Einbau von Al3+ in Ir3O12-Oktaedertripel in Ba4Ir2AlO10

Incorporation of Al³⁺ in Ir₃O₁₂ Octahedra-Triple in Ba₄Ir₂AlO₁₀ Single crystals of Ba₄Ir₂AlO₁₀ were prepared by solid state/flux reactions. It crystallizes with orthorhombic symmetry: space group D–Cmca; a = 5.778; b = 13.352; c = 13.084 Å; Z = 4. The structure is characterized by face connection of three IrO₆- or Ir/AlO₆-octahedra. X-ray investigations show an ordered occupation of the centric octahedron by Ir and a statistically distribution of Ir and Al in the adjacent octahedra. Calculations of the coulomb term of the lattice energy support a charge distribution in the manner Ir⁵⁺/Al³⁺? Ir⁴⁺? Ir⁵⁺/Al³⁺.     

Ba5AlIr2O11: Eine neue Verbindung mit Iridium(IV,V)

Ba₅AlIr₂O₁₁: A New Compound with Iridium(IV, V) The hitherto unknown compound Ba₅AlIr₂O₁₁ was prepared and investigated by X-ray technique (space group D–Pnma, a = 18.8360; b = 5.7887; c = 11.1030 Å; Z = 4). Iridium has an octahedral coordination in each case two octahedra are connected by a plane. These double octahedra form with corner connected AlO₄ tetrahedra [Ir₂AlO₁₁]^10? units. Ba₅AlIr₂O₁₁ is not related to the perovskite type compounds.     

Ein neues quaternäres Oxotitanat: Ba4Ti10Al2O27

A New Quaternary Oxotitanate: Ba₄Ti₁₀Al₂O₂₇ Single crystal of Ba₄Ti₁₀Al₂O₂₇ were prepared by heating oxide mixtures with NaOH flux for 20 days to 1300°C. X-ray investigations show monoclinic symmetry: a = 1973.7; b = 1134.9; c = 983.7 pm; β = 109.4°; space group C_2h³—C2/m. Ti⁴⁺/Al³⁺ occupy statistically more or less distorted octahedra, Ba²⁺ has an coordination number of 11 or 12, respectively. The complex frame work of octahedra is discussed.     

Über Neue Oxoruthenate vom Typ der 6 L-Perowskite: Ba3SrRu2−xTaxO9 (x = 0,8 und 1,4) mit einem Beitrag über Ba3CaRu2O9

On Novel Oxoruthenates of the 6 L-Perovskite Type: Ba₃SrRu_2?xTa_xO₉ (x = 0.8 and 1.4) with a Comment on Ba₃CaRu₂O₉ Single crystals of the phases Ba₃SrRu_2?xTa_xO₉ [(I): x = 0.8 and (II): x = 1.4] and the compound (III): Ba₃CaRu₂O₉ were prepared by a BaCl₂ flux and investigated by X-ray methods. (I)–(III) crystallizes with hexagonal symmetry space group P6 2c with lattice constants: (I) a = 6.003 Å; c = 15.227 Å; (II) a = 5.988 Å; c = 15.220 Å and (III) a = 5.891 Å; c = 14.571 Å. The crystal structures of these substances corresponds to the 6 layer perovskites with the stacking sequence (hcc)₂. All of them show a so far not described slightly distorted oxygen framework caused by the Sr²⁺ and Ca²⁺ ions.     

