Alkalimetall‐Oxoantimonate: Synthesen,Kristallstrukturen und Schwingungsspektren von ASbO2 (A = K,Rb), A4Sb2O5 (A = K,Rb, Cs) und Cs3SbO4

Alkaline Metal Oxoantimonates: Synthesis, Crystal Structures, and Vibrational Spectroscopy of ASbO₂ (A = K, Rb), A₄Sb₂O₅ (A = K, Rb, Cs), and Cs₃SbO₄ The compounds ASbO₂ (A = K/Rb; monoclinic, C2/c, a = 785.4(3)/799.6(1) pm, b = 822.1(4)/886.32(7) pm, c = 558.7(3)/559.32(5) pm, β = 124.9(1)/123.37(6)°, Z = 4) are isotypic with CsSbO₂ and the corresponding bismutates. The structures of the antimonates A₄Sb₂O₅ (A = K/Rb: orthorhombic, Cmcm, a = 394.9(1)/407.34(7) pm, b = 1807.4(1)/1893.5(1) pm, c = 636.34(9)/655.60(8) pm, Z = 2) and Cs₄Sb₂O₅ (monoclinic, Cm, a = 1059.81(7) pm, b = 692.68(8) pm, c = 811.5(1) pm, β = 98.7(1)°, Z = 2) both contain the anion [O₂SbOSbO₂]^4–. Cs₃SbO₄ (orthorhombic, Pnma, a = 1296.1(1) pm, b = 919.24(8) pm, c = 679.95(6) pm, Z = 4) crystallizes with the K₃NO₄ structure type.     

Strukturen caesiumhaltiger Fluoride. VII. Cs6Ni5F16 – eine neue Verbindung im System CsF/NiF2 und ihre Kristallstruktur

Structures of Caesium-containing Fluorides. VII. Cs₆Ni₅F₁₆ – a New Compound in the System CsF/NiF₂ and its Crystal Structure Single crystals of a more caesium-containing phase of composition Cs₆Ni₅F₁₆, forming in the course of solid state CsNiF₃ preparation, could be isolated and their structure determined: a = 618.4(1), b = 1. 455.5(2), c = 2145.1(2) pm, space group Cmca, Z = 4, R = 0.030 (1936 independent reflections). The structure contains chains of five face-sharing octahedra, which are connected at their ends via corners to form a zig-zag layer. The Ni? Ni distances within the chains are 264.1 and 270.2 pm, the average Ni? F distance is 202.0 pm. The caesium atoms exhibit 10-, 11-, and 12-coordination. The structural relations to 2L? CsNiF₃ and Cs₄Ni₃F₁₀ are discussed.     

Zur Kenntnis des Systems Cs/Cu/F: Über CsCuIICuIIIF6

The System Cs/Cu/F: On CsCu^IICu^IIIF₆ ?CsCuF_3,6’? is described in literature as a darkbrown powder which is supposed to crystallize in a cubic lattice (a = 882 pm, Debyeogramms). However Guinier photographs show that ?CsCuF_3,6’? is a mixture of CsCu^IICu^IIIF₆ (black, isotypic to CsNi^IINi^IIIF₆, a = 706.7 b = 727.7, c = 1032.2 pm, Z = 4) and Cs₂CuCu^IIIF₆ (auburn, pseudocubic, a = 623.4 c = 886.4 pm, Z = 2).     

Selten-Erd-Hydrogensulfate M(HSO4)3 (M = La,Ce–Nd): Derivate des UCl3-Typs

Rare Earth Hydrogensulfates M(HSO₄)₃ (M = La, Ce–Nd): Derivatives of the UCl₃ Type of Structure Hydrogensulfates of the lighter lanthanides are obtained from the reaction of the respective anhydrous sulfates with conc. sulfuric acid at 200 °C. According to X-ray single crystal determinations on La(HSO₄)₃ (hexagonal, P6₃/m, a = 945.64(9) pm, c = 590.87(5) pm), Ce(HSO₄)₃ (a = 943.34(10) pm, c = 587.88(5) pm), Pr(HSO₄)₃ (hexagonal, P6₃/m, a = 939.8(1) pm, c = 584.82(9) pm) and Nd(HSO₄)₃ (hexagonal, P6₃/m, a = 935.67(8) pm, c = 582.36(4) pm) they all crystallize analogous to the UCl₃ type of structure with nine-coordinate M³⁺ ions. The OH groups of the [HOSO₃]^– ”︁tetrahedra”︁”︁ build up channels parallel [00.1] typical for this type of structure. Hydrogen bonding, however, is only weak in these compounds.     

