scholarly journals The orthorhombic/monoclinic symmetry change in single crystals of zeolite ZSM-5

1987 ◽  
Vol 43 (a1) ◽  
pp. C136-C136
Author(s):  
H. van Koningsveld ◽  
H. van Bekkum ◽  
J. C. Jansen
Keyword(s):  
Single Crystals ◽  
Monoclinic Symmetry ◽  
Symmetry Change

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.

Synthese and Krystalchemie der β-Form eines gemischten Zinkorthoarsenats: Zn2,28Mg0,72(AsO4)2 / Synthesis and Crystal Chemistry of the β-Form of a Mixed Zinc Orthoarsenate: Zn2.28Mg0.72(AsO4)2

1996 ◽  
Vol 51 (4) ◽  
pp. 469-472 ◽  
Author(s):  
D. Frerichs ◽  
Hk. Müller-Buschbaum
Keyword(s):  
Single Crystals ◽  
Crystal Chemistry ◽  
Lattice Parameters ◽  
Monoclinic Symmetry ◽  
Space Group ◽  
Laser Techniques ◽  
Symmetry Space ◽  
Symmetry Space Group

Abstract Single crystals of Zn2.28Mg0.72(AsO4)2 have been prepared by CO2 LASER techniques. The compound crystallizes with monoclinic symmetry space group C52h-P21/n and the lattice parameters a = 5.292(2), b = 8.450(3), c = 7.737(3) Å , β = 96.33(3)°, Z = 2. Zn2.28Mg0.72(AsO4)2 is isotypic to β-Zn3(AsO4)2. The formation of the β-Zn3(AsO4)2 struc­ture instead of other possible orthoarsenates is discussed.

Ein Beitrag zur Kristallchemie von Verbindungen mit Johillerit-Struktur: KCo3Cu(As2,58V0,42)O12 / On the Crystal Chemistry of Compounds with Johillerite Structure: KCo3Cu(As2,58V0,42)O12

1994 ◽  
Vol 49 (11) ◽  
pp. 1463-1466 ◽  
Author(s):  
D. Frerichs ◽  
Hk. Müller-Buschbaum
Keyword(s):  
Solid State ◽  
Melting Point ◽  
Single Crystals ◽  
Crystal Chemistry ◽  
Structure Type ◽  
Solid State Reactions ◽  
Tetrahedral Coordination ◽  
Monoclinic Symmetry ◽  
Symmetry Space ◽  
Symmetry Space Group

Single crystals of KCo3Cu(As2.58V0.42)O12 were prepared by solid state reactions below the melting point of the reaction mixture (K2CO3, CuO, COC2O4, V2O5 and 3 As2O5 · 5H2O). It crystallizes with monoclinic symmetry, space group C62h-C2/c, a = 12.207, b = 12.730, c = 6.811 Å, β = 113.69°, Z = 4. The structure type is characterized by isolated twisted-square CuO4-polygons, CoO6-octahedra and a special 4+4-coordination of the potassium ion. As5+ and V5+ are in tetrahedral coordination with a partly statistical distribution of these ions.

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.

Kristallstrukturuntersuchung am Barium-Yanadyl-Vanadat: Ba2(VO)V2O8 / Crystal Structure Investigation of the Barium Vanadyl-Vanadate: Ba2(VO)V2O8

1996 ◽  
Vol 51 (4) ◽  
pp. 489-492 ◽  
Author(s):  
J. Feldmann ◽  
Hk. Müller-Buschbaum
Keyword(s):  
Crystal Structure ◽  
Solid State ◽  
Single Crystals ◽  
Structure Type ◽  
Solid State Reactions ◽  
Tetrahedral Coordination ◽  
Structure Investigation ◽  
Monoclinic Symmetry ◽  
Symmetry Space ◽  
Symmetry Space Group

Abstract Single crystals of Ba2(VO)V2O8 have been prepared by solid state reactions of Ba2V2O7, V2O3 and V2O5 in sealed silica tubes. This compound crystallizes with monoclinic symmetry, space group C22 -P21, a = 8.1174(9), b = 5.9699(9), c = 9.2903(9) Å , β = 113.94(1)°, Z = 2. V 5+ shows tetrahedral coordination. V 4+ inside 1∞ [V (3)O4] chains is characterized by a square pyramidal coordination with a short apical V-O distance of 1.6 Å typically for vanadyl groups. Ba2(VO)V2O8 represents a new structure type and is not isotypic to Sr2(VO)V2O8.

