Die Kristallstruktur von Perowskiten ANiIIMVIO6. II. Das Sr2NiWO6

The Crystal Structure of Perovskites A Ni^IIM^VIO₆. II. Sr₂NiWO₆ The results of an X-ray single crystal study of the perovskite Sr[Ni^IIW^VI]⁽⁶⁾O₆, ordered in the octahedral sites, are given. While Sr[Ni^IITe^VI]⁽⁶⁾O₆ crystallizes in a monoclinically deformed structure of the perovskite (elpasolite) type, showing a phase transition to a tetragonal lattice at 675 °K, Sr[Ni^IIW^VI]⁽⁶⁾O₆ is tetragonal already at 298°K (space group: C; a = b = 5.559 Å; c = 7.918 Å; Z = 2). The Ni? O distances found for the tungsten compound are nearly identical with those of the tellurium perovskite. In contradiction to crystal field theory very different values of the ligand field parameter Δ (ca. 25%) are observed for these two compounds however. Obviously this effect is caused by the rather different kind of bonding within the NiO₆ polyhedra in the two compounds. On the basis of the structural results the Ni? O-bonding in the two perovskites is discussed in dependence of the next nearest cationic environment.     

Isolierte quadratische Koordination von Pt2+ in BaNd2PtO5

Isolated Square-Planar Coordinated Pt²⁺ Inside of BaNd₂PtO₅ Single crystals of the hitherto unknown compound BaNd₂PtO₅ were prepared and examined by X-ray technique. The compound crystallizes with tetragonal symmetry D? P4 b2; a = 6.7569(6) and c = 5.9119(13) Å; Z = 2. The structure is discussed in respect of the isolated square-planare coordination of Pt²⁺ ions and its relation with other planar coordinated platinum of oxocompounds.     

Synthese und Kristallstruktur von [N(Hex)4][Cu2(CN)3]

Synthesis and Crystal Structure of [N(Hex)₄] [Cu₂(CN)₃] [N(Hex)₄][Cu₂(CN)₃] has been prepared by solvothermal reaction of CuCN with Tetra‐n‐hexylammoniumiodide in acetone. The crystal structure is built up by condensed (CuCN)₆ and (CuCN)₇ rings, forming a zeolith type cyanocuprate(I) framework [Cu₂(CN)₃^—]. Space group R3; α = 44.482(6), c = 21.283(4) Å, V = 36471(9) ų; Z = 9.     

Über Geordnete Perowskite mit Kationenfehlstellen. IX. Verbindungen vom Typ Sr2Sr1/4B□1/4WO6≙Sr8SrB□W4O24 (BIII  La,Pr, Nd,Sm – Tm,Y)

On Ordered Perovskites with Cationic Vacancies. IX. Compounds of the Type Sr₂Sr_1/4B □_1/4WO₆?Sr₈SrB ?W₄O₂₄ (B^III ? La, Pr, Nd, Sm–Tm, Y) The compounds Sr₂Sr_1/4B□_1/4WO₆?Sr₈SrB?W₄O₂₄ belong to the group of perovskites with octahedral cationic vacancies (cation/vacancy ratio (CN 6) ?:1). For the larger B^III ions (La, Pr, Nd, Sm–Dy) different ordering effects are observed. The perovskites with B^III ? Sm, Eu, Gd are polymorphic too (HT modification: higher ordered cubic perovskite (B^III ? Gd: a = 2X8.23₄ Å); LT modification: hexagonal perovskite stacking polytype (B^III ? Gd: a = 9.95₄ Å; c = 19.0₄ Å)). With the smaller B^III ions (Ho, Er, Tm and Y) a cubic, 1:1 ordered perovskite type is observed.     

Das erste Alkali-Erdalkali-Oxocuprat(II,III): NaBa2Cu22+Cu3+O6

The first Alkaline Alkaline-Earth Oxocuprate (II, III): NaBa₂Cu₂²⁺Cu³⁺O₆ The compound NaBa₂Cu₃O₆ was prepared by heating of Na₂O₂, BaO₂, Cu₂O in closed Ag-tubes. X-ray single crystal investigations led to orthorhombic symmetry, space group D-Fmmm; a = 8.4229; b = 11.4418; c = 14.4063 Å; Z = 8. Cu²⁺ and Cu³⁺ show square planar polygones of four and Na⁺ trigonal prisms of six O^2?. The two barium point positions show coordination numbers C.N. = 8 and 6 + 4. The crystal structure is discussed.     

