scholarly journals Structural Study of Ferroelectric Phase in Acid–Base Supramolecule

2014 ◽  
Vol 70 (a1) ◽  
pp. C553-C553
Author(s):  
Akiko Nakao ◽  
Reiji Kumai ◽  
Sachio Horiuchi ◽  
Yoshinori Tokura ◽  
Takashi Ohhara ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Phase Transitions ◽  
Structure Analysis ◽  
Ferroelectric Phase ◽  
Structural Parameters ◽  
Imaging Plate ◽  
Hydrogen Atoms ◽  
Acid Base ◽  
Space Group ◽  
Successive Phase

Supramolecular ferroelectric cocrystal of phenazine (Phz) with chloranilic acid (H2ca), which exhibits three successive phase transitions, have been characterized by the interplay between their structural transformations and solid-state acid–base (proton transfer) reactions (Figure) [1]. This material undergoes a ferroelectric phase (FE-I phase) transition of displacive-type at 253 K followed by successive phase transitions to the lattice modulated phases with incommensurate periodicities and with commensurate 2-fold periodicity (FE-II phase) at lower temperature [2]. To elucidate the origin of the ferroelectricity in the FE-I phase, it is crucial to study the crystal structure using single crystals. The synchrotron x-ray diffraction experiment was carried out on the imaging-plate diffractometer at BL-8A of Photon Factory in KEK. Superstructure reflections with the modulation wave vector q=(1/2 1/2 1/2) were clearly observed below 103 K. Considering the preserved 2/m Laue symmetry, the lattice can be transformed to a C-centered monoclinic lattice, which is related by (-2a, -2b, a + c) or (2a, -2b, -a - c) with the FE-I structure. Although the lattice distortion and the intensities of the superlattice reflections are consistent with the 2/m Laue symmetry, the space group C1 is deduced from the polar nature and a subgroup symmetry of the FE-I structure. Moreover, we performed single-crystal neutron diffraction experiments at SENJU of MLF/J-PARC in order to determine the displacement of the hydrogen atom. The crystal structure analysis at 10 K was carried out using the reflections measured in a half-sphere of reciprocal space at d > 0.4. The structure analysis was performed on the basis of the space group C1, where four Phz and four H2ca become crystallographically inequivalent. Finally, all the structural parameters including all hydrogen atoms were successfully refined. In the FE-II phase, the neutral and ionic molecules alternately align along the π-molecular stack.

Primäre und sekundäre Ethyl-und i-Propylsulfoniumsalze sowie Kristallstruktur von i-C3H7SH2+SbF6- [1]

1996 ◽  
Vol 51 (2) ◽  
pp. 277-285
Author(s):  
Rolf Minkwitz ◽  
Ulrike Lohmann ◽  
Hans Preut
Keyword(s):  
Crystal Structure ◽  
Structure Analysis ◽  
Bond Distance ◽  
Crystal Structure Analysis ◽  
Unit Cell ◽  
Monoclinic Space Group ◽  
Spectroscopic Methods ◽  
Sulfonium Salt ◽  
Space Group

Abstract The synthesis of salts of the type RnSH3-n+MF6- (R = C2H5, i-C3H7; n = 1, 2; M = As, Sb) by protonation of the corresponding thiols and sulfides in the superacid systems HF/MF5 is reported. The salts have been characterized by vibrational and NMR spectroscopic methods. Isopropylsulfonium hexafluoroantimonate is the first known example of a sulfonium salt, for which a SH bond distance has been determined by a crystal structure analysis, i-C3H7SH2+SbF6- crystallizes in the monoclinic space group P21/m with a = 568.0(4), b = 801.1(6), c = 1019.7(8) pm, β = 82.63(6) °, with two formula units per unit cell.

