Single Crystals of C–La2Se3, C–Pr2Se3, and C–Gd2Se3 with Cation‐Deficient Th3P4‐Type Structure

Ruby‐red, bead‐shaped single crystals of C‐type La₂Se₃ (a = 905.21(6) pm), Pr₂Se₃ (a = 891.17(6) pm), and Gd₂Se₃ (a = 872.56(5) pm) are obtained by oxidation of the respective rare‐earth metal (M = La, Pr and Gd) with selenium (molar ratio 2 : 3) in evacuated silica tubes at 750 °C in the presence of fluxing CsCl within seven days. Their crystal structure belongs to a cation‐deficient Th₃P₄‐type variant (cubic, I 4 3d) according to M_2.667□_0.333Se₄ (Z = 4) or M₂Se₃ (Z = 5.333) offering coordination numbers of eight (Se^2– arranged as trigonal dodecahedra) to the M³⁺ cations. In spite of the high Cs⁺ activity in molten CsCl, no cesium incorporation into the M_5.333□_0.667Se₈‐frame structure (e. g. as CsM₅Se₈ with Z = 2) could be achieved, judged from both results of electron beam X‐ray microanalyses and refined occupation factors of the metal position very close to x = 8/9 for M_3xSe₄.     

Quaternäre Caesium‐Kupfer(I)‐Lanthanoid(III)‐Selenide vom Typ CsCu3M2Se5 (M = Sm,Gd — Lu)

Quaternary Cesium Copper(I) Lanthanoid(III) Selenides of the Type CsCu₃M₂Se₅ (M = Sm, Gd — Lu) By oxidation of mixtures of copper and lanthanoid metal with elemental selenium in molar ratios of 1 : 1 : 2 and in addition of CsCl quaternary cesium copper(I) lanthanoid(III) selenides with the formula CsCu₃M₂Se₅ (M = Sm, Gd — Lu) were obtained at 750 °C within a week from torch‐sealed evacuated silica tubes. An excess of CsCl as flux helps to crystallize golden yellow or red, needle‐shaped, water‐resistant single crystals. The crystal structure of CsCu₃M₂Se₅ (M = Sm, Gd — Lu) (orthorhombic, Cmcm, Z = 4; e. g. CsCu₃Sm₂Se₅: a = 417.84(3), b = 1470.91(8), c = 1764.78(9) pm and CsCu₃Lu₂Se₅: a = 407.63(3), b = 1464.86(8), c = 1707.21(9) pm, respectively) contains [MSe₆]^9— octahedra which share edges to form double chains running along [100]. Those are further connected by vertices to generate a two‐dimensional layer parallel to (010). By edge‐ and vertex‐linking of [CuSe₄]^7— tetrahedra two crystallographically different Cu⁺ cations build up two‐dimensional puckered layers parallel to (010) as well. These sheet‐like structure interconnects the equation/tex2gif-stack-3.gif{[M₂Se₅]^4—} layers to create a three‐dimensional network according to equation/tex2gif-stack-4.gif{[Cu₃M₂Se₅]^—}. Thus empty channels along [100] form, apt to take up the Cs⁺ cations. These are surrounded by eight plus one Se^2— anions in the shape of (2+1)‐fold capped trigonal prisms with Cs—Se distances between 348 and 368 pm (8×) and 437 (for M = Sm) or 440 pm (for M = Lu), respectively, for the ninth ligand.     

Röntgenstrukturanalysen an Einkristallen von Ce2S3 im A- und C-Typ

X-Ray Structure Analyses for Single Crystals of A- and C-type Ce₂S₃ Dark red, lath-shaped single crystals of A-type Ce₂S₃ (orthorhombic, Pnma, a = 753.23(6), b = 409.67(3), c = 1572.76(9) pm, V_m = 73.065(8) cm³/mol, Z = 4) are obtained along with deep red, bead-shaped single crystals of C-type Ce₂S₃ (cubic, I 4 3d, a = 865.24(5) pm, V_m = 73.140(7) cm³/mol, Z = 5.333) and cinnabar (α-HgS) during unsuccessful efforts to synthesize HgCe₂S₄ by the oxidation of mercury and cerium metal with sulfur (molar ratio 1 : 2 : 4) in evacuated silica tubes at 400 °C in the presence of a fluxing KCl–LiCl mixture within seven days. Their crystal structures belong to the α-Gd₂S₃- (A type) or a cation-deficient Th₃P₄-type family (C type) according to M_2.667□_0.333S₄ (Z = 4) or M₂S₃ (Z = 5.333), respectively, offering coordination numbers of seven and eight (S^2– arranged as mono- or bicapped trigonal prisms in A-Ce₂S₃) or eight only (S^2– arranged as trigonal dodecahedra in C-Ce₂S₃) to the Ce³⁺ cations.     