Die Kristallstruktur der hydratisierten Cyanokomplexe NMe4MnII[(Mn, Cr)III(CN)6] · 3 H2O und NMe4Cd[MIII(CN)6] · 3 H2O (MIII = Fe,Co): Verwandte des Berliner Blaus

The Crystal Structure of the Hydrated Cyano Complexes NMe₄Mn^II[(Mn, Cr)^III(CN)₆] · 3 H₂O and NMe₄Cd[M^III(CN)₆] · 3 H₂O (M^III = Fe, Co): Compounds Related to Prussian Blue The crystal structures of the isotypic tetragonal compounds (space group I4, Z = 10) NMe₄Mn^II · [(Mn, Cr)^III(CN)₆] · 3 H₂O (a = 1653.2(4), c = 1728.8(6) pm), NMe₄Cd[Fe(CN)₆] · 3 H₂O (a = 1642.7(1), c = 1733.1(1) pm) and NMe₄Cd[Co(CN)₆] · 3 H₂O (a = 1632.1(2), c = 1722.4(3) pm) were determined by X‐rays. They exhibit ⊥ c cyanobridged layers of octahedra [M^III(CN)₆] and [M^IIN₄(OH₂)₂], which punctually are interconnected also || c to yield altogether a spaceous framework. The M^II atoms at the positions linking into the third dimension are only five‐coordinated and form square pyramids [M^IIN₅] with angles N–M^II–N near 104° and distances of Mn–N: 1 × 214, 4 × 219 pm; Cd–N: 1 × 220 resp. 222, 4 × 226 resp. 228 pm. Further details and structural relations within the family of Prussian Blue are reported and discussed.     

Untersuchungen zur Reaktivität in den Systemen A/Cu/M/O (A = Na–Cs und M = Co,Ni, Cu,Ag); Synthese und Kristallstrukturen von K3Cu5O4 und Cs3Cu5O4

Reactivity in the Systems A/Cu/M/O (A = Na–Cs and M = Co, Ni, Cu, Ag); Synthesis and Crystal Structures of K₃Cu₅O₄ und Cs₃Cu₅O₄ The systems A/Cu/M/O with A = Na–Cs and M = Co, Ni, Cu, Ag have been investigated with preparative, thermoanalytical and in situ X‐ray techniques to study the reactivity. For the redox reaction Co/CuO in the presence of Na₂O the intermediate, NaCuO, has been characterized. K₃Cu₅O₄ was obtained by annealing intimate mixtures of K₂O and CuO (molar ratio 1 : 1) in Ag containers at 500 °C. Cs₃Cu₅O₄ could be synthezised by reaction of KCuO₂ with Cs₂O (molar ratio 1 : 1) in Cu containers at 500 °C. Both compounds crystallize in the space group P2₁/c with Z = 4 isotypic to Rb₃Cu₅O₄ [IPDS data, Mo–Kα; K₃Cu₅O₄: a = 946.0(1), b = 735.61(6), c = 1401.3(2) pm, β = 107.21(1)°; 2249 F²(hkl), R₁ = 7.09%, wR₂ = 11.42%; Cs₃Cu₅O₄: a = 1027.7(1), b = 761.42(7), c = 1473.4(2) pm, β = 106.46(1)°, 1712 F²(hkl), R₁ = 6.04%, wR₂ = 14.22%]. Force constants obtained from FIR experiments for the deformation mode δ(O–Cu–O), the Madelung Part of the Lattice Energie, MAPLE, Effective Coordination Numbers, ECoN, calculated via Mean Effective Ionenradii, MEFIR, are given.     

