ISOLATED B10Se20-MACROTETRAHEDRA IN THE NOVEL QUATERNARY SELENOBORATE Li6 - 2xSr2 +xB10Se20 (x ≈ 0.7)

We report the synthesis and crystal structure of Li_6-2xSr_2+xB₁₀Se₂₀ (x ≈ 0.7). Li_6?2xSr_2+xB₁₀Se₂₀ (x ≈ 0.7) crystallizes tetragonal and its lattice parameters are a = 14.735(1) Å, c = 14.144(2) Å. The structure solution in space group I4₁/a (No. 88) yielded residuals of R1 = 0.036 and wR2 = 0.078.     

Li6+2x[B10Se18]Sex (x ≈ 2), ein ionenleitendes Doppelsalz

Li_6+2x[B₁₀Se₁₈]Se_x (x ≈ 2), an Ion‐conducting Double Salt Li_6+2x[B₁₀Se₁₈]Se_x (x ≈ 2) was prepared in a solid state reaction from lithium selenide, amorphous boron and selenium in evacuated carbon coated silica tubes at a temperature of 800 °C. Subsequent cooling from 600 °C to 300 °C gave amber colored crystals with the following lattice parameters: space group I2/a (at 173 K); a = 17.411(1) Å, b = 21.900(1) Å, c = 17.820(1) Å, β = 101.6(1)°. The crystal structure contains a well‐defined polymeric selenoborate network of composition ([B₁₀Se₁₆Se_4/2]^6?)_n consisting of a system of edge‐sharing [B₁₀Se₁₆Se_4/2] adamantanoid macro‐tetrahedra forming large channels in which a strongly disorderd system of partial occupied Li⁺ cations and additional disordered Se^2? anions is observed. The crystal structure of the novel selenoborate is isotypic to Li_6+2x[B₁₀S₁₈]S_x (x ≈ 2) [1]. X‐ray and ⁷Li magic‐angle spinning NMR data suggest that the site occupancies of the three crystallographically distinct lithium ions exhibit a significant temperature dependence. The lithium ion mobility has been characterized by detailed temperature dependent NMR lineshape and spin‐lattice relaxation measurements.     

Li5B7S13 und Li9B19S33: Zwei Lithiumthioborate mit neuen hochpolymeren Anionengerüsten

Li₅B₇S₁₃ and Li₉B₁₉S₃₃: Two Lithium Thioborates with Novel Highly Polymeric Anion Networks Li₅B₇S₁₃ (C2/c; a = 17.304(2) Å, b = 21.922(3) Å, c = 12.233(2) Å, β = 134.91(1)°; Z = 8) and Li₉B₁₉S₃₃ (C2/c; a = 23.669(9) Å, b = 14.361(3) Å, c = 12.237(3) Å, β = 103.77(2)°; Z = 4) were prepared by reaction of stoichiometric amounts of lithium sulfide, boron, and sulfur at 750°C (Li₅B₇S₁₃) and 700°C (Li₉B₁₉S₃₃) with subsequent annealing. The crystal structures consist of interpenetrating, polymeric boron sulfur anion networks which are formed by corner-sharing of B₄S₁₀ and B₁₀S₂₀ units (Li₅B₇S₁₃), or B₁₉S₃₆ units (Li₉B₁₉S₃₃). The lithium cations are situated in between with a strong disorder in Li₉B₁₉S₃₃.     

Synthese und Kristallstrukturen des Zink‐Rhodiumborids Zn5Rh8B4 und der Lithium‐ Magnesium‐Rhodiumboride LixMg5−xRh8B4 (x = 1.1 und 0.5) und Li8Mg4Rh19B12

