Untersuchungen zum chemischen Transport der wasserfreien Europiumchloride EuCl2, Eu5Cl11, Eu4Cl9, Eu14Cl33 und EuCl3 mit AlCl3

Investigations on the Chemical Transport of the Anhydrous Europium Chlorides EuCl₂, Eu₅Cl₁₁, Eu₄Cl₉, Eu₁₄Cl₃₃ and EuCl₃ with AlCl₃ . Aluminium trichloride is known as a versatile transporting agent for rare-earth trichlorides, but in case of europium the dichloride EuCl₂ as well as the mixed-valence compounds Eu₅Cl₁₁, Eu₄Cl₉ and Eu₁₄Cl₃₃ can be chemically transported, too. The observed transport directions are discussed in terms of partial-pressure and solubility diagrams. Under appropriate conditions the gas-phase complex Eu(AlCl₄)₂ is obtained as a crystalline solid. Being isostructural with Sr(AlCl₄)₂, the crystal structure of which has been determined very recently, Eu(AlCl₄)₂ is the first chloroaluminate of a rare-earth element in the divalent state.     

Quaternäre Chloride des zweiwertigen Europiums mit dreiwertigen Übergangsmetallen: Synthese und Kristallstruktur von Na6Eu3M4Cl24 (M = Ti,V, Cr)

Quaternary Chlorides of Divalent Europium and Trivalent Transition Metal Ions: Synthesis and Crystal Structure of Na₆Eu₃M₄Cl₂₄ (M = Ti, V, Cr) The reaction of EuCl₂, NaCl and MCl₃ (M = Ti, V, Cr) yields the chlorides Na₆Eu₃M₄Cl₂₄. According to X‐ray single crystal investigations, their crystal structure is a variant of the monoclinic cryolite‐type structure. One crystallographic site is occupied by Na1 and Eu simultaneously. For charge compensation the Na2 site is not fully occupied. In Na₆Eu₃Ti₄Cl₂₄ (P2₁/n, Z = 1/2, a = 663.8(1) pm, b = 718.3(1) pm, c = 953.3(2) pm, β = 91.55(2)°, R_all = 0.0314), Na₆Eu₃V₄Cl₂₄ (P2₁/n, Z = 1/2, a = 660.4(1) pm, b = 715.8(1) pm, c = 946.5(2) pm, β = 91.41(2)°, R_all = 0.0313) and Na₆Eu₃Cr₄Cl₂₄ (P2₁/n, Z = 1/2, a = 654.8(1) pm, b = 706.5(1) pm, c = 945.4(2) pm, β = 91.07(2)°, R_all = 0.0368) the ratio of Na1 : Eu amounts to 5 : 3. The colours of the compounds, orange yellow for M = Ti, orange red for M = V and dark red for M = Cr, indicate electronic interactions between Eu²⁺ and M³⁺.     

(Hg2)Hg(OH)2(ClO4)2: Das erste gemischtvalente Quecksilberperchlorat

(Hg₂)Hg(OH)₂(ClO₄)₂: The First Mixed Valent Mercury Perchlorate Colorless single crystals of (Hg₂)Hg(OH)₂(ClO₄)₂ (C2/c, Z = 4, a = 1847.7(5), b = 490.8(1), c = 1086.2(3) pm, β = 93.80(2)°, R_all = 0.0610) were obtained as a side product during the dehydration of Hg₂(ClO₄)₂ · 2H₂O. The crystal structure consists of infinite zig‐zag chains {_∞¹[(Hg₂)_1/2(OH)Hg_1/2]⁺}₂ which are separated by the ClO₄^— ions.     