Die Antimonid–Triantimonidometallate(III) Cs6K3Sb[AlSb3] und Cs6K3Sb[GaSb3]

The Antimonide Triantimonidometallates(III) Cs₆K₃Sb[AlSb₃] and Cs₆K₃Sb[GaSb₃] The novel compounds Cs₆K₃Sb[AlSb₃] and Cs₆K₃Sb[GaSb₃] are formed from stoichiometric mixtures of Cs, AlSb (GaSb) and KSb in sealed niobium ampoules at 950 K. The hexagonal structures are especially characterized by one-dimensional rod packings ¹∞[Cs₆K₃Sb] which are formed from columns of condensed (Cs₆K_6/2) icosahedra. The icosahedra are centered by Sb^3-? anions. The trigonal planar anions [AlSb₃]^6-? and [GaSb₃]^6-? are embedded between the icosahedra columns, and they are coordinated by alkali metal atoms. The FIR spectra were assigned to the vibrations of the [MSb₃]^6-? anions, with respect to the 6 m2-D_3h symmetry. (P6₃/mmc, No. 194; a = 1101.7 and 1097.2 pm; c = 1158.9 and 1150.1 pm; Z = 2; Single crystal data: 574 and 546 reflections; R = 0.073 and 0.029. Distances:d(Al? Sb) = 265.4 pm; d(Ga? Sb) = 265.1 pm; d(Sb? Cs) = 401.6–423.0 pm; d(Sb? K) = 358.6–367.3 pm).     

Die Kristallstrukturen der Vanadium-Weberite Na2MIIVIIIF7 (MII  Mn,Ni, Cu) und von NaVF4

The Crystal Structures of the Vanadium Weberites Na₂M^IIV^IIIF₇ (M^II ? Mn, Ni, Cu) and of NaVF₄ At single crystals of the vanadium(III) compounds NaVF₄ (a = 790.1, b = 531.7, c = 754.0 pm, β = 101.7°; P2₁/c, Z = 4), Na₂NiVF₇ (a = 726.0, b = 1031.9, c = 744.6 pm; Imma, Z = 4) and Na₂CuVF₇ (a = 717.6, b = 1043.5, c = 754.6 pm; Pmnb, Z = 4) X-ray structure determinations were performed, at Na₂MnVF₇ (a = 746.7, c = 1821.6 pm; P3₂21, Z = 6) a new refinement. NaVF₄ crystallizes in the layer structure type of NaNbO₂F₂. The fluorides Na₂M^IIVF₇ represent new orthorhombic (M^II ? Ni; Cu) resp. trigonal (M^II ? Mn) weberites. The average distances within the [VF₆] octahedra of the four compounds are in good agreement with each other and with data of related fluorides (V? F: 193.3 pm). The differences between mean bond lengths of terminal and bridging F ligands are 5% in NaVF₄, but less than 1% in the weberites. Details and data for comparison are discussed.     

KCuMIVF7 (MIV = Zr4+, Hf 4+), ein neuer Strukturtyp

KCuM^IVF₇ (M^IV = Zr⁴⁺, Hf ⁴⁺) a New Type of Structure KCuZrF₆ (colourless, orthorhombic, Cmcm – D (No. 63); a = 829,6 pm, b = 1276,5 pm, c = 1011,6 pm, Z = 8) and KCuHfF₇ (colourless, orthorhombic, Cmcm – D (Nr. 63); a = 829,6 pm, b = 1276,5 pm, c = 1011,6 pm, Z = 8) could be prepared by heating up in a goldtube at 700 °C for 3 weeks a mixture of KF, CuF₂, and ZrF₄ or HfF₄, respectively. Both compounds crystallize isotypic in a previous unknown structure.     

Tetragonale Fluorperowskite AM0,75 ▭ 0,25F3 mit Kationendefizit: K4MnIIMn2IIIF12 und Ba2Cs2Cu3F12

Tetragonal Fluoroperovskites AM_0,75 □ _0,25F₃ Deficient in Cations: K₄Mn^IIM₂^IIIF₁₂ and Ba₂Cs₂Cu₃F₁₂ By heating 2KMnF₃ + K₂MnF₆ and BaF₂, CsF + CuF₂ respectively, the isostructural tetragonal compounds K₄Mn₃F₁₂ (a = 832.2, c = 1643.0 pm) and Ba₂Cs₂Cu₃F₁₂ (a = 854.1, c = 1704.1 pm) were prepared. They crystallize in a cation-deficient perovskite structure exhibiting ordering of octahedral vacancies. Single crystal structures determinations in the space group I4₁/amd, Z = 4, yielded the following average distances within the octahedra, which are Jahn-Teller distorted for Mn^III and Cu^II:Mn^II? F = 208.3 pm, Mn^III? F = 4 × 183.0/2 × 209.7 pm; Cu? F = 190.7/227.1 and 190.6/236.4 pm, respectively. The results are discussed in comparison with related compounds.     

