Zur Kenntnis von Ba(MgZn)V2O8, BaMn2V2O8 und Ba1/2Sr1/2Ni2V2O8

On Ba(MgZn)V₂O₈, BaMn₂V₂O₈, and Ba_1/2Sr_1/2Ni₂V₂O₈ Ba(Mg, Zn)V₂O₈ (A), BaMn₂V₂O₈ (B) and Ba_1/2Sr_1/2Ni₂V₂O₈ (C) were prepared by solid state reactions (A and B) and crystallization from a melt (C) respectively. (A? C) crystallize in the space group: D-I4₁/acd, Nr. 142. [Lattice constants (A): a = 12.4524(57) Å, c = 8.4408(36) Å; (B): a = 12.5563(14) Å, c = 8.5942(9) Å; (C): a = 12.2248(20) Å, c = 8.3245(15) Å]. (A), (B) and (C) are isotypic to SrNi₂V₂O₈ but showing higher symmetry.     

Ein Beitrag zur Kristallstruktur von CuYW2O8, CuHoW2O8 und CuYbW2O8

A Contribution on the Crystal Structure of CuYW₂O₈, CuHoW₂O₈, and CuYW₂O₈ Single crystals of (I) CuY₂O₈, (II), CuHoW₂O₈, and (III) CuYbW₂O₈ were prepared and investigated by X-ray technique. (I) crystallizes with triclinic symmetry, space group C? P1 (a = 5.939 Å, b = 6.042 Å, c = 5.025 Å; α = 112.30°, β = 111.77°; Z = 1). (II) and (III) belong to monoclinic symmetry, space group C? P2/n (II) (a = 10.045 Å, b = 5.808 Å, c = 5.021 Å; β = 94.38°; z = 2 (III) a = 9.948 Å, b = 5.824 Å, c = 5.008 Å; β = 93.36°; Z = 2). The crystal structures will be discussed with respect to other to copper rare earth tungstates.     

Synthese und Kristallstruktur von KMgCu4V3O13

Synthesis and Crystal Structure of KMgCu₄V₃O₁₃ . Single crystals of KMgCu₄V₃O₁₃ were prepared by supercooled melts. It crystallizes with monoclinic symmetry space group C–P2₁/m (Nr. 11), unit cell dimensions: a = 10.7144 Å, b = 6.0282 Å, c = 8.3365 Å, β = 98.075°, Z = 2. The crystal structure is closely related to the BaMg₂Cu₈O₆O₂₆ type. Cu²⁺ occurs in an unusual trigonal bipyramidal coordination.     

Ein Beitrag zur Kristallstruktur von CuSmMo2O8 und CuGdMo2O8

A Contribution on the Crystal Structure of CuSmMo₂O₈ and CuGdMo₂O₈ Single crystals of (I) CuSmMo₂O₈ and (II) CuGdMo₂O₈ were prepared and investigated using an X-ray technique. Both compounds crystallize with orthorhombic symmetry, space group D-Pbca with Z = 8. ((I): a = 10.302, b = 9.796, c = 14.697 Å; (II): a = 10.200, b = 9.779, c = 14.646 Å). The crystal structure and the classification into the already known Copper(I) Lanthanoidemolybdates are discussed.     

Zur Kristallchemie der Kupfer-Lanthanoid-Oxowolframate: (I) triklin-α-CuTbW2O8, (II) monoklin-CuInW2O8 und (III) monoklin-CuYW2O8

The Crystal Chemistry of Copper Rare-Earth Oxotungstates: (I): triclinic-α-CuTbW₂O₈, (II): monoclinic-CuInW₂O₈ and (III): monoclinic-CuYW₂O₈ Single crystals of (I), (II) and (III) were prepared by recrystallisation in closed systems and examined by X-ray technique. (I): space group C? P1 , a = 7.3080, b = 7.8945, c = 7.1476 Å, α = 115.23, β = 116.21, γ = 56.98°, Z = 2; (II): space group C? C2/c, a = 9.6576, b = 11.6496, c = 4.9863 Å, β = 91.17°, Z = 4; (III): space group C? P2/n, a = 10.0504, b = 5.8214, c = 5.0224 Å, β = 94.23°, Z = 2. The crystal structures are discussed with respect to calculations of the coulombterms of lattice energy and possible valence states of Cu²⁺ and Mo⁵⁺.     

