, vibrational spectra, cis-trans isomerism
Pages: 38-45

Abstract >>
The structure and vibrational spectra of twelve tautomers are calculated in the B3LYP/6-311+G(d,p) approximation and analyzed. Spectral manifestations of isomeric uracil transformations into one out of the twelve tautomeric forms and cis-trans-isomeric transformations of the tautomers themselves are considered. All tautomeric transformations are shown to be characterized by the presence of at least one vibration, whose frequency is different by ~100-200 cm-1 from a similar vibrational frequency of the precursor and also by a pronounced change in the intensity of bending vibrations of hydroxyl groups and stretching vibrations of bonds.



6.
Infrared spectroscopY and the structure of La0.33Zr2(PO4)3-Yb0.33Zr2(PO4)3 solid solutions

E. Y. Borovikova, V. S. Kurazhkovskaya, D. M. Bykov, A. I. Orlova
Keywords: infrared spectroscopy, factor-group analysis of vibrations, rare earth orthophosphates, NASICON structural type
Pages: 46-50

Abstract >>
Solid solutions of double orthophosphates of zirconium and rare earth lanthanum and ytterbium (La0.33Zr2(PO4)3-Yb0.33Zr2(PO4)3) that belong to the NASICON (NZP) structural type are synthesized and studied by IR spectroscopy. The factor-group analysis of P-O vibrations in phosphates with (La0.33Zr2(PO4)3) and (Yb0.33Zr2(PO4)3) space groups allows us to assign the intermediate representatives of this series to two different space groups by their IR spectra, which is difficult to perform based on powder X-ray diffraction results. A morphotropic transition → is found to occur near the La1/18Yb5/18Zr2(PO4)3 composition.



7.
STUDY OF THE 1A15T2 SPIN TRANSITION IN MIX-LIGAND COMPLEXES OF IRON(II) HEXAFLUOROSILICATE WITH 1,2,4-TRIAZOLE AND 4-AMINO-1,2,4-TRIAZOLE

O. G. Shakirova, M. Grunert, D. Y. Naumov, F. G??tlich, L. G. Lavrenova
Keywords: complexes, iron(II), static magnetic susceptibility, spin transition, 1,2,4-triazoles
Pages: 51-57

Abstract >>
Synthesis procedures for mix-ligand complexes with a composition of Fe(Htrz)3(1-x)(NH2trz)3xSiF6mH2O, 0 ≤ x ≤ 1, m = 1, 2 are developed. Solid phases are isolated from water-ethanol solutions and studied by X-ray phase analysis, the method of static magnetic susceptibility (temperature range of 100 K to 400 K), IR and Mössbauer spectroscopy (at 200 K and 298 K). The temperatures of direct and inverse transitions are shown to depend on the complex composition.



8.
Crystal structure, energy band and optical properties of benzoic acid - 2-amino-4,6-dimethylpyrimidine (1:1) co-crystals

Z. Li, J. Huang, A. Meng, B. Zheng
Keywords: CASTEP, band structure, optical properties, DFT
Pages: 58-64

Abstract >>
Co-crystals formed between benzoic acid and 4,6-dimethyl-2-aminopyrimidine in 1:1 molar ratio (C6H9N3C7H6O2) have been prepared and studied. According to single crystal XRD analysis, the structure is monoclinic, P21/c, a = 6.7019(9), b = 7.647(1), c = 25.285(3) Å, β = 91.36(2), V = 1295.4(3) Å3, Z = 4. The asymmetric unit contains 2-amino-4,6-dimethylpyrimidine and benzoic acid molecules linked to each other by two hydrogen bonds
[O1-H1N1, HN = 1.819; N3-H3AO2, HO = 2.157 Å]. Calculations of band structure, density of states, absorption and reflectivity spectra have been performed in the frame of density functional theory using the CASTEP code, and the corresponding experimental optical properties have been investigated. The theoretical results indicate that C6H9N3C7H6O2 single crystal is a wide band-gap semiconductor with the theoretical direct band gap 3.0271 eV. The title co-crystal may become promising host for fluorescence-emitting; it can absorb ultraviolet radiation.



