Synthesis,Crystal, and Molecular Structure of bis(Thiosemicarbazide)Nickel(II) 1,5-Naphthalene Disulfonate Dihydrate Complex [Ni(Tsc)<Subscript>2</Subscript>](1,5-Nds) · 2H<Subscript>2</Subscript>O

Complex [Ni(Tsc)₂](1.5-Nds) · 2H₂O (I), where Tsc = thiosemicarbazide, NH₂NHC(=S)NH₂; 1,5-Nds^2– is double deprotonated anion of 1,5-naphthalene disulfonic acid \(\rm{CH_{10}H_6(SO_3)_2^{2-}}\) was synthesized, characterized by IR spectroscopy, and studied by thermogravimetry and X-ray diffraction. Crystal I is built of complex cations [Ni(Tsc)₂]²⁺, anions (Nds)^2–, and crystallization water molecules. The Ni atom is coordinated along the vertices of the trans-square by two sulfur atoms and two nitrogen atoms of two bidentate chelating ligands Tsc. The structural units of crystal I are joined by a branched network of N–H···O and O–H···O hydrogen bonds with the participation of donors, namely, the hydrogen atoms of two NH₂ groups and the NH group of complex cation [Cu(Tsc)]²⁺ and the H atoms of water molecules, and acceptors, namely, oxygen atoms of the sulfate group of anion 1,5-Nds^2– and solvate water molecules.     

Synthesis and physicochemical investigation of LiMTif6

Mixed alkali hexafluorotitanates of the composition LiMTiF₆ are synthesized, which crystallize with the orthorhombic symmetry. The lattice parameters of these materials are determined. It is shown that substitution of the Li⁺ cation in Li₂TiF₆ by Na⁺, K⁺, Rb⁺, and Cs⁺ leads to various degrees of distortion of the hexafluoroion. It is determined (¹⁹F NMR data) that the change in the dynamic state of the octahedral [TiF₆]^2– ions is related to their transition from the hindered-rotational to the isotropic state.Institute of Chemistry, Far-Eastern Branch, Russian Academy of Sciences, 690022 Vladivostok. Translated fromIzvestiya Akademii Nauk, Seriya Khimicheskaya, No. 11, pp. 2483–2490, November, 1992.     

1-(Cyano[benzimidazole-2-yl])methylene-3,3-Dimethyl-1,2,3,4-Tetrahydroisoquinoline: Synthesis,Structure, Spectral Parameters

1-(cyano[benzimidazole-2-yl])methylene-3,3-dimethyl-1,2,3,4-tetrahydroisoquinoline was synthesized and studied by X-ray diffraction analysis and IR and electronic absorption spectroscopy. The model quantum-chemical calculations were performed.     

Ionic mobility, ionic transport, and charge transfer mechanism in solid solutions (1 ? x )PbF2- x MF n by the NMR and impedance spectroscopy data

The internal mobility and ionic conduction of solid solutions in systems PbF₂-MF₂ and PbF₂-MF₃ are studied by the NMR (¹⁹F, ²⁷Al, ²⁰⁷Pb) and impedance spectroscopy methods. Factors that define the form of ionic movements and their energy characteristics in the temperature region 150 to 550 K are considered and analyzed. Temperature shifts of the frequency range that defines the ionic conduction of solid solutions are discovered on the basis of impedance spectroscopy data and explained. It is established that the high ionic conductance in lead difluoride doped with fluorides of metals of Groups II and III is caused by the diffusion of fluoride ions. The large values of specific conductance (10⁻⁴ to 10⁻³ S cm⁻¹) at a relatively low activation energy (less than 0.6 eV) allow one to consider the solid solutions studied in the role of a basis for the obtaining of new fluoride materials with high ionic conductance. Original Russian Text ? V.Ya. Kavun, A.B. Slobodyuk, S.L. Sinebryukhov, E.V. Tararako, V.K. Goncharuk, S.V. Gnedenkov, V.I. Sergienko, 2007, published in Elektrokhimiya, 2007, Vol. 43, No. 6, pp. 643–656. Based on the report delivered at the 8th International Meeting on Fundamental Problems of Solid-State Ionics, Chernogolovka (Russia), 2006.     

