Crystal structure determination for crystals with twinning by hemihedry or pseudohemihedry

1991 ◽  
Vol 194 (3-4) ◽  
Author(s):  
Takaharu Araki
Keyword(s):  
Crystal Structure ◽  
Least Squares ◽  
Structure Determination ◽  
Difficult Case ◽  
Proper Selection ◽  
Space Group ◽  
Geometrical Symmetry ◽  
Symmetry Space ◽  
Symmetry Space Group ◽  
Selection Of

AbstractAn approach to structure determination for a crystal from component crystals in equal volume fractions, the most difficult case to the solution, is outlined with precautions for stepwise initialization. Proper selection of a crystal geometrical symmetry space group from a corresponding twin anti-symmetry space group and interpretation of a Patterson space are indispensable prerequisite for the solution. Observations unique to the case are briefly described in a sequence of Patterson synthesis, Fourier approach and least-squares refinement for efficient interpretation and processing.

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 das Oxomolybdat AgKCu3Mo4O16 mit Silber in siebenfacher Koordination / About the Oxomolybdate AgKCu3Mo4O16 with Silver in Seven-Fold Coordination

1995 ◽  
Vol 50 (2) ◽  
pp. 252-256 ◽  
Author(s):  
H. Szillat ◽  
Hk. Müller-Buschbaum
Keyword(s):  
Crystal Structure ◽  
Single Crystals ◽  
Monoclinic Symmetry ◽  
Space Group ◽  
X Ray ◽  
Silver Copper ◽  
Symmetry Space ◽  
Symmetry Space Group

Single crystals of AgKCu3Mo4O16 have been prepared by crystallization from melts and investigated by X-ray diffractometer techniques. This compound crystallizes with monoclinic symmetry, space group C2h5 - P21/c, a = 5.056(1), b = 14.546(4), c = 19.858(9) Å, β = 86.64(5)°, Z = 4. The crystal structure of AgKCu3Mo4O16 is closely related to K2Cu3Mo4O16 showing ribbons of edge-sharing CuO6 and AgO7 polyhedra. The ribbons are linked by tetrahedrally coordinated molybdenum and K2O10 groups. Another kind of MoO4 tetrahedra occupies the cavities inside the ribbons. The crystal structure and the coordination of silver, copper, potassium and molybdenum by oxygen are discussed with respect to K2Cu3Mo4O16.

Über einen 9L-Perowskit der Zusammensetzung Ba9Ru3,2Mn5,8O27/ On a 9L-Perovskite of the Composition Ba9Ru3.2Mn5.8O27

1995 ◽  
Vol 50 (4) ◽  
pp. 585-588 ◽  
Author(s):  
S. Frenzen ◽  
Hk. Müller-Buschbaum
Keyword(s):  
Crystal Structure ◽  
Single Crystals ◽  
Space Group ◽  
X Ray ◽  
Group D ◽  
Symmetry Space ◽  
Symmetry Space Group ◽  
Rhombohedral Symmetry

Single crystals of Ba9Ru3.2Mn5.8O27 have been prepared by flux techniques. X-ray four circle diffractometer measurements led to trigonal (rhombohedral) symmetry, space group D53d - R3̄̄̄m , a = 5.7043(5), c = 21.255(4) Å , Z = 1. This phase is isotypic to BaRuO3. The crystal structure and the occupation of the M3O12 triple octahedra by ruthenium and manganese are discussed with respect to other oxides containing M3O12 groups in an ordered and disordered way.