Zur Kristallstruktur von CuInMo2O8

On the Crystal Structure of CuInMo₂O₈ . Single crystals of CuInMo₂O₈ were prepared and investigated by X-ray work. It shows monoclinic symmetry, space group C—C2/c; a = 9.549 Å, b = 11.529 Å, c = 5.000 Å; β = 91.38(2)°, Z = 4. CuInMo₂O₈ represents a LiYbW₂O₈ related structure, characterised by zigzag-chains of MoO₆-octahedrons and octahedrons around copper and indium. With respect to LiFeW₂O₈ the single and three-valent ions are in opposite distribution. There are strong evidence for molybdenum in lowered oxidation state.     

Na2BaCuV2O8: Ein neuer Strukturtyp der Alkali-Erdalkalimetall Kupfer-Oxovanadate

Na₂BaCuV₂O₈: A New Structure Type of the Alkaline-Alkaline Earth Copper Oxovanadates Single crystals of Na₂BaCuV₂O₈ were prepared by a high temperature flux. It crystallizes with monoclinic symmetry space group C–C2/c, a = 9.4329 Å, b = 5.6858 Å, c = 14.0488 Å, β = 92.344° Z = 4 and represents a new structure type. The crystal structure show VO₄ tetrahedra, stretched CuO₆ octahedra, trigonal bipyramids around Na⁺ and a BaO₁₀₊₂ polyedron.     

Zur Kenntnis eines Alkali-Erdalkalimetall-Cadmium-Oxovanadats: KBaCd2(VO4)(V2O7)

On an Alkali Alkaline-Earth Cadmium Oxovanadate: KBaCd₂(VO₄)(V₂O₇) Single crystals of KBaCd₂(VO₄)(V₂O₇) have been prepared by crystallization from melts. X-ray investigations led to monoclinic symmetry, space group C? P2₁/n, a = 10.359(3), b = 6.986(2), c = 15.331(3) Å, β = 94.77(2), Z = 4. The hitherto unknown compound represents a new structure type and is one of those few examples containing VO₄ and V₂O₇ groups.     

Über hexagonale Perowskite mit Kationenfehlstellen. XXVI. Ba12Ba2 2/3M 1/3□2O33□3 (MV = Nb,Ta) – die ersten Stapelvarianten eines rhomboedrischen 36 L-Typs

On Hexagonal Perovskites with Cationic Vacancies. XXVI. Ba₁₂Ba_{2 2/3}M _1/3□₂O₃₃□₃ (M^V = Nb, Ta) – the First Stacking Polytypes of a Rhombohedral 36 L-Type In the systems BaO? MO₅(M^V = Nb, Ta) for a Ba:M^V ratio of 2:1 polymorphism is observed. Here the low temperature modifications are described. They crystallize in a rhombohedral 36 L structure with three formula units Ba₁₂Ba_{2 2/3}M _1/3□₂O₃₃□₃ for the trigonal setting (M^V = Nb: a = 5.92₂ Å; c = 93.₂₅ Å; Ta: a = 5,92₂ Å; s = 93.4 Å).     

Synthese und Struktur einer neuen Form von CuYMo2O8

Synthesis and Structure of a New form of CuYMo₂O₈ Single crystals of a new form of CuYMo₂O₈ were prepared and investigated by X-ray diffractometer technique [space group D-Pbca; a = 10.160 Å, b = 9.701 Å, c = 14.527 Å; Z = 8]. CuYMo₂O₈ represents a new structure type characterised by MoO₄-tetrahedrons, Cu⁺ with coordination number 2 + 1 and square antiprisms around Y³⁺. The crystal structure and the Cu⁺ coordination are discussed.     

Ein Wechsel des Strukturtyps in den Oxiden BaCoGd2O5, BaCoDy2O5 und BaCoY2O5

A Change of Structure Type in the Oxides BaCoGd₂O₅, BaCoDy₂O₅, and BaCoY₂O₅ (I) BaCoGd₂O₅, (II) BaCoDy₂O₅, and (III) BaCoY₂O₅ were prepared for the first time and examined by single crystal work. (I) and (II) belong to the BaNiLn₂O₅-type. (I): a = 3.770; b = 5.860; c = 11.620 Å; Z = 2; (II): a = 3.755; b = 5.798; c = 11.514 Å; Z = 2; space group D–Immm. (III) crystallizes in the BaCuLn₂O₅-type, space group D–Pnma, a = 12.287; b = 5.713; c = 7.067 Å; Z = 4. The coordination of Co²⁺ changes from (I, II) to (III) from octahedral to tetragonal pyramidal.     

