Polymere,bandförmige Tellurkationen in den Strukturen des Chloroberyllats Te7[Be2Cl6] und des Chlorobismutats (Te4)(Te10)[Bi4Cl16]

Polymeric, Band Shaped Tellurium Cations in the Structures of the Chloroberyllate Te₇[Be₂Cl₆] and the Chlorobismutate (Te₄)(Te₁₀)[Bi₄Cl₁₆] Te₇[Be₂Cl₆] is obtained at 250 °C in an eutectic Na₂[BeCl₄] / BeCl₂ melt from Te, TeCl₄ und BeCl₂ in form of black crystals, which are sensitive towards hydrolysis in moist air. (Te₄) (Te₁₀)[Bi₄Cl₁₆] is prepared from Te, TeCl₄ und BiCl₃ by chemical vapour transport in sealed evacuated glass ampoules in a temperature gradient 150 ° → 90 °Cin form of needle shaped crystals with a silver lustre. The structures of both compounds were determined based on single crystal X‐ray diffraction data (Te₇[Be₂Cl₆]: orthorhombic, Pnnm, Z = 2, a = 541.60(3), b = 974.79(6), c = 1664.4(1) pm; (Te₄)(Te₁₀)[Bi₄Cl₁₆]: triclinic, P1¯, Z = 2, a = 547.2(3), b = 1321.1(7), c = 1490(1) pm, α = 102.09(5)°, β = 95.05(5)°, γ = 96.69(4)°). The structure of Te₇[Be₂Cl₆] consists of one‐dimensional polymeric cations (Te₇²⁺)_n which form folded bands and of discrete [Be₂Cl₆]^2— anions which form double tetrahedraconnected by a common edge. By a different way of folding compared with the cations present in the structures of Te₇[MOX₄]X (M = Nb, W; X = Cl, Br) the (Te₇²⁺)_n cation in Te₇[Be₂Cl₆]represents a new, isomeric form. The structure of (Te₄)(Te₁₀)[Bi₄Cl₁₆] contains two different polymeric cations. (Te₁₀²⁺)_n consists of planar Te₁₀ groups in the form of three corner‐sharing Te₄ rings connected to folded bands. (Te₄²⁺)_n forms in contrast to the so far notoriously observed discrete, square‐planar E₄²⁺ ions a chain of rectangular planar Te₄ rings (Te—Te 274 and 281 pm) connected by Te‐Te bonds of 297 pm. [Bi₄Cl₁₆]^4— has a complex one‐dimensional structure of edge‐ and corner‐sharing BiCl₇ units.     

A Facile Route for the Synthesis of Polycationic Tellurium Cluster Compounds: Synthesis in Ionic Liquid Media and Characterization by Single‐Crystal X‐ray Crystallography and Magnetic Susceptibility

An innovative soft chemical approach was applied, using ionic liquids as an alternative reaction medium for the synthesis of tellurium polycationic cluster compounds at room temperature. [Mo₂Te₁₂]I₆, Te₆[WOCl₄]₂, and Te₄[AlCl₄]₂ were isolated from the ionic liquid [BMIM]Cl/AlCl₃ ([BMIM]⁺: 1‐n‐butyl‐3‐methylimidazolium) and characterized. Black, cube‐shaped crystals of [Mo₂Te₁₂]I₆, which is not accessible by conventional chemical transport reaction, were obtained by reaction of the elements at room temperature in [BMIM]Cl/AlCl₃. The monoclinic structure (P2₁/n, a = 1138.92(2) pm, b = 1628.13(2) pm, c = 1611.05(2) pm, β = 105.88(1) °) is homeotypic to the triclinic bromide [Mo₂Te₁₂]Br₆. In the binulear complex [Mo₂Te₁₂]⁶⁺, the molybdenum(III) atoms are η⁴‐coordinated by terminal Te₄²⁺ rings and two bridging η²‐Te₂^2– dumbbells. Despite the short Mo···Mo distance of 297.16(5) pm, coupling of the magnetic moments is not observed. The paramagnetic moment of 3.53 μ_B per molybdenum(III) atom corresponds to an electron count of seventeen. Black crystals of monoclinic Te₆[WOCl₄]₂ are obtained by the oxidation of tellurium with WOCl₄ in [BMIM]Cl/AlCl₃. Tellurium and tellurium(IV) synproportionate in the ionic liquid at room temperature yielding violet crystals of orthorhombic Te₄[AlCl₄]₂.     