Über Sauerstoffperowskite mit fünf- und vierwertigem Iridium Verbindungen vom Typ Ba2B3+Ir5+O6 und Ba3B3+Ir4,5+2O9

Perovskites with pentavalent iridium of type Ba₂B³⁺Ir⁵⁺O₆ are for B³⁺ = La, Nd, Sm, Gd, Dy, Y cubic and with B³⁺ = In hexagonal (6 L structure of BaTiO₃ type; sequence (hcc)₂). According to the intensity calculations of powder patterns for Ba₃SmIr₂O₉ and Ba₃YIr₂O₉ the new series Ba₃B³⁺Ir₂O₉ (B³⁺ = Sm, Eu, Gd, Dy, Ho, Yb, Sc, Y, In; mean oxidation state of iridium + 4.5) crystallize in a hexagonal 6 L structure of BaTiO₃ type (space group $\text{P6}{}_3\text{mmc}$; sequence (hcc)₂). The intensity-related R′ value is 8.6% for B³⁺ = Sm and 10.0% for Y. In the octahedral net the double groups of face-connected octahedra are occupied by the iridium atoms, which are dislocated from their ideal positions such that the IrIr distance has increased (2.72₀ Å (Sm) or 2.63₂ Å (Y)). The ir spectra are reported and discussed in connection with the corresponding factor group analysis.     

Über Ba3ReSb□O9 - eine neue Perowskit-verwandte struktur

On Ba₃ReSb□O₉ — a New Perovskite-Related Structure The light yellow Ba₃ReSb□O₉ crystallizes tetragonally with a = 3.96₄ Å; c = 14.6₄ Å and one formula unit in the cell (ρ_exp = 6.1₀ g/cm³; ρ_cal = 6.23₂ g/cm³). According to the intensity calculations on powder data the structure consists of three perovskite units, piled up in c direction; the cationic vacancies are partially ordered. With the space group P4 the intensity related R′ value is 16.1%.     

Über hexagonale Perowskite mit Kationenfehlstellen. XX. Ba6Nb4Zr□O18 – eine neue Stapelvariante mit rhomboedrischer 18 L-Struktur

On Hexagonal Perovskites with Cationic Vacancies. XX. Ba₆Nb₄Zr□o₁₈ - a New Stacking Polytype with a Rhombohedra1 18 L Structure The white Ba₆Nb₄Zr□O₁₈ crystallizes in a rhombohedral 18 L structure (a = 5.82₁ Å; c = 42.6₃ Å; space group R3 m) with three formula units for the trigonal setting (?_exp = 6.0₅ g/cm³; ?_calc = 6.27₁ g/cm³). The corresponding Ti^IV and Hf^IV compounds, Ba₆Nb₄Zr□O₁₈ and Ba₆Nb₄Hf□O₁₈, are isotypic.     

Zur Kenntnis von Ba6La2Co4O15

About Ba₆La₂Co₄O₁₅ Ba₆La₂Co₄O₁₅ were prepared and investigated by X-ray single crystal work. It crystallizes with hexagonal symmetry, space group C–P6₃mc; a = 11.8082; c = 7.0019 Å; Z = 2. Ba²⁺ show face connected BaO₆-octahedra and larger polyhedra of C.N. = 10 and 12. Co³⁺ is surrounded by four and six (tetrahedra, octahedra) oxygen. The Ba²⁺ and La³⁺ ions occupy one point position statistically.     

Crystal growth of new perovskite and perovskite related iridates: Ba3LiIr2O9, Ba3NaIr2O9, and Ba3.44K1.56Ir2O10

Single crystals of Ba₃LiIr₂O₉, Ba₃NaIr₂O₉, and Ba_3.44K_1.56Ir₂O₁₀ were grown from hydroxide fluxes. Ba₃LiIr₂O₉ and Ba₃NaIr₂O₉ form in the 6H–BaTiO₃ or triple perovskite structure, which is derived from the hexagonal and cubic stacking of [AO₃] layers. The structure contains face-sharing Ir₂O₉ octahedra pairs, which are connected via corner shared LiO₆ (NaO₆) octahedra. Both compounds crystallize in the space group P6₃/mmc, Z=2, with a=5.7804(4) and c=14.302(1) and a=5.866(4) and c=14.596(1) for the Li and Na member, respectively. The structure of Ba_3.44K_1.56Ir₂O₁₀ is derived from the stacking of [AO₃] and mixed [A₂O] layers, and is an n=3 member of the [A_nM_n−1O_3n][A₂O] family of hexagonal perovskite related oxides. The structure of Ba_3.44K_1.56Ir₂O₁₀ consists of (Ba₃Ir₂O₉) slabs separated by [(Ba,K)₂O] layers and is isostructural with Ba₅Ru₂O₁₀. The (Ba₃Ir₂O₉) slabs contain isolated, face-sharing Ir₂O₉ octahedra pairs. The compound crystallizes in the space group P6₃/mmc, Z=2, with a=5.91330(1) Å and c=18.1792(7) Å. The magnetic moments determined from the temperature dependence of the magnetic susceptibility are low for all three oxides, which is thought to be due to a combination of spin–orbit coupling and strong exchange interactions within the iridium octahedra pairs.     

