Das Zintl-Konzept als Syntheseprinzip: Darstellung und Kristallstrukturen von K2Ba3Sb4 und KBa4Sb3O

Starting from the Zintl-Concept: Syntheses and Crystal Structures of K₂Ba₃Sb₄ and KBa₄Sb₃O The black, metallic lustrous, air sensitive compounds K₂Ba₃Sb₄ and KBa₄Sb₃O were prepared from melts of mixtures of the elements, in case of KBa₄Sb₃O with a stoichiometric amount of Sb₂O₃. K₂Ba₃Sb₄ crystallizes in the orthorhombic system, space group Pnma (a = 870.5(1) pm, b = 1770.2(2) pm, c = 923.6(1) pm, Z = 4) and is the first Sb compound with only [Sb₂]^4– dumbbells in the anionic partial structure. The compound KBa₄Sb₃O crystallizes in the tetragonal system, space group I4/mcm (a = 882.4(1) pm, c = 1659.4(2) pm, Z = 4). In this structure antimony forms [Sb₂]^4–-dumbbells and isolated ions Sb^3–. Each antimony ion of the dumbbells – in K₂Ba₃Sb₄ as well as in KBa₄Sb₃O – is coordinated in form of a bicapped skew trigonal prism. The isolated Sb^3– ions in KBa₄Sb₃O center bicapped tetragonal antiprisms, the O^2– ions occupy tetrahedral voids.     

Effect of metal substitution for cobalt on the oxygen adsorption properties of YBaCo<Subscript>4</Subscript>O<Subscript>7</Subscript>

YBaCo₄O₇ compound is capable to intake and release a large amount of oxygen in the temperature range of 200–400°C. In the present study, the effect of Zn, Ga and Fe substitution for Co on the oxygen adsorption/desorption properties of YBaCo₄O₇ were investigated by thermogravimetry (TG) method. Due to fixed oxidation state of Zn2+ ions, the substitution of Zn²⁺ for Co²⁺ suppresses the oxygen adsorption of YBaCo_4−xZn_xO₇. The substitution of Ga³⁺ for Co³⁺ also decreases the oxygen absorption capacity of YBaCo_4−xGa_xO₇. This can be explained by the strong affinity of Ga³⁺ ions towards the GaO₄ tetrahedron. Compared with Zn- and Ga-substituted samples, the drop of oxygen adsorption capacity is smallest for Fe-substituted samples because of the similar changeability of oxidation states of Co and Fe ions.     

Neue Oxogallate der Alkalimetalle: Über K6[Ga2O6] und Rb6[Ga2O6], sowie Na3GaO3 und Cs6[Ga2O6]

New Oxogallates of Alkaline Metals: On K₆[Ga₂O₆] and Rb₆[Ga₂O₆] as well as Na₃GaO₃ and Cs₆[Ga₂O₆] Due to powder and single crystal data K₆[Ga₂O₆] a = 7.09₉; b = 11.11₆; c = 6.48₄ Å; ß = 101.6₆° and Rb₆[Ga₂O₆] a = 7.39₃; b = 11.47₅; c = 6.79₈ Å; ß = 103.5° crystallize isotypic with K₆[Fe₂O₆]; space group C2/m-C₃^2h; As well has been prepared the hitherto unknown Na₃GaO₃ a = 11.48, b = 10.82, c = 6.13 Å, space-group Imcm or I2cm Z = 8; and Cs₆[Ga₂O₆] a = 7.2₆, b = 12.1, c = 7.6₈ Å, ß = 105°, Z = 4, space-group P2₁/a.     

Zur Kenntnis von Zn4Ta2O9

About the New Compound Zn₄Ta₂O₉ The hitherto unknown compound Zn₄Ta₂O₉was prepared by high temperature reaction (CO₂-LASER technique). The X-ray investigation of single crystal shows monoclinic symmetry (space group C? C2/c) with a = 15.002(6), b = 8.954(1), c = 10.345(4)Å and β = 93.64(3)°. Zn₄Ta₂O₉ consists of a Zn/O-network with incorporated one-dimensional TaO₆-chains. The edge connected TaO₆-octahedrals are occupied by Ta⁵⁺ and 0.5 Zn²⁺ respectively. The crystal chemistry of this compound in respect to other Zn-oxotantalates are discussed.     