Eu2+在多相体系中的发光

研究了基质结构与离子半径的形成关系和Ｅｕ２＋在同时形成的多相体系中的发光现象．在ＭＭｇＡｌ１０Ｏ１７体系中,当Ｍ离子半径小于０．１０ｎｍ时,体系形成多相共存．首次观察到在磁铅矿、尖晶石和α－Ａｌ２Ｏ３三相同时共存体系中,Ｅｕ２＋优先占据离子半径和电荷与之匹配的磁铅矿中的Ｃａ２＋离子格位,不进入尖晶石和α－Ａｌ２Ｏ３晶相中的Ｍｇ２＋、Ａｌ３＋离子格位,仅产生Ｅｕ２＋的ｄ→ｆ跃迁宽带发射,且观察不到Ｅｕ３＋的特征光谱;在尖晶石和α－Ａｌ２Ｏ３两相同时共存体系中,Ｅｕ２＋可进入尖晶石和α－Ａｌ２Ｏ３晶相中的Ｍｇ２＋、Ａｌ３＋离子格位,分别产生Ｅｕ２＋的ｄ→ｆ和ｆ→ｆ跃迁发射,同时还观察到相当强的Ｅｕ３＋的特征光谱;在α－Ａｌ２Ｏ３单一相中,Ｅｕ２＋产生ｆ→ｆ跃迁发射,并观察到明显的Ｅｕ３＋的特征光谱,在α－Ａｌ２Ｏ３与γ－Ａｌ２Ｏ３同时存在的混合相中,Ｅｕ２＋的ｆ→ｆ跃迁发射消失,产生新的ｄ→ｆ跃迁宽带发射     

Ce3Cl5[SiO4] und Ce3Cl6[PO4]: Ein chloridreiches Chloridsilicat und ‐phosphat des Cers im Vergleich

Ce₃Cl₅[SiO₄] and Ce₃Cl₆[PO₄]: A Chloride‐Rich Chloride Silicate of Cerium as Compared to the Phosphate By reacting CeCl₃ with CeO₂, cerium and SiO₂, or P₂O₅, respectively, in molar ratios of 5 : 3 : 1 : 3 or 8 : 3 : 1 : 2, respectively, in sealed evacuated silica tubes (7 d, 850 °C) colorless, rod‐shaped single crystals of Ce₃Cl₅[SiO₄] (orthorhombic, Pnma; a = 1619.7(2), b = 415.26(4), 1423.6(1) pm; Z = 4) and Ce₃Cl₆[PO₄] (hexagonal, P6₃/m; a = 1246.36(9), c = 406.93(4) pm; Z = 2) are obtained as products insensitive to air and water. Excess cerium trichloride as flux promotes crystal growth and can be rinsed off again with water after the reaction. The crystal structures are determined by discrete [SiO₄]^4– or [PO₄]^3– tetrahedra as isolated units. Both, the chloride silicate Ce₃Cl₅[SiO₄] and the chloride phosphate Ce₃Cl₆[PO₄], exhibit structural similarities to CeCl₃ (UCl₃ type), when four or three Cl^– anions are each substituted formally by one [SiO₄]^4– or [PO₄]^3– unit, respectively, in the tripled formula (Ce₃Cl₉). The coordination number for Ce³⁺ is thus raised from nine in CeCl₃ to ten in Ce₃Cl₅[SiO₄] and Ce₃Cl₆[PO₄], along with a drastic reduction of the molar volume with the transition from Ce₃Cl₉ (V_m = 186.17 cm³/mol) to Ce₃Cl₅[SiO₄] (V_m = 144.15 cm³/mol) and Ce₃Cl₆[PO₄] (V_m = 164.84 cm³/mol). The polyhedra of coordination around Ce³⁺ can be described as quadruple‐capped trigonal prisms, which in addition to seven Cl^– anions each also show another three oxygen atoms of two ortho‐silicate or ortho‐phosphate tetrahedra, respectively.     

Zwei neue Silicat-Chloride mit zweiwertigem Europium: LiEu3[SiO4]Cl3 und Li7Eu8[SiO4]4Cl7