C–Gd2S3 und C–Tb2S3: Darstellung und Röntgenstrukturanalyse von Einkristallen

C–Gd₂S₃ and C–Tb₂S₃: Synthesis and X-Ray Structure Analysis of Single Crystals Pale yellow, bead-shaped single crystals of C-type Gd₂S₃ (a = 838.47(9) pm) and Tb₂S₃ (a = 835.23(9) pm) are obtained upon the oxidation of the respective rare-earth metal (M = Gd and Tb) with sulfur (molar ratio 2 : 3) in evacuated silica tubing at 700 °C in the presence of fluxing CsCl within five days. Their crystal structure belongs to a cation-deficient Th₃P₄-type variant (cubic, I43d) according to M_2.667□_0.333S₄ (Z = 4) or M₂S₃ (Z = 5.333) offering coordination numbers of eight (S^2– arranged as trigonal dodecahedra) to the cations. In spite of the high Cs⁺ activity in molten CsCl, no cesium incorporation into the M_5.333□_0.667S₈-frame structure (e. g. as CsM₅S₈ with Z = 2) can be achieved, judged from refined occupation factors of M³⁺ very close to x = 8/9 for M_3xS₄.     

Nd4N2Se3 und Tb4N2Se3: Zwei nicht‐isotype Lanthanoid(III)‐Nitridselenide

Nd₄N₂Se₃ and Tb₄N₂Se₃: Two non‐isotypical Lanthanide(III) Nitride Selenides The non‐isotypical nitride selenides M₄N₂Se₃ of neodymium (Nd₄N₂Se₃) and terbium (Tb₄N₂Se₃) are formed by the reaction of the respective rare‐earth metal with sodium azide (NaN₃), selenium and the corresponding rare‐earth tribromide (MBr₃) at 900 °C in evacuated silica ampoules after seven days. Each of them crystallizes monoclinically in the space group C2/c with Z = 4 for Nd₄N₂Se₃ (a = 1300.47(4), b = 1009.90(3), c = 643.33(2) pm, β = 90.039(2)°) and in the space group C2/m with Z = 2 for Tb₄N₂Se₃ (a = 1333.56(5), b = 394.30(2), c = 1034.37(4) pm, β = 130.377(2)°), respectively. The crystal structures differ fundamentally in the linkage of the structure dominating N^3‐ centred (M³⁺)₄ tetrahedra. In Nd₄N₂Se₃, the [NNd₄] units are edge‐linked to bitetrahedra which are cross‐connected to [N(Nd1)(Nd2)]³⁺ layers via their remaining four corners, whereas the [NTb₄] tetrahedra in Tb₄N₂Se₃ share cis‐oriented edges to form strands [N(Tb1)(Tb2)]³⁺. Both structures contain two crystallographically different M³⁺ cations, that show coordination numbers of six and seven (Nd₄N₂Se₃) or twice six (Tb₄N₂Se₃), respectively, relative to the anions (N^3‐ und Se^2‐). Each of the two independent kinds of Se^2‐ anions provide the three‐dimensional linkage as well as the charge balance. The particular axial ratio a/c and the monoclinic reflex angle offer two choices for fixing the unit cell of Tb₄N₂Se₃.     

Synthese,Struktur und Eigenschaften von [(C4H9)2NH2]4[Sn2Se6], [(C4H9)2NH2]4[Sn4Se10] · 2 H2O und [(C3H7)3NH]2[Sn3Se7]