Synthesis and Crystal Structures of Zinc Rhodium Boride Zn₅Rh₈B₄ and the Lithium Magnesium Rhodium Borides Li_xMg_5?xRh₈B₄ (x = 1.1 and 0.5) and Li₈Mg₄Rh₁₉B₁₂ The title compounds were prepared by reaction of the elemental components in metal ampoules under argon atmosphere (1100 °C, 7 d). In the case of Zn₅Rh₈B₄ (orthorhombic, space group Cmmm, a = 8.467(2) Å, b = 16.787(3) Å, c = 2.846(1) Å, Z = 2) a BN crucible enclosed in a sealed tantalum container was used. The syntheses of Li_xMg_5?xRh₈B₄ (orthorhombic, space group Cmmm, Z = 2, isotypic with Zn₅Rh₈B₄, lattice constants for x = 1.1: a = 8.511(3) Å, b = 16.588(6) Å, c = 2.885(1) Å, and for x = 0.5: a = 8.613(1) Å, b = 16.949(3) Å, c = 2.9139(2) Å) and Li₈Mg₄Rh₁₉B₁₂ (orthorhombic, space group Pbam, a = 26.210(5) Å, b = 13.612(4) Å, c = 2.8530(5) Å, Z = 2) were carried out in tantalum crucibles enclosed in steel containers using lithium as a metal flux. The crystal structures were solved from single crystal X‐ray diffraction data. In both structures Rh atoms reside at z = 0 and all non‐transition metal atoms at z = 1/2. Columns of Rh₆B trigonal prisms running along the c‐axis are laterally connected to form three‐dimensional networks with channels of various cross sections containing Li‐, Mg‐, and Zn‐atoms, respectively. A very short Li‐Li distance of 2.29(7) Å is observed in Li₈Mg₄Rh₁₉B₁₂.     

Na2B2Se7, K2B2S7 und K2B2Se7: Drei Perchalkogenoborate mit neuem polymeren Anionengerüst

Na₂B₂Se₇, K₂B₂S₇, and K₂B₂Se₇: Three Perchalcogenoborates with a Novel Polymeric Anion Network Na₂B₂Se₇ (I 2/a; a = 11.863(4) Å, b = 6.703(2) Å, c = 13.811(6) Å, β = 109.41(2)°; Z = 4), K₂B₂S₇ (I 2/a; a = 11.660(2) Å, β = 6.827(1) Å, c = 12.992(3) Å, β = 106.78(3)°; Z = 4), and K₂B₂Se₇ (I 2/a; a = 12.092(4) Å, b = 7.054(2) Å, c = 13.991(5) Å, β = 107.79(3)°; Z = 4) were prepared by reaction of stoichiometric amounts of sodium selenide (potassium sulfide) with boron and sulfur or of potassium selenide and boron diselenide, respectively, at 600°C with subsequent annealing. The crystal structures consist of polymeric anion chains of composition ([B₂S₇]^2?)_n or ([B₂Se₇]^2?)_n formed by spirocyclically connected five-membered B₂S₃ (B₂Se₃) rings and six-membered B₂S₄ (B₂Se₄) rings. The nine-coordinate alkaline metal cations are situated in between.     

Na2B2S5 and Li2B2S5: Two Novel Perthioborates with Planar 1,2,4-Trithia-3,5-Diborolane Rings

For the first time perthioborates with trigonal planar coordination of boron were prepared. Na₂B₂S₅ (Pnma, a = 12.545(2) Å, b = 7.441(1) Å, c = 8.271(1) Å, Z = 4) and Li₂B₂S₅ (Cmcm, a = 15.864(1) Å, b = 6.433(1) Å, c = 6.862(1) Å, Z = 4) were obtained by reaction of the metal sulfides with stoichiometric amounts of boron and an excess of sulfur (effective molar ratio M:B:S = 1:1:4) at 600°C (650°C) and subsequent annealing. The non-isotypic structures contain exactly planar [B₂S₅]^2? groups consisting of five-membered B₂S₃ rings with one additional exocyclic sulfur on each of the boron atoms. The alkaline metal cations are four-coordinate (lithium) and (four + four)-coordinate (sodium) respectively.     