[Te8][NbOCl4]2 containing an infinite chain‐like {[Te–Te–Te–(Te5)]2+}n polycation

The title compound, [Te₈][NbOCl₄]₂, was obtained as translucent black crystals by reaction of elemental tellurium, niobium(V) chloride and niobium(V) oxychloride in the ionic liquid BMImCl (BMImCl is 1‐butyl‐3‐methylimidazolium chloride). The synthesis was performed in argon‐filled glass ampoules. According to X‐ray structure analysis based on single crystals, the title compound crystallizes with triclinic lattice symmetry and consists of infinite {[Te₈]²⁺}_n cations associated with pyramidal [NbOCl₄]⁻ anions. The novel catena‐octatellurium(2+) cation is composed of Te₅ rings that are linked via Te₃ units [Te—Te = 2.6455 (18)–2.8164 (19) Å]. The composition and purity of [Te₈][NbOCl₄]₂ were further confirmed by energy‐dispersive X‐ray diffraction (EDX) analysis.     

Synthesis and Crystal Structure of Te6[MCl6] (M = Zr,Hf), Containing a Polymeric Chalcogen Cation (Te62+)n

The reaction of tellurium, tellurium tetrachloride, and ZrCl₄ or HfCl₄, respectively, under the conditions of chemical vapour transport in a temperature gradient 220 → 200 °C yields black crystals of Te₆[ZrCl₆] and Te₆[HfCl₆]. While Te₆[ZrCl₆] is formed almost quantitatively, Te₆[HfCl₆] is always accompanied by neighbored phases such as Te₄[HfCl₆] and Te₈[HfCl₆]. The crystal structures of Te₆[ZrCl₆] (orthorhombic, Pbcm, a = 1095.4(1), b = 1085.2(1), c = 1324.5(1) pm) and Te₆[HfCl₆] (a = 1094.8(2), b = 1086.3(2), c = 1325.0(2) pm) are isotypic and consist of one‐dimensional polymeric (Te₆²⁺)_n cations and of discrete, only slightly distorted octahedral [MCl₆]^2‐ anions (M = Zr, Hf). The cations are build of five membered rings which are connected via single Te atoms to a polymer ‐Te‐Te₅‐Te‐Te₅‐. Out of the six Te atoms of the asymmetric unit of the chain four atoms exhibit two bonds and two atoms exhibit three bonds. The connecting, threefold coordinated Te atoms of the five membered rings carry formally the positive charges. In consistence with the assumption of the presence of throughout localized bonds eH band structure calculations for Te₆[ZrCl₆] show semiconducting behaviour with a band gap of 1.8 eV.     

Die Oxochlorotantalate (PPh4)2[Ta2OCl9]2 · 2 CH2Cl2, (PPh4)2[Ta2OCl10] · 2 CH3CN und (K-18-Krone-6)4[Ta4O6Cl12] · 12 CH2Cl2

The Oxochlorotantalates (PPh₄)₂[Ta₂OCl₉]₂ · 2 CH₂Cl₂, (PPh₄)₂[Ta₂OCl₁₀] · 2 CH₃CN, and (K-18-crown-6)₄[Ta₄O₆Cl₁₂] · 12 CH₂Cl₂ (K-18-crown-6)₄[Ta₄O₆Cl₁₂] · 12 CH₂Cl₂ was obtained from a reaction of tantalum pentachloride, K₂S₅ and 18-crwon-6 in dichlormethane. According to its crystal structure analysis it is tetragonal (space group I 4 2d) and contains [Ta₄O₆Cl₁₂]^4– ions that have an adamantane-like Ta₄O₆ skeleton. Each K⁺ ion is coordinated by the oxygen atoms of the crown ether molecule from one side and with three Cl atoms of one [Ta₄O₆Cl₁₂]^4– ion from the opposite side. (PPh₄)₂[Ta₂OCl₁₀] · 2 CH₃CN was a product from PPh₄Cl and TaCl₅ in acetonitrile in the presence of Na₂S₄. Its crystals are monoclinic (space group P2₁/c) and contain centrosymmetric [Ta₂OCl₁₀]^2– ions having a linear Ta–O–Ta grouping with short bonds (Ta–O 189 pm). TaCl₅ and H₂S formed a solid substance (TaSCl₃) from which a small amount of (PPh₄)₂[Ta₂OCl₉]₂ · 2 CH₂Cl₂ was obtained by the reaction with PPh₄Cl in CH₂Cl₂. The anions in the monoclinic crystals (space group P2₁/n) consist of two Ta₂OCl₉^– units which are joined by chloro bridges; each Ta₂OCl₉^– unit has a nearly linear Ta–O–Ta group with differing bond lengths (179 and 202 pm). The oxygen in the compounds probably was introduced by traces of water in the crown ether, acetonitrile or H₂S, respectively.     