About Selenidostannates. I Synthesis, Structure, and Properties of [Sn₂Se₆]^4–, [Sn₄Se₁₀]^4–, and [Sn₃Se₇]^2– The selenidostannates [(C₄H₉)₂NH₂]₄Sn₂Se₆ · H₂O ( I ), [(C₄H₉)₂NH₂]₄Sn₄Se₁₀ · 2 H₂O ( II ) und [(C₃H₇)₃NH]₂Sn₃Se₇ ( III ) were prepared by hydrothermal syntheses from the elements and the amines. I crystallizes in the monoclinic spacegroup P2₁/n (a = 1262.9(3) pm, b = 1851.3(4) pm, c = 2305.2(4) pm, β = 104.13(3)° and Z = 4). The [Sn₂Se₆]^4– anion consists of two edge‐sharing tetrahedra. II crystallizes in the orthorhombic spacegroup Pna2₁ (a = 2080.3(4) pm, b = 1308.2(3) pm, c = 2263.5(5) pm and Z = 4). The anion is formed from four SnSe₄ tetrahedra which are joined by common corners to the adamantane cage [Sn₄Se₁₀]^4–. III crystallizes in the orthorhombic spacegroup Pbcn (a = 1371.1(3) pm, b = 2285.4(5) pm, c = 2194.7(4) pm and Z = 8). The anion is a chain, built from edge‐sharing [Sn₃Se₅Se_4/2]^2– units, in which two corner sharing tetrahedra are connected to a trigonal bipyramid by an edge of one and a corner of the other tetrahedron. The results of the TG/DSC measurements and of temperature dependent X‐ray diffractograms reveal that I and II decompose at first by release of minor quantities of triethylammonium to compounds with layer structure and larger cell dimensions. At still higher temperature the rest of triethylammonium and H₂Se is evolved, leaving SnSe₂ and Se in the bulk. The former decomposes partially at the highest temperature to SnSe. In the measurements of III the complex intermediate compound was not observed. III decomposes directly to SnSe₂.     

[(C2H5)3NH]2Sn3Se7 · 0,25 H2O und [(C3H7)2NH2]4Sn4Se10 · 4 H2O

Synthesis, Structure, and Properties of Some Selenidostannates. II. [(C₂H₅)₃NH]₂Sn₃Se₇ · 0,25 H₂O and [(C₃H₇)₂NH₂]₄Sn₄Se₁₀ · 4 H₂O The new selenidostannate hydrates [(C₂H₅)₃NH]₂Sn₃Se₇ · 0.25 H₂O ( I ) and [(C₃H₇)₂NH₂]₄Sn₄Se₁₀ · 4 H₂O ( II ) were synthesized from an aqueous suspension of triethylammonium (tripropylammonium), tin, selenium I and in addition sulfur II at 130 °C. I crystallizes at ambient temperature in the monoclinic space group P2₁/n (a = 2069,3(4) pm, b = 1396,6(3) pm, c = 2342,8(5) pm, β = 114,68(3)°, Z = 8) and is characterized by two different anions, chains from edge‐sharing [Se₃Se₇]^2– units and nets from trigonal SnSe₅ bipyramids. II crystallizes at ambient temperature in the tetragonal space group I4₁/amd (a = 2150,0(3) pm, c = 1174,4(2) pm, Z = 4) and contains adamantane like [Sn₄Se₁₀]^4–‐cages. The UV‐VIS spectra of the selenidostannates demonstrate that the absorption edges red shift as the dimensionality of the compounds is increased.     

Gd3(SeO3)4F: Ein Fluoridselenit mit μ3‐SeO32–und μ3‐F–‐überkappten Gd3‐Ringen

Gd₃(SeO₃)₄F: A Fluoride Selenite with μ₃‐SeO₃^2– and μ₃‐F^– Capped Gd₃ Rings The decomposition of Gd₂(SeO₄)₃ in the presence of LiF in sealed gold ampoules yields single crystals of Gd₃(SeO₃)₄F (hexagonal, P6₃mc, Z = 2, a = 1044.3(1), b = 694.32(7) pm, R_all = 0.0286). In the crystal structure one SeO₃^2– group and one F^– ion cap a ring of three Gd atoms. Furthermore, the crystal structure is strongly influenced by the lone pairs of the SeO₃^2– ions.     