9.
Probability of fluctuations of the number of nearest neighbors in A hard sphere liquid: asymptotic decomposition

Y. T. Pavlyukhin
Keywords: asymptotic decompositions in statistic mechanics, hard sphere liquid, simple liquids, liquid with the SW interaction potential
Pages: 65-73

Abstract >>
Fluctuations of the number of nearest neighbors Mλ inside the coordination sphere of a given radius λ in a hard sphere liquid (Mλ is the total number of neighbors for all N particles of the system) are analyzed. For the probability density distribution of this random value, an exact asymptotic decomposition over the number of particles N in the system has been derived, and the decomposition coefficients were recorded in terms of the semi-invariants of the random value of Mλ. The result coincides completely with the asymptotic decomposition in the central limiting theorem of the probability theory. Due to this, the number of nearest neighbors in a liquid of N hard spheres can be represented as the sum of N independent random values with equal distributions. The hard sphere liquid of N particles was simulated by the Monte Carlo method in the canonical Gibbs ensemble over a wide range of densities (N = 864, periodic boundary conditions, occupancy η from 0.005 to 0.500). The theoretical equations are in good agreement with the results of simulation.



10.
STRUCTURE OF HETEROASSOCIATES FORMED IN THE HF-(C2H5)2O LIQUID SYSTEM

E. G. Tarakanova, G. V. Yukhnevich
Keywords: binary liquid system, IR spectrum, quantum-chemical calculation, hydrogen bond, heteroassociates, hydrogen fluoride, diethyl ether
Pages: 74-80

Abstract >>
The aim of this work was to determine the structure of stable heteroassociates (HAs) with the stoichiometric ratios 1:2, 2:1, and 4:1 of molecules formed in the HF-(C2H5)2O binary liquid system. The stretching frequencies of HF molecules found for each HA using a special procedure for processing IR spectra were compared with the calculated frequencies νHF of the stable molecular complexes (HF)m((C2H5)2O)n (m = 1, 2, 4, 8; n = 1, 2) with different topologies by the density functional method (B3LYP/6-31++G(d,p)). As a result, it was shown that the most stable (among H-bonded complexes with the same stoichiometric ratio of molecules) HAs HF((C2H5)2O)2, (HF)4((C2H5)2O)2, and (HF)8((C2H5)2O)2 formed in HF solutions in diethyl ether. All of them had a cyclic structure and a common peculiarity of structure: only one lone electron pair of the oxygen atom of the (C2H5)2O molecules is involved in hydrogen bonding.



11.
THERMAL COEFFICIENTS AND INTERNAL PRESSURE OF AQUEOUS UREA. CONCENTRATION, TEMPERATURE, AND ISOTOPY EFFECTS

V. P. Korolev
Keywords: urea, aqueous solutions, thermal coefficients, internal pressure
Pages: 81-87

Abstract >>
The thermal expansion α, isothermal compressibility βT, and internal pressure coefficients of 2-(NH2)2CO and D2O-(ND2)2CO π systems at 278 K, 298 K, and 318 K and aquamolality m ≤ 1.5 were calculated. The changes in the isotope differences Δα, ΔβT, and Δπ at different solute concentrations and temperature are discussed. In contrast to Δα and Δπ, ΔβT is almost independent of the urea concentration already at 298 K and independent of m at 318 K. The derivative ∂π/∂ increased in dilute solution, at lower temperatures, and on passing from protium to deuterium system, which corresponded to increased structuring. The isotope difference for the Grüneisen constant at given temperatures and concentrations is shown to be independent of the urea content.