Neue Halogenochalkogen(IV)‐Säuren: [H3O(Benzo‐18‐Krone‐6)]2[Te2Br10] und [H5O2(Dibenzo‐24‐Krone‐8)]2[Te2Br10]

Novel Halogenochalcogeno(IV) Acids: [H₃O(Benzo‐18‐Crown‐6)]₂[Te₂Br₁₀] and [H₅O₂(Dibenzo‐24‐Crown‐8)]₂[Te₂Br₁₀] Systematic studies on halogenochalcogeno(IV) acids containing tellurium and bromine led to the new crystalline phases [H₃O(Benzo‐18‐Crown‐6)]₂[Te₂Br₁₀] ( 1 ) and [H₅O₂(Dibenzo‐24‐Crown‐8)]₂[Te₂Br₁₀] ( 2 ). The [Te₂Br₁₀]^2‐ anions consists of two edge‐sharing distorted TeBr₆ octahedra, the oxonium cations are stabilized by crownether. ( 1 ) crystallizes in the monoclinic space group P2₁/n with a = 14.520(5) Å, b = 22.259(6) Å, c = 16.053(5) Å, β = 97.76(3)° and Z = 4, whereas ( 2 ) crystallizes in the triclinic space group with a = 11.005(4) Å, b = 12.103(5) Å, c = 14.951(6) Å, α = 71.61(3)°, β = 69.17(3)°, γ = 68.40(3)° and Z = 1.     

Neutral tellurium rings in the coordination polymers [Ru(Te9)](InCl4)2, [Ru(Te8)]Cl2, and [Rh(Te6)]Cl3

Shiny black, air‐insensitive crystals of tellurium‐rich one‐dimensional coordination polymers were synthesized by melting a mixture of the elements with TeCl₄. The compounds [Ru(Te₉)](InCl₄)₂ and [Ru(Te₈)]Cl₂ crystallize in the monoclinic space group type C2/c, whereas [Rh(Te₆)]Cl₃ adopts the trigonal space group type R$\bar 3Shiny black, air-insensitive crystals of tellurium-rich one-dimensional coordination polymers were synthesized by melting a mixture of the elements with TeCl(4). The compounds [Ru(Te(9))](InCl(4))(2) and [Ru(Te(8))]Cl(2) crystallize in the monoclinic space group type C2/c, whereas [Rh(Te(6))]Cl(3) adopts the trigonal space group type R ?3c. In the crystal structures, linear, positively charged [M(m+) (Te(n)(±0))] (M=Ru, m=2; Rh, m=3) chains run parallel to the c axes. Each of the uncharged Te(n) molecules (n=6, 8, 9) coordinates two transition-metal atoms as a bridging bis-tridentate ligand. Because the coordinating tellurium atoms act as electron-pair donors, the 18-electron rule is fulfilled for the octahedrally coordinated transition-metal cations. Based on DFT calculations, the quantum theory of atoms in molecules (QTAIM) and the electron localizability indicator (ELI) provide insight into the principles of the polar donor bonding in these complexes. Comparison with optimized ring geometries reveals substantial tension in the coordinating tellurium molecules.     