Two New Silicate-Chlorides with Divalent Europium: LiEu₃[SiO₄]Cl₃ and Li₇Eu₈[SiO₄]₄Cl₇ LiEu₃[SiO₄]Cl₃ was prepared by reaction of LiCl with Eu₂SiO₄ and Li₇Eu₈[SiO₄]₄Cl₇ from Li with Eu₂O₃, SiO₂ and LiCl. The crystal structures of LiEu₃[SiO₄]Cl₃ (Pmna, a = 946.95(13); b = 699.52(8); c = 1 368.0(2) pm; Z = 4; R1 = 0.0325, R2_w = 0.0642) and Li₇Eu₈[SiO₄]₄Cl₇ (P2₁/c; a = 851.85(5); b = 948.62(7); c = 1 679.0(2) pm; β = 96.221(8)°; Z = 2; R1 = 0.0352, R2_w = 0.0744) were determined from four-circle diffractometer data. LiEu₃[SiO₄]Cl₃ contains [Li(SiO₄)₂] units and LiCl₆ octahedra while in Li₇Eu₈[SiO₄]₄Cl₇ larger ?lithosilicate”? groups are found. In both structures, the Eu²⁺ ions are coordinated mostly eightfold by O^2? and Cl^? ligands.     

Metallampullen als Mini‐Autoklaven: Synthese und Kristallstrukturen der Ammoniakate [Al(NH3)4Cl2][Al(NH3)2Cl4] und (NH4)2[Al(NH3)4Cl2][Al(NH3)2Cl4]Cl2

Metal Ampoules as Mini‐Autoclaves: Syntheses and Crystal Structures of [Al(NH₃)₄Cl₂][Al(NH₃)₂Cl₄] and (NH₄)₂[Al(NH₃)₄Cl₂][Al(NH₃)₂Cl₄]Cl₂ The salts [Al(NH₃)₄Cl₂]⁺[Al(NH₃)₂Cl₄]^–≡AlCl₃ · 3 NH₃ ( 1 ) and (NH₄⁺)²[Al(NH₃)₄Cl₂]⁺[Al(NH₃)₂Cl₄]^–(Cl^–)₂≡ AlCl₃ · 3 NH₃ · (NH₄)Cl ( 2 ) have been obtained as single crystals during the reactions of aluminum and aluminum trichloride, respectively, with ammonium chloride in sealed Monel metal containers. The crystal structure of 1 was determined again [triclinic, P‐1; a = 574.16(10); b = 655.67(12); c = 954.80(16) pm; α = 86.41(2); β = 87.16(2); γ = 84.89(2)°], that of 2 for the first time [monoclinic, I2/m; a = 657.74(12); b = 1103.01(14); c = 1358.1(3) pm; β = 103.24(2)°].     

Pr6C2‐Doppeltetraeder in Pr6C2Cl10 und Pr6C2Cl5Br5

Pr₆C₂‐Bitetrahedra in Pr₆C₂Cl₁₀ and Pr₆C₂Cl₅Br₅ The compounds Pr₆C₂Cl₁₀ and Pr₆C₂Cl₅Br₅ are prepared by heating stoichiometric mixtures of Pr, PrCl₃, PrBr₃ and C in sealed Ta capsules at 810 ? 820 °C. They form bulky transparent yellow to green and moisture sensitive crystals which have different structures: space groups C2/c, (a = 13.687(3) Å, b = 8.638(2) Å, c = 15.690(3) Å, β = 97.67(3)° for Pr₆C₂Cl₁₀ and a = 13.689(1) Å, b = 10.383(1) Å, c = 14.089(1) Å, β = 106.49(1)° for Pr₆C₂Cl₅Br₅). Both crystal structures contain C‐centered Pr₆C₂ bitetrahedra, linked via halogen atoms above edges and corners in different ways. The site selective occupation of the halogen positions in Pr₆C₂Cl₅Br₅ is refined in a split model and analysed with the bond length‐bond strength formalism. The compound is further characterized via TEM investigations and magnetic measurements (μ_eff = 3.66 μ_B).     

Eu5F[SiO4]3 und Yb5S[SiO4]3: Gemischtvalente Lanthanoid‐Silicate mit Apatit‐Struktur