[Ga(en)3][Ga3Se7(en)] · H2O: Ein Galliumchalkogenid mit Ketten aus [Ga3Se6Se2/2(en)]3–-Bicyclen

[Ga(en)₃][Ga₃Se₇(en)] · H₂O: A Gallium Chalcogenide with Chains of [Ga₃Se₆Se_2/2(en)]^3– Bicycles The new selenidogallate [Ga(en)₃][Ga₃Se₇(en)] · H₂O ( I ) was produced from a ethylendiamine suspension of Ga and Se at 130 °C. I crystallizes in the orthorhombic space group Pna2₁ with unit constants a = 1347.9(3) pm, b = 961.6(1) pm, c = 1967.6(4) pm and Z = 4. The crystal structure contains an anion so far not observed in gallium chalcogenides. It is built from [Ga₃Se₆Se_2/2(en)]^3– bicycles of three Ga^IIIL₄ tetrahedra (L = en, Se) connected via selenium corners to linear chains. The cations, Ga^III ions coordinated by three ethylendiamine in a distorted octahedral geometry are positioned in the holes of the hexagonal rod packing of these chains.     

Einkristalle von CuPrS2 im A— und Pr2S3 im C—Typ bei Versuchen zur Synthese ternärer Kupfer(I)—Praseodym(III)—Sulfide

Single Crystals of A—type CuPrS₂ and C—type Pr₂S₃ from Attempts to Synthesize Ternary Copper(I) Praseodymium(III) Sulfides Coarse, yellowish‐green single crystals of the ternary copper(I) praseodymium(III) sulfide CuPrS₂ form within seven days at 800°C by oxidation of elemental copper and praseodymium with sulfur (molar ratio: 1:1:2) in evacuated silica tubes when equimolar quantitites of CsCl are present as flux. Attempts to synthesize CuPr₃S₅ or CuPr₅S₈ under analogous conditions always yield two‐component mixtures of CuPrS₂ and Pr₂S₃ (C type) instead of the desired target compounds. The crystal structure of CuPrS₂ (monoclinic, P2₁/c; a = 655.72(6), b = 722.49(6), c = 686.81(6)pm, β = 98.686(7)°; Z = 4) exhibits undulated layers {[Cu(S1)_3/3(S2)_1/1]^3—} parallel (100) which consist of vertex‐linked pairs of two [CuS₄]^7— tetrahedra ([Cu₂S₆]^10—) sharing a common edge. Their three‐dimensional cross‐linkage is achieved by Pr³⁺ cations in monocapped trigonal prismatic coordination of seven S^2— anions each. The metal sulfur distances in the [CuS₄] units cover with 233 (Cu—S2) and 236 (Cu—S1) as well as 247 (Cu—S1′) and 248pm (Cu—S1″) a rather broad interval, whereas those (Pr—S: 284—304 pm) within the [PrS₇] polyhedra lie relatively closer together. According to Pr_2.677□_0.333S₄ (with Z = 4), C—Pr₂S₃ crystallizes in a cation‐deficient Th₃P₄‐type structure (cubic, I4¯3d; a = 857.68(7) pm; Z = 5.333 for Pr₂S₃). In conformity with the Niggli formula {PrS_8/5.333} Pr³⁺ is surrounded trigon‐dodecahedrally by eight S^2— at distances of 287 (4×) and 307pm (4×). Neither the X‐ray single‐crystal structure refinement nor electron‐beam microprobe analyses leave any evidence for the incorporation of Cu⁺ cations into this crystal structure.     

Syntheses and Crystal Structures of Rb2B2Se7, Tl2B2Se7, Cs3B3Se10, and Tl3B3Se10: New Perseleno‐selenoborates with Polymeric Anionic Chains

