K2MCl5(M = La—Dy) und Rb2MCl5 (M = La—Eu): Ino-Chloride mit siebenfach koordinierten Seltenen Erden

K₂MCl₅(M = La—Dy) and Rb₂MCl₅ (M = La—Eu): Ino-chlorides with Seven—Coordinated Rare Earths K₂PrCl₅ crystallizes with a = 1263.1(8), b = 875.6(3), c = 797.3(4) pm, Z = 4, orthorhombic, Pnma, isotypic to e. g. Y₂HfS₅. Monocapped trigonal prisms (C.N. = 7) are connected to chains via common edges in [010] direction according to [PrCl_3/1^tCl_4/2^k]^2? with d?(Pr? Cl) = 281 pm. The chlorides K₂MCl₅ (M = La—Dy) and Rb₂MCl₅ (M = La—Eu) are isotypic to K₂PrCl₅. Thermal expansion of Rb₂PrCl₅ in [010] direction is remarkably smaller than parallel to (010).     

Ternäre Halogenide vom Typ A3MX6. I A3YCl6 (A = K,NH4, Rb,Cs): Synthese,Strukturen, Thermisches Verhalten. Über einige analoge Chloride der Lanthanide

Ternary Halides of the A₃MX₆ Type I. A₃YCI₆ (A = K, NH₄, Rb, Cs): Synthesis, Structures, Thermal Behaviour. Some Analogous Chlorides of the Lanthanides Reaction of the trichlorides MCl₃ (M = Y, Tb? Lu) with alkali chlorides AC1 (A = K, Rb, Cs) in evacuated silica ampoules at 850?900°C yields A₃MCl₆-type chlorides. (NH₄)₃YCl₆ is obtained via the ammonium-chloride route. The crystal structure of Rb₃YCl₆ (monoclinic, C2/c (no. 15), Z = 8, a = 2583(1)pm, b = 788.9(4)pm, c = 1283.9(7)pm, p = 99.63(4)°, R = 0.062, R_w = 0.050) is that of Cs₃BiCl₆. The Rb₃YCl₆/Cs₃BiCl₆ structure and the closely related structures of K₃MoCl₆ and In₂CI₃ are derived from the elpasolite-type of structure (K₂NaAlF₆) making use of the model of closest-packed layer structures. Cell parameters for the chlorides Rb₃MCl₆ (M = Y, Tb? Lu) and Cs₃YCl₆ and Cs₃ErCl₆ as well, which are all isostructural with Rb₃YCl₆, are given. The “system” (K, NH₄, Rb, Cs)YCl₆ has been investigated by DTA and high-temperature X-ray powder diffractometry.     

Ternäre Chloride in den Systemen ACl/DyCl3 (A = Cs,Rb, K)

Ternary Chlorides in the Systems ACl/DyCl₃ (A = Cs, Rb, K) The phase diagrams of the pseudobinary systems ACl/DyCl₃ (A = Cs, Rb, K) were investigated by DTA. With all alkali metals compounds A₃DyCl₆ (elpasolite family) and Ady₂Cl₇ are formed. Compounds A₂DyCl₅ exist only with Cs (Cs₂DyCl₅-type) and K (K₂PrCl₅-type). By solution calorimetry the formation enthalpies of the ternary chlorides from (nACl + DyCl₃) were measured and ‘synproportionation enthalpies’ for the formation from the compounds, adjacent in the phase diagrams, calculated. K₃DyCl₆ is the only compound, which is formed with a loss in lattice enthalpy. E.m.f. measurements in dependence on the temperature have revealed that, as for the other compounds A₃DyCl₆, a remarkable gain in entropy exists, which stabilizes K₃DyCl₆ at T ≧ 312 K. This entropy gain correlates with the existence of isolated DyCl₆^3? octahedra.     

Synthese und Kristallstruktur der Ternären Selten-Erd-Chloride Na2MCl5 (M = Sm,Eu, Gd)

Synthesis and Crystal Structure of the Ternary Rare Earth Chlorides Na₂MCl₅ (M = Sm, Eu, Gd) Single crystals of Na₂EuCl₅ were obtained from the melt of NaCl and EuCl₃ in a 2:1.2 molar ratio by slow cooling. It crystallizes in the orthorhombic crystal system (space group Pnma) with the structure of K₂PrCl₅ with a = 1 204.0(3) pm, b = 833.9(3) pm, c = 768.2(3) pm, Z = 4. Pure powder samples of the compounds Na₂MCl₅ (M = Sm? Gd) are available by heating mixtures of the binary components below the melting point.     