Darstellung und Kristallstruktur von Cs4SnO3

Preparation and Crystal Structure of Cs₄SnO₃ Crystals of Cs₄SnO₃ were synthesized by reaction of SnO with elemental Cs. The compound crystallizes with the triclinic spacegroup P1 with lattice constants a = 737.61(9) pm, b = 1171.3(1) pm, c = 1199.2(1) pm, α = 66.08(3)°, β = 80.88(2)°, γ = 82.28(3)° and Z = 4. The crystal structure exhibits isolated stannate(II) ions [Sn^IIO₃]^4– of ψ-tetrahedral form. Whereas a new structure type is present, there is a close relationship with the structures of the Cs stanntates and plumbates(IV).     

Kristallstrukturbestimmungen an vier monoklinen Weberiten Na2MIIMIIIF7 (MII = Fe,Co; MIII = V,Cr)

Crystal Structure Determinations of Four Monoclinic Weberites Na₂M^IIM^IIIF₇ (M^II = Fe, Co; M^III = V, Cr) By solid state reaction of the binary fluorides single crystals of the following weberites were prepared and their monoclinic structure (space group C2/c, Z = 16) determined by X-ray methods: Na₂FeVF₇ (a = 1 271.0(3), b = 742.9(1), c = 2 471.6(5) pm, β = 100.03(3)°; R₁ = 0.043 (1 545 Reflexe); Fe? F = 203.8, V? F = 193.0 pm); Na₂FeCrF₇ (a = 1 262.5(3), b = 739.1(1), c = 2 460.5(5) pm, β = 99.93(3)°; R₁ = 0.029 (2 340); Fe? F = 203.6, Cr? F = 190.5 pm); Na₂CoVF₇ (a = 1 270.3(5), b = 739.1(3), c = 2 465.1(10) pm, β = 100.02(3)°; R₁ = 0.028 (2 250); Co? F = 201.6, V? F = 193.6 pm); Na₂CoCrF₇ (a = 1 257.8(3), b = 733.5(1), c = 2 441.5(5) pm, β = 99.64(3)°; R₁ = 0.030 (2 227); Co? F = 201.2, Cr? F = 190.2 pm). Concerning the above average distances within the distorted [MF₆] octahedra and the shape of [NaF₈] coordination details are given and discussed.     

Rubidium‐ und Caesium‐Verbindungen mit dem Isopolyanion [Ta6O19]8– – Synthesen,Kristallstrukturen, thermische und schwingungsspektroskopische Untersuchungen der Oxotantalate A8[Ta6O19] · n H2O (A = Rb,Cs; n = 0, 4, 14)

Rubidium und Caesium Compounds with the Isopolyanion [Ta₆O₁₉]^8– – Synthesis, Crystal Structures, Thermogravimetric and Vibrational Spectrocopic Analysis of the Oxotantalates A₈[Ta₆O₁₉] · n H₂O (A = Rb, Cs; n = 0, 4, 14) The compounds A₈[Ta₆O₁₉] · n H₂O (A = Rb, Cs; n = 0, 4, 14) contain the isopoly anion [Ta₆O₁₉]^8–, which consists of six [TaO₆] octahedra connected via corners to form a large octahedron. They transform into each other by reversible hydratation/dehydratation processes, as shown from thermoanalytic measurements (TG/DSC), and show also structural similarities. Cs₈[Ta₆O₁₉] (tetragonal, I4/m, a = 985.9(1) pm, c = 1403.3(1) pm, Z = 2), the isotypic phases A₈[Ta₆O₁₉] · 14 H₂O (A = Rb/Cs; monoclinic, P2₁/n, a = 1031.30(6)/1055.4(1) pm, b = 1590.72(9)/1614.9(6) pm, c = 1150.43(6)/1171.4(1) pm, β = 100.060(1)/99.97(2)°, Z = 2) and Rb₈[Ta₆O₁₉] · 4 H₂O (monoclinic, C2/c, a = 1216.9(4) pm, b = 1459.2(5) pm, c = 1414.7(4) pm, β = 90.734(6)°, Z = 4) have been characterised on the basis of single crystal x‐ray data. Furthermore the RAMAN spectra allow a detailled comparison of the hexatantalate ions in the four compounds.     