Kristallstruktur und Konstitution des Perchlorbenzocyclobutens (β-C8Cl8)

1974 ◽  
Vol 29 (5) ◽  
pp. 831
Author(s):  
J. Haase ◽  
P. Widmann
Keyword(s):  
Crystal Structure ◽  
Structure Analysis ◽  
Crystal Structure Analysis ◽  
Spectroscopic Measurements ◽  
Space Group

Abstract The crystal structure of perchlorobenzocyclobutene (β-C8Cl8) has been investigated and solved by means of the unusual Patterson projection along the axis of twinning, by which the space group had been determined. As a result of the crystal structure analysis the constitution of the molecule, derived by J. Brandmüller and E. Ziegler from spectroscopic measurements, has been found to be true.

Cyclisierung von Amidoximen mit Oxybis(diphenylboran) / Cyclization of Amidoximes with Oxybis(diphenylborane)

1991 ◽  
Vol 46 (9) ◽  
pp. 1219-1222 ◽  
Author(s):  
Hans Möhrle ◽  
Karin Bluhme-Hensen ◽  
Birgit Middelhauve ◽  
Dietrich Mootz ◽  
Hartmut Wunderlich
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bond ◽  
Structure Analysis ◽  
Heterocyclic Ring ◽  
Crystal Structure Analysis ◽  
Monoclinic Space Group ◽  
Space Group ◽  
Bifurcated Hydrogen Bond ◽  
Boron Heterocycles

Substituted amidoximes when reacted with oxybis(diphenylborane) do not yield ester chelates as main products but boron heterocycles. The compound obtained from p-toluamidoxime was found by crystal structure analysis to be 2-phenyl-4-(4-methylphenyl)-2,3-dihydro-1,3,5,2-oxadiazaborol (9). The conformation of the molecule is determined by angles of 29.1 and 24.4° between the planes of adjacent rings. Except N–O all bonds in the heterocyclic ring contain significant π character. Molecules are linked to chains by a weak bifurcated hydrogen bond. 9 crystallizes with the monoclinic space group P21/c, Ζ = 4, a = 5.574(2), b = 18.274(4), c = 12.754(4) Å, β = 106.41(2)°. Refinement of 227 parameters using 1709 observed reflections converged at R = 0.037.

79Br, 127I NQR of Diammoniumalkyl Halides and Piperazinium Halides. Crystal Structure of Piperazinium Dibromide Monohydrate and Piperazinium Monoiodide

1989 ◽  
Vol 44 (1) ◽  
pp. 41-55 ◽  
Author(s):  
Jutta Hartmann ◽  
Shi-Qi Dou ◽  
Alarich Weiss
Keyword(s):  
Crystal Structure ◽  
Phase Transitions ◽  
Hydrogen Bonds ◽  
Crystal Structures ◽  
Monoclinic Space Group ◽  
Orthorhombic Space Group ◽  
Space Group ◽  
Temperature Range

Abstract The 79Br and 127I NQR spectra were investigated for 1,2-diammoniumethane dibromide, -diiodide, 1,3-diammoniumpropane dibromide, -diiodide, piperazinium dibromide monohydrate, and piperazinium monoiodide in the temperature range 77 ≦ T/K ≦ 420. Phase transitions could be observed for the three iodides. The temperatures for the phase transitions are: 400 K and 404 K for 1,2-diammoniumethane diiodide, 366 K for 1,3-diammoniumpropane diiodide, and 196 K for piperazinium monoiodide.The crystal structures were determined for the piperazinium compounds. Piperazinium dibromide monohydrate crystallizes monoclinic, space group C2/c, with a= 1148.7 pm, 0 = 590.5 pm, c= 1501.6pm, β = 118.18°, and Z = 4. For piperazinium monoiodide the orthorhombic space group Pmn 21 was found with a = 958.1 pm, b = 776.9 pm, c = 989.3 pm, Z = 4. Hydrogen bonds N - H ... X with X = Br, I were compared with literature data.