Isolierte 1∞[TeO5]-Oktaederketten im Bleitellurat Pb2TeO5 / Isolated 1∞[TeO5] Chains of Octahedra in the Lead Tellurate Pb2TeO5

1998 ◽  
Vol 53 (3) ◽  
pp. 287-290 ◽  
Author(s):  
B. Wedel ◽  
L. Wulff ◽  
Hk. Müller-Buschbaum
Keyword(s):  
Crystal Structure ◽  
Single Crystals ◽  
Lone Pair ◽  
Lattice Energy ◽  
Monoclinic Symmetry ◽  
Space Group ◽  
X Ray ◽  
Symmetry Space ◽  
Symmetry Space Group

Abstract Single crystals of Pb2TeO5 have been prepared by flux techniques. X-ray investigations showed a new crystal structure with monoclinic symmetry, space group C4S -Cc, a = 13.099(3), b = 5.714(1), c = 7.520(2) Å, β = 123,80(3)°, Z = 4. Pb2TeO5 is characterized by 1∞[TeO5] chains of octahedra isolated from each other and incorporated into an edge, corner and face connected frame of PbO7 polyhedra. Possible positions of the lone pair of electrons of Pb2+ are estimated by calculations of Coulomb terms of lattice energy.

Oxotitanate mit gemischter Valenz, II Zur Kenntnis von Sr2Ti6O13 / Oxotitanates with Mixed Valence, II About Sr2Ti6O13

1980 ◽  
Vol 35 (1) ◽  
pp. 4-6 ◽  
Author(s):  
J. Schmachtel ◽  
Hk. Müller-Buschbaum
Keyword(s):  
Single Crystals ◽  
Mixed Valence ◽  
Vacuum Furnace ◽  
Monoclinic Symmetry ◽  
Space Group ◽  
X Ray

Abstract Single crystals of Sr2Ti6O13 were prepared by heating a mixture of SrO·Ti2O3·2TiO2 in a vacuum furnace to 1800 °C for 6 hours. X-ray investigations show monoclinic symmetry (a = 1525,0, b = 376,9, c = 916,4 pm; β = 99,15°, space group C32h-C2/m). Sr2Ti6O13 is isotypic with Ba2Ti6O13.

Zwei Beispiele fiir partielle und totale Defekte im Ba▪Ln2Mo4O16-Typ: BaCu0,41▪0,59Pr2Mo4O16 und Ba▪Yb2Mo4O16 / Two Examples of Partial and Total Defects in the Ba▪Ln2Mo4O16-Typ: BaCu0,41▪0,59Pr2Mo4O16 and Ba▪Yb2Mo4O16

1996 ◽  
Vol 51 (1) ◽  
pp. 85-89 ◽  
Author(s):  
St. Gallinat ◽  
Hk. Müller-Buschbaum
Keyword(s):  
Crystal Structure ◽  
Single Crystals ◽  
Crystal Chemistry ◽  
Reference Compound ◽  
Monoclinic Symmetry ◽  
Space Group ◽  
First Case ◽  
Symmetry Space ◽  
Symmetry Space Group

Abstract Single crystals of (I) BaCu0,41Pr2Mo4O16 and (II) BaYb2Mo4O16 have been prepared by flux technique. Both compounds crystallize with monoclinic symmetry, space group C62h-C2/c with (I): a = 5.352(11), b = 12.888(2), c = 19.399(4) Å; β = 90.89(3)°; (II): a = 5.181(7), b = 12.467(3), c -19.350(3) Å , β -91.93(2)°, Z = 4. The crystal structure is characterized by 1∞[BaMO12]-chains along [010]. In the first case the M positions are occupied by copper by about 41%, in the second case these positions remain completely unoccupied. With respect to the crystal chemistry of the reference compound Ba(Cu0.22Mg0,78)Nd2Mo4O16 all substances of the composition BaLn2Mo4O16 should be written as Ba▪Ln2Mo4O16 indicating the holes in the 1∞[BaMO12]-chains by ▪.

Ein Cadmium-Kupfer-Phosphat mit einfach überkappten trigonalen CdO6-Prismen-Netzen: Cd1.35Cu1.65(PO4)2

1996 ◽  
Vol 51 (2) ◽  
pp. 229-232 ◽  
Author(s):  
S. Münchau ◽  
Hk. Müller-Buschbaum
Keyword(s):  
Crystal Structure ◽  
Solid State ◽  
Melting Point ◽  
Single Crystals ◽  
Solid State Reactions ◽  
Monoclinic Symmetry ◽  
Space Group ◽  
Symmetry Space ◽  
Light Green ◽  
Symmetry Space Group

Abstract Single crystals of Cd1.35Cu1.65(PO4)2 have been prepared by solid state reactions below the melting point of the starting compounds. The light green crystals crystallize with monoclinic symmetry, space group C52h-P21/c , a = 9.062(2), b = 11.669(2), c = 5.950(2) Å , β = 97.88(2)°, Z = 4. Cd1.35Cu1.65(PO4)2 shows relationship to the mineral graftonite. The crystal structure is characterized by nets of corner connected Cd2O12 polyhedra. One point position is statistically occupied by Cd2+ and Cu2+ ions.

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