12.
Structure of Ir and Ir-Al2O3 coatings obtained by chemical vapor deposition in the presence of oxygen

N. V. Gelfond, N. B. Morozova, I. K. Igumenov, E. S. Filatov, S. A. Gromilov, Y. V. Shubin, R. I. Kvon, V. S. Danilovich
Keywords: Ir and Ir-Al2O3 composite coatings, chemical vapor deposition, iridium(III), aluminium(III), tris-acetylacetonates
Pages: 88-97

Abstract >>
By chemical vapor deposition Ir and Ir-Al2O3 coatings are obtained with a thickness of up to 40 μm on steel substrates precoated with a layer of Al2O3. Tris-acetylacetonates of iridium(III) and aluminium(III) are used as precursors. The deposition processes are carried out at atmospheric pressure in the presence of oxygen. The obtained coatings are studied by X-ray diffraction, X-ray photoelectron spectroscopy, and scanning electron microscopy. The dependences of coating structures and compositions on the preparation conditions are found. An increase in the deposition temperature results in the formation of Ir coatings with loose discontinuous structure, an increase in the size of metal crystallites, and the growth of the oxygen concentration in their composition. An increase in the concentration of precursor vapors in the deposition zone at a constant deposition temperature results in the formation of Ir coatings that consist of differently structured layers (compact, columnar, and granular). Mixed Ir-Al2O3 coatings which composed of metal Ir and amorphous Al2O3 crystallites, which exhibit a pronounced iridium texture in the [111] direction, have the most perfect compact structure. The introduction of the oxide phase in the coating composition halves the Ir crystallite size.



13.
SPECIFIC NON-VALENT IODINECHLORINE INTERACTIONS IN THE STRUCTURES OF COPPER(II) CHLORIDE COMPLEXES WITH BIS(3,5-DIMETHYL-4-IODOPYRAZOL-1-YL)METHANE

A. V. Virovets, D. A. Piryazev, E. V. Lider, A. I. Smolentsev, S. F. Vasilevskii, L. G. Lavrenova
Keywords: crystal structure, copper, non-valent interactions, bis(3, 5-dimethyl-4-iodopyrazole-1-yl)methane
Pages: 98-104

Abstract >>
Copper(II) chloride complexes with bis(3,5-dimethyl-4-iodopyrazol-1-yl)methane (L) with a composition of CuLCl2 (1), [Cu22-Cl)2L2(H2O)2]Cl22(CH3)2CO (2), and [Cu32-Cl)6L2](CH3)2CO (3) are synthesized. Single crystal X-ray diffraction is used to determine the molecular and crystal structures of these compounds. In the structures of compounds 2 and 3, shortened non-valent ICl contacts with a length of 3.222(1)-3.439(2) Å are found. They involve uncoordinated and coordinated chloride ions and iodine atoms of organic ligands.



14.
FIRST EXAMPLE OF RUTHENIUM NITROSO MONOAMMINE COMPLEX. CRYSTAL STRUCTURE OF [Ru(NO)(NH3)3(H2O)Cl]×[Ru(NO)(NH3)3(OH)Cl][Ru(NO)(NH3)Cl4]2Cl2H2O

M. A. Il'in, V. A. Emel'yanov, I. A. Baidina
Keywords: ruthenium, nitroso complexes, ammine complexes, chloro complexes, single crystal X-ray diffraction analysis, IR spectroscopy
Pages: 105-112

Abstract >>
The structure of the interaction products of (NH4)2[Ru(NO)Cl5] solution with ammonium acetate on heating is studied. The crystal structure of the [Ru(NO)(NH3)3(H2O)Cl][Ru(NO)(NH3)3(OH)Cl]×
[Ru(NO)(NH3)Cl4]2Cl2H2O compound (compound I) containing a previously unknown anion of the nitrosomonoammine series is determined: Cc space group; a = 33.530(7) Å, b = 8.202(2) Å, c = 11.844(2) Å; β = 101.54(3).



15.
Tin(IV) porphyrin complexes. Crystal structures of meso-tetraphenylporphyrinatotin(IV) diacetate, bis(dichloroacetate), bis(trifluoroacetate) and diformate, and structural correlations for tin(IV) porphyrin complexes with O-bound anionic ligands

J.C. Mcmurtrie, D.P. Arnold
Keywords: tin porphyrins, X-ray crystallography, carboxylato complexes, structure correlations
Pages: 113-119