Synthesis and Crystal Structure of Manganese‐tris(1,2‐ethanediamine)tetratelluride [Mn(en)3]Te4 Exhibiting Intermolecular Interactions between the Tetratelluride Anions

Air‐sensitive black crystals of the new compound [Mn(en)₃]Te₄ were synthesized by reacting MnCl₂ · 4 H₂O, K₂Te₃ and elemental Te in 1,2‐ethanediamine (en) under solvothermal conditions at 433 K. The compound crystallizes in the monoclinic space group P2₁/n with lattice parameters a = 839.51(7) pm, b = 1551.3(1) pm, c = 1432.6(1) pm, and β = 90.28(2)°. Isolated [Mn(en)₃]²⁺ cations and Te₄^2– anions are arranged in an alternating fashion parallel to the crystallographic b‐axis. One terminal Te atom of the Te₄^2– anions exhibits a short intermolecular contact to a neighboured anion thus forming Te₈^4– anions. A slightly longer interionic Te…Te separation is observed between two of the inner Te atoms of neighboured Te₈^4– anions. Taking these longer separations into account infinite Te‐chains are formed running parallel to [001]. The intermolecular Te…Te interactions affect the Te–Te bond lengths within the Te₄^2– anion leading to a lengthening of the average Te–Te distance. Short N–H…Te distances indicate hydrogen bonding between the cations and anions. DTA‐TG measurements show that at 441 K the material decomposes in one step. The resulting crystalline material consists of MnTe₂ and Te.     

Crystal Structure of the B‐type Dierbium Oxide ortho‐Oxosilicate Er2O[SiO4]

The crystal structure of B‐type Er₂O[SiO₄] has been determined by single crystal X‐ray diffraction. It crystallizes with the (Mn,Fe)₂[PO₄]F type structure in the monoclinic space group C2/c (a = 14.366(2), b = 6.6976(6), c = 10.3633(16) Å, ß = 122.219(10)°, Z = 8) and shows anionic tetrahedral [SiO₄]^4– units and non‐silicon‐bonded O^2– anions in distorted [OEr₄]¹⁰⁺ tetrahedra. The [(Er1)O₆₊₁] and [(Er2)O₆] polyhedra form infinite chains which are connected by common edges.     

[Ge4O6Te4]4—, an Adamantanoid Oxotellurido Germanate(IV) with a Central Ge4O6 Core

[Mn(en)₃]₂[Ge₄O₆Te₄]·1.5en ( 1 ) and (enH)₃[Mn(en)₃]₃[Ge₄O₆Te₄]₂I·4.7en ( 2 ) may be prepared at 150 °C by solvothermal reaction of elemental Ge and Te with Mn(OOCCH₃)₂ ·4H₂O in the presence of [CH₃)₄N]I as a mineralizer in respectively superheated ethylenediamine (en) or an en/CH₃OH (3:2) mixture. Both contain the novel [Ge₄O₆Te₄]^4— anion with a central adamantanoid Ge₄O₆ core and four terminal Te atoms and represent the first examples of such a mixed [M₄E₆E₄′]^4— anion (M = Si‐Sn; E = O‐Te). As a result of their increased polarity, the Ge‐Te bonds of 2 are markedly shorter (2.438 — 2.462Å) than those previously reported for telluridogermanates(IV).     

Die Kristallstrukturen der Hexachlorometallate NH4[SbCl6], NH4[WCl6], [K(18‐Krone‐6)(CH2Cl2)]2[WCl6]·6CH2Cl2 und (PPh4)2[WCl6]·4CH3CN

Crystal Structures of the Hexachlorometalates NH₄[SbCl₆], NH₄[WCl₆], [K(18‐crown‐6)(CH₂Cl₂)]₂[WCl₆]·6CH₂Cl₂ and (PPh₄)₂[WCl₆]·4CH₃CN The crystal structures of the title compounds were determined by single crystal X‐ray methods. NH₄[SbCl₆] and NH₄[WCl₆] crystallize isotypically in the space group C2/c with four formula units per unit cell. The NH₄⁺ ions occupy a twofold crystallographic axis, whereas the metal atoms of the [MCl₆]^— ions occupy a centre of inversion. There exist weak interionic hydrogen bridges. [K(18‐crown‐6)(CH₂Cl₂)]₂[WCl₆]·6CH₂Cl₂ crystallizes in the orthorhombic space group R3¯/m with Z = 3. The compound forms centrosymmetric ion triples, in which the potassium ions are coordinated with a WCl₃ face each. In trans‐position to it the chlorine atom of a CH₂Cl₂ molecule is coordinated so that, together with the oxygen atoms of the crown ether, coordination number 10 is achieved. (PPh₄)₂[WCl₆]·4CH₃CN crystallizes in the monoclinic space group P2₁/c with Z = 4. This compound, too, forms centrosymmetric ion triples, in which in addition the acetonitrile molecules are connected with the [WCl₆]^2— ion via weak C—H···Cl contacts.     