Zur Synthese und Kristallstruktur von manganhaltigen Boratoxiden: MnFe(BO3)O und MnAl0,5Yo,5(BO3)O / Synthesis and Crystal Structure of Manganese Borate Oxides: MnFe(BO3)O and MnAl0,5Yo,5(BO3)O

1995 ◽  
Vol 50 (8) ◽  
pp. 1146-1150 ◽  
Author(s):  
Anne Utzolino ◽  
Karsten Bluhm
Keyword(s):  
Crystal Structure ◽  
Metal Ions ◽  
Single Crystals ◽  
Orthorhombic Symmetry ◽  
Monoclinic Symmetry ◽  
Synthesis And Crystal Structure ◽  
Space Group ◽  
Group D ◽  
Symmetry Space ◽  
Symmetry Space Group

Single crystals of the compounds MnFe(BO3)O (I) and MnAl0.5Y0.5(BO3)O (II), were obtained by a B2O3 flux technique. I crystallizes with orthorhombic symmetry, space group D162h -Pnma (Nr.62), a = 939.92; b = 319.41; c = 939.11 pm; Z = 4 and II with monoclinic symmetry, space group C52h-P21/n (Nr. 14). a = 325.6; b = 955.1; c = 929.2 pm; β = 90.70° ; Z = 4. I is isotypic to the mineral Warwickite, while II is a distorded variant of this structure. All metal ions are octahedrally coordinated. Both structures contain isolated, trigonal planar BO3 units and oxygen atoms that are not coordinated to boron.

scholarly journals N′-[(E)-4-Bromobenzylidene]-2-(4-isobutylphenyl)propanohydrazide

2009 ◽  
Vol 65 (6) ◽  
pp. o1184-o1185 ◽  
Author(s):  
Hoong-Kun Fun ◽  
Ching Kheng Quah ◽  
K. V. Sujith ◽  
B. Kalluraya
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bond ◽  
Asymmetric Unit ◽  
Higher Symmetry ◽  
Space Group ◽  
Compound C ◽  
Benzene Rings ◽  
Independent Molecules ◽  
Symmetry Space ◽  
Symmetry Space Group

The asymmetric unit of the title compound, C20H23BrN2O, contains two independent molecules (AandB), in which the orientations of the 4-isobutylphenyl units are different. The dihedral angle between the two benzene rings is 88.45 (8)° in moleculeAand 89.87 (8)° in moleculeB. MoleculesAandBare linked by a C—H...N hydrogen bond. In the crystal, molecules are linked into chains running along theaaxis by intermolcular N—H...O and C—H...O hydrogen bonds. The crystal structure is further stabilized by C—H...π interactions. The presence of pseudosymmetry in the structure suggests the higher symmetry space groupPbca. However, attempts to refine the structure in this space group resulted in a disorder model with highR(0.097) andwR(0.257) values. The crystal studied was an inversion twin with a 0.595 (4):0.405 (4) domain ratio.

Zur Kenntnis des Kupfer-Oxid-Arsenats Cu4O(A sO4)2 / On the Copper Oxide Arsenate Cu4O(AsO4)2

1996 ◽  
Vol 51 (9) ◽  
pp. 1279-1282 ◽  
Author(s):  
M. Staack ◽  
Hk. Müller-Buschbaum
Keyword(s):  
Crystal Structure ◽  
Copper Oxide ◽  
Single Crystal ◽  
Copper Ions ◽  
Space Group ◽  
X Ray ◽  
Different Types ◽  
Symmetry Space ◽  
Symmetry Space Group ◽  
Anionic Part

The copper oxide arsenate Cu4O(AsO4)2 has been prepared and investigated by single crystal X-ray techniques. The compound crystallizes with triclinic symmetry, space group C1i-P1̄, a = 6.4148(7), b = 7.6549(5), c = 8.2241(7) Å, α = 98.52(1), β = 112.39(1), 7 = 98.38(1)°, Z = 2. Cu4O(AsO4)2 is isotypic to Cu4(PO4)2O . Copper ions on one of the four specified sites show nearly planar coordination by O2- and may be assigned to the anionic part of the crystal structure. One of the nine different types of oxygen atoms is coordinated by copper exclusively. The compound is therefore classified as an oxide arsenate.

scholarly journals Synthese und Kristallstruktur eines Alkali-Erdalkali-Kupfer-Halogeno-Oxovanadats: KBaCuV2O7Cl / Synthesis and Crystal Structure of an Alkaline Alkaline-Earth Halide Oxide of Copper and Vanadium: KBaCuV2O7Cl