Abstract >>
Structures of four tetraphenylporphyrinatotin(IV) bis(carboxylato) complexes [Sn(tpp)(OCOR)2] have been determined by single crystal X-ray diffraction. All complexes have typical octahedral geometry. The average Sn-N bond lengths for R = CH3, CHCl2, CF3 and H are 2.091, 2.084, 2.082 and 2.086 Å, respectively. The Sn-O bond lengths are 2.096, 2.091, 2.109 and 2.090 Å respectively. These bond lengths and those of all other reported Sn(tpp) complexes of O-bound anionic ligands are compared. There is an inverse correlation between the Sn-N and Sn-O bond lengths, indicating that stronger electron donation by the axial anionic ligand results in an expansion of the porphyrin core. Correlation of the Sn-O bond lengths with the pKa of the conjugate acids of the axial ligands shows that the stronger the acid, the longer the Sn-O bonds, indicating that the bonding is dominated by electrostatic effects.



16.
CRYSTAL AND MOLECULAR STRUCTURE OF 1,1′-bis-(ACETOACETYL)FERROCENE

A. D. Vasiliev, O. A. Bayukov, A. A. Kondrasenko, E. E. Sergeev, P. V fabinskiy, V. A. Fedorov
Keywords: acetoacetylferrocene, crystal and molecular structure, single crystal X-ray study, IR, NMR, electronic spectrum, M?ssbauer effect, 1,1?-bis-(acetoacetyl)ferrocene
Pages: 120-125

Abstract >>
Using physicochemical methods, the crystal and molecular structure of 1,1′-bis-(acetoacetyl)ferrocene is studied. The compound crystallizes in the form of two crystallographically independent molecules with slightly different conformations and mutually perpendicular orientation. Crystals are monoclinic, C18H18FeO4, a = 35.68(1) Å, b = 5.733(2) Å, c = 30.30(1) Å; β = 96.831(5); V = 6154(3) Å3, Z = 16, dx = 1.529 g/cm3, 2/ space group. The molecule consists of the ferrocene fragment and two acetylacetonyl substituents.



17.
Structure and properties of Bis{[2-(4-tert-butyl)phen]ethyl}phosphine sulfide

N. K. Gusarova, S. F. Malysheva, N. A. Belogorlova, O. N. Kazheva, A. N. Chekhlov, G. G. Aleksandrov, O. A. D'yachenko, L. M. Sinegovskaya, B. A. Trofimov
Keywords: phosphine sulfides, four-coordinated phosphorus atom, tautomeric equilibrium, single crystal XRD, spectral methods, phosphorus centered nucleophiles
Pages: 126-130

Abstract >>
Previously unknown bis{[2-(4-tert-butyl)phen]ethyl}phosphine sulfide is obtained with a high yield from 4-tert-butyl styrene, red phosphorus, and elemental sulfur. Using single crystal XRD, multinuclear NMR, IR, and UV spectroscopy, it is found that the phosphorus atom is four-coordinated in the bis{[2-(4-tert-butyl)phen]ethyl}phosphine sulfide molecule (regardless of the phase state of the compound: crystal, solution). By the example of phosphorylation of bis{[2-(4-tert-butyl)phen]ethyl}phosphine sulfide acetylene in the K-DMSO system it is shown that the reaction proceeds by double addition with the participation of phosphorus-centered nucleophiles.



18.
A METHOD TO CALCULATE THE ENERGY LEVELS OF NANOOBJECTS WITH A PERIODIC FRAMEWORK STRUCTURE

L. A. Gribov
Keywords: nanoobjects, energy levels, periodic structure, quasi-diagonalization
Pages: 131-136

Abstract >>
A method to calculate electronic and vibrational energy levels in nanoobjects with a periodic internal structure is proposed. The approach allows us to reduce the general problem to a set of order problems corresponding to the repeating atomic arrangement. Further refinement is performed using perturbation theory.