Eu₅F[SiO₄]₃ and Yb₅S[SiO₄]₃: Mixed‐Valent Lanthanoid Silicates with Apatite‐Type of Structure By the reaction of Eu, EuF₃, Eu₂O₃ with SiO₂ in evacuated gold ampoules, using NaF as flux, at a temperature of 1000 °C for ten hours, dark‐red, platelet‐shaped single crystals of Eu₅F[SiO₄]₃ are obtained. Similarly dark‐red, but pillar‐shaped single crystals of Yb₅S[SiO₄]₃ are obtained by the reaction of Yb, Yb₂O₃ and S with SiO₂ in the presence CsBr as flux in evacuated silica ampoules at 850 °C and an annealing time of seven days. Both compounds crystallize hexagonally (P6₃/m, Z = 2; Eu₅F[SiO₄]₃: a = 954.79(9), c = 704.16(6) pm; Yb₅S[SiO₄]₃: a = 972.36(9), c = 648.49(6) pm) in the case of Eu₅F[SiO₄]₃ analogous to the mineral fluorapatite and for Yb₅S[SiO₄]₃ as a bromapatite—type variety. The crystal structure containing isolated [SiO₄]^4— tetrahedra distinguishes two rare‐earth cation positions with coordination numbers of nine (M1) and seven (M2), in which the position M1 of the europium fluoride silicate is almost exclusively occupied by Eu²⁺ cations, whereas in ytterbium sulfide silicate it contains di‐ and trivalent Yb cations in the ratio 1 : 1. In both cases, however, the M2 position is only populated with M³⁺.     

Na2[Pr4O2]Cl9 und K2[Pr4O2]Cl9, die ersten reduzierten quaternären Praseodymchloride mit anti-SiS2-analogen [Pr4/2O]-Ketten

Na₂[Pr₄O₂]Cl₉ and K₂[Pr₄O₂]Cl₉, the First Reduced Quaternary Praseodymium Chlorides with Anti-SiS₂ Analogous [Pr_4/2O] Chains The compounds A₂[Pr₄O₂]Cl₉ (A = Na, K) are the first reduced quaternary praseodymium chlorides with anti-SiS₂ analogous [Pr_4/2O] chains. Synthesis took place in the temperature range from 900 to 600°C in silica-jacketed niobium containers from Pr metal, PrCl₃, PrOCl and NaCl (KCl) as starting materials. The X-ray structure analysis of a single crystal of Na₂[Pr₄O₂]Cl₉ (monoclinic, P2₁/m (No. 11), Z = 2, a = 812.2(2) pm, b = 1 134.1(2) pm, c = 937.6(2) pm, β = 106.51(2)°, R = 0.048, R_w = 0.037) exhibits trans-edge connected chains of [Pr_4/2O] tetrahedra running along [001] which are connected by surrounding common chloride ions forming layers parallel to (001). These layers are connected by further chloride ions to a three-dimensional network. The sodium ions surrounded by a heavily distorted octahedron of chloride ions are placed between the layers. The X-ray structure analysis of a single crystal of the otherwise isotypic K₂[Pr₄O₂]Cl₉ (monoclinic, P2₁/m (No. 11), Z = 2, a = 820.6(2) pm, b = 1 133.2(4) pm, c = 949.2(3) pm, β = 103.94(2)°, R = 0.073, R_w = 0.054) shows that potassium is coordinated by nine chloride ions.     

Zwei neue Sulfidchloride der Lanthanide: Synthese und Kristallstruktur von Pr7S6Cl9 und Nd7S6Cl9