Composition-induced phase transition in Ca14Zn6−xGa10+xO35+x/2 (x=0.0 and 0.5)

Novel complex oxides Ca₁₄Zn₆Ga₁₀O₃₅ and Ca₁₄Zn_5.5Ga_10.5O_35.25 were prepared in air at 1200 °C, 72 h. Refinements of their crystal structures using X-ray powder diffraction data showed that Ca₁₄Zn₆Ga₁₀O₃₅ is ordered (S.G. F23, =0.0458, R_p=0.0485, R_wp=0.0659, χ²=1.88) and Ca₁₄Zn_5.5Ga_10.5O_35.25 disordered (S.G. F432, =0.0346, R_p=0.0601, R_wp=0.0794, χ²=2.82) variants of the crystal structure of Ca₁₄Zn₆Al₁₀O₃₅. In the crystal structure of Ca₁₄Zn₆Ga₁₀O₃₅, there are large empty voids, which could be partially occupied by additional oxygen atoms upon substitution of Zn²⁺ by Ga³⁺ as in Ca₁₄Zn_5.5Ga_10.5O_35.25. These oxygen atoms are introduced into the crystal structure of Ca₁₄Zn_5.5Ga_10.5O_35.25 only as a part of four tetrahedra (Zn, Ga)O₄ groups sharing common vertex. This creates a situation where even a minor change in the chemical composition leads to considerable anion and cation disordering resulting in a change of space group from F23 (no. 196) to F432 (no. 209).     

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.     

K2Zn3O4 und Rb2Zn3O4, zwei neue Oxozincate mit Gerüststruktur [1]

K₂Zn₃O₄ and Rb₂Zn₃O₄, Oxozincates with Framework Structure For the first time single crystals of K₂Zn₃O₄ were obtained by heating mixtures of the binary oxides (K: Zn = 2.2:3) in sealed Ag- or Pt-capsules at 800°C (5 w). Powder of this colourless and moisture-sensitive oxide was prepared analogously at 500°C. It crystallizes monoclinic, space group C2/c with a = 1482.7(2), b = 637.3(1), c = 571,9(1) pm, β = 102.79(1)°, Z = 4, d_x = 4.265 g/cm³, d_pyk = 4.00 g/cm³. The crystal structure was determined from four-circle diffractometer data (MoKα, 730 unique hkl) and refined to R = 5.9%, R_w = 6.4%. It shows a Zn₃O₄ framework which consists of SiS₂-like chains [ZnO_4/2] connected by puckered layers of [ZnO_3/3]. The crystal structure can be derived from a cubic closet packing of O^2? and K⁺. Effective Coordination Numbers and the Madelung Part of Lattice Energy (MAPLE) are calculated. Rb₂Zn₃O₄ was prepared from the binary oxides at 400°C (colourless hygroscopic powder). According to powder data it crystallizes isostructural to K₂Zn₃O₄ with a = 1523.5(4), b = 649.8(2), c = 574.0(2) pm, β = 101.43(3)°, Z = 4, d_x = 5.141 g/cm³, d_pyk = 5.20 g/cm³.     

Na10Zn4O9 – ein neues Oxozinkat mit trigonal-planar koordiniertem Zink

Na₁₀Zn₄O₉, a Novel Oxozincate with Trigonal Planar Coordinated Zinc Using a new preparation method for sodium oxometallates we have succeeded in the synthesis of the new ternary oxide Na₁₀Zn₄O₉. Active ZnO reacted with Na₂O generated in situ from NaN₃ and NaNO₂. The compound consists of ZnO₄ tetrahedra which are connected via edges and corners to form layers of the composition ZnO₂. Furthermore, the structure was found to contain isolated, trigonal planar ZnO₃ units. 21 of 60 Na⁺ ions within the unit cell are disordered. Na₁₀Zn₄O₉ crystallizes in the space group R3 m (Nr. 166). The lattice constants are: a = 10.815(3), c = 17.930(7) Å; Z = 6; 8056 reflections; R = 0.062. The sodium ion conductivity at 400°C is 6 × 10^?3 Ω^?1 cm^?1.     

Experimente zur Mischkristallbildung zwischen Zinktantalaten und -antimonaten: ZnTa2−xSbxO6 und Zn4Ta2−xSbxO9

Experiments about the Mixed Crystal Formation between Zincoxotantalates and -antimonates: ZnTa_2?xSb_xO₆ and Zn₄Ta_2?xSb_xO₉ In the area of substituted oxotantalates of zinc two new phases of the composition A: ZnTa_1·8Sb_0·2O₆ and B: Zn₄Ta_1·2Sb_0·8O₉ were prepared and investigated by X-ray single crystal technique. A crystallizes with tetragonal symmetry (space group D–P4₂/mnm, a = 4.7314; c = 9.2160 Å; Z = 2). B is monoclinic (space group C–C2/c; a = 15.103; b = 8.839; c = 10.378 Å; β = 93.81°; Z = 8). A crystallizes with trirutile structure, although there is a small replacement of Ta⁵⁺ by Sb⁵⁺. B maintains the Zn₄Ta₂O₉ structure. One of the point positions of the M⁵⁺ ions is occupied statistically by Ta⁵⁺/Sb⁵⁺ and Zn²⁺. B is a metastable compound.     