19.
FEATURES OF THE REAL STRUCTURE OF PSEUDOBOEHMITES: VIOLATIONS OF THE STRUCTURE AND LAYER PACKING CAUSED BY CRYSTALLIZATION WATER

K. I. Shefer, S. V. Cherepanova, É. M. Moroz, E. Y. Gerasimov, S. V. Tsybulya
Keywords: pseudoboehmite, aluminum hydroxide, structure, simulation of diffraction patterns
Pages: 137-147

Abstract >>
Rietveld structure refinement and simulation of the diffraction patterns of partially disordered materials are used to study the real structure of nanoscale pseudoboehmite samples obtained by different technologies. The effect of various violations in the structure of these nanomaterials on diffraction patterns is analyzed. The introduction of corrections for the Lorentz and polarization factors in the determination of the cell parameter b by the position of the 020 diffraction peak in the pattern is shown to be important. A model for the atomic structure of pseudoboehmite is proposed. The model involves additional water molecules as compared to the structure of boehmite. The water molecules in the interlayer space of the layered boehmite structure are found to violate its regularity, which results in a decrease in the size of crystallites.



20.
MOLECULAR PAIR INTERACTION ENERGY. I. ANALYSIS OF SUPRAMOLECULAR ARCHITECTURE IN THE CRYSTALS OF POLYFLUORINATED ENAMINOIMINES AND ENAMINOKETONES OF INDAN SERIES

T. V. Rybalova, Y. V. Gatilov
Keywords: crystal packing, quantum chemical calculations, N-HO and N-HN hydrogen bonds, ππ, Fπ, Oπ, Nπ, F, and FF intermolecular interactions, polyfluoroaromatic compounds
Pages: 148-154

Abstract >>
Calculated by DFT (PBE/3z) based on the experimental crystal atom coordinates, the molecular pair (MP) interaction energies are used to analyze the crystal packing for compounds 1-6. Supplementing the visual geometric approach used in the PLATON and MERCURY programs, the MP interaction energies make it possible to describe the crystal architecture more completely and structurally, to identify supramolecular motifs more reliably, and to determine their hierarchy.



21.
MOLECULAR PAIR INTERACTION ENERGY. II. ANALYSIS OF THE SUPRAMOLECULAR CRYSTAL ARCHITECTURE OF THE COMPLEXES OF POLYFLUORO- AROMATIC ENAMINOIMINE AND ENAMINOKETONES WITH DIOXANE AND PYRIDINE

T. V. Rybalova, Y. V. Gatilov
Keywords: crystal packing, quantum chemical calculations, N-HO and N-HN hydrogen bonds, ππ, Fπ, Oπ, Nπ, FH, and FF intermolecular interactions, polyfluoro aromatic compounds
Pages: 155-161

Abstract >>
Molecular pair (MP) interaction energies, DFT calculated (PBE/3z) based on the experimental crystal atomic coordinates, are used to analyze the crystal packing of enaminoimine and related enaminoketones complexes with dioxane and pyridine. The sign of the interaction energy of enaminoimine molecules in the chain (complex 4) and in the supermolecule (complex 5) indicates that they are held in the observed position by the intermolecular interaction with solvent. The enaminoketone molecules in complexes 6 and 7 are, on the contrary, linked by N-HO hydrogen bonds into dimers, which interacting with solvent molecules form chains (complex 6) and supermolecules (complex 7). In addition to the visual geometrical approach of PLATON and MERCURY programs, the MP interaction energies allow a more complete and structural description of the crystal architecture, a more reliable determination of supramolecular motifs and their hierarchy.



22.
QUANTITATIVE PHASE ANALYSIS ON A SINGLE CRYSTAL X-RAY DIFFRACTOMETER EQUIPPED WITH A TWO-DIMENSIONAL FLAT DETECTOR

A. V. Alexeev, S. A. Gromilov
Keywords: quantitative powder X-ray diffraction analysis, full profile refinement, CCD-detector, Debye-Scherrer method
Pages: 162-171

Abstract >>
The work describes the procedure for performing a quantitative powder X-ray diffraction analysis in the Debye-Scherrer scheme on a single crystal diffractometer equipped with a flat two-dimensional detector. Specially prepared mixtures of polycrystalline phases (α-Al2O3, Si, α-SiO2, and W) with substantially different linear absorption coefficients are analyzed. It is shown that even when crystallites are most prone to preferred orientation, it is possible to perform measurements with an accuracy no worse than traditional 5 wt.%.