Zur Kenntnis von Ca3IrCuO6

On Ca₃IrCuO₆ Single crystals of Ca₃IrCuO₆ were prepared by a flux technique and investigated by single crystal X-ray work. It crystallizes with monoclinic symmetry, space group C—C12/c1; a = 9.032, b = 9.295, c = 6.466 Å, β = 91.35°, Z = 4. Ca₃IrCuO₆ is isotypic to Sr₃IrCuO₆. The square planare CuO₄ polygones show probably a slightly deficit accompanied by an adequate part of iridium in the oxydation state Ir⁵⁺.     

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.     

Ein neuer Strukturtyp beim ersten Erdalkalimetall-Oxoiridat-Cuprat: Sr3IrCuO6

A New Structure Type on the first Alkaline-Earth-Iridium-Copper Oxide: Sr₃IrCuO₆ Sr₃IrCuO₆ was prepared by solid state reactions and investigated by single crystal X-ray work (space group C – C12/c1; a = 9.300; b = 9.717; c = 6.997 Å; β = 92.15°). The so far unknown compound forms a new structure type. Typical features of the crystal structure are isolated chains of alternate IrO₆ octahedra and square planar CuO₄ polygones. The coordination of Sr₂₊ can be described as a square antiprism.     

Control of Oxidation States of Transition Elements (Cr,Mn) in Nitridometalates and the Solid Solution Series Li6(Ca1‐xSrx)2[Mn2N6]

The formation of ternary nitridometalates from the elements in the case of the systems Li—Cr, V, Mn—N leads to compounds which contain the transition metals in the highest (V^V, Cr^VI) or a comparably high (Mn^V) oxidation state. In the corresponding calcium and strontium systems, the transition metals show a lower oxidation state (V^III, Cr^III, Mn^III). Transition metals with intermediate oxidation states (Cr^V, Mn^IV) are present in the quaternary (mixed cation) compounds Li₄Sr₂[CrN₆], Li₆Ca₂[MnN₆], and Li₆Sr₂[MnN₆] (R3¯(#148), a = 585.9(3) pm, c = 1908.6(4) pm, Z = 3), as well as in the solid solution series Li₆(Ca_1—xSr_x)₂[MnN₆].     

Die Kristallstrukturen der hexagonalen Elpasolithe Ba3NiSb2O9 und Ba3CuSb2O9 – röntgenographische und spektroskopische Ergebnisse

The Structures of the Hexagonal Elpasolite-Type Compounds Ba₃NiSb₂O₉ and Ba₃CuSb₂O₉ The results of an X-ray single crystal study of the hexagonal elpasolite Ba(NiSb₂)⁽⁶⁾O₉ are given. (Space group: C; a = b = 5.837 Å, c = 14.392 Å; Z = 2). The structure can be described by close-packed BaO₃ layers alternating in the sequence c c h c c h … (hex. BaTiO₃ type). Groups of two octahedra with common faces are connected by SbO₆ octahedra via common corners. They are occupied alternately by Ni and Sb. The final reliability index was R = 3.0%. The Cu²⁺-compound is of the same structural type. The ligand field and EPR spectra are discussed in comparison with related Ni²⁺ and Cu²⁺ compounds.     

Ein neues Gemischtvalentes Oxoniobat: Sr7Nb24+Nb45+O21 \documentclass{article}\pagestyle{empty}\begin{document}$ \widehat = $\end{document} Sr1,167 NbO3,5

A New Mixed Valence Strontium Niobium Oxide Sr₇Nb₂⁴⁺Nb₄⁵⁺O₂₁ \documentclass{article}\pagestyle{empty}\begin{document}$ \widehat = $\end{document} Sr_1.167NbO_3.5 The unknown compound Sr₇Nb₆O₂₁ kristallisiert nach Einkristall-Röntgenbeugungsdaten rhomboedrisch (Raumgruppe C? R3 ; a = 16,450(5) Å, α = 19,85(1)° trigonale Aufstellung: a = 5,670(1), c = 48,364(13) Å). The compound is built up by perovskite blocks with a width of 6 octahedra. The crystal chemistry especially of the interspace between those blocks is discussed in respect to related compounds.     