Ternäre Chloride in den Systemen ACl/GdCl3 (A = Na?Cs)

Ternary Chlorides in the Systems ACl/GdCl₃ (A = Na? Cs) The phase diagrams of the pseudobinary systems ACl/GdCl₃ (A = Na? Cs) were investigated by DTA. Their powder diffractograms were indexed in analogy to known structure families. By solution calorimetry and measurements of e.m.f. = f(T) in galvanic cells for solid electrolytes the enthalpies ΔH⁰ and free enthalpies ΔG⁰ for the formation of the ternary chlorides from the compounds adjacent in the systems were determined. The systems with A = K, Rb, Cs are analogous to those with Sm³⁺ and Eu³⁺. There exist compounds A₃GdCl₆, A₂GdCl₅ and AGd₂Cl₇. Cs₂GdCl₅ is crystallysing in the Cs₂DyCl₅ type; the Rb- and K-compounds and also Na₂GdCl₅ have the K₂PrCl₅?structure. In the system NaCl/GdCl₃ additionally the compounds NaGdCl₄ and Na₃GdCl₆ were found. L? Na₃GdCl₆ is metastable compared with (NaCl + Na₂GdCl₅); above 265°C stable H? Na₃GdCl₆ is existing (cryolite-structure).     

Zur Stabilität von Doppelchloriden in den Systemen ACI/PrCl3(A  Na?Cs)

Stability of Double Chlorides in the Systems ACl/PrCl₃(A = Na? Cs) The pseudobinary systems ACl/PrCl₃(A = Na? Cs) were reinvestigated by means of DTA. The following chlorides were found. (Primary detected compounds are underlined.): K₃PrCl₆; K₂PrCl₅; Rb₂PrCl₅, Cs₃PrCl₆, , CsPr₂Cl₇. Measurements of the solution enthalpies and of the free (Gibbs) enthalpies of formation from ACl and PrCl₃ together with the free enthalpies of synproportionation from the adjacent compounds in the phase diagrams with a galvanic cell for solid electrolytes revealed, that only the chlorides A₂PrCl₅ are stable at ambient temperature. All other compounds are high temperature forms. The crystal structures of the compounds were determined by X-ray analysis on powders; the compounds are isotypic with the analogous double chlorides of La and Ce. Magnetic susceptibilities in the range from 80—300 K were measured with a Gouy-balance.     

Penta‐Ammoniates of Aluminium Halides: The Crystal Structures of AlX3·5NH3 with X = Cl,Br, I

Colourless crystals grow in the colder part of a glass ampoule when AlX₃·5NH₃ with X = Cl, Br, I is heated for 3—6 d to 330 °C (Cl), 350 °C (Br) and 400 °C (I), respectively. The chloride forms hexagonal prisms while the bromide and iodide were obtained as a bunch of lancet‐like crystals. The chloride and bromide crystallize isotypic whereas the iodide has an own structure type. All three are related to the motif of the K₂PtCl₆ type. So the formula of the ammoniates may be written as X₂[Al(NH₃)₅X] ≙ [Al(NH₃)₅X]X₂. The compounds are characterized by the following crystallographic data AlCl₃·5NH₃: Pnma, Z = 4, a = 13.405 (1)Å, b = 10.458 (1)Å, c = 6.740 (2)Å AlBr₃·5NH₃: Pnma, Z = 4, a = 13.808 (2)Å, b = 10.827 (1)Å, c = 6.938 (1)Å AlI₃·5NH₃: Cmcm, Z = 4, a = 9.106 (2)Å, b = 11.370 (2)Å, c = 11.470 (2)Å For the chloride and the bromide the structure determinations were successful including hydrogen positions. All three compounds contain octahedral molecular cations [Al(NH₃)₅X]²⁺ located in distorted cubes formed by the remaining 2X^— ions. The orientation of the octahedra to each other is clearly different for those with X = Cl, Br in comparison to the one with X = I.     