Struktur und Magnetismus von Fluoriden Cs2MCu3F10 (M = Mg,Mn, Co,Ni), Varianten des CsCu2F5‐Typs

Structure and Magnetism of Fluorides Cs₂MCu₃F₁₀ (M = Mg, Mn, Co, Ni), Variants of the CsCu₂F₅ Type X‐ray structure determinations of single crystals showed that compounds Cs₂MCu₃F₁₀ crystallize with Z = 2 in space group P2₁/n (No.14) (M = Mn) of the CsCu₂F₅ type resp. in its supergroup I2/m (No.12) (M = Mg, Co, Ni). Cs₂MgCu₃F₁₀: a = 714.9(1), b = 736.8(1), c = 940.4(1) pm, b = 96.29(1)°, (Mg‐F: 199.2 pm); Cs₂MnCu₃F₁₀: a = 725.1(1), b = 742.7(1), c = 951.0(2) pm, b = 97.28(3)°, (Mn‐F: 209.1 pm); Cs₂CoCu₃F₁₀: a = 717.8(3), b = 739.1(2), c = 939.4(4) pm, b = 97.49(2)°, (Co‐F: 203.1 pm); Cs₂NiCu₃F₁₀: a = 716.3(1), b = 737.7(1), c = 938.2(2) pm, b = 97.09(1)°, (Ni‐F: 201.0 pm). As determined directly for the Mg compound and generally concluded from the average distances M‐F noted, M substitution concerns mainly the octahedrally coordinated position of the CsCu₂F₅ structure, the distortion of which is very much reduced thereby. Within the remaining [CuF₄] and [CuF₅] coordinations, in contrast to CsCu₂F₅, one F ligand is disordered, in case of the Mn compound the pyramidally coordinated Cu atom, too. The magnetic properties are complex and point to frustration and spin glass effects. Only at the diamagnetically substituted variants with M = Mg, Zn no Néel point appears, which is reached at 27, 23, 36 and 55 K for M = Mn, Co, Ni and Cu, resp. At lower temperatures ferri‐ resp. weak ferromagnetism and hysteresis is observed.     

Carbonat‐Hydrate der schweren Alkalimetalle: Darstellung und Struktur von Rb2CO3 · 1,5 H2O und Cs2CO3 · 3 H2O

Carbonate Hydrates of the Heavy Alkali Metals: Preparation and Structure of Rb₂CO₃ · 1.5 H₂O und Cs₂CO₃ · 3 H₂O Rb₂CO₃ · 1.5 H₂O and Cs₂CO₃ · 3 H₂O were prepared from aqueous solution and by means of the reaction of dialkylcarbonates with RbOH and CsOH resp. in hydrous alcoholes. Based on four‐circle diffractometer data, the crystal structures were determined (Rb₂CO₃ · 1.5 H₂O: C2/c (no. 15), Z = 8, a = 1237.7(2) pm, b = 1385.94(7) pm, c = 747.7(4) pm, β = 120.133(8)°, V_EZ = 1109.3(6) · 10⁶ pm³; Cs₂CO₃ · 3 H₂O: P2/c (no. 13), Z = 2, a = 654.5(2) pm, b = 679.06(6) pm, c = 886.4(2) pm, β = 90.708(14)°, V_EZ = 393.9(2) · 10⁶ pm³). Rb₂CO₃ · 1.5 H₂O is isostructural with K₂CO₃ · 1.5 H₂O. In case of Cs₂CO₃ · 3 H₂O no comparable structure is known. Both structures show [(CO₃^2–)(H₂O)]‐chains, being connected via additional H₂O forming columns (Rb₂CO₃ · 1.5 H₂O) and layers (Cs₂CO₃ · 3 H₂O), respectively.     

Ternäre Selenide der Lanthanide mit Alkalimetallen: I. Der Formeltyp Cs3M7Se12 (M = Gd–Ho)