Sr3(BS3)2 und Sr3(B3S6)2: Zwei neue nicht‐oxidische Chalkogenoborate mit trigonal‐planar koordiniertem Bor

Sr₃(BS₃)₂ and Sr₃(B₃S₆)₂: Two Novel Non‐oxidic Chalcogenoborates with Boron in a Trigonal‐Planar Coordination The thioborates Sr₃(BS₃)₂ and Sr₃(B₃S₆)₂ were prepared from strontium sulfide, amorphous boron and sulfur in solid state reactions at a temperature of 1123 K. In a systematic study on the structural cation influence on this type of ternary compounds, the crystal structures were determined by single crystal X‐ray diffraction. Sr₃(BS₃)₂ crystallizes in the monoclinic spacegroup C2/c (No. 15) with a = 10.187(4) Å, b = 6.610(2) Å, c = 15.411(7) Å, β = 102.24(3)° and Z = 4. The crystal structure of Sr₃(B₃S₆)₂ is trigonal, spacegroup R3¯ (Nr. 148), with a = 8.605(1) Å, c = 21.542(4) Å and Z = 3. Sr₃(BS₃)₂ contains isolated [BS₃]^3— anions with boron in a trigonal‐planar coordination. The strontium cations are found between the layers of orthothioborate anions. Sr₃(B₃S₆)₂ consists of cyclic [B₃S₆]^3— anions and strontium cations, respectively.     

Cs2B2S4 – Ein Salz der dimeren Metathioborsäure

Cs₂B₂S₄ – A Derivative of the Dimeric Metathioboric Acid Cs₂B₂S₄ (structure: I4₁/acd; a = 7.270(1) Å, c = 35.737(7) Å; Z = 8; substructure: I4/mmm; a′ = 5.141(1) Å, c′ = 17.868(4) Å, Z = 2) is prepared by the reaction of cesium sulfide with stoichiometric amounts of boron and sulfur (effective molar ratio M:B:S = 2:2:4) at 600°C and subsequent annealing. The crystal structure contains isolated [B₂S₄]^2? groups consisting of four-membered B₂S₂ rings with two exocyclic sulfur atoms on each of the boron atoms. The cesium cations are nine-coordinate between these rings. The structural feature of two edge-sharing BS₃ groups forming an isolated anion appears for the first time in thioborate chemistry, although it is known as a part of the polymeric network in B₂S₃.     

Die Perthioborate RbBS3, TIBS3 und TI3B3S10

The Perthioborates RbBS₃, TIBS₃, and Tl₃B₃S₁₀ . RbBS₃ (P2₁/c, a=7.082(2) Å, b=11.863(4) Å, c=5.794(2) Å, β=106.54(2)°) was prepared as colourless, plate-shaped crystals by reaction of stoichiometric amounts of rubidium sulfide, boron, and sulfur at 600°C and subsequent annealing. TlBS₃ (P2₁/c, a=6.874(3) Å, b=11.739(3) Å, c=5.775(2) Å, β=113.08(2)°) which is isotypic with RbBS₃ was synthesized from a sample of the composition Tl₂S · 2 B₂S₃. The glassy product which was obtained after 7 h at 850°C was annealed in a two zone furnace for 400 h at 400→350°C. Yellow crystals of TlBS₃ formed at the warmer side of the furnace. Tl₃B₃S₁₀ (P1 , a=6.828(2) Å, b=7.713(2) Å, c=13.769(5) Å, α=104.32(2)°, β=94.03(3)°, γ=94.69(2)°) was prepared as yellow plates from stoichiometric amounts of thallium sulfide, boron, and sulfur at 850°C and subsequent annealing. All compounds contain tetrahedrally coordinated boron. The crystal structures consist of polymeric anion chains. In the case of RbBS₃ and TlBS₃ nonplanar five-membered B₂S₃ rings are spirocyclically connected via the boron atoms. To obtain the anionic structure of Tl₃B₃S₁₀ every third B₂S₃ ring of the polymeric chains of MBS₃ is to be substituted by a six-membered B(S₂)₂B ring.     