Darstellung und Kristallstruktur von (NH4)2[V(NH3)Cl5]. Die Kristallchemie der Salze (NH4)2[V(NH3)Cl5], [Rh(NH3)5Cl]Cl2 und M2VXCl5 mit M = K,NH4, Rb,Cs und X = Cl,O

Preparation and Crystal Structure of (NH₄)₂[V(NH₃)Cl₅]. The Crystal Chemistry of the Compounds (NH₄)₂[V(NH₃)Cl₅], [Rh(NH₃)₅Cl]Cl₂, and M₂VXCl₅ with M = K, NH₄, Rb, Cs and X ? Cl, O (NH₄)₂[V(NH₃)Cl₅] crystallizes like [Rh(NH₃)₅Cl]Cl₂ in the orthorhombic space group Pnma with Z = 4. The compounds are built up by isolated NH₄⁺ or Cl^? and complex MX₅Y ions. The following distances have been observed: V? N: 213.8, V? Cl: 235.8–239.1, Rh? N: 207.1–208.5, Rh? Cl: 235.5 pm. Both structures differ from the K₂PtCl₆ type mainly in the ordering of the MX₅Y polyhedra. The compounds M₂VCl₆ and M₂VOCl₅ with M = K, NH₄, Rb, and Cs crystallize with exception of the orthorhombic K₂VOCl₅ in the K₂PtCl₆ type. The ordering of the MX₅Y polyhedra in the compounds (NH₄)₂[V(NH₃)Cl₅], [Rh(NH₃)₅Cl]Cl₂ and K₂VOCl₅ enables a closer packing.     

Cs2BeCl4 und Cs2 YbCl4: Endglieder der homologen Reihe Cs2MCl4

Cs₂BeCl₄ and Cs₂YbCl₄: End Members of the Homologous Series Cs₂MCl₄ Cs₂BeCl₄ belongs to the β-K₂SO₄ type structure (orthorhombic, Pnma, Z = 4, a = 964.2(4), b = 717.8(3), c = 1246.8(5) pm) and Cs₂YbCl₄ to the K₂NiF₄ type (tetragonal, I4/mmm, Z = 2, a = 541.8(2), c = 1727.6(10) pm). They are with the exception of Cs₂TmCl₄ the end members of minimum and maximum molar volume of the homologous series Cs₂MCl₄. The application of the “theorem of optimal (preferred) volumes” suggests that the other members of the series also can only belong to one of these two structure types (β-K₂SO₄ and K₂NiF₄ type, respectively).     

Crystal structures of M2FeO4 (M = K,Rb, Cs)

The crystal structure of K₂FeO₄, which is isomorphous with β-K₂SO₄, K₂MnO₄ and K₂CrO₄, has been determined in detail. In addition, Rb₂FeO₄ and Cs₂FeO₄ are shown to be of the same structural type. Crystals of K₂FeO₄ are orthorhombic, space group Pnma, a = 7.694(5), b = 5.858(7), c = 10.335(7) with Z = 4. The integrated intensities of 1174 independent reflections were measured with an automated diffractometer and refined to a weighted least-squares residue of 0.046. The average tetrahedral [FeO] bond length, corrected for libration effects, is 1.656(6) Å which is equal within experimental error to values observed for [CrO] and [MnO] tetrahedral bonds.     

Neue Fluorperowskite mit Cr‴ und Mn‴: A(B03Cr0.5)F3 und A(B05Mn0,5)F3; A,B=Alkalimetall

New fluoroperovskites with Cr^III and Mn^III: A(B_0.5Cr_0.5)F₃ and A(B_0.5Mn_0.5)F₃; A, B = alkali We obtained Cs₂KCrF₆ (a = 9.00₄ Å), Rb₂KCrF₆ (a = 8.81₇ Å), Rb₂NaCrF_e(a = 8.41₈ Å) (all green, K₂NaCrF₆-type) and Cs₂NaCrF₈ as well as Rb₂NaMnF₆ (tetragonally distorted K₂NaCrF₆-type; a = 8.36₅, c = 8.66₀ Å; F4/mmm), and Rb₂KMnF₆ and Cs₂NaMnF₆, all violet. Jahn-Teller-distortion and lattice energy of Rb₂NaMnF₆ and K₂NaMnF₆ are discussed.     

Zur Magnetochemie des zweiwertigen Silbers Neue Fluoroargentate(II): Cs2AgF4, Rb2AgF4 und K2AgF4

Magnetochemistry of Divalent Silver. New Fluoroargentates(II): Cs₂AgF₄, Rb₂AgF₄, and K₂AgF₄ Hitherto unknown blue compounds Rb₂AgF₄ and Cs₂AgF₄ are prepared. Guinier patterns show, that Cs₂AgF₄ cristallise in the K₂NiF₄ structure (a = 4.58₁, c = 14.19₂ Å). The structure of the Rb-compound is still unknown. The magnetic behaviour of K₂AgF₄, Rb₂AgF₄, and Cs₂AgF₄ is discussed.     