The perseleno‐selenoborates Rb₂B₂Se₇ and Cs₃B₃Se₁₀ were prepared from the metal selenides, amorphous boron and selenium, the thallium perseleno‐selenoborates Tl₂B₂Se₇ and Tl₃B₃Se₁₀ directly from the elements in evacuated carbon coated silica tubes by solid state reactions at temperatures between 920 K and 950 K. All structures were refined from single crystal X‐ray diffraction data. The isotypic perseleno‐selenoborates Rb₂B₂Se₇ and Tl₂B₂Se₇ crystallize in the monoclinic space group I 2/a (No. 15) with lattice parameters a = 12.414(3) Å, b = 7.314(2) Å, c = 14.092(3) Å, β = 107.30(3)°, and Z = 4 for Rb₂B₂Se₇ and a = 11.878(2) Å, b = 7.091(2) Å, c = 13.998(3) Å, β = 108.37(3)° with Z = 4 for Tl₂B₂Se₇. The isotypic perseleno‐selenoborates Cs₃B₃Se₁₀ and Tl₃B₃Se₁₀ crystallize in the triclinic space group P1 (Cs₃B₃Se₁₀: a = 7.583(2) Å, b = 8.464(2) Å, c = 15.276(3) Å, α = 107.03(3)°, β = 89.29(3)°, γ = 101.19(3)°, Z = 2, (non‐conventional setting); Tl₃B₃Se₁₀: a = 7.099(2) Å, b = 8.072(2) Å, c = 14.545(3) Å, α = 105.24(3)°, β = 95.82(3)°, γ = 92.79(3)°, and Z = 2). All crystal structures contain polymeric anionic chains of composition ([B₂Se₇]^2–)_n or ([B₃Se₁₀]^3–)_n formed by spirocyclically fused non‐planar five‐membered B₂Se₃ rings and six‐membered B₂Se₄ rings in a molar ratio of 1 : 1 or 2 : 1, respectively. All boron atoms have tetrahedral coordination with corner‐sharing BSe₄ tetrahedra additionally connected via Se–Se bridges. The cations are situated between three polymeric anionic chains leading to a nine‐fold coordination of the rubidium and thallium cations by selenium in M₂B₂Se₇ (M = Rb, Tl). Coordination numbers of Cs⁺ (Tl⁺) in Cs₃B₃Se₁₀ (Tl₃B₃Se₁₀) are 12(11) and 11(9).     

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.     

Vier Oxidselenide des Praseodyms: Pr10OSe14, Pr2OSe2, Pr2O2Se und Pr4O4Se3

Four Oxyselenides of Praseodymium: Pr₁₀OSe₁₄, Pr₂OSe₂, Pr₂O₂Se, and Pr₄O₄Se₃ By reacting elemental praseodymium with selenium and selenium dioxide (SeO₂) as oxygen source in suitable stoichiometric ratios, it is possible to prepare the single‐phase praseodymium(III) oxyselenides Pr₁₀OSe₁₄, Pr₂OSe₂, Pr₂O₂Se, and Pr₄O₄Se₃ each within seven days at 750 °C in torch‐sealed evacuated silica tubes. The addition of equimolar amounts of CsCl as flux guarantees quick and complete reactions to single‐crystalline, water‐ and air‐resistant products. Pr₁₀OSe₁₄ (tetragonal, I4₁/acd; a = 1568.74(8), c = 2073.4(1) pm; Z = 8) crystallizes as dark‐red polyhedra. Pr₂OSe₂ (monoclinic, P2₁/c; a = 882.05(6), b = 732.89(5), c = 732.94(5) pm, β = 100.288(7)°; Z = 4) and Pr₂O₂Se (trigonal, P3m1; a = 401.12(3), c = 705.51(5) pm; Z = 1) accumulate as yellowish green platelets with rectangular and hexagonal cross‐sections, respectively. Pr₄O₄Se₃ (orthorhombic, Amm2; a = 849.92(6), b = 402.78(3), c = 1292.57(9) pm; Z = 2) forms lath‐shaped, pleochroitic crystals with a strong tendency for twinning, which appear green along [001], but red along [100] and [010]. All the crystal structures of these oxyselenides are dominated by [OPr₄] tetrahedra, whose condensation rate strongly increases with growing oxygen content. Se^2– anions, in the case of Pr₄O₄Se₃ (≡ {(Pr³⁺)₄(O^2–)₄(Se^2–)[Se₂]^2–}) as well as [Se₂]^2– dumb‐bells, take care of charge balance and threedimensional cross‐linkage. In the oxygen‐poor Pr₁₀OSe₁₄ the [OPr₄]¹⁰⁺ tetrahedra occur isolated and are embedded in the complex anionic matrix framework {(Pr₆Se₁₄)^10–}. The oxygen‐rich links in this row show according to {[OPr_3/3Pr_1/1]}Se₂ (≡ Pr₂OSe₂), {([OPr_4/4]₂)}Se (≡ Pr₂O₂Se), and {([OPr_4/4]₄)}[Se₂]Se (≡ Pr₄O₄Se₃) [OPr₄] tetrahedra which are connected to more or less dense layers via corners and respectively one, three and four common edges.     