[Hg4Te8(Te2)4]8−: A Heavy Metal Porphyrinoid Embedded in a Lamellar Structure

The use of ionic liquids (C_nC₁Im)[BF₄] with long alkyl chains (n=10, 12) in the ionothermal treatment of Na₂[HgTe₂] led to lamellar crystal structures with molecular macrocyclic anions [Hg₈Te₁₆]^8? ( 1 ), the heaviest known topological relative of porphyrin. [Hg₈Te₁₆]^8? differs from porphyrin by the absence of an electronic π‐system, which prevents a “global” aromaticity. Quantum chemical studies reveal instead small ring currents in the pyrrole‐type five‐membered rings that indicate weak local (σ) aromaticity. As a result of their lamellar nature, the compounds are promising candidates for the formation of sheets containing chalcogenidometalate anions.     

New Ionic Liquid Compounds Based on Tantalum Pentachloride TaCl5: Synthesis,Structural, and Spectroscopic Elucidation of the (μ‐Oxido)‐Chloridotantalates(V) [BMPy][TaCl6], [BMPy]4[(TaCl6)2(Ta2OCl10)], and [EMIm]2[Ta2OCl10]

1‐Butyl‐4‐methylpyridinium hexachloridotantalate(V), [BMPy][TaCl₆] ( 1 ), tetrakis(1‐butyl‐4‐methylpyridinium) bis(hexachloridotantalate(V) (μ‐oxido)‐decachloridotantalate(V), [BMPy]₄[(TaCl₆)₂(Ta₂OCl₁₀)] ( 2 ), and bis(1‐ethyl‐3‐methylimidazolium)‐(μ‐oxido)‐decachloridoditantalate(V), [EMIm]₂[Ta₂OCl₁₀] ( 3 ) were synthesized and characterized by single‐crystal X‐ray diffraction and vibrational spectroscopy. Compounds 1 and 3 crystallize in the monoclinic space group P2₁/c (no. 14), whereas compound 2 crystallizes in the triclinic space group P (no. 2). All compounds are built up by the mentioned bulky organic cations and octahedral [TaCl₆]^– respective linear [Ta₂OCl₁₀]^2– anions. Coulomb interactions are dominant between the ionic species. FT‐IR and FT‐Raman spectra were recorded and interpreted, especially with respect to the inorganic species [TaCl₆]^– (O_h) and [Ta₂OCl₁₀]^2– (C_i symmetry, approximately D_4h). The melting temperatures of compounds 1 – 3 are given.     

Selen‐Polykationen stabilisiert durch polymere Chlorobismutat‐Anionen: Synthesen und Kristallstrukturen von Se4[Bi4Cl14] und Se10[Bi5Cl17]

Selenium Polycations Stabilized by Polymeric Chlorobismuthate Anions: Syntheses and Crystal Structures of Se₄[Bi₄Cl₁₄] and Se₁₀[Bi₅Cl₁₇] Reactions of selenium with selenium(IV) chloride and bismuth(III) chloride in sealed evacuated glass ampoules at temperatures between 110 and 155 °C yield a series of compounds which are composed of discrete selenium polycations and polymeric chlorobismutate anions. Besides the already known Se₈[Bi₄Cl₁₄] two new compounds have been identified by crystal structure analyses as Se₄[Bi₄Cl₁₄] (tetragonal, P4/n, a = 1089.1(2) pm, c = 993.7(2) pm, Z = 2) and Se₁₀[Bi₅Cl₁₇] (monoclinic, P2₁/c, a = 1079.24(8) pm, b = 2062.9(2) pm, c = 1676.1(2) pm, β = 90.87(1)°, Z = 4). Se₄[Bi₄Cl₁₄] was obtained as red transparent platelike crystals and is the first example of a compound with (chalcogen₄)²⁺ ions of exact square‐planar symmetry and molecular point group D_4h in the solid state. The cations are surrounded by layers of two‐dimensional polymeric anions [Bi₄Cl₁₄]^2–. Se₁₀[Bi₅Cl₁₇] forms dark grey crystals with a reddish luster. The structure contains the known bicyclic polycation Se₁₀²⁺ which is disordered over two positions and the first three‐dimensional polymeric chlorobismutate anion [Bi₅Cl₁₇]^2–. The different BiCl_x polyhedra are linked by sharing common vertices, edges, and faces.     