Über hexagonale Perowskite mit Kationenfehlstellen. XVI Die rhomboedrischen 12 L-Stapelvarianten Ba3AIIIM□O12 mit MV = Nb,Ta

On Hexagonal Perovskites with Cationic Vacancies. XVI. Rhombohedral 12 L-Stacking Polytypes Ba₃A^IIIM □O₁₂ with M^V = Nb, Ta The white quaternary oxides Ba₃LaM□O₁₂ with M^V = Nb, Ta belong to the group of hexagonal perovskites with cationic vacancies. They crystallize in a rhombohedral 12 L-structure (sequence (hhcc)₃; space group R3 m) with a = 5.75₁ Å; c = 28.1₁ Å (M^V = Nb); a = 5.74₆ Å; c = 28.2₀ Å (Ta) and Z = 3. Signs for the formation of isotypic compounds with A^III = Pr, Nd could be obtained as well.     

Ein Beitrag über CuPrMo2O8 und CuTbMo2O8

A Contribution on CuPrMo₂O₈ and CuTbMo₂O₈ Single crystals of (I): CuPrMo₂O₈ and (II): CuTbMo₂O₈ were prepared by solid state reactions in closed copper tubes. They crystallize with orthorhombic symmetry, space group D-Pbca, (I): a = 10.4114, b = 9.8917, c = 14.8287 Å, (II): a = 10.2243, b = 9.7385, c = 14.6000, Z = 8. Both compounds are isotypic to CuYMo₂O₈, showing isolated MoO₄ tetrahedra, square antiprismatic coordination of Ln³⁺ and Cu⁺ besides one edge of an O^2? triangle. Calculations of the coulombterm of lattice energy support the oxidation state Cu²⁺ in combination with mixed valences of Mo⁶⁺ and Mo⁵⁺ on the molybdenum point positions.     

Crystal Structures of {[Cd(phen)](C6H8O4)3/3} and {[Cd(phen)](C7H10O4)3/3} · 2H2O with C6H10O4 = Adipic Acid and C7H12O4 = Pimelic Acid

Two coordination polymers {[Cd(phen)](C₆H₈O₄)_3/3} ( 1 ) and {[Cd(phen)](C₇H₁₀O₄)_3/3} · 2H₂O ( 2 ) were structurally characterized by single crystal X‐ray diffraction methods. In 1 (C2/c (no. 15), a = 16.169(2)Å, b = 15.485(2)Å, c = 14.044(2)Å, β = 112.701(8)°, U = 3243.9(7)ų, Z = 8), the Cd atoms are coordinated by two N atoms of one phen ligand and five O atoms of three adipato ligands to form mono‐capped trigonal prisms with d(Cd‐O) = 2.271‐2.583Å and d(Cd‐N) = 2.309, 2.390Å. The [Cd(phen)] moieties are bridged by adipato ligands to generate {[Cd(phen)](C₆H₈O₄)_3/3} chains, which, via interchain π—π stacking interactions, are assembled into layers. Complex 2 (P1¯(no. 2), a = 9.986(1)Å, b = 10.230(3)Å, c = 11.243(1)Å, α = 66.06(1)°, β = 87.20(1)°, γ = 66.71(1)°, U = 955.7(2)ų, Z = 2) consists of {[Cd(phen)](C₇H₁₀O₄)_3/3} chains and hydrogen bonded H₂O molecules. The Cd atoms are pentagonal bipyramidally coordinated by two N atoms of one phen ligand and five O atoms of three pimelato ligands with d(Cd‐O) = 2.213—2.721Å and d(Cd‐N) = 2.329, 2.372Å. Through interchain π—π stacking interactions, the {[Cd(phen)](C₇H₁₀O₄)_3/3} chains resulting from [Cd(phen)] moieties bridged by pimelato ligands are assembled in to layers, between which the hydrogen bonded H₂O molecules are sandwiched.     

Darstellung und Kristallstruktur eines Kalium—Magnesium-Oxocuprat/-vanadats: KMg2Cu2V3O12

Preparation and Crystal Structure of Potassium Magnesium Oxocuprate/-vanadate: KMg₂Cu₂V₃O₁₂ . Single crystals of KMg₂Cu₂V₃O₁₂ were prepared by solid state reactions below the melting point of the reaction mixture (K₂CO₃, MgCO₃, CuO, V₂O₅). It crystallizes with monoclinic symmetry space group C? C2/c, a = 12.1592 Å, b = 12.7204 Å, c = 6.8557 Å, β = 111.73°, Z = 4. The structure type is characterized by VO₄ tetrahedra, twisted CuO₄ square units, MgO₆ octahedra and a special 2 + 4 + 2 coordination around the potassium ion.     