Neue Kronenether‐stabilisierte Oxoniumhalogenochalkogenate: [H3O(Dibromo‐benzo‐18‐Krone‐6)]2[Se3Br10] und [H5O2(Bis‐dibromo‐dibenzo‐24‐Krone‐8]2[Se3Br8]

Novel Oxonium Halogenochalcogenates Stabilized by Crown Ethers: [H₃O(Dibromo‐benzo‐18‐crown‐6)]₂[Se₃Br₁₀] and [H₅O₂(Bis‐dibromo‐dibenzo‐24‐crown‐8]₂[Se₃Br₈] Two novel complex oxonium bromoselenates(II,IV) and –(II) are reported containing [H₃O]⁺ and [H₅O₂]⁺ cations coordinated by crown ether ligands. [H₃O(dibromo‐benzo‐18‐crown‐6)]₂[Se₃Br₁₀] ( 1 ) and [H₅O₂(bis‐dibromo‐dibenzo‐24‐crown‐8]₂[Se₃Br₈] ( 2 ) were prepared as dark red crystals from dichloromethane or acetonitrile solutions of selenium tetrabromide, the corresponding unsubstituted crown ethers, and aqueous hydrogen bromide. The products were characterized by their crystal structures and by vibrational spectra. 1 is triclinic, space group (Nr. 2) with a = 8.609(2) Å, b = 13.391(3) Å, c = 13.928(3) Å, α = 64.60(2)°, β = 76.18(2)°, γ = 87.78(2)°, V = 1404.7(5) ų, Z = 1. 2 is also triclinic, space group with a = 10.499(2) Å, b = 13.033(3) Å, c = 14.756(3) Å, α = 113.77(3)°, β = 98.17(3)°, γ = 93.55(3)°. V = 1813.2(7) ų, Z = 1. In the reaction mixture complex redox reactions take place, resulting in (partial) reduction of selenium and bromination of the crown ether molecules. In 1 the centrosymmetric trinuclear [Se₃Br₁₀]^2? consists of a central Se^IVBr₆ octahedron sharing trans edges with two square planar Se^IIBr₄ groups. The novel [Se₃Br₈]^2? in 2 is composed of three planar trans‐edge sharing Se^IIBr₄ squares in a linear arrangement. The internal structure of the oxonium‐crown ether complexes is largely determined by the steric restrictions imposed by the aromatic rings in the crown ether molecules, as compared to complexes with more flexible unsubstituted crown ether ligands.     

Die Kristallstrukturen der Polyselenide [Cs(18-Krone-6)]2Se5 · DMF, [Rb(222-Crypt)]2Se6, [Ba(15-Krone-5)2]Se6 · DMF und [Na(12-Krone-4)2]2Se7

Crystal Structures of the Polyselenides [Cs(18-Crown-6)]₂Se₅ · DMF, [Rb(222-Crypt)]₂Se₆, [Ba(15-Crown-5)₂]Se₆ · DMF, and [Na(12-Crown-4)₂]Se₇ . The title compounds have been prepared by reactions of the corresponding diselenides with excess selenium in the presence of crown ethers in dimethylformamide solutions, forming black crystals. [Cs(18-Crown-6)]₂Se₅ · DMF: Space group P2₁/m, Z = 2, 2 194 observed unique reflections, R = 0.119. Lattice dimensions at 20°C: a = 1 041.2; b = 1 496.3; c = 1 459.7 pm; β = 100.39°. The compound forms an ionic triple with Cs…Se-contacts between 374 and 381 pm. [Rb(222-Crypt)]₂Se₆: Space group P1 , Z = 2, 7 405 observed unique reflections, R = 0.056. Lattice dimensions at – 70°C: a = 1 106.8; b = 1 460.8; c = 1 718.8 pm; α = 89.22°; β = 86.65°; γ = 71.53°. The compound contains Se₆^2? chains without direct contact with each other. [Ba(15-Crown-5)₂]Se₆ · DMF: Space group P2₁/n, Z = 4, 2 680 observed unique reflections, R = 0.055. Lattice dimensions at – 80°C: a = 1 051.9; b = 1 322.4; c = 2 729.9 pm; β = 100.93°. The compound contains Se₆^2? chains, which are isolated from each other by the cations and the included DMF molecules. [Na(12-Crown-4)₂]₂Se₇: Space group P1 , Z = 2, 7 313 observed unique reflections, R = 0.042. Lattice dimensions at – 70°C: a = 1 260.9; b = 1 433.6; c = 1 462.9 pm; α = 80.27°; β = 78.60°; γ = 69.34°. The compound contains Se₇^2? chains without direct contacts with each other.     