Synthesis and crystal structure of the molecules of 1-(2-benzothiazolyl)-3,5-dimethylpyrazole C12H11N3S and dioxodichloro[1-(2-benzothiazolyl)-3,5-dimethylpyrazole]molybdenum(VI) [MoO2(C12H11N3S)Cl2]

N. S. Kurnakov Institute of General and Inorganic Chemistry, Academy of Sciences of the USSR. Scientific-Research Institute of, Physical and Organic Chemistry, Rostov State University. Voroshilovgrad Mechanical Engineering Institute. Translated from Zhurnal Strukturnoi Khimii, Vol. 31, No. 5, pp. 45–53, September–October, 1990.     

Synthesis and Structure of (4-Acetyl-3-hydroxyphenoxy)tetraphenylantimony

Pentaphenylantimony was reacted with 4-acetyl-1,3-dihydroxybenzene in toluene at elevated temperature to obtain (4-acetyl-3-hydroxyphenoxy)tetraphenylantimony in 93% yield. According to X-ray diffraction data, the antimony atom in (4-acetyl-3-hydroxy-phenoxy)tetraphenylantimony has a distorted trigonal-bipyramidal configuration. The Sb-O and Sb-C distances are 2.237(1) and 2.112(1), 2.114(2), 2.118(2), 2.170(2) Å, respectively, and the CSbO angle is 177.86(5)°.     

Crystal Structures of LiCsTiF6 and Cs2TiF6 and Internal Mobility of Complex Anions

Single crystals of LiCsTiF₆(I) and Cs₂TiF₆(II) are characterized by X-ray diffraction analysis (DAR-UMBk and SMART 1000 CCD diffractometers, MoK radiation, graphite monochromator; anisotropic least squares refinement to R = 0.038 and R _w = 0.046 (I) and R ₁ = 0.017 and wR ₂ = 0.046 (II)). Packing modes of structural units in the crystals are considered. Types of internal motions of complex TiF₆ ^2– ions are established, and their activation energies in the crystals of LiCsTiF₆ and Cs₂TiF₆ are estimated in the temperature range 200–500 K.     

The structure of an infinite,complete, convex hypersurface inE 4 with bounded mean curvature

The following theorem is proved. THEOREM. If on an infinite, complete, convex hypersurface F in E⁴ the mean curvature is 1 – H 1, where 0 10^–11, then F is a cylindrical hypersurface.Translated from Ukrainskii Geometricheskii Sbornik, No. 34, pp. 8–9, 1991.     

Mixed-ligand complexes based on asymmetric gadolinium β-diketonates: Synthesis, crystal structure, and theoretical modeling

Mixed-ligand complexes of asymmetric gadolinium β-diketonates with 2,2′-bipyridyl (Bipy)—[Gd(Pa)₃(Bipy)] (HPa is pivaloylacetone) (I) and [Gd(Pta)₃(Bipy)] (HPta is pivaloyltrifluoroacetone) (II)-have been obtained by direct interaction of initial reagents and their structures have been studied by X-ray crystallography. Crystals of I are monoclinic: a = 9.536(1) Å, b = 15.037(1) Å, c = 13.280(1) Å, β = 109.56(1)°, V = 1798.7(3) ų, Z = 2, space group P2₁. Crystals of II are triclinic: a = 9.6696(17) Å, b = 12.1348(9) Å, c = 18.243(3) Å, α = 100.257(12)°, β = 103.997(2)°, γ = 101.438(11)°, V = 1977.4(5), Z = 2, space group P $\bar 1$ . The coordination polyhedron of the central gadolinium atom in I and II is a distorted square antiprism formed by six oxygen atoms of the three β-diketonate ligands (av. Gd-O, 2.35(2) and 2.351(5) Å in I and II, respectively) and two nitrogen atoms of the Bipy ligand (av. Gd-N, 2.47(2) and 2.584(7) Å in I and II, respectively). Although the molecular structures of these complexes are similar, they have different crystal packings. In II, the planes of the Bipy ligands of neighboring molecules related by an inversion center are bound by stacking interaction (the distance between the Bipy planes is 3.45 Å). The structure and properties of these mixed-ligand complexes have been discussed based on the results of quantum-chemical density functional theory calculations (DFT/B3PW91). The nature of the substituents in the β-diketonate ligand has an effect on the structure and properties of the complexes. The correlation between the Gd-Dik and Gd (Dik)₃-Bipy bond energies has been studied.