Crystal and molecular structure of nitraminotetrazole and nitramino-1,2,4-triazole. IV. 5-nitraminotetrazole sodium salt sesquihydrate

The structure of 5-nitraminotetrazole sodium salt sesquihydrate was determined by X-ray diffraction. The crystals are monoclinic, space group P2₁/c;a = 3.551(1) Å, b = 21.834(4) Å, c = 9.075(2) Å; = 110.68(3)°; V = 658.3(2) ų; Z = 4; _calc = 1.807 g/cm³. The anion is planar and has an intramolecular hydrogen bond. The negative charge of the anion is localized on one of the oxygens of the nitro group. The sodium cation (c.n.6) is coordinated by three oxygen atoms of different anions and three oxygens of crystallization water. One of the crystallization water molecules is disordered in the unit cell. The anions are hydrogen-bonded with each other and with crystallization water molecules.Original Russian Text Copyright © 2004 by A. M. Astakhov, A. D. Vasiliev, M. S. Molokeev, L. A. Kruglyakova, A. M. Sirotinin, and R. S. StepanovTranslated from Zhurnal Strukturnoi Khimii, Vol. 45, No. 3, pp. 562–565, May–June 2004.     

Reaction of cyclopentadienyllutetium anthracenide with azobenzene. Synthesis and molecular and crystal structure of the binuclear complex [C5H5(THF)Lu(μ−η2:η2−PhN—NPh)]2(THF)2 and its dynamic behavior in solution

The reaction of the cyclopentadienyllutetium anthracenide, C₅H₅Lu(C₁₄H₁₀)²⁻(THF)₂ (1), with azobenzene yielded the [C₅H₅(THF)Lu(μ−η²:η²−PhN—NPh)]₂(THF)₂ (2) binuclear complex. The structure of the reaction product was established by X-ray structural analysis. The dynamic behavior of complex2 in a THF-d₈ solution was studied by¹H NMR spectroscopy in the temperature range of 265–330 K. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 9, pp. 1667–1671, September, 1997.     

Color Displays with Gel-Glass Dispersed Liquid Crystals

Liquid crystal microdroplets trapped into silica gel-glasses by sol-gel processes may be used for display applications. Gel-glass dispersed liquid crystals (GDLC) are switched between opaque and transparent states by applying external AC-voltage signals; no polarizers are required. The feasibility of applying these materials to colored displays has been explored. A comparative study of different dyes for GDLC color displays, which were either embedded in the sol-gel matrix or dissolved in the liquid crystal microdroplets is presented.     

Reaction of Tetracopper(I)-Phosphonitocavitand with PhSeSiMe3: Synthesis and Structure of a Polyanionic Cluster [pyH]6[(CuCl)9(μ3-SePh)5(μ4-SePh)]

Treatment of tetracopper(I)-phosphonitocavitand [1·Cu₄(μ-Cl)₄(μ₄-Cl)] (2) (1 = tetraphosphonitocavitand [rccc-2,8,14,20-tetrakis-(iso-butyl)-phosphonitocavitand (C₄₄H₄₈O₈P₄Ph₄)]) with PhSeSiMe₃ in THF at low temperature afforded a novel polyanionic cluster [pyH]₆[(CuCl)₉(μ₃-SePh)₅(μ₄-SePh)] (4) as a major product along with a new tetracopper(I)-phosphonitocavitand (3) with a centered μ₃-Cl. Molecular structure of anionic cluster in 4 consists of six PhSe⁻ bridging ligands containing five μ₃-SePh and one exceptional μ₄-SePh bridging nine copper atoms, of which eight copper atoms have trigonal coordination geometry and the other has distorted tetrahedral geometry. Dedicated to Professor Han-Qin Liu on the occasion of his 70th birthday.     

Strukturen aus AIB2− und BaAl4−analogen Einheiten. I Die Verbindungen Sr4Pd5P5 und Sr2Pd3P3

Structures with AIB₂? and BaAl₄?type Units. I The Compounds Sr₄Pd₅P₅ and Sr₂Pd₃P₃ Sr₄Pd₅P₅ (Cmcm, a = 4.177(1) Å, b = 31.377(5) Å, c = 8.581(2) Å, Z = 4) und Sr₂ Pd₃P₃(Pmmm, a = 4.199(1) Å, b = 4.212(1) Å, c = 34.227(4) Å, Z = 4) have been prepared by heating the elements. Both structures contain exclusively units characteristic for the AIB_2? and BaAl₄?type. The ratio between isolated P-atoms and P₂?pairs is interpreted with an ionic splitting of the formulas.     