Ternary Selenides of the Lanthanides with Alkali Metals: I. The Composition Cs₃M₇Se₁₂ (M = Gd–Ho) When the lanthanides gadolinium, terbium, dysprosium and holmium are oxidized with selenium in a molar ratio of 2 : 3 in evacuated silica tubes (700 °C, 7 d) and CsCl is added, ternary cesium lanthanide selenides with the composition Cs₃M₇Se₁₂ (M = Gd–Ho) readily form. Surplus CsCl as flux accelerates the crystallization of the yellow, transparent needles. Since these crystals are stable to hydrolysis, excess CsCl and the chloride by-products (e. g. Cs₃MCl₆) can be rinsed off easily with water. The crystal structure of the flanking representatives Cs₃Gd₇Se₁₂ and Cs₃Ho₇Se₁₂ (orthorhombic, Pnnm (no. 58), Z = 2; Cs₃Gd₇Se₁₂: a = 1294.8(3), b = 2650.1(5), c = 419.36(9) pm, R₁ = 0.098, wR₂ = 0.173; Cs₃Ho₇Se₁₂: a = 1280.4(3), b = 2621.2(5), c = 412.13(8) pm, R₁ = 0.096, wR₂ = 0.126) was determined and refined on the basis of X-ray data from single crystals. With the help of powder diffraction Cs₃Tb₇Se₁₂ (a = 1289.4(1), b = 2640.3(2), c = 416.82(3) pm) and Cs₃Dy₇Se₁₂ (a = 1285.3(1), b = 2631.5(2), c = 414.47(3) pm) were established to be isotypic. The four new compounds crystallize isostructurally with Cs₃Y₇Se₁₂, so that a three-dimensional framework {[M₇Se₁₂]^3–} of vertex- and edge-sharing [MSe₆] octahedra is present. Wave-like, one-dimensional infinite ”︁triple-channels”︁ run through the structure along [001] which are filled with two crystallographically different Cs⁺ cations (CN(Cs1) = 7 + 1, CN(Cs2) = 6). Owing to much too close Cs⁺–Cs⁺ contacts only a semi-occupation is possible for the Cs2 position which the structure refinements inevitably prove.     

Pniktogenidostannate(IV) mit isolierten Tetraeder‐Anionen: Neue Vertreter (E1)4(E2)2[Sn(E15)4] (mit E1 = Na,K; E2 = Ca,Sr, Ba; E15 = P,As, Sb,Bi) vom Na6[ZnO4]‐Typ und die Überstrukturvariante von K4Sr2[SnAs4]

Pnictogenidostannates(IV) with Discrete Tetrahedral Anions: New Representatives (E1)₄(E2)₂[Sn(E15)₄] (with E1 = Na, K; E2 = Ca, Sr, Ba; E15 = P, As, Sb, Bi) of the Na₆[ZnO₄] Type and the Superstructure Variant of K₄Sr₂[SnAs₄] The silvery to dark metallic lustrous compounds (E1)₄(E2)₂[Sn(E15)₄] (E1 = Na, K; E2 = Ca, Sr, Ba; E15 = P, As, Sb, Bi) were prepared from melts of stoichiometric mixtures of the elements. They crystallize in the Na₆[ZnO₄]‐type structure (hexagonal, space group: P6₃mc, Z = 2; Na₄Ca₂[SnP₄]: a = 938.94(7), c = 710.09(8) pm; K₄Sr₂[SnAs₄]: a = 1045.0(2), c = 767.0(1) pm; K₄Ba₂[SnP₄]: a = 1029.1(6), c = 780.2(4) pm; K₄Ba₂[SnAs₄]: a = 1051.3(1), c = 795.79(7) pm; K₄Ba₂[SnSb₄]: a = 1116.9(2), c = 829.2(1) pm; K₄Ba₂[SnBi₄]: a = 1139.5(2), c = 832.0(2) pm). The anionic partial structure consists of tetrahedra [Sn(E15)₄]^8– orientated all in the same direction along [001]. In the cationic partial structure one of the two cation positions is occupied statistically by alkali and alkaline earth metal atoms. Up to now only for K₄Sr₂[SnAs₄] a second modification could be isolated, forming a superstructure type with three times the unit cell volume (hexagonal, space group: P6₃cm, Z = 6; a = 1801.3(2), c = 767.00(9) pm) and an ordered cationic partial structure.     