Zwei Fluoridborate des Gadoliniums: Gd2F3[BO3] und Gd3F3[BO3]2

Two Fluoride Borates of Gadolinium: Gd₂F₃[BO₃] and Gd₃F₃[BO₃]₂ By flux‐supported solid‐state reaction of Gd₂O₃ and GdF₃ with B₂O₃ (flux: CsCl, molar ratio: 1 : 1 : 1 : 6, sealed tantalum capsule, 700 °C, 7 d) the new gadolinium fluoride borate Gd₂F₃[BO₃] (monoclinic, P2₁/c; a = 1637.2(1), b = 624.78(4), c = 838.04(6) pm, β = 93.341(8)°; V_m = 64.418(6) cm³/mol, Z = 8) was obtained as colourless, prismatic, face‐rich single crystals. The four crystallographically different Gd³⁺ cations (CN = 9) are all capped square‐antiprismatically surrounded by fluoride and oxide anions, in which the latter represent always components of isolated trigonal planar [BO₃]^3— anions. The six crystallographically independent F^— anions all reside in more or less planar coordination of three Gd³⁺ cations. Thus the constitution of Gd₂F₃[BO₃] can be described as a sequence of alternating layers each of the composition Gd[BO₃] and GdF₃ parallel (100), respectively. The crystal structures of Gd₂F₃[BO₃] and the shortly published Gd₃F₃[BO₃]₂ (monoclinic, C2/c; a = 1253.4(1), b = 623.7(1), c = 836.0(1) pm, β = 97.404(6)°; V_m = 97.571(9) cm³/mol, Z = 4) are compared with each other. Due to the structural analogies between these two gadolinium fluoride borates, a disorder model of the boron atoms frequently found for Gd₂F₃[BO₃] is able to be transferred to Gd₃F₃[BO₃]₂ as well.     

Synthese und Kristallstruktur von [Se3N2Cl]+ GaCl4−

Synthesis and Crystal Structure of [Se₃N₂Cl]⁺GaCl₄^? [Se₃N₂Cl]⁺GaCl₄^? has been prepared by the reduction of [Se₂NCl₂]⁺GaC1₄^? with SbPh₃ in CH₂Cl₂ solution, forming red crystals, which were characterized by an X-ray structure determination. Space group P2₁/n, Z = 4, 1640 observed unique reflections, R = 0.050. Lattice dimensions at ? 80 °C: a = 929.4(1), b= 1078.8(1), c = 1135.7(1) pm, β = 92.026(9)°. The cations from nearly planar Se₃N₂ five membered rings with Se? N bond lengths from 170 to 176pm and a Se? Se bond of 242.2 pm. One of the selenium atoms is bonded to the chlorine atom.     

Neue Gold‐Selen‐Komplexverbindungen: Synthesen und Strukturen von [Au10Se4(dpppe)4]Br2, [Au2Se(dppbe)]∞, [(Au3Se)2(dppbp)3]Cl2 und [Au34Se14(tpep)6(tpepSe)2]Cl6

Novel Gold Selenium Complexes: Syntheses and Structures of [Au₁₀Se₄(dpppe)₄]Br₂, [Au₂Se(dppbe)]_∞, [(Au₃Se)₂(dppbp)₃]Cl₂, and [Au₃₄Se₁₄(tpep)₆(tpep^Se)₂]Cl₆ The reaction of gold phosphine complexes [(AuX)(PR₃)] (X= halogen; R = org. group) with Se(SiMe₃)₂ yield to new chalcogeno bridged gold complexes. Especially within the use of polydentate phosphine ligands cluster complexes like [Au₁₀Se₄(dpppe)₄]Br₂ ( 1 ) (dpppe = 1, 5‐Bis(diphenylphosphino)pentane), [Au₂Se(dppbe)]_∞ ( 2 ) (1, 4‐Bis(diphenylphosphino)benzene), [(Au₃Se)₂(dppbp)₃]Cl₂ ( 3 ) (dppbp = 4, 4′‐Bis‐diphenylphosphino)biphenyl) und [Au₃₄Se₁₄(tpep)₆(tpep^Se)₂]Cl₆ ( 4 ) (tpep = 1, 1, 1‐Tris(diphenylphosphinoethyl)phosphine, tpep^Se = 1, 1‐Bis(diphenylphosphinoethyl)‐1‐(diphenylselenophosphinoethylphosphine) could be isolated and their structures could be determined by X‐ray diffraction. ( 1: Space group P1 (No. 2), Z = 2, a = 1642.1(11), b = 1713.0(9), c = 2554.0(16) pm, α = 80.41(3)°, β = 76.80(4)°, γ = 80.92(4)°; 2: Space group P2₁/n (No. 14), Z = 4, a = 947.3(2), b = 1494.9(3), c = 2179.6(7) pm, β = 99.99(3)°; 3: Space group P2₁/c (No. 14), Z = 8, a = 2939.9(6), b = 3068.4(6), c = 3114.5(6) pm, β = 109.64(3)°; 4: Space group P1 (No. 2), Z = 1, a = 2013.7(4), b = 2420.6(5), c = 2462.5(5) pm, α = 77.20(3), β = 74.92(3), γ = 87.80(3)°).     