Re: Crystal Structures of Pyroaurite and Sjögrenite

1994 ◽  
Vol 38 ◽  
pp. 749-755 ◽  
Author(s):  
A. Olowe
Keyword(s):  
Crystal Structure ◽  
Crystal Structures ◽  
Structure Analysis ◽  
Crystal Structure Analysis ◽  
Metallic Ions ◽  
Chemical Formula ◽  
Metal Hydroxides ◽  
Space Group ◽  
Previous Discussion ◽  
Positively Charged

Abstract Pyroaurite and sjogrenite belong to the group of sandwiched lamellar metal hydroxides which have a fixed metallic ions MII:MIII ratio for a particular class. Their crystal structure consists of positively charged metal hydroxide blocks intercalated with negatively charged interlayers. The atomic positions for the interlayer are definite for a particular class. The exact chemical formula of the pyroaurite class is determined from crystal structure analysis to be MII 6MIII 2(OH)16-CO3-4.5H2O; it crystallizes in the space group Rm with a = 12.4376 Å and c = 23.4126 Å. Sjogrenite, MII 6 MIII 2(OH)16-CO3-4H2O crystallizes in the space group P63/mcm. The crystallogiraphy and structural relationship between these classes are discussed. Previous discussion on these compounds did not give any conclusion on the exact chemical formula and the atomic positions.

A New Copper (II) Complex with the N,N'-Bis(antipyryl-4-methyl)-piperazine (BAMP) Ligand: [Cu(BAMP)](ClO4)2

2002 ◽  
Vol 57 (12) ◽  
pp. 1454-1460 ◽  
Author(s):  
Otilia Costișor ◽  
Ramona Tudose ◽  
Ingo Pantenburg ◽  
Gerd Meyer
Keyword(s):  
Crystal Structure ◽  
Copper Complex ◽  
Structural Parameters ◽  
Complex Molecule ◽  
Lattice Parameters ◽  
Tetragonal Symmetry ◽  
Apical Position ◽  
Space Group ◽  
Symmetry Space ◽  
Symmetry Space Group

The synthesis of the Mannich base N,N’-bis(antipyryl-4-methyl)-piperazine (BAMP) (1), its crystal structure as well as the synthesis and the crystal structure of the copper complex Cu(BAMP)(ClO4)2 (2) are reported. C28H34N6O2 ∙ 4H2O (BAMP ∙ 4H2O) crystallizes with triclinic symmetry, space group P1̄, lattice parameters: a = 704,9(2), b = 983,4(2), c = 1198,9(3) pm, α = 68,72°, β = 73,62°, γ = 78,49°. The copper-complex Cu(BAMP)(ClO4)2 crystallizes with tetragonal symmetry, space group P42/n, lattice parameters: a = 2295,1(3), c = 1412,2(2) pm. The copper(II) atom is five-coordinate by the two nitrogen atoms belonging to the piperazine ring and the oxygen atoms of the antipyrinemoieties. The geometry of the copper(II) atom can be described as a square-based pyramid with the N2O2 donor atoms of BAMP forming the basal plane and an oxygen atom of the neighbouring complex molecule occupying the apical position. BAMP acts as a tetradentate ligand, which incorporates a piperazine-fused ring. The structural parameters illustrate well the reinforcing effect exerted by the double “straps” of the piperazine molecule.

Über die Darstellung der (Chlorthio)sulfoniumsalze [(CH3)2SSSCl]+SbF6-, [(CH3)2SSCl]+SbF6- und des isomeren [(CH3)(Cl)S – SCH3]+SbCl6- / On the Preparation of the (Chlorothio)sulfonium Salts [(CH3)2SSSCl]+SbF6-, [(CH3)2SSCl]+SbF6- and the Isomer [(CH3)(Cl)S–SCH3]+SbCl6-

1990 ◽  
Vol 45 (12) ◽  
pp. 1637-1642 ◽  
Author(s):  
Rolf Minkwitz ◽  
Andreas Kornath ◽  
Renate Krause ◽  
Hans Preut
Keyword(s):  
Crystal Structure ◽  
Structure Analysis ◽  
Crystal Structure Analysis ◽  
Molar Ratio ◽  
Sulfonium Salts ◽  
Space Group

The preparation of the stable compounds [(CH3)2SSCl]+SbF6- and [(CH3)2,SSSCl]+SbF6- from [(CH3)2SH]+SbF6- and SCl2 and S2Cl2, resp., is reported.The isomer [(CH3)(Cl)S–SCH3]+SbCl6- is prepared from [SCl3]+SbCl6- and CH3SH in the molar ratio 1:2. For this salt a crystal structure analysis was carried out (Space group P212121, Z = 4, a = 750.1(4), b = 1133.7(3), c = 1614.8(3) pm).