Neue mehrkernige Indium–Stickstoff‐Verbindungen – Synthese und Kristallstrukturen von [In4X4(NtBu)4] (X = Cl,Br, I) und [In3Br4(NtBu)(NHtBu)3]

New Polynuclear Indium Nitrogen Compounds – Synthesis and Crystal Structures of [In₄X₄(N^tBu)₄] (X = Cl, Br, I) and [In₃Br₄(N^tBu)(NH^tBu)₃] The reaction of the indium trihalides InX₃ (X = Cl, Br, I) with LiNH^tBu in THF leads to the In₄N₄‐heterocubanes [In₄X₄(N^tBu)₄] (X = Cl 1 , Br 2 , I 3 ). Additionally [In₃Br₄(N^tBu)(NH^tBu)₃] ( 4 ) was obtained as a by‐product in the synthesis of 2 . 1 – 4 have been characterized by x‐ray crystal structure analysis. 1 – 3 consist of In₄N₄ heterocubane cores with an alternating arrangement of In and N atoms. The In atoms are coordinated nearly tetrahedrally by three N‐atoms and a terminal halogen atom. 4 contains a tricyclic In₃N₄ core which can be formally derived from an In₄N₄‐heterocubane by removing one In atom.     

Hochdrucksynthese und Struktur von Rb2PtH6 und Cs2PtH6, ternären Hydriden mit K2PtCl6-Struktur

High-pressure Synthesis and Structure of Rb₂PtH₆ and Cs₂PtH₆, Ternary Hydrides with K₂PtCl₆-Structure The ternary platinum hydrides Rb₂PtH₆ and Cs₂PtH₆ were synthesized by the reaction of rubidium hydride and cesium hydride, respectively, with platinum sponge under a hydrogen pressure above 1 500 bar at 500°C. X-ray investigations on powdered samples and elastic neutron diffraction experiments on the deuterated compounds at the time-of-flight spectrometer POLARIS led to their complete structure determination. Their atomic arrangements are isotypic with that of K₂PtCl₆ containing isolated [PtH₆]^2?-octahedra (space group: Fm3 m, Z = 4).     

Crystal structure of trans-pyH[MoBr4py2] and reactivity of Trans-pyH[MBr4py2] (M = Mo,W; py = pyridine) towards nitrogen ligands and bromine Oxidation

The crystal structure of trans-pyH[MoBr₄py₂] has been determined: orthorhombic, Pnma (No. 62), a = 16.197(3), b = 13.995(3), c = 8.615(1) Å, Z = 4, D_c = 2.23, D_o = 2.20(3) g/cm³, V = 1 953(1) ų. R₁, R_w = 0.057 and 0.053. Trans-[MoBr₄py₂]^? anions with staggered conformation of pyridine rings are located on the mirror planes. Mo? Br, Mo? N(pyridine) distances are 2.593(1), 2.573(1), 2.227(8) and 2.213(7) Å. Cations are located on the symmetry centers. The cation in trans-pyH[MBr₄py₂] can be replaced. Trans-NH₄[MBr₄py₂] · H₂O, Cs[MBr₄py₂], LH[MBr₄py₂] (M = Mo, W; L = 4-methylpyridine, 4-pic; 2,2′-bipyridyl, bipy) were prepared. The compounds of molybdenum and tungsten with the same chemical composition are isostructural. All compounds react with pyridine and 4-methylpyridine. The products are trans-MBr₃L₃, and in the case of molybdenum, also trans-MoBr₃py₂(4-pic). Bromine oxidizes trans-M^I[MBr₄py₂] to trans-MBr₄py₂.     

Die Kristallstruktur von Cs2PrO3, sowie über Cs2CeO3, Cs2TbO3, Rb2CeO3 und Rb2TbO3

Crystal Structure of Cs₂PrO₃ and also about Cs₂CeO₃, Cs₂TbO₃, Rb₂CeO₃, and Rb₂TbO₃ New prepared Cs₂PrO₃ (dark brown) is orthorhombic due to single crystal data, K₂PbO₃ type of structure (Cmc2₁) with a = 11.4₇, b = 7.72₂, c = 6.42₇ Å and Z = (4). Cs₂CeO₃ (colourless, a = 11.49₅, b = 7.75₃, c = 6.43₇ Å), Cs₂TbO₃ (red-brown, a = 11.3₇, b = 7.72₆, c = 6.14₂ Å), and the low-temperature form of (LT-) Rb₂TbO₃ (red-brown, a = 10.9₁, b = 7.39₀, c = 6.09₉ Å) are isotypic. Hitherto unknown HT-Rb₂CeO₃ (high-temperature form, colourless, a = 3.83₇, c = 18.4₇ Å, Z = 2, hexagonal) and “HT-Rb₂TbO₃” (red-brown, a = 3.77₃, c = 18.0₀ Å) correspond according to powder-data to the α-NaFeO₂ type of structure. Cs₂PrO₃ has been measured magnetically (100–300 K). The Madelung Part of Lattice Energy (MAPLE) is calculated and discussed.     