Modified Tellurium Subhalides in the New Structure Type [Te15X4]n[MOX4]2n (M = Mo,W; X = Cl,Br)

The reactions of Te₂Br with MoOBr₃, TeCl₄ with MoNCl₂/MoOCl₃, and Te with WBr₅/WOBr₃ yield black, needle-like crystals of [Te₁₅X₄][MOX₄]₂ (M = Mo, W; X = Cl, Br). The crystal structure determinations [Te₁₅Br₄][MoOBr₄]₂: monoclinic, Z = 1, C2/m, a = 1595.9(4) pm, b = 403.6(1) pm, c = 1600.4(4) pm, β = 112.02(2)°; [Te₁₅Cl₄][MoOCl₄]₂: C2/m, a = 1535.3(5) pm, b = 402.8(2) pm, c = 1569.6(5) pm, β = 112.02(2)°; [Te₁₅Br₄][WOBr₄]₂: C2, a = 1592.4(4) pm, b = 397.5(1) pm, c = 1593.4(5) pm, β = 111.76(2)° show that all three compounds are isotypic and consist of one-dimensional ([Te₁₅X₄]²⁺)_n and ([MOX₄]^?)_n strands. The structures of the cationic strands are closely related to the tellurium subhalides Te₂X (X = Br, I). One of the two rows of halogen atoms that bridges the band of condensed Te₆ rings is stripped off, and additionally one Te position has only 75% occupancy which leads to the formula ([Te₁₅X₄]²⁺)_n (X = Cl, Br) for the cation. The anionic substructures consist of tetrahalogenooxometalate ions [MOX₄]^? that are linked by linear oxygen bridges to polymeric strands. The compounds are paramagnetic with one unpaired electron per metal atom indicating oxidation state M^v, and are weak semiconductors.     

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.     

Solvothermal Synthesis and Crystal Structure of Te8[U2Br10], Containing a Polymeric Chalcogen Cation (Te82+)n

Under solvothermal conditions, the reaction of Te, TeBr₄ and UBr₅ in SiBr₄ at 200?C yields Te₈[U₂Br₁₀] as silvery crystals. The crystal structure (triclinic, P&1macr;, a = 900.8(4), b = 1205.1(5), c = 1366.0(6) pm, α = 80.93(4)?, β = 76.83(3)?, γ = 78.84(3)?, Z = 2) is built of one‐dimensional polymeric (Te₈²⁺)_n cations consisting of boat‐shaped Te₆ rings, which are linked by Te₂ bridges. The anions [U₂Br₁₀^2‐]_n are also polymeric, consisting of edge sharing UBr₇ pentagonal bipyramids [UBr₃Br_4/2^2‐]_n and contain U(IV). Both chains are parallel to each other and run along the crystallographic a‐axis. The cation represents a formerly unknown isomer of Te₈²⁺ ions. So far, Te₈²⁺ has been known as molecular clusters in Te₈[MCl₆](M = Zr, Hf, Re) and (Te₈)(Te₆)[WCl₆]₄, or in form of linked bicyclic monomers that are present in Te₈[WCl₆]₂. A polymeric chain‐like form closely related to Te₈[U₂Br₁₀] was found in Te₈[Bi₄Cl₁₄].     

Synthese und Kristallstruktur von Te3O3(PO4)2, einer Verbindung mit fünffach koordiniertem Tellur(IV)

Synthesis and Crystal Structure of Te₃O₃(PO₄)₂, a Compound with 5‐fold Coordinate Tellurium(IV) Polycrystalline Te₃O₃(PO₄)₂ is formed during controlled dehydration of (Te₂O₃)(HPO₄) with (Te₈O₁₀)(PO₄)₄ as an intermediate product. Colourless single crystals were prepared by heating stoichiometric amounts of the binary oxides P₂O₅ und TeO₂ in closed silica glass ampoules at 590 °C for 8 hours. The crystal structure (P2₁/c, Z = 4, α = 12.375(2), b = 7.317(1), c = 9.834(1)Å, β = 98.04(1)°, 1939 structure factors, 146 parameters, R[F² > 2σ(F²)] = 0.0187, wR2(F² all) = 0.0367) was determined from four‐circle diffractometer data and consists of [TeO₅] polyhedra und PO₄ tetrahedra as the main building units. The framework structure is made up of cationic zigzag‐chains of composition [Te₂O₃]²⁺ which extend parallel to [001] and anionic [Te(PO₄)₂]^2— units linked laterally to these chains. This leads to the formation of [Te₂O₃][Te(PO₄)₂] layers parallel to the bc plane which are interconnected via weak Te‐O bonds.     