Zur Kenntnis der Oxoplatinate Na2PtO2, Na2PtO3, „K2PtO3”︁ und „Rb2PtO3”︁

The oxoplatinates Na₂PtO₂, Na₂PtO₃, ?K₂PtO₃”? and ?Rb₂PtO₃”?. Hitherto unknown Na₂PtO₂ (greyish black) was prepared. Na₂PtO₂ (orthorhombic, D—Immm; a = 4.58₅, b = 3.11₉, c = 9.58₈ Å) is isotypic with Li₂CuO₂. α-Na₂PtO₃ (darkyellow; red as single-crystals) is monoclinic, C—C2/c (a = 5.41₉, b = 9.38₅, c = 10.75₂ Å, β = 99.67°), Li₂SnO₃-type. According to 3-dimensional single crystal data hitherto unknown β-Na₂PtO₃ (red crystals) is an orthorhombic variant of the Li₂SnO₃-type (a = 18.83₈, b = 6.28₂, c = 9.06₂ Å, Z = 16, D—Fddd; parameters see text); R = 0.080₉, R' = 0.094₈ [256 reflexes (hk0—hk6)]. The Madelung part of the lattice energy (MAPLE) is calculated and discussed for α-, β-Na₂PtO₃, α- and β-PtO₂. For the first time we got K₂PtO₃ and Rb₂PtO₃.     

Darstellung und Kristallstruktur von Cu2SrSnS4

Preparation and Crystal Structure of Cu₂SrSnS₄ Cu₂SrSnS₄ was prepared from a mixture of the three binary sulfides at 620-700° C. The structure analyses by single crystal X-ray investigations yields a trigonal C-symmetrie for the unit of the structure with a = 6.29₀ and c = 15.57₈ Å and three formula units. Space group: C–P3₁ (No. 144). Copper and tin have tetrahedral surrounding of S^2?. The neighbourhood of Sr²⁺ has the shape of a deformed archimedic antiprisma.     

Kristallstruktur und Eigenschaften von Calcium- und Strontiumhexathiodiphosphat(IV), Ca2P2S6 und Sr2P2S6, mit einem Beitrag zu Ca5P8 und Pb2P2S6

Crystal Structure and Properties of Calcium and Strontium Hexathiodiphosphate(IV), Ca₂P₂S₆ and Sr₂P₂S₆, with a Contribution on Ca₅P₈ and Pb₂P₂S₆ Ca₂P₂S₆ and Sr₂P₂S₆ were prepared from metal and a mixture of red phosphorus and sulfur (molar ratio M:P:S = 1:1:3) in 2 corundum crucibles inserted in quartz ampullae under vacuum (20 d 900°C). The compounds were obtained as colourless, crystalline powders containing single crystals. They crystallize in the Sn₂P₂S₆ (high temperature form) type structure (P2₁/c, Z = 2): Ca₂P₂S₆ a = 653.2(2)pm, b = 728.1(2)pm, c = 1110.1(4)pm, β = 124.00(4)°, d = 2.50(2); Sr₂P₂S₆ a = 664.3(2)pm, b = 755.7(3)pm, c = 1139.7(3)pm, β = 124.07(2)°, d = 2.97(2). The anions P₂S have staggered confirmation and are arranged with the motif of a cubic close-packing. Sr²⁺ is coordinated by 8S which form a twofold face-capped trigonal prism and belong to 4P₂S. Structure calculations clearly show that Pb₂P₂S₆ also crystallizes in P2₁/c and not in Pc [1]. Also, Raman- and IR-spectra of Ca₅P₈ were recorded at 20°C. The stretching vibrations of P were assigned in analogy to those of P₂S in alkaline earth hexathiodiphosphates(IV). The range of their frequencies (480 to 340 cm^?1) is essentially smaller and shifted to smaller values compared with P₂S in Ca₂P₂S₆ and Sr₂P₂S₆ (620 to 390 cm^?1). The symmetry of P is not D_3d but C_2h as in the case of P₂S.     