Two Novel Sulfide Chlorides of the Lanthanides: Synthesis and Crystal Structure of Pr₇S₆Cl₉ and Nd₇S₆Cl₉ The reactions of the elemental lanthanides (M = Pr and Nd, resp.) with sulfur and the respective trichlorides (MCl₃) in evacuated silica tubes (850 °C, 7 d) yield single-phase sulfide chlorides of the composition M₇S₆Cl₉ when appropriate molar ratios (4 : 6 : 3) of the reactants (M : S : MCl₃) are used. A slight excess of trichloride as a flux promotes the formation of lath-shaped transparent single crystals (Pr₇S₆Cl₉: pale green, Nd₇S₆Cl₉: pale violet) which prove to be water soluble and sensitive to hydrolysis. The crystal structure was determined from X-ray single-crystal data taking Nd₇S₆Cl₉ (monoclinic, P2/c (no. 13); a = 2425.0(9), b = 664.2(2), c = 691.8(2) pm, β = 97.43(3)°, Z = 2; R = 0.060, R_w = 0.048) as an example. According to Guinier powder data, Pr₇S₆Cl₉ crystallizes isotypically with a = 2441.6(9), b = 669.1(2), c = 696.3(2) pm, and β = 97.74(3)°. Thus four crystallographically independent cations (M³⁺) are present, each except for M2 coordinated by four S^2– but differing in the number of their next Cl^– neighbors. The figures of coordination are completed by four Cl^– about M1 (square antiprism, CN = 8) and by three Cl^– each about M3 and M4 (monocapped trigonal prisms, CN = 7, 2 Ç ). In contrast, M2 is coordinated by only two S^2– but five (plus one) Cl^– as bicapped trigonal prism (CN = 7 + 1). Eight crystallographically different anions, although indistinguishable by X-ray diffraction, exhibit coordination numbers of four (3 Ç S^2– and 1 Ç Cl^–) and three (4 Ç Cl^–) with respect to the cations. So PbO-analogous layers of the composition ²_∞{[(S6/7Cl_1/7)M_4/4]₇}⁸⁺ parallel (010) are formed, consisting of 6/7 of S^2– and only 1/7 of Cl^– as centering anions for the edge-shared (M³⁺)₄ tetrahedra for reasons of charge neutrality. These cationic layers are held together by alternatingly sheathed layers of Cl^– with only threefold coordinated anions.     

M3S2Cl5 (M = Nd,Dy): Zwei Formen von Sulfidchloriden des Neodyms und Dysprosiums mit Doppelketten 1∞{[S2M3]5+} kantenverknüpfter [SM4]‐Tetraeder

M₃S₂Cl₅ (M = Nd, Dy): Two Types of Neodymium and Dysprosium Sulfide Chlorides with Double Chains ¹_∞{[S₂M₃]⁵⁺} of Edge‐Sharing [SM₄] Tetrahedra Nd₃S₂Cl₅ (monoclinic, P2₁/c; a = 2176.9(2), b = 654.62(6), c = 703.91(7) pm, β = 97.879(8)°; Z = 4) and Dy₃S₂Cl₅ (orthorhombic, Pnma; a = 682.34(7), b = 2153.2(2), c = 638.21(6) pm; Z = 4) are formed by reacting neodymium or dysprosium metal with sulfur and the respective trichloride (MCl₃) in suitable molar ratios (M : S : MCl₃ = 4 : 6 : 5) within ten days in evacuated silica tubes at 850 °C. The crystal structure of Dy₃S₂Cl₅ (P 2₁/n 2₁/m 2₁/a) can be transferred to that of Nd₃S₂Cl₅ (P 1 1 2₁/a ≡ P 1 2₁/c 1) through a lattice‐equivalent transition of the index 2 (t2) by the loss of two screw axes, one diagonal glide plane, and one simple mirror plane. The moisture sensitive, transparent, pale violet (Nd₃S₂Cl₅) or faint yellow (Dy₃S₂Cl₅) sulfide chlorides both exhibit infinite double strands {[S₂M₃]⁵⁺} (M = Nd, Dy) as main structural feature, which can be built of two condensed anti‐SiS₂‐analogous chains of trans‐edge sharing [SM₄] tetrahedra. These are running parallel [001] in Nd₃S₂Cl₅ or [100] in Dy₃S₂Cl₅ and arrange as a hexagonal closest packing of rods. The coordination polyhedra about the M³⁺ cations can be described as bicapped trigonal prisms (CN = 8) in both crystal structures, where by the collapse of two symmetrically equivalent particles the total number of three in the case of Nd₃S₂Cl₅ is reduced to two crystallographically different ones in Dy₃S₂Cl₅. Correspondingly, only three independent Cl^– anions are present in the crystal structure of Dy₃S₂Cl₅ for charge compensation and three‐dimensional cross‐linkage of the {[S₂M₃]⁵⁺} strands as compared to five in Nd₃S₂Cl₅. The analogue holds for the S^2–anions: The two distinct ones in the monoclinic Nd₃S₂Cl₅ structure unite to a single one in orthorhombic Dy₃S₂Cl₅.     