Zur Kristallchemie von Ba3In2Zn5O11. Ein tOxoindat/zinkatsol;zinkat mit Zn10O20- und In4O16-Makropolyedern und erstmals O2− in tetraedrischer Koordination durch Zn2+

On the Crystal Structure of Ba₃In₂Zn₅O₁₁. An Oxoindate/zincatesol;zincate with Zn₁₀O₂₀ and In₄O₁₆ Macropolyhedra with Zn²⁺ in Tetrahedral Coordination by O^2? Ba₃In₂Zn₅O₁₁ was prepared for the first time by a flux technique and investigated by single crystal X-ray work. It crystallizes with cubic symmetry, space group T-F4 3m, a = 13.3588 Å, Z = 8. Zn²⁺ show tetrahedral coordination by O^2?, forming Zn₁₀O₂₀ macropolyhedra. In addition the nZn/Osol;O part of the crystal structure is made up of Zn₁₀O₂₀ parts. Edge connection of four InO₆ octahedra results in In₄O₁₆ groups. The crystal structure will be shown and discussed.     

Über Oxocadmate: K2Cd2O3

New obtained is K₂Cd₂O₃ (brownish red), which – according to single crystal work [487 h 01–h 41, Mo? Kα, R = 9.7₃%, R′ = 10.7₆%] – crystallises monoclinic with a = 6.41₇, b = 6.72₃, c = 6.58₆ Å, β = 116.0° in P2₁/c–C [K⁺, Cd²⁺ and O(1)^2? in 4(e), O(2)^2? in 2(a)] and is isotypic with Na₂Zn₂O₃. [Parameters see text]. The Madelung Part of Lattice Energy is calculated and discussed.     

Refinement of the Superstructure of C-Type Gallium Tris(metaphosphate), Ga(PO3)3

Single crystals of Ga(PO₃)₃ were grown in polyphosphoric acid melts by heating a mixture of Ga₂O₃ and H₃PO₄ (350 °C, 7 d). The compound belongs to the series of metaphosphates M^III(PO₃)₃ forming the C-type structure (monclinic, Cc, Z = 12, a = 13.0058(21), b = 18.915(3), c = 9.3105(15) Å, β = 126.900(11), 5348 independent reflections (I > 0); 354 variables; 39 atoms in asymetric unit; R1 = 0.048, wR2 = 0.1034). The structure is characterized by a superstructure with tripled monoclinic b-axis. Three crystallographically independent Ga^IIIO₆ octahedra (d¯(Ga–O) = 1.950 Å) are linked by ¹_∞(PO₃)^– chains.     

Eine weitere Oxovanadat-Phase mit Granatstruktur: Ca5Mg3ZnV6O24

An Additional Oxovanadate Phase with Garnet Structure: Ca₅Mg₃ZnV₆O₂₄ Single crystals of Ca₅Mg₃ZnV₆O₂₄ were prepared by solid state reactions some degree below the melting point of the reaction mixture. It crystallizes with cubic symmetry, space group T-I4 3 d with a = 12.429 Å, Z = 4. The crystal structure is nearly related to the Garnet structure showing Ca²⁺ within distorted cubes (C.N. = 8) of O^2? on a partly unfilled position. the octahedra position are occupied by Mg²⁺ and Zn²⁺ statistically.     

Synthese und Kristallstruktur von Ba6Lu4Zn10O22 mit [OBa6]-Oktaedern

On the Synthesis and Crystal Structure of Ba₆Lu₄Zn₁₀O₂₂ with [OBa₆] Octahedra Single crystals of Ba₆Lu₄Zn₁₀O₂₂ have been prepared by high temperature reactions and investigated by X-ray techniques. This compound is isotypic to Ba₃In₂Zn₅O₁₁ and the first member of the Rare Earth elements. Ba₆Lu₄Zn₁₀O₂₂ crystallizes with cubic symmetry, space group T-F4 3m, a = 13.452(1) Å and Z = 4. Zn²⁺ shows a tetrahedral, Lu³⁺ an octahedral and Ba²⁺ a three-fold capped trigonal prismatic coordination by O^2?. The ZnO₄ tetrahedra and LuO₆ octahedra are forming macro polyhedra of the type Zn₁₀O₂₀ and Lu₄O₁₆. A discussion is given for the Ba₆O₃₃ and Ba₆O₄₂ groups.     