Syntheses,Crystal Structures,and Reactivity of [enH]4[Sn2Se6]·en, [enH]4[Sn2Te6]·en and [enH]4[Sn2S6]: Known Anions within Novel Coordination Spheres obtained by Novel Synthesis Routes

The hexachalcogenodistannates K₆[Sn^III₂Se₆] or Li₄[Sn^IV₂Te₆]·8en were recently reported to simultaneously act as mild oxidants and chalcogenide sources in reactions with CoCl₂/LiCp* (Cp* = pentamethylcyclopentadienide) while the Sn—E (E = Se, Te) fragment is not kept in the products, e.g. [(Cp*Co)₃(μ₃‐Se)₂], [(Cp*Co)₃(μ₃‐Se)₂][Cl₂Co(μ₂‐Cl)₂Li(thf)₂] or [(Cp*Co)₄(μ₃‐Te)₄]. In search of related reagents with possibly different reaction behavior, we isolated and crystallographically characterized isotypic compounds [enH]₄[Sn^IV₂Se₆]�en ( 1 ), and [enH]₄[Sn^IV₂Te₆]·en ( 2 ) (en = 1, 2‐diaminoethane), that result from an uncommon disproportion/re‐arrangement reaction: distannate(III) K₆[Sn₂E₆] (E = Se, Te) was reacted with en·2HCl to yield 1 or 2 under disproportion of Sn^III to Sn^II and Sn^IV. Another pathway was necessary to synthesize the respective but solvent‐free thiostannate [enH]₄ [Sn^IV₂S₆] ( 3 ), since the phase “K₆[Sn₂S₆]” is unknown. This second method started out from SnCl₄·2THF and S(SiMe₃)₂ in en solution. However, using E(SiMe₃)₂ (E = Se, Te) instead of S(SiMe₃)₂, 1 and 2 are also obtained this way. 1—3 are the first chalcogenostannates that exhibit exclusively [enH]⁺ counterions. The compounds were characterized by means of X‐ray crystallography and NMR spectroscopy. They seem to be suitable for reactions towards group 8‐10 metal complexes. Preliminary experiments indicate that the binary anions 1 — 3 coordinated by 1‐aminoethylammonium ions react more slowly compared to the anionic phases tested until now.     

Synthese und Kristallstrukturen von (NEt4)2[TeS3], (NEt4)2[Te(S5)(S7)] und (NEt4)4[Te(S5)2][Te(S7)2]

Synthesis and Crystal Structures of (NEt₄)₂[TeS₃], (NEt₄)₂[Te(S₅)(S₇)], and (NEt₄)₄[Te(S₅)₂][Te(S₇)₂] (NEt₄)₂[TeS₃] was obtained by the reaction of NEt₄Cl, Na₂S₄ and tellurium in acetonitrile. It reacts with sulfur, yielding (NEt₄)₂[Te(S₅)(S₇)], which is transformed to (NEt₄)₄[Te(S₅)₂][Te(S₇)₂] by recrystallization from hot acetonitrile. According to the X-ray structure analysis, crystals of (NEt₄)₂[TeS₃] are monoclinic (space group P2₁/c) and form twins with the twinning plane (001); they contain pyramidal TeS₃^2– ions. (NEt₄)₂[Te(S₅)(S₇)] forms triclinic twins (space group P1) with the twinning plane (010). In the [Te(S₅)(S₇)]^2– ion an S₅ and an S₇ atom group are bonded in a chelate manner to the tellurium atom, which has square coordination. (NEt₄)₄[Te(S₅)₂][Te(S₇)₂] (monoclinic, space group P2₁/c) contains two kinds of anions, the known [Te(S₅)₂]^2– and the new [Te(S₇)₂]^2– ion which has two S₇ chelating groups.