Ein neuer Bautyp der Oxohalogenoferrate: Ba3 Fe2 O5 Cl2 und Ba3 Fe2 O5 Br2

New Structure Type of the Two Oxohalogenoferrites: Ba₃Fe₂O₅Cl₂ and Ba₃Fe₂O₅Br₂ The hitherto unknown compounds Ba₃Fe₂O₅Cl₂ (A) and Ba₃Fe₂O₅Br₂ (B) are pre-pared and examined by single crystal techniques. (A) and (B) crystallizes in the cubic space group I2₁ 3-T⁵; (A) a = 9.9705(3) and (B) a = 10.0039(8) Å, Z = 4. The new structure consists of 10 corner-shared tetrahedra which are connected to a two-dimensional ring system. The differences to the previously investigated compound Sr₃Fe₂O₅Cl₂ are discussed.     

Zur Atomverteilung in Ba2SrIn2O6 mit einem Beitrag zur Existenz des Calciumferrat(III)-Typs bei Oxoindaten

On the Atomic Distribution in Ba₂SrIn₂O₆ with a Contribution to the Existence of the Calciumferrite-Type of Oxoindates (I) Ba₂SrIn₂O₆ and (II) Sr_0.93Ba_0.07In₂O₄ were prepared and investigated by single crystal X-ray technique. I crystallizes with tetragonal symmetry, space group D – I4/mmm, a = 4.168; c = 21.290 Å; Z = 2; II belongs to the orthorhombic space group D – Pnma, a = 9.858; b = 3.273; c = 11.520 Å; Z = 4. I shows in respect to the formerly investigated compound BaSr₂In₂O₆ an unexpected statistically distribution of Ba²⁺ and Sr²⁺ with the La₂SrCu₂O₆ type. II marks the range of existence of the calciumferrite type within the alkaline earth oxoindates in direction of large radii of M²⁺ ions.     

Synthese und Struktur von Ba10[Ti4N12], ein ternäres Nitrid mit vierkernigen cyclischen Nitridotitanat-Ionen

Synthesis and Structure of Ba₁₀[Ti₄N₁₂], a Ternary Nitride with Tetranuclear Cyclic Nitridotitanate Ions Ba₁₀[Ti₄N₁₂] results from the reaction of Ba₃N₂, TiN, and N₂ at 980°C. It crystallizes in the triclinic space group P1 with the lattice parameters a = 644.3(4); b = 942.9(7); c = 966.9(7) pm, α = 106.37(4)°; β = 102.22(4)°; γ = 108.56(4)°, Z = 1. The crystal structure is built up by Ba²⁺ cations and tetranuclear cyclic nitridotitanate(IV) anions. In the anions four TiN₄ tetrahedra are each connected by two corners to form centrosymmetrical rings, which are stacked along [100] forming tubes. The Ti? N distances range from 192 to 199 pm.     

Ba2BiV3O11 mit Bismut in geschlossener Koordination

Ba₂BiV₃O₁₁ containing Bismuth within closed Coordination A new barium bismuth oxovanadate, Ba₂BiV₃O₁₁, was prepared and investigated by X-Ray single crystal technique. It crystallizes with monoclinic symmetry space group C—P2₁/a, lattice constants a = 24.6473; b = 7.7347; c = 5.6375 Å, β = 103.16°; Z = 4. Octahedra arround Bi³⁺, tetrahedra and double tetrahedra arround V⁵⁺ form a tunnel structure. The tunnel positions are occupied by Ba(2).     