K2Br(OH) und Rb2Br(OH): Zwei neue ternäre Alkalimetallhalogenidhydroxide mit ausgeprägter Strukturverwandtschaft zu KOH bzw. RbOH

K₂Br(OH) and Rb₂Br(OH): Two New Ternary Alkali Metal Halide Hydroxides with a Pronounced Structural Relationship to KOH resp. RbOH Two isotypic compounds K₂Br(OH) and Rb₂Br(OH) were prepared in the systems KOH/KBr and RbOH/RbBr. Their structures were determined by single crystal X-ray methods: K₂Br(OH): P2₁/m, Z = 2, a = 6.724(1) Å, b = 4.272(4) Å, c = 8.442(2) Å, β = 108.14(2)°, Z(F_o) = 651 with (F_o)² ≥ 3σ(F_o)², Z(parameter) = 28, R/R_w = 0.041/0.047 Rb₂Br(OH): P2₁/m, Z = 2, a = 6.918(3) Å, b = 4.483(2) Å, c = 8.850(5) Å, β = 108.08(6)°, Z(F_o) = 326 mit (F_o)² ≥ 3σ(F_o)², Z(parameter) = 27, R/R_w = 0.074/0.082. The compounds are built up by chains of [M₂(OH)⁺] connected via Br^?. The structure of the chains as well as their orientation to one another show a pronounced relationship to the structures of the room temperature modifications of the isotypic binary hydroxides KOH and RbOH.     

Synthesis,crystal structure,magnetism, and absorption spectra of A2UX5 Type Halides (A = K,Rb; X = Cl,Br, I)

The ternary uranium(III) halides A₂UX₅ (A = K, Rb; X = Cl, Br, I) have been prepared from the binary components AX and UX₃ in sealed tantalum containers. According to their Guinier X-ray powder patterns, they all crystallize with the K₂PrCl₅/Y₂HfS₅ type of structure. Lattice constants for ambient temperature are reported. Single-crystal structure refinemens were undertaken for K₂UI₅ and Rb₂UCl₅. Magnetic susceptibility data were recorded with a SQUID magnetometer from liquid helium to room temperature. One-dimensional (intrachain) and three-dimensional antiferromagnetic ordering occur at low temperatures dependent upon the U³⁺? U³⁺ distance. Absorption spectra were recorded between 4 000 and 28 000 cm^?1. They show f—f transitions typical for U³⁺ and, depending on the halide, very strong f—d transitions above 14 000 to 15 000 cm^?1, respectively.     

Ternäre Halogenide vom Typ A3MX6. III [1, 2]. Synthese,Strukturen und Ionenleitfähigkeit der Halogenide Na3MX6 (X = Cl,Br)

Ternary Halides of the A₃MX₆ Type. III [1, 2]. Synthesis, Structures, and Ionic Conductivity of the Halides Na₃MX₆ (X = Cl, Br) The bromides Na₃MBr₆ crystallize with the stuffed LiSbF₆-type structure (type I; M = Sm? Gd) or with the structure of the mineral cryolite (type II; M = Gd? Lu). The structure types were refined from single crystal X-ray data (Na₃SmBr₆: trigonal, space group R3 , a = 740.8(2) pm, c = 1 998.9(8) pm, Z = 3; Na₃YBr₆: monoclinic, space group P2₁/n, a = 721.3(4) pm, b = 769.9(2) pm, c = 1 074.8(4) pm, β = 90.60(4)°, Z = 2). Reversible phase transitions from one structure to the other occur. The phase transition temperatures were determined for the bromides as well as for the chlorides Na₃MCl₆ (M = Eu? Lu). The refinement of both structures for one compound was possible for Na₃GdBr₆ (I: trigonal, space group R3 , a = 737.1(5) pm, c = 1 887(2) pm, Z = 3; II: monoclinic, space group P2₁/n, a = 725.2(1) pm, b = 774.1(3) pm, c = 1 080.1(3) pm, β = 90.76(3)°, Z = 2). All compounds exhibit ionic conductivity of the sodium ions which decreases with the change from type I to type II. The conductivity of the bromides is always higher when compared with the respective chlorides.