Ein neues Alkali-Erdalkalimetall-Kupfer-Oxovanadat: Kba3Ca4Cu3V7O28

A new Alkaline-Alkaline-Earth-Copper-Oxovanadate: Kba₃Ca₄Cu₃V₇O₂₈ . Single crystals of Kba₃Ca₄Cu₃V₇O₂₈ were prepared by solid state reactions below the melting point of the reaction mixture. It crystallizes with hexagonal symmetry, space group C?P6₃mc, a=11.160, c=12.428 Å, Z=2. Kba₃Ca₄Cu₃V₇O₂₈ represents a new structure type with special coordination polyhedra around Ba²⁺, trigonal prisms and octahedra around Ca²⁺ and Cu²⁺ inside square pyramids. The crystal structure will be shown and discussed.     

Zur Verbindungsbildung von MeO: M2O3. Ein neuer Bautyp: SrCa2Sc6O12

The Reaction of MeO:M₂O₃. A New Structure Type: SrCa₂Sc₆O₁₂ The compound Sr_0.33Ca_0.67Sc₂O₄ shows a hitherto unknown hexagonal crystal structure (a = 9.659, c = 3.136 Å; Space group C?P6₃/m). A detailed discussion of the coordination polyhedrals and the similarity to CaSc₂O₄ are given.     

Synthese und Kristallstruktur der molekularen Clusterverbindung W6Br14

Synthesis and Crystal Structure of the Molecular Cluster Compound W₆Br₁₄ Brownish-black crystals of W₆Br₁₄ are formed in the direct synthesis from W₆Br₁₂ and Br₂ (400 K). The compound crystallizes cubically with neutral cluster molecules ([W₆Br]Br): a = 13.458 Å; Pn3 (Nr. 201); d?(W? W) = 2.653 Å; d?(W? Brⁱ) = 2.616 Å; d?(W? Br^a) = 2.569 Å. The W atoms are 0.03 Å outside of the Br cube faces. The molecules are arranged according to a cF point configuration, but each is rotated ?23° about a threefold axis in order to avoid short inter cluster distances Br^a? Br^a. Nevertheless, via 12 short intermolecular distances per cluster of about d(Brⁱ …? Br^a) = 3.487 Å the clusters are interconnected by forming two independent and interpenetrating 3D nets (Cu₂O type). Although local distortion of the M₆X cluster does not occur, as is expected for this system with 22 electrons per M₆ octahedron, it is assumed that the Jahn-Teller theorem is fulfilled collectively via the low-symmetry nets of intermolecular interactions.     

Zur Kenntnis von Ba6Ru2PtO12Cl2

About Ba₆Ru₂PtO₁₂Cl₂ Single crystals of Ba₆Ru₂PtO₁₂Cl₁₂ were prepared by a BaCl₂ flux and investigated by X-ray methods (D? P3 M1; a = 5,805; c = 15.006 Å; Z = 1). The characteristic face shared M₃O₁₂-octahedratriples show an ordered (Ru/Pt/Ru) occupation. Calculation of the Coulomb term of lattice energy support the charge distribution (5⁺/4⁺/5⁺) ions engage three point sites with different coordinations. The connection to other compounds are discussed.     

Zur Kristallstruktur von Cu3NbTaO8

On the Crystal Structure of Cu₃NbTaO₈ Single crystals of Cu₃NbTaO₈ were prepared by solid state reaction. X-ray investigations led to triclinic symmetry, space group C? P1 with a = 5.179; b = 5.474; c = 6.003 Å; α = 72.85°; β = 83.39°; γ = 65.77°; Z = 1. Nb⁵⁺ and Ta⁵⁺ occupy one point position statistically. Both ions show an octahedral oxygen surrounding. Cu(1) is inside an elongated CuO₆ octahedra and Cu(2) is coordinated by 5 O^2? forming a distorted square pyramid. The polyhedra connection is shown and discussed.     

Über ternäre Oxocuprate. X. Zur Kenntnis von Ba2Cu3O4Cl2

About Ternary Oxocuprates. X. On Ba₂Cu₃O₄Cl₂ The preparation of Ba₂Cu₃O₄Cl₂ and results by single crystal X-ray methods are described (a = 5.517, c = 13.808 Å; Space group D–I4/mmm). A so far unknown arrangement of square coordinated Cu²⁺ was detected. The Cu²⁺/O^2?-squares are partly completed to a distorted octahedral coordination by two Cl^?.