1994 ◽  
Vol 49 (3) ◽  
pp. 355-359 ◽  
Author(s):  
F.-D. Martin ◽  
H. Müller-Buschbaum
Keyword(s):  
Crystal Structure ◽  
Single Crystals ◽  
Alkaline Earth ◽  
Copper Ion ◽  
Tetragonal Symmetry ◽  
Synthesis And Crystal Structure ◽  
Space Group ◽  
X Ray ◽  
Symmetry Space ◽  
Symmetry Space Group

Abstract Single crystals of KBaCuV2O7Cl have been prepared by a flux technique and investigated by X-ray analysis. The compound crystallizes with tetragonal symmetry, space group C24v-P4 bm, a = 8.8581, c = 5.4711 Å, Z = 2. The crystal structure shows Cu2+ within a one sided strongly distorted CuO4Cl2 octahedron. The copper ion is shifted towards the nearer Cl- neighbour to form a CuO4Cl square pyramid. Two VO4 tetrahedra are connected to give stretched V2O7 double tetrahedra, and linked in planes via the oxygen corners of the CuO4Cl pyramids. The crystal structure and the structure of the complex BaO8Cl2 polyhedron are discussed.

Ein Silber- Kupfer - Oxovanadato-Oxomolybdat mit Silber in quadratisch-planarer Koordination: Ag0,5Cu3V0,5Mo2,5O12 / On a Silver Copper Oxovanadate-Oxomolybdate with Silver in Square Planar Coordination: Ag0,5Cu3V0,5Mo2,5O12

1995 ◽  
Vol 50 (6) ◽  
pp. 879-883 ◽  
Author(s):  
H. Szillat ◽  
Hk. Müller-Buschbaum
Keyword(s):  
Crystal Structure ◽  
Single Crystals ◽  
Statistical Distribution ◽  
Space Group ◽  
X Ray ◽  
Point Position ◽  
Square Planar ◽  
Symmetry Space ◽  
Ray Methods ◽  
Symmetry Space Group

Single crystals of Ag0.5Cu3V0,5Mo2,5O12 have been prepared by crystallization from melts and investigated by X -ray methods. They crystallize with triclinic symmetry, space group Ci1 -P 1̄ , a = 6.797(6), b = 8.575(6), c = 9.897(7) Å, α = 103.47(6), β = 103.69(6), γ = 101.48(6)° and Z = 4. The crystal structure is characterized by chains of edge-sharing CuO6 octahedra and CuO5 pyramids. Special features of this com pound are the square planar surrounding of Ag+ by O2− and a statistical distribution of molybdenum and vanadium at one point position.

Hochtemperatursynthese und Kristallchemie der Oxotantalate Cr2+0,761Ta2,095O6 und FeTa2O6 / High Temperature Synthesis and Crystal Chemistry of the Oxotantalates Cr2+0,761Ta2,095O6 and FeTa2O6

1995 ◽  
Vol 50 (5) ◽  
pp. 712-716 ◽  
Author(s):  
E. Peters ◽  
Hk. Müller-Buschbaum
Keyword(s):  
Crystal Structure ◽  
High Temperature ◽  
Monoclinic Symmetry ◽  
Temperature Synthesis ◽  
Space Group ◽  
High Temperature Synthesis ◽  
Laser Techniques ◽  
Group D ◽  
Symmetry Space ◽  
Symmetry Space Group

Abstract Black single crystals of Cr0.761Ta2.095O6 have been prepared by CO2-LASER techniques. This phase crystallizes with monoclinic symmetry, space group C52h-P21/c, a = 4.748(1). b = 4.750(2), c = 10.405(3) Å, β = 117.152(13)°, Z = 2. The crystal structure is closely related to the trirutile type, although the metal positions are partly statistically occupied by Cr2+ and Ta5+ or underoccupied by Ta5+, respectively. FeTa2O6, prepared by the same m ethod does neither show any statistic occupation nor deviations from the trirutile structure, space group D144h-P42/mnm, a = 4.7595(5) Å, c = 9.201(2)A, Z = 2 .

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