Synthese und Untersuchung von NiNb2O6-Einkristallen mit Columbit- und Rutilstruktur

Synthesis and Investigation of NiNb₂O₆ Single Crystals of Columbite and Rutil Type C-NiNb₂O₆ (columbite type) and R-NiNb₂O₆ (rutil type) single crystals were prepared by solid state reactions. C-NiNb₂O₆ a = 14.032; b = 5.687; c = 5.033 Å, space group D—Pbcn. R-NiNb₂O₆ a = 4.710; c = 3.038 Å, space group D—P4₂/mnm. The metal positions of the rutil structure are statisticaly occupied by Ni²⁺ and Nb⁵⁺ ions. R-NiNb₂O₆ is in respect to lower temperatures a metastable compound.     

Synthese und Struktur einer neuen Form von CuNdW2O8: β-CuNdW2O8

Synthesis and Structure of a New Form of CuNdW₂O₈: β-CuNdW₂O₈ Single crystals of an unknown form of CuNdW₂O₈ were prepared and investigated by X-ray diffractometer technique [space group C? P₁; a = 6.1330; b = 6.0760; c = 5.0190 Å; α = 111.79°; β = 93.24°; γ = 111.20°; Z = 1]. β-CuNdW₂O₈ represents a new structure type characterized by WO₆ octahedral chains and O? Cu? O dumbbells. Its structure is discussed in respect to other copper tungstates.     

Zur Kristallchemie der Blei-Lanthanoid-Oxoaluminate. Zur Kenntnis von Pb2HoAl3O8 und Pb2LuAl3O8

Crystal Chemistry of the Lead Lanthanide Oxoaluminates. On Pb₂HoAl₃O₈ and Pb₂LuAl₃O₈ . Single crystals of (I) Pb₂HoAl₃O₈ and (II) Pb₂LuAl₃O₈ were prepared by flux technique and investigated by X-ray methods. It crystallizes with cubic symmetry, space group O–P4₂/n 3 2/m, (I): a = 9.4164(13) Å, (II): a = 9.3486(8) Å, Z = 4. The new structure type shows AlO₄ tetrahedra, LnO₈ hexagonal bipyramids and one sided coordinated Pb²⁺ within heterocubane units. The crystal chemical relationships to other lead oxides containing heterocubane Pb₄O₄ units are discussed.     

Zur Kenntnis einer modifizierten Form des β-CuNdW2O8-Typs: γ-CuTbW2O8

On a Modified Form of the β-CuNdW₂O₈ Type: γ-CuTbW₂O₈ Single crystals of γ-CuTbW₂O₈ were prepared by flux in closed copper tubes. X-ray investigations show triclinic symmetry, space group C-P1 , with a = 6.722, b = 9.831, c = 15.352 Å, α = 72.82, β = 88.53, γ = 71.76°, Z = 6. γ-CuTbW₂O₈ is closely related to β-CuNdW₂O₈. One significant difference can be seen in an alternate staggered location of Tb³⁺ ions along [110].     

Zwei neue Verbindungen mit Zink in tetragonal pyramidaler Koordination: BaZnDy2O5 und Ba1,25ZnHo2O5,25 (Ba5Zn4Ho8O21)

New Compounds with Zinc in Square Pyramidal Coordination: BaZnDy₂O₅ and Ba_1.25ZnHo₂O_5.25 (Ba₅Zn₄Ho₈O₂₁). Single crystals of (I): BaZnDy₂O₅ and (II): Ba₅Zn₄Ho₈O₂₁ were prepared by high temperature reactions and investigated by X-ray technique. (I) belongs to the BaCuLn₂O₅ type, space group D-Pbnm; a = 7.084; b = 12.368; c = 5.728 Å, Z = 4. (II) is isotypic to Ba₅Mn₄Ln₈O₂₁, space group C-I4/m; a = 13.779; c = 5.707 Å, Z = 2. The two different structure types are caused by the small difference in the composition of 0.25 BaO. Analogies and differences will be discussed. In addition the lattice constants of powder samples of Ba₅Zn₄Ln₈O₂₁ (Ln = Eu, Gd, Dy, Ho, Er and Y) are given.