Zur Kenntnis der Fluoride zweiwertiger Lanthanoide. III. Neue Fluoroperowskite vom Typ CsLn1−xLn′xF3 und RbLn1−xLn′xF3 mit Ln = Eu2+ bzw. Sm2+ und Ln′ = Yb2+

On Fluorides of Divalent Lanthanoids. III. New Fluoroperovskites of the MLn_1?xLn′_xF₃ Type with M = Cs, Rb; Ln = Eu²⁺, Sm²⁺; Ln′ Yb²⁺ New fluoroperovskites with divalent lanthanoids have been prepared. They are: CsEu_1?xYb_xF₃, yellow, with x = 0.25, a = 4.737(1) Å; x = 0.50, a = 4.696(1) Å; x = 0.75, a = 4.653(1) Å; CsSm_xYb_1?xF₃, violet, with x = 0.25, a = 4.656(1) Å; x = 0.18, a = 4.645(1) Å, the latter mixed with Sm_0.68Yb_0.32F₃, a = 5.781(1) Å; RbEu_xYb_1?xF₃, orange, with x = 0.25, a = 4.573(1) Å; x = 0.23, a = 4.568(1) Å, the latter mixed with Eu_0.94Yb_0.06F₂, a = 5.827(1) Å; RbSm_0.13Yb_0.87F₃, brown, a = 4.555(1) Å.     

Darstellung und Kristallstruktur der Phasen Li26Na58Ba38Ex (E = N,H; x = 0 – 1)

Preparation and Crystal Structures of Li₂₆Na₅₈Ba₃₈E_x Phases (E = N, H; x = 0 – 1) Li₂₆Na₅₈Ba₃₈E_x (E = N, H; x = 0–1) were prepared as a majority phase by the reactions of the metals with Ba(N₃)₂ or BaH₂ at 250 °C for five days. According to single crystal and powder X‐ray diffraction investigation, all compounds are cubic, space group with the unit cell parameter a ranging from 27.335(2) (x = 0) to 27.554(3) (x = 1, E = N, H) Å and Z = 4. This compound series can be described as a filled variant of Li₁₃Na₂₉Ba₁₉, in which nitrogen or hydrogen atoms are found in the centre of Li₂₆ clusters in tetrahedral environment. Li₂₆Na₅₈Ba₃₈E_x represents a new group of metal‐rich compounds extending the growing family of subnitrides.     

Strukturen aus AIB2− und BaAl4−analogen Einheiten. I Die Verbindungen Sr4Pd5P5 und Sr2Pd3P3

Structures with AIB₂? and BaAl₄?type Units. I The Compounds Sr₄Pd₅P₅ and Sr₂Pd₃P₃ Sr₄Pd₅P₅ (Cmcm, a = 4.177(1) Å, b = 31.377(5) Å, c = 8.581(2) Å, Z = 4) und Sr₂ Pd₃P₃(Pmmm, a = 4.199(1) Å, b = 4.212(1) Å, c = 34.227(4) Å, Z = 4) have been prepared by heating the elements. Both structures contain exclusively units characteristic for the AIB_2? and BaAl₄?type. The ratio between isolated P-atoms and P₂?pairs is interpreted with an ionic splitting of the formulas.     

Spinelle mit substituierten Nichtmetallteilgittern. IV. Rötgenographische Untersuchung der Systeme CuCr2(S1−xSex)4 und CuCr2(Se1−xTex)4

Spinels with substituted Nonmetal Sublattices. IV. CuCr₂(S_1?xSe_x)₄ and CuCr₂(Se_1?xTe_x)₄ Polycrystalline samples of the spinel system CuCr₂(S_1?xSe_x)₄ have been prepared with 0 ≤ x ≤ 1. We found that in the spinel system CuCr₂(Se_1?xTe_x)₄ no solid solution is existent in the range 0.01 ≤ x ≤ 0.70. When S is substituted by Se and Se by Te the lattice constants increase linearely by 0.52 Å and 0.81 Å respectively. The anion-sublattice shows random distribution of the chalcogen atoms, the chalcogen parameters u are constant in the system CuCr₂(S_1?xSe_x)₄ with a mean value of u = 0.382₉. The calculated anion-cation-distances lead to a covalent tetrahedral radius r_Cu = 1.23 Å. This radius is in agreement with the radius r_Cu = 1.22 Å of Cu spinels with Cu in the valence +1.     