Synthesis and luminescent properties of a new blue light-emitting phosphor KBa<Subscript>2−<Emphasis Type="Italic">x</Emphasis></Subscript>Tm<Subscript><Emphasis Type="Italic">x</Emphasis></Subscript>P<Subscript>5</Subscript>O<Subscript>15</Subscript>

A new blue phosphor KBa_2?xTm _x P₅O₁₅ for white light-emitting diodes (W-LEDs) was prepared by the high-temperature solid-state synthesis method. Its structure, morphology, elementary composition, and luminescent properties were investigated. The phosphor KBa_1.96Tm_0.04P₅O₁₅ exhibits an irregular morphology with a diameter of about 10 μm. The emission spectra consisted of two emission peaks centered at 451 and 477 nm due to the ¹D₂ → ³F₄ and ¹G₄ → ³H₆ transitions of Tm³⁺ activator, respectively. The optimum dopant concentration of Tm³⁺ activator in KBa₂P₅O₁₅ host matrix is about 4 mol%. The critical distance is calculated to be 25 Å, and the concentration quenching mechanism of Tm³⁺ ions in KBa₂P₅O₁₅ was confirmed to be d–q interaction. The CIE coordinates of KBa_1.96Tm_0.04P₅O₁₅ phosphor was calculated to be (0.1503, 0.0542), corresponding to blue color with a high color purity of about 92%. Hence, we may expect that the obtained phosphor KBa_2?xTm _x P₅O₁₅ would be potentially used as a blue phosphor for W-LEDs.     

Untersuchungen an elektronenleitenden Oxidsystemen. XXI. Stabile spinelle ZnzNiMn2−zO4 und Vergleich mit Spinellen MgzNiMn2−zO4

Investigations on Electronically Conducting Oxide Systems. XXI [1] Stable Spinels Zn_zNiMn_2?zO₄ and Comparison with Spinels Mg_zNiMn_2?zO₄ Stable spinels are obtained in the result of substitution of Zn^II for manganese in the series Zn Ni^IIMnMnO₄ (O ? z ≤1). Different from spinels Mg Ni^IIMnMnO₄ (O ? z ?1)they don't be submitted to decomposition in air during slow cooling at medium temperatures. ZnNiMnO₄ (z=1) could not be prepared in a mono-phase state which is indicated by the composition of ZnNiMnO_3.96 deduced from analysis by oxidimetric titration. The comparably small variation of the specific electrical conductivity and of the activation energy observed in the range O ? z ? 2/3 for Zn_zNiMn_2?z is discussed in relation to larger alterations in the series Mg_zNiMn_2?zO₄. Structural interpretation is proposed based on the comparison of the molar volume of spinels M Mn₂O₄ (M: Mn, Fe, Co, Ni, Cu, Zn, Mg).     

Synthese und Kristallstruktur von Ba25Cu142+Cu43+Zn4O49

Synthesis and Crystal Structure of Ba₂₅Cu₁₄²⁺Cu₄³⁺Zn₄O₄₉ Single crystals of Ba₂₅Cu₁₄²⁺Cu₄³⁺Zn₄O₄₉ were prepared with solid state and flux reactions. X-ray investigations show tetragonal symmetry, space group D⁷_4th–P4/nmm, a = 18.2146, c = 9.3230 Å, Z = 2. The hitherto unknown structure type shows copper in square pyramids and planar polygones, connected to six member rings or Cu₅O₂₀ groups. Slightly bent Cu₅O₁₂ groups produced by edge connection of five CuO₄ polygones are connected with ZnO₄ tetrahedra forming Cu₅Zn₄O₂₀ units. The complicated structure is shown step by step.     