Benzo-18-krone-6 -Acetonitril (1/2): Kristallisation und Tieftemperatur- Röntgenstrukturanalyse / Benzo-18 -crown-6 -Acetonitrile (1/2): Crystallization and Low-Temperature X-Ray Analysis

1998 ◽  
Vol 53 (12) ◽  
pp. 1528-1530 ◽  
Author(s):  
Karna Wijaya ◽  
Oliver Moers ◽  
Armand Blaschette ◽  
Peter G. Jones
Keyword(s):  
Crystal Structure ◽  
Low Temperature ◽  
Data Collection ◽  
Single Crystals ◽  
Title Complex ◽  
Monoclinic Space Group ◽  
Hydrogen Atoms ◽  
Space Group ◽  
X Ray ◽  
Mecn Solution

Abstract Benzo-18 -crown-6 -Acetonitrile (1/2), Crystal Structure Single crystals of the title complex resulted fortuitously during an attempt to co-crystallise MeN(SO2Me)2 with benzo-18-crown-6 from an MeCN solution at -30 °C. The crystal structure has been determined via data collection at -100 °C (monoclinic, space group P21/n, Z = 4). The nitrile molecules are located with their me­ thyl groups above and below the plane of the 18-membered crown ring, the Me hydrogen atoms being rotationally disordered about the MeCN axes; C(methyl)···O(crown) distances range from 309.4(3) to 384.9(3) pm.

scholarly journals The crystal structure of cyanotrichite

2015 ◽  
Vol 79 (2) ◽  
pp. 321-335 ◽  
Author(s):  
Stuart J. Mills ◽  
Andrew G. Christy ◽  
Fernando Colombo ◽  
Jason R. Price
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonding ◽  
Local Structure ◽  
Unit Cell ◽  
Group Symmetry ◽  
Hydrogen Atoms ◽  
Unit Cell Parameters ◽  
Space Group ◽  
Cell Parameters ◽  
Bonding Scheme

AbstractWe report the single-crystal average structure of cyanotrichite, Cu4Al2[SO4](OH)12(H2O)2, from the Maid of Sunshine mine, Arizona, USA. Cyanotrichite crystallizes in space group C2/m, with the unit-cell parameters a = 12.625(3), b = 2.8950(6), c = 10.153(2) Å and β = 92.17(3)o. All non-hydrogen atoms were located and refined to R1 = 0.0394 for all 584 observed reflections [Fo > 4σFo] and 0.0424 for all 622 unique reflections. The cyanotrichite structure consists of a principal building unit of a three-wide [Cu2Al(OH)6] ribbon of edge-sharing Cu and Al polyhedra || b, similar to that found for camerolaite. The ribbons lie in layers || (001) and between these layers, while SO4 tetrahedra and H2O molecules form rods running || b. A hydrogen-bonding scheme is also proposed.A sample of cyanotrichite from the Cap Garonne mine, Le Pradet, France, showed a 4b superstructure with the following unit cell: space group P2/m, a = 12.611(2) Å, b = 11.584(16) = 4 × 2.896(4) Å, c = 10.190(1) Å and β = 92.29(6)o. The supercell could not be refined in detail, but nevertheless imposes constraints on the local structure in that while the space-group symmetry prevents full order of SO4 and H2O in the 4b supercell, it requires that the sequence of species along any given rod is [-SO4-SO4-(H2O)2-(H2O)2-] rather than [-SO4-(H2O)2-SO4-(H2O)2-].

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