Application of Liquid Crystalline NMR Solvents to a Mixture of Ketones

A series of dilute liquid crystalline solvents are used to study the effect of slight anisotropy caused by partial alignment on chemical shift and residual dipolar coupling (RDC) in small molecules. The residual dipolar couplings between protons in solutes are found to be almost independent of the local environment. It is also found that the chemical shift does not change over the concentration range observed. A linear relationship between residual dipolar coupling and liquid crystal concentration is observed at relatively low concentrations, but is severely violated at high concentrations.     

Crystal structure of KAsUO<Subscript>6</Subscript>·<Subscript>3</Subscript>H<Subscript>2</Subscript>O at 100 and 293 K

The crystal structure of KAsUO₆·3H₂O was solved at 100 K and 293 K. KAsUO₆·3H₂O at T = 100 K: tetragonal, P4/ncc, a = 7.2037(6) Å, c = 17.811(2) Å; Z = 4, R1 = 0.0263, wR2 = 0.0546, for 618 independent reflections; at T = 293 K: tetragonal, P4/ncc, a = 7.1600(4) Å, c = 17.746(1) Å; Z = 4, R1 = 0.0263, wR2 = 0.0433 for 427 independent reflections. The results of X-ray analysis are compared with our previous data on heat capacity of this compound, and changes that take place in the structure at elevated temperature are considered.     

Synthesis, Crystal Structure Determination, and Physicochemical Study of the Nickel(II) Complex of 4-(Pyridyl-2)-1,2,4-triazole

A new trinuclear nickel(II) complex with 4-(pyridyl-2)-1,2,4-triazole (pytrz), [Ni₃(pytrz)₆(H₂O)₆](NO₃)₆, has been synthesized, and its crystal structure has been determined. The compound was studied by X-ray phase analysis (XRPA), magnetochemical measurements, and electronic and IR spectroscopy.     

Synthesis and Characterization of the Isocyanide Ligated Centered Zirconium Halide Cluster [(Zr6Be)Cl12(CNXyl)6]

The first isocyanide ligated hexanuclear zirconium halide cluster is reported. The unoxidized [(Zr₆Be)Cl₁₂(CNXyl)₆] (CNXyl = 2,6-dimethylphenyl isocyanide) was obtained from the solid state precursor K₃Zr₆Cl₁₅Be by dissolution in CH₃CN in the presence of CNXyl. The CNXyl ligands occupy all the axial positions on the cluster. The compound was recrystallized from CH₂Cl₂ and Et₂O. [(Zr₆Be)Cl₁₂(CNXyl)₆].2CH₂Cl₂ crystallizes in the space group (#2) with a = 12.092(5) Å, b=12.728(5) Å, c = 14.102(8) Å, = 104.98(4)°, =107.11°, = 100.94°, V = 1919(2) ų, Z = l, R = 11.3% and R _W = 27.0%. For the bound isocyanide ligands, v _CN increases to 2140 cm^–1.     

Li2H4I2O10, das erste Tetrahydrogendimesoperiodat

Li₂H₄I₂O₁₀, the First Tetrahydrogendimesoperiodate Li₂H₄I₂O₁₀ has been obtained as an intermediate during the dehydration of LiH₄IO₆ · H₂O to LiIO₄, for the first time. According to the results of an X-ray structure determination (monoclinic, P2₁/n, a = 533.98(4), b = 471.85(4), c = 1431.48(10) pm, β = 91.614(7)°, Z = 2, 726 diffractometer data, R = 0.056), Li₂H₄I₂O₁₀ contains the previously unknown tetrahydrogendimesoperiodate ion H₄I₂O₁₀^2?, consisting of two edge-shared IO₆ octahedra. They are connected with LiO₆ octahedra via common edges and vertices. The crystals are non-merohedrally twinned along (100).