Zwei neue Erdalkalimetall-Oxoindate: BaCa2In6O12 und BaSr2In6O12

Two New Alkaline-Earth-Oxoindates: BaCa₂In₆O₁₂ and BaSr₂In₆O₁₂ The hitherto unknown compounds (I): BaCa₂In₆O₁₂ and (II): BaSr₂In₆O₁₂ were prepared and examined by single crystal X-Ray work. (I) and (II) crystallize with hexagonal symmetry, space group C? P6₃/m, with (I): a = 9.880, c = 3.211 Å; (II): a = 9.9443; c = 3.2671 Å, Z = 1. Both compounds are isotypic to the metastable oxide AM₂Ln₆O₁₂, but without metastable behavior. The [In₆O₁₂]^6? network is occupied by the alkaline earth ions. One of the tunnels is stuffed by Ca²⁺ and Sr²⁺ respectively, the other one by Ba²⁺ in a statistical distribution on possible point positions. (I) and (II) prove the existence of the AM₂Ln₆O₁₂-type in respect to small Ln³⁺ ions.     

Halogenide der Seltenerdmetalle Ln4X5Z. Teil 3: Das Chlorid La4Cl5B4 – Präparation,Struktur und Verwandtschaft zu La4Br5B4, La4I5B4

Rare Earth Halides Ln₄X₅Z. Part 3: The Chloride La₄Cl₅B₄ – Preparation, Structure, and Relation to La₄Br₅B₄, La₄I₅B₄ La₄Cl₅B₄ is synthesized by reaction of LaCl₃, La metal and boron in sealed Ta containers at 1050 °C < T < 1350 °C. It crystallizes in the monoclinic space group C2/m with a = 16.484(3) Å, b = 4.263(1) Å, c = 9.276(2) Å and β = 120.06(3)°. Ce₄Cl₅B₄ is isotypic, a = 16.391(3) Å, b = 4.251(1) Å, c = 9.180(2) Å and β = 120.20(3)°. The La atoms form strings of trans-edge shared La octahedra, and the B atoms inside the strings form B₄-rhomboids, which are condensed to chains via opposite corners. The Cl atoms interconnect the channels according to La₂La_4/2Clⁱ⁻ⁱ_6/2Cl^i−a_2/2Cl^a−i_2/2. The crystal structures of the bromide and the iodide are comparabel, however, the interconnection of the strings is different in the three structure types, as 14 Cl, 13 Br and 12 I atoms surround the La₆ octahedra.     

NaEu2Cl6 und Na0,75Eu2Cl6: Gemischtvalente Chloride des Europiums mit Natrium

NaEu₂Cl₆ and Na_0.75Eu₂Cl₆: Mixed Valent Chlorides of Europium with Sodium The reaction of Na₂EuCl₅ with Eu metal in sealed gold tubes yields blue single crystals of NaEu₂Cl₆. It crystallizes with the hexagonal crystal system (space group P6₃/m) with a = 755.74(8) pm, c = 429.81(5) pm, Z = 1; the structure is closely related to the UCl₃-type. Green single crystals of Na_0.75Eu₂Cl₆ were first obtained as a by-product in the synthesis of Na₂EuCl₅ in evacuated silica tubes and may be prepared by reduction of EuCl₃ with sodium. Na_0.75Eu₂Cl₆ crystallizes isotypic to NaEu₂Cl₆ with a = 753.69(11) pm and c = 416.3(2) pm.     

Zwei Chloridsilicate des Yttriums: Y3Cl[SiO4]2 und Y6Cl10[Si4O12]