Ce2[SeO3]3 and Pr2[SeO3]3: Non‐Isostructural Oxoselenates(IV) of the Light Lanthanoids

The crystal structures of Ce₂[SeO₃]₃ and Pr₂[SeO₃]₃ have been refined from X‐ray single‐crystal diffraction data. The compounds were obtained using stoichiometric mixtures of CeO₂, SeO₂, Ce, and CeCl₃ (molar ratio 3:3:1:1) or Pr₆O₁₁, SeO₂, Pr, and PrCl₃ (molar ratio 3:27:1:2) heated in evacuated sealed silica tubes at 830 °C for one week. Ce₂[SeO₃]₃ crystallizes orthorhombically (space group: Pnma), with four formula units per unit cell of the dimensions a = 839.23(5) pm, b = 1421.12(9) pm, and c = 704.58(4) pm. Its structure contains only a single crystallographically unique Ce³⁺ cation in tenfold coordination with oxygen atoms arranged as single‐face bicapped square antiprism and two different trigonal pyramidal [SeO₃]^2? groups. The connectivity among the [CeO₁₀] polyhedra results in infinite sheets of face‐ and edge‐sharing units propagating normal to [001]. Pr₂[SeO₃]₃ is monoclinic (space group: P2₁/n) with twelve formula units per unit cell of the dimensions a = 1683.76(9) pm, b = 705.38(4) pm, c = 2167.19(12) pm, and β = 102.063(7)°. Its structure exhibits six crystallographically distinct Pr³⁺ cations in nine‐ and tenfold coordination with oxygen atoms forming distorted capped square antiprisms or prisms (CN = 9), bicapped square antiprisms and tetracapped trigonal prisms (CN = 10), respectively. The [PrO₉] and [PrO₁₀] polyhedra form double layers parallel to (111) by edge‐ or face‐sharing, which are linked by nine different [SeO₃]^2? groups to build up a three‐dimensional framework. In both compounds, the discrete [SeO₃]^2? anions (d(Se⁴⁺–O^2?) = 166–174 pm) show the typical Ψ¹‐tetrahedral shape owing to the non‐bonding “lone‐pair” electrons at the central selenium(IV) particles. Moreover, their stereochemical “lone‐pair” activity seems to flock together in large empty channels running along [010] in the orthorhombic Ce₂[SeO₃]₃ and along [101] in the monoclinic Pr₂[SeO₃]₃ structure, respectively.     

Na2ZrS3: Ein ternäres Sulfid des Zirconiums mit aufgefüllter AlCl3‐Struktur

Na₂ZrS₃: A Ternary Zirconium Sulfide with Stuffed AlCl₃‐type Structure Dark green, plate‐like single crystals of Na₂ZrS₃ (monoclinic, C2/m; a = 664.69(6), b = 1152.5(1), c = 695.48(7) pm, β = 108.78(1)°; Z = 4) are obtained along with pale yellow platelets of NaZr₂N₂SCl (trigonal, R3m; a = 363.56(3), c = 2951.2(4) pm; Z = 3) upon oxidation of zirconium metal with sulfur and sodium azide (NaN₃) in the presence of fluxing NaCl (molar ratio 7:6:2:3) in evacuated silica tubes at 850°C within three weeks. The crystal structure is best described as stuffed AlCl₃ type with all cations (Na⁺ and Zr⁴⁺) in octahedral coordination of the S^2– anions, which build up a cubic closest packed host lattice. The internuclear metal sulfur distances range from 276 to 296 pm for all three crystallographically different Na⁺ cations, and from 258 to 260 pm for Zr⁴⁺.