23.
HYDROGEN BOND IN THE COMPLEX. FEATURES OF THE ELECTRON DENSITY DISTRIBUTION

I. V. Drebushchak, S. G. Kozlova
Keywords: hydrogen bond, hydroxonium ion, quantum theory of atoms in molecules, QTAIM, electron localization function, ELF
Pages: 172-175

Abstract >>
A quantum chemical study of the hydrogen bond in the complex is carried out using topological methods: quantum theory of atoms in molecules (QTAIM) and of electron localization f unction (ELF) theory. In the complex, three lone electron pairs on the oxygen atom in Ph3PO are found to be combined in one ELF basin, and they all participate in the hydrogen bond formation. The observed topological features of the complex are compared to the topological features of related complexes and the literature data.



24.
STRUCTURAL, ELECTRONIC, AND MAGNETIC PROPERTIES OF CaCNi3, SrCNi3, AND BaCNi3 ANTIPEROVSKITES IN COMPARISON TO SUPERCONDUCTING MgCNi3

V. V. Bannikov, I. R. Shein, A. L. Ivanovskii
Keywords: antiperovskites, CaCNi3, SrCNi3, BaCNi3, band structure, formation energy, magnetism, modeling
Pages: 176-178

Abstract >>
Within the first principle FLAPW-GGA band method we predict the structural, electronic, and magnetic properties of CaCNi3, SrCNi3, and BaCNi3 hypothetical antiperovskites. The results are discussed in comparison to the MgCNi3 isostructural superconductor.



25.
CRYSTAL STRUCTURE OF TRIPLE MOLYBDATE IN THe Rb2MoO4-Nd2(MoO4)3-Zr(MoO4)2 SYSTEM

O. D. Chimitova, B. G. Bazarov, R. F. Klevtsova, A. G. Anshits, K. N. Fedorov, A. V. Dubentsov, T. A. Vereshchagina, Y. L. Tushinova, L. A. Glinskaya, Z. G. Bazarova, L. I. Gongorova
Keywords: rubidium, neodymium, zirconium, molybdate, synthesis, crystal structure
Pages: 179-182

Abstract >>
Using X-ray phase analysis, the Rb2MoO4-Nd2(MoO4)3-Zr(MoO4)2 ternary salt system is studied. The crystals of rubidium-neodymium-zirconium triple molybdate are grown by solution-melt crystallization under spontaneous nucleation. According to the X-ray diffraction data (automatic X8 APEX diffractometer, Kα radiation, 1345 F(hkl), R = 0.0356), the crystal structure and its composition is determined: Rb4.7Nd0.7Zr1.3(MoO4)6. The sizes of the trigonal unit cell are as follows: a = b = 10.7561(2) Å, c = 38.7790(12) Å, V = 3885.41(16) Å3, Z = 6, space group. The three-dimensional mixed framework structure consists of tetrahedra and two types of octahedra: (Nd,Zr)O6. The distribution of Nd3+ and Zr4+ cations over two crystallographic sites is also refined. Two types of rubidium atoms are located in large cavities of the framework.



26.
SYNTHESIS AND STRUCTURE OF C17H22FN3OCuCl

A. D. Vasiliev, N. N. Golovnev
Keywords: fluoroquinolone, pefloxacin, copper chloride, crystal structure, hydrogen bonds, π-π-interaction
Pages: 183-186

Abstract >>
A new compound [pefloxacindium tetrachlorocuprate(II)], C17H20FN3O3 - 1-ethyl-6-fluoro-1,4-dihydro-4-oxo-7-(4-methyl-1-piperazinyl)-3-quinoline carboxylic acid (pefloxacin, PefH) is synthesized and characterized by single crystal X-ray diffraction technique. The crystal structure of the compound contains one cation and one anion. The supramolecular architecture of the crystal is determined.