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.     

Über ein neues Oxoiridat(IV): Ba7Ir6O19

Summary The so far unknown compound Ba₇Ir₆O₁₉ was prepared by long time solid state reactions using a flux of BaCl₂. X-ray single crystal work lead to the space group C _2h ³ —C2/m;a=14.913;b=5.778;c=10.979 Å; =99.58°;Z=2. It crystallizes with a new structure type characterized by three face-shared octahedra. The Ir₃O₁₂-groups build up a threedimensional network with an incorporated Ba/O-frame.

     

Zur Kenntnis von Ba4MgTa10O30 und Ba4NiTa10O30. Verbindungen mit Verwandtschaft zur tetragonalen Wolframbronze und zum NaNb6O15F-Typ

About Ba₄MgTa₁₀O₃₀ and Ba₄NiTa₁₀O₃₀. Compounds with Relations to the Tetragonal Tungsten Bronze and the NaNb₆O₁₅F-Type (I) Ba₄MgTa₁₀O₃₀ and (II) Ba₄NiTa₁₀O₃₀ single crystals are prepared and investigated by X-ray technique (space group C-Amm2, (I): a = 3.90, b = 10.22, c = 14.97 Å, (II): a = 3.91, b = 10.21, c = 14.96 Å; Z = 1), (I) and (II) are isotypic to Ba₄CoTa₁₀O₃₀. The relations to other [M₁₀O₃₀]-framework tunnelstructures are discussed.     

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).     

Über das Oxoindat Ba4In2O7

On the Oxoindate Ba₄In₂O₇ Ba₄In₂O₇ was prepared for the first time by solid state reaction and investigated by X-ray methods. (Space group D_4h¹⁷–14/mmm, a = 4.175; c = 29.483 Å; Z = 2). It shows a close crystal chemical relationship to Ba₃In₂O₆ and La₂SrCu₂O₆. One of the oxygen point positions is occupied only by a half. This fact alleviates the understanding of the layer structure of Ba₄In₂O₇. The compound is compared with Sr₄Tl₂O₇ and a further discussion in respect to Ba₅In₂O₈ shows the probable identity of Ba₅In₂O₈ with Ba₄In₂O₇.     

Mononuclear Thiolatecobalt Carbonyls

A Partial Statistically Incorporation of Ca²⁺ into the Ba₆Nd₂Al₄O₁₅-Type: Ba₅CaLa₂Fe₄O₁₅ Using high temperature reactions we succeeded in incorporating Ca²⁺ into the Ba₆Nd₂Al₄O₁₅ type. Single crystal X-ray methods reveal a partly ordered alkaline earth distribution. Ba²⁺ and Ca²⁺ occupy face connected MO₆-octahedra as well as a further point position together with La³⁺ ions (space group C−P6₃mc; a = 11.770; c = 7.039 Å; Z = 2).     

Synthese und Kristallstruktur von Ba4,5Ca1,5La2Fe4O15, Ba5CaEu2Fe4O15 und Ba5CaNd2Co4O15

Synthesis and Crystal Structure of Ba_4.5Ca_1.5La₂Fe₄O₁₅, Ba₅CaEu₂Fe₄O₁₅ and Ba₅CaNd₂Co₄O₁₅ The compounds (I) Ba_4.5Ca_1.5La₂Fe₄O₁₅, (II) Ba₅CaEu₂Fe₄O₁₅ and (III) Ba₅CaNd₂Co₄O₁₅ were prepared and investigated by single crystal X-Ray technique. They belong to the Ba₆Nd₂Al₄O₁₅ typ, space group C? P6₃mc, (I): a = 11.677, c = 6.959 Å; (II): a = 11.570, c = 6.892 Å; (III): a = 11.604, c = 6.839 Å, Z = 2. The crystal chemistry of these substances will be discussed.