Kristallstrukturuntersuchungen an den Alkali- und BariumÜbergangsmetallfluoriden RbK2Mn2F7, BaNiF4 und einer 5 : 3-Phase im System BaLiF3/NaCoF3

Crystal Structural Studies of the Alkali and Barium Transition Metal Fluorides RbK₂Mn₂F₇, BaNiF₄, and a 5 : 3-Phase of the System BaLiF₃/NaCoF₃ At single crystals of the compounds RbK₂Mn₂F₇, BaNiF₄, and of a phase 0.618 BaLiF₃/0.382 NaCoF₃ the X-ray crystal structures were refined. RbK₂Mn₂F₇ is tetragonal (a = 421.1(1), c = 2188.3(2) pm, I4/mmm, Z = 2) and belongs to the Sr₃Ti₂O₇ type. The average distances are Mn–F: 210.7 pm for the [MnF₆] octahedron and A–F: 290.6 resp. 297.1 pm for the [AF₉] resp. [AF₁₂] coordination of the mixed alkali positions (A = Rb/3 + 2 K/3). BaNiF₄ (a = 413.7(1), b = 1443.1(3), c = 578.1(1) pm, Cmc2₁, Z = 4) is of the orthorhombic BaZnF₄ type; Ni–F: 200.3 pm, Ba–F: 274.3 pm for CN6 and CN9, resp.. The phase of approximate composition 5 : 3, isolated from a 1 : 1 batch BaLiF₃/NaCoF₃, is cubic (a = 801.8(1) pm, Im3, Z = 8 AMF₃) and forms a strongly disordered perovskite super-structure, the features of which are discussed.     

Die ersten oligomeren Anionen bei Fluoro-Litho-Metallaten mit Oktaeder-Sandwich-Motiv: Cs4K{[F3MIIIF3]Li[F3MIIIF3]}, MIII = Ga,Fe [1]

The First Oligomeric Anions of Fluoro-Litho Metallates with Octahedra Sandwich Motive: Cs₄K{[F₃M^IIIF₃]Li[F₃M^IIIF₃]}, M^III = Ga, Fe Colourless single crystals of Cs₄K{Li[Ga₂F₁₂]} ( A ) and Cs₄K{Li[Fe₂F₁₂]} ( B ) have been obtained by solid state reaction from intimate mixtures of the corresponding binary fluorides (Pt-tube, 750°C, 40 d). The trigonal unit cells with ( A ) a = 631,3(1)pm; c = 3059,9(6)pm and ( B ) a = 635,0(1)pm; c = 3089,2(7)pm, respectively (Z = 3, Guinier-Simon data, Cu-Kα₁), are confirmed by single crystal investigations. The compounds crystalize isostructural in the space group R3 m (No. 166). The structures were determined using four-circle diffractometer data (Siemens AED 2) with ( A ) R = 2.95%, 3627 I_o and ( B ) R = 1.86%, 4179 I_o, respectively (SHELX-76), and are characterized by triplets of facesharing octahedra parallel [00.1] with the cation-sequence M^III? Li? M^III, six of which are connected by [KF₆]-octahedra via common corners and each triplet is surrounded by six different [KF₆]-octahedra. The structure is completed by Cs⁺ filling the cavities. The Madelung Part of Lattice Energy (MAPLE), Mean Fictive Ionic Radii (MEFIR) and Effective Coordination Numbers (ECoN) are calculated and compared. The classification as lithometallate could be verified by a new MAPLE concept. The Charge Distribution (CHARDI) was calculated and compared with the results according to ‘bond length-bond strength’.     

Die Zinn-Rhodiumboride SnRh3B1−x,Sn4Rh6B und Sn5Rh6B2

The Tin Rhodium Borides SnRh₃B_1–x, Sn₄Rh₆B, and Sn₅Rh₆B₂ The new compounds SnRh₃B_1–x (x ～ 0.2, tetragonal, P4/mbm, a = 570.31(2) pm, c = 835.99(8) pm, Z = 4, 514 reflexions, 26 parameters, R = 0.026), Sn₄Rh₆B (hexagonal, P6₃/mmc, a = 560.01(3) pm, c = 1367.5(1) pm, Z = 2, 746 reflexions, 17 parameters, R = 0.035), and Sn₅Rh₆B₂ (hexagonal, P6 2m, a = 654.80(7) pm, c = 557.32(9) pm, Z = 1, 361 reflexions, 16 parameters, R = 0.039) were prepared by reaction of the elements. SnRh₃B_1–x crystallizes with the filled U₃Si type of structure, a distortion variant of the cubic perovskite; the structure of Sn₄Rh₆B may be derived from the hexagonal perovskite BaNiO₃. Both compounds contain nearly regular Rh₆B-octahedra. Sn₅Rh₆B₂ with the Sn₅Ir₆B₂ type of structure contains isolated colums composed of trigonal Rh₆B-prisms.