Ag6B10S18: Ein neues Thioborat mit tetraedrischer Koordination des Bors

Ag₆B₁₀S₁₈: A Novel Thioborate with Tetrahedral Coordination of Boron Ag₆B₁₀S₁₈ was prepared as a novel thioborate from the reaction of stoichiometric amounts of Ag₂S, B, and S at 700°C with successive annealing at 580–460°C. The orange-yellow compound crystallizes in the monoclinic space group C2/c with a = 21.663(8), b = 21.639(8), c = 16.572(5) Å, ß = 129.40(4)°, Z = 8, d_x = 2.948 g · cm^?3. According to the complete X-ray crystal structure analysis the anionic part of the Ag₆B₁₀S₁₈ structure contains B₁₀S₂₀ “supertetrahedra” consisting of ten parallel corner-sharing BS₄ tetrahedra; the B₁₀S₂₀ groups are linked through corners to form a layer-like arrangement of (B₁₀S₁₆S_4/2^6?)_n = (B₁₀S₁₈^6?)_n polyantions. The mean B? S bond length is 1.915 Å. The electron densities in the regions of the Ag⁺ ions show a dynamically disordered arrangement which can be described by a distribution of the 6 Ag⁺ ions of the asymmetric unit over 18 partially occupied sites, these structural characteristics making Ag₆B₁₀S₁₈ an Ag⁺ ionic conductor. The i.r. spectrum of the compound shows B? S stretching vibrations at 610, 640, 685, 735, and 760 cm^?1.     

Fe and Cr K‐edges EXAFS Study of Double Perovskite (Sr2‐xCax)FeMoO6 (0 ≤ x ≤ 2.0) and Sr2CrMO6 (M = Mo,W) Systems

The local structure of the double perovskite (Sr_2‐xCa_x)FeMoO₆ (0 ≤ × ≤ 2.0) and Sr₂CrMO₆ (M = Mo, W) systems have been probed by extended X‐ray absorption fine structure (EXAFS) spectroscopy at the Fe and Cr K‐edges. We found Fe‐O (ave) distance apparently decreases from 1.999 Å (x = 0) to 1.991 Å (x = 1.0) in (Sr_2‐xCa_x)FeMoO₆ (tetragonal structure). When x is increased further from 1.5 to 2.0, the Fe‐O bond distance decreased from 2.034 Å to 2.012 Å (monoclinic structure). In addition, Cr‐O, Sr‐Cr, and Cr‐Mo bond distances in Sr₂CrWO₆ are all slightly larger than the bond distances of Sr₂CrMoO₆, which is due to the ionic radius of the W⁵⁺ (0.62 Å) which is larger than the ionic radius of Mo⁵⁺ (0.61 Å). The results are consistent with our XRD refinements data.     

High Pressure Synthesis and Characterization of New Members of the RuSr2(RE,Ce)2Cu2O10 Family (RE = Y,Dy)

New members of the RuSr₂(RE_2?x, Ce_x)Cu₂O₁₀ family of magnetically ordered phases have been synthesized under high pressure / high temperature conditions for RE = Y (x = 0.5, 0.7) and Dy (x = 0.5). All compounds show tetragonal symmetry with cell parameters a ≈ 3.82 Å and c ≈ 28.4 Å. Magnetic susceptibility vs temperature measurements show ferromagnetic behaviour of these compounds with T_M = 120–140 K, depending on Ce content. These compounds are semiconducting and tend to transform into insulator, by increasing Ce content, as observed by the temperature dependence of the resistance.     

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.     