Die Kristallstruktur von (Al0,5Ga0,5)CuOAsO4 – Kupfer zwischen planarer und geschlossener Koordination

The Crystal Structure of (Al_0,5Ga_0,5)CuOAsO₄ – Copper Intermediate between Planar and Closed Coordination Single crystals of the new oxide arsenate (Al_0.5Ga_0.5)CuOAsO₄ (monoclinic, P2₁/c, a = 734.3(2) pm, b = 1024.79(9) pm, c = 563.4(2) pm, β = 99.93(1)°, Z = 4) were obtained by reaction of Al/As/Cu/Ga-alloys with oxygen. The crystal structure was determined from four-circle diffractometer data (w2R = 0.039 for 1211 F² values and 76 parameters). The structure contains [Cu₂O₆] double squares arranged in slabs perpendicular to the a axis such that a [4 + 1]-coordination of the copper atoms by oxygen atoms results which is intermediate between square-planar and square-pyramidal. Along [100] layers of corner sharing (Al/Ga)O₄ and AsO₄ tetrahedra are alternating with buckled Cu layers.     

KBa7Mg2B14O28F5, a new borate with an unusual heptaborate group and double perovskite unit

A new borate, potassium barium magnesium borate fluoride, KBa₇Mg₂B₁₄O₂₈F₅, with a nominal 7:1 composition of BaB₂O₄ to KMg₂F₅, has been found during the growth of BaMgBO₃F crystals with a KF flux. It crystallized in the space group C2/c and is composed of isolated heptaborate [B₇O₁₄]⁷⁻ groups and double perovskite [Mg₂O₆F₅]¹³⁻ units.     

Zinkselenid- und Zinktelluridcluster mit Phenylselenolat- und Phenyltellurolatliganden. Die Kristallstrukturen von [NEt4]2[Zn4Cl4(SePh)6], [NEt4]2[Zn8Cl4Se(SePh)12], [Zn8Se(SePh)14(PnPr3)2], [HPnPr2R]2[Zn8Cl4Te(TePh)12] (R = nPr,Ph) und [Zn10Te4(TePh)12(PR3)2] (R = nPr,Ph)

Zincselenide- and Zinctellurideclusters with Phenylselenolate- and Phenyltellurolateligands. The Crystal Structures of [NEt₄]₂[Zn₄Cl₄(SePh)₆], [NEt₄]₂[Zn₈Cl₄Se(SePh)₁₂], [Zn₈Se(SePh)₁₄(PⁿPr₃)₂], [HPⁿPr₂R]₂[Zn₈Cl₄Te(TePh)₁₂] (R = ⁿPr, Ph), and [Zn₁₀Te₄(TePh)₁₂(PR₃)₂] (R = ⁿPr, Ph) In the prescence of NEt₄Cl ZnCl₂ reacts with PhSeSiMe₃ or a mixture of PhSeSiMe₃/Se(SiMe₃)₂ to form the ionic complexes [NEt₄]₂[Zn₄Cl₄(SePh)₆] 1 or [NEt₄]₂[Zn₈Cl₄Se(SePh)₁₂] 2 respectively. The use of PⁿPr₃ instead of the quarternary ammonia salt leads in toluene to the formation of crystalline [Zn₈Se(SePh)₁₄(PⁿPr₃)₂] 3 . Reactions of ZnCl₂ with PhTeSiMe₃ and tertiary phosphines result in acetone in crystallisation of the ionic clusters [HPⁿPr₂R]₂[Zn₈Cl₄Te(TePh)₁₂] (R = ⁿPr 4 , Ph 5 ) and in THF of the uncharged [Zn₁₀Te₄(TePh)₁₂(PR₃)₂] (R = ⁿPr 6 , Ph 7 ). The structures of 1–7 were obtained by X-ray single crystal structure. ( 1 : space group P2₁/n (No. 14), Z = 4, a = 1212,4(2) pm, b = 3726,1(8) pm, c = 1379,4(3) pm β = 99,83(3)°; 2 space group P2₁/c (Nr. 14), Z = 4, a = 3848,6(8) pm, b = 1784,9(4) pm, c = 3432,0(7) pm, β = 97,78(3)°; 3 : space group Pnn2 (No. 34), Z = 2, a = 2027,8(4) pm, b = 2162,3(4) pm, c = 1668,5(3) pm; 4 : space group P2₁/c (No. 14), Z = 4, a = 1899,8(4) pm, b = 2227,0(5) pm, c = 2939,0(6) pm, β = 101,35(3)°; 5 : space group space group P2₁/n (No. 14), Z = 4, a = 2231,0(5) pm, b = 1919,9(4) pm, c = 3139,5(6) pm, β = 109,97(4)°; 6 : space group I4₁/a (No. 88), Z = 4, a = b = 2566,0(4) pm, c = 2130,1(4) pm; 7 : space group P1¯ (No. 2), Z = 2, a = 2068,4(4) pm, b = 2187,8(4) pm, c = 2351,5(5) pm, α = 70,36°, β = 84,62°, γ( = 63,63°)