Two Chloride Silicates of Yttrium: Y₃Cl[SiO₄]₂ and Y₆Cl₁₀[Si₄O₁₂] The chloride‐poor yttrium(III) chloride silicate Y₃Cl[SiO₄]₂ crystallizes orthorhombically (a = 685.84(4), b = 1775.23(14), c = 618.65(4) pm; Z = 4) in space group Pnma. Single crystals are obtained by the reaction of Y₂O₃, YCl₃ and SiO₂ in the stoichiometric ratio 4 : 1 : 6 with ten times the molar amount of YCl₃ as flux in evacuated silica tubes (7 d, 1000 °C) as colorless, strongly light‐reflecting platelets, insensitive to air and water. The crystal structure contains isolated orthosilicate units [SiO₄]^4– and comprises cationic layers {(Y2)Cl}²⁺ which are alternatingly piled parallel (010) with anionic double layers {(Y1)₂[SiO₄]₂}^2–. Both crystallographic different Y³⁺ cations exhibit coordination numbers of eight. Y1 is surrounded by one Cl^– and 7 O^2– anions as a distorted trigonal dodecahedron, whereas the coordination polyhedra around Y2 show the shape of bicapped trigonal prisms consisting of 2 Cl^– and 6 O^2– anions. The chloride‐rich chloride silicate Y₆Cl₁₀[Si₄O₁₂] crystallizes monoclinically (a = 1061,46(8), b = 1030,91(6), c = 1156,15(9) pm, β = 103,279(8)°; Z = 2) in space group C2/m. By the reaction of Y₂O₃, YCl₃ and SiO₂ in 2 : 5 : 6‐molar ratio with the double amount of YCl₃ as flux in evacuated silica tubes (7 d, 850 °C), colorless, air‐ and water‐resistant, brittle single crystals emerge as pseudo‐octagonal columns. Here also a layered structure parallel (001) with distinguished cationic double‐layers {(Y2)₅Cl₉}⁶⁺ and anionic layers {(Y1)Cl[Si₄O₁₂]}^6– is present. The latter ones contain discrete cyclo‐tetrasilicate units [Si₄O₁₂]^8– of four cyclically corner‐linked [SiO₄] tetrahedra in all‐ecliptical arrangement. The coordination sphere around (Y1)³⁺ (CN = 8) has the shape of a slightly distorted hexagonal bipyramid comprising 2 Cl^– and 6 O^2– anions. The 5 Cl^– and 2 O^2– anions building the coordination polyhedra around (Y2)³⁺ (CN = 7) form a strongly distorted pentagonal bipyramid.     

BaClSCN und Na4Mg(SCN)6: Zwei neue wasserfreie Thiocyanate der Erdalkalimetalle

BaClSCN and Na₄Mg(SCN)₆: Two New Thiocyanates of the Alkaline Earth Metals The reaction of BaCl₂ and NaSCN yielded single crystals of BaClSCN (P 2₁/m, Z = 2, a = 588.6(1) pm, b = 465.8(1) pm, c = 864.4(2) pm, β = 100.20(3)°, R_all = 0.0214). According to X‐ray single crystal investigations, the structure consists of anionic SCN^– and Cl^– layers, respectively, alternating in [001] direction. The SCN^–‐ions are connected via the N and the S atoms to the cations. Na₄Mg(SCN)₆ (P 3 1c, Z = 2, a = 863.8(1) pm, c = 1399.3(2) pm, R_all = 0.0870), which was obtained from a melt of NaSCN and MgCl₂, consists of anionic layers with the cations between the sheets. The holes are filled altenatingly by Na⁺ or Na⁺ and Mg²⁺. Regarding only the C‐atoms of the SCN^– group, the structure can be described as a hexagonal closest packing whith the cations occupying 5/6 of the octahedral voids.     

Die Benzonitril‐Addukte [Ho2Cl6(PhCN)6] und [HoCl3(PhCN)]: Synthese,Kristallstrukturen, FIR‐ und MIR‐Spektroskopische Untersuchungen

The Benzonitrile Adducts [Ho₂Cl₆(PhCN)₆] and equation/tex2gif-stack-4.gif [HoCl₃(PhCN)]: Syntheses, Crystal Structures, FarIR and MIR Spectroscopy Investigations Transparent light pink crystals of the compound [Ho₂Cl₆(PhCN)₆] were obtained by the reaction of a mixture of HoCl₃ and AlCl₃ with benzonitrile at 150μ °C. Transparent pink crystals of the compound equation/tex2gif-stack-5.gif[HoCl₃(PhCN)] were obtained by the same reaction under solvothermal conditions at 200μ °C. [Ho₂Cl₆(PhCN)₆] exhibits a dimeric structure of linked pentagonal bipyramids whereas equation/tex2gif-stack-6.gif[HoCl₃(PhCN)] forms a layer structure of trigonal Cl prisms around Ho, linked via corners and separated by coordinating PhCN molecules.