LiBaBS3 und LiBaB3S6: Zwei neue quaternäre Thioborate mit trigonal-planar koordiniertem Bor

LiBaBS₃ and LiBaB₃S₆: Two New Quaternary Thioborates with Trigonally Coordinated Boron LiBaBS₃ (P2₁/c; a = 7.577(2) Å, b = 8.713(2) Å, c = 8.687(2) Å, β = 116.22(2)°; Z = 4) und LiBaB₃S₆ (Cc; a = 15.116(3) Å, b = 8.824(2) Å, c = 8.179(2) Å, β = 117.46(3)°; Z = 4) were prepared by reaction of stoichiometric amounts of the metal sulfides, boron, and sulfur at 750°C. The anionic part of the structure of the orthothioborate LiBaBS₃ consists of isolated planar [BS₃]^3? anions. The crystal structure of the metathioborate LiBaB₃S₆ contains [B₃S₆]^3? anions formed by six-membered B₃S₃ rings with three exocyclic sulfur atoms. The metal cations are situated between the anion units leading to a ninefold sulfur coordination of the barium atoms and to a fivefold (LiBaBS₃) and fourfold (LiBaB₃S₆) coordination of the lithium atoms.     

Synthese und Kristallstruktur von K2Mn3S4

Synthesis and Crystal Structure of K₂Mn₃S₄ Single crystals of K₂Mn₃S₄ have been prepared by a fusion reaction of potassium carbonate with manganese in a stream of hydrogen sulfide at 900 °C. K₂Mn₃S₄ crystallizes in a new monoclinic layered structure type (P2/c, a = 7.244(2) Å, b = 5.822(1) Å, c = 11.018(5) Å, β = 112.33(3)°, Z = 2) which can be described as a stacking variant of the orthorhombic Cs₂Mn₃S₄ structure type. Measurements of the magnetic susceptibilities show antiferro‐magnetic interactions.     

Präparation und Strukturanalyse der Verbindungen Ba2Pb4F10Br2–xIx (x = 0–2) mit verwandten kristallchemischen Motiven aus der Fluoritund Matlockitstruktur

Preparation and Structure of the Compounds Ba₂Pb₄F₁₀Br_2–xI_x (x = 0–2) with Related Structure Motifs of the Fluorites and Matlockites Colourless single crystals of Ba₂Pb₄F₁₀Br_2–xI_x (x = 0–2) have been obtained under hydrothermal conditions (T = 250 °C, 10 d), starting from stoichiometric amounts of BaF₂, PbF₂, PbBr₂ and PbI₂. The compounds crystallize in the tetragonal space group P4/nmm (No. 129). A complete miscibility in the region x = 0–2 has been observed. The mixed crystals follow Vegard's rule. For the compounds with the composition Ba₂Pb₄F₁₀Br₂ (a = 5.9501(2) Å, c = 9.6768(10) Å, R[F² > 2σ(F²)] = 0.022, wR(F² all reflections) = 0.059), Ba₂Pb₄F₁₀Br_1.1I_0,9 (a = 5.9899(3) Å, c = 9.7848(5) Å, R[F² > 2σ(F²)] = 0.014, wR(F² all reflections) = 0.035) and Ba₂Pb₄F₁₀I₂ (a = 6.6417(3) Å, c = 9.9216(10) Å, R[F² > 2σ(F²)] = 0.023, wR(F² all reflections) = 0.049) complete structure analyses have been performed on the basis of single crystal diffractometer data. Microcrystalline single phase compounds Ba₂Pb₄F₁₀Br_2–xI_x (x = 0–2) have been obtained by coprecipitation from aqueous solutions of KF, KBr (KI) and Ba(CH₃COO)₂, Pb(NO₃)₂ in acetic acid medium. For Ba₂Pb₄F₁₀Br_1.5I_0.5 and Ba₂Pb₄F₁₀Br_0.5I_1.5 powder data of microcrystalline samples were used for the Rietveld analyses (R_Bragg = 0.077 for Ba₂Pb₄F₁₀Br_1,5I_0,5 and R_Bragg = 0.065 for Ba₂Pb₄F₁₀Br_0.5I_1.5). The crystal structure comprises alternating structural features of fluorite related type (CaF₂) around Ba and matlockite related type (PbFCl) around Pb1 and Pb2 along the c axis. Barium shows a {8 + 4} cuboctahedral coordination of fluorine. The coordination polyhedron around the two crystallographically independent lead atoms is a monocapped quadratic antiprism built of {4 + 1} fluorine and {4} bromine or iodine atoms, respectively.