27.
X-RAY STUDY OF M(Aet)28H2O (M = Sr, Ba) AND THE CRYSTAL STRUCTURE OF [Sr(Aet)(OH2)5](Aet)3H2O

É. B. Miminoshvili, K. ??. Miminoshvili, L. A. Beridze, S. R. Zazashvili
Keywords: complex compounds, X-ray diffraction analysis, Sr(II), Ba(II), sulfaethiodole, sulfanilamides
Pages: 187-191

Abstract >>
An X-ray phase and X-ray structural analysis of M(Aet)28H2O compounds, where M(II) = Sr and Ba; (Aet)- = (C10H11N4O2S2) is the sulfaethiodole (2-(para-aminobenzene-sulfamido)-5-ethyl-1,3,4-thiadiazole) anion is carried out. Symmetry and unit cell parameters of Sr(Aet)28H2O and Ba(Aet)28H2O are found: P21/c, Z = 4, = 10.390(2) Å, b = 14.609(3) Å, c = 21.931(5) Å, β = 92.42(2), R = 0.041; and P21/c, Z = 4, = 9.793(2) Å, b = 15.408(4) Å, c = 22.553(6) Å, β = 94.98(2) respectively. The considered compounds are isostructural. The structure of Sr(Aet)28H2O is fully studied; the crystals of the compound are composed of the complex centrosymmetric dimeric [(H2O)5Sr(Aet)2Sr(OH2)5]2+ cations, (Aet)- anions, and water molecules; the independent part of the structural formula of the compound is [Sr(Aet)(OH2)5](Aet)3H2O. The sulfaethiodole anion is coordinated to the complexing metal atom by oxygen and nitrogen atoms with the formation of a four-membered ring.



28.
CRYSTAL STRUCTURE OF [Co(N2C2H8)3][AuBr4]2Br BIS(TETRABROMOAURATE(III))TRIS(ETHYLENEDIAMINE) COBALT(III) BROMIDE

I. A. Baidina, E. V. Makotchenko
Keywords: gold(III), cobalt(III), complexes, single crystal X-ray analysis
Pages: 192-194

Abstract >>
A double complex salt [Co(N2C2H8)3][AuBr4]2Br is obtained and characterized using single crystal X-ray diffraction analysis. The crystallographic data of C6H24Au2Br9CoN6 are as follows: a = 21.6479(17) Å, b = 14.9085(12) Å, c = 8.2676(7) Å, β = 110.820(2), V = 1538.92(12) Å3, C2/c space group, Z = 4, dx = 3.602 g/cm3. Square planar coordination of the gold atom in the complex anion is completed to a tetragonal pyramid by an additional bromine atom of the adjacent complex anion at the AuBr distance of 3.677 Å.



29.
CRYSTAL STRUCTURE REFINEMENT OF fac-Co(NH2C2H4O)33H2O: OCTAHEDRON OR TRIGONAL PRISM?

A. V. Virovets, Y. A. Mikhailenko, E. V. Peresypkina, S. V. Tkachev, T. G. Cherkasova
Keywords: cobalt, crystal structure, hydrogen bonds, disorder
Pages: 195-198

Abstract >>
The compound fac-[Co(NH2CH2CH2O)3]3H2O (I) was synthesized and its crystal structure determined. Crystal data for C6H24CoN3O6: a = 14.5236(3) Å, c = 4.9346(2) Å, V = 901.43(5) Å3, T = 90 K, space group R3, Z = 3, ρcalc = 1.620 g/cm3. In the complex, the octahedral environment of the (III) atom is formed by three monoethanolamine ligands using N and O atoms. The structure is disordered in such a way that the two oppositely orientated CoN3O3 octahedra are superimposed on each other at an angle.



30.
CRYSTAL STRUCTURE AND LUMINESCENCE OF TERBIUM(III) METHACRYLATE

B. V. Bukvetskii, N. V. Petrochenkova, A. G. Mirochnik
Keywords: crystal structure, terbium (III), methacrylate, luminescence
Pages: 199-202

Abstract >>
Using the X-ray structural analysis the atomic structure of luminescent terbium methacrylate is determined (orthorhombic crystal system, a = 14.791(1) Å, b = 12.9306(8) Å, c = 7.6869(5) Å, Cmc21 space group, Z = 4, ρx = 1.867 g/cm3). The crystal structure is represented by continuous chains of C12H15TbO6 molecules along the crystallographic c axis, which are linked by the van der Waals interaction.