Synthese und Kristallstrukturbestimmung von Dimethyldi-(N-Methylimidazolium)siliciumbromid

Synthesis and Crystal Structure Determination of Dimethyldi-(N-Methylimidazolium)silicon Bromide The reaction of dibromodimethylsilane with n-methylimidazole (NMI) leads to a 1:2 compound stable at room temperature. The reaction was carried out at room temperature and colorless, moisture sensitive crystals were obtained by sublimation. The addition compound crystallizes in the orthorhombic space group Pcam (No. 57) with lattice constants a = 1 110 96(8) pm, b = 1 142.3(2) pm and c = 1 238.9(3) pm. For 1 317 independent reflections, measured at 21°C, the structure could be refined to R = 0.040 and R_w = 0.041.     

Untersuchungen an Polyhalogeniden. XVI. Darstellung und Kristallstrukturen der Bipyridiniumpolyiodide Bipy · HIn mit n = 3, 5 und 7

Studies on Polyhalides. 16. Preparation and Crystal Structures of Bipyridiniumpolyiodides Bipy · HI_n with n = 3, 5, and 7 With simply protonated α,α′-Bipyridyl Bipy · H⁺ a triiodide Bipy · HI₃, a pentaiodide Bipy · HI₅ and a heptaiodide Bipy · HI₇ may be prepared in the presence of iodide ions I^? and dependent of the iodine I₂ content. Bipyridiniumtriiodide C₁₀H₉N₂I₃ crystallizes at room temperature monoclinically in P2₁/n with a = 1 122.8(1) pm, b = 1 072.7(1) pm, c = 1 200.2(3) pm, β = 98.02(2)° and Z = 4. The crystal structure is built up from mixed cationic and anionic layers. Bipyridiniumpentaiodide C₁₀H₉N₂I₅ crystallizes at room temperature monoclinically in P2₁/c with a = 887.3(5) pm, b = 2 527.9(12) pm, c = 830.7(3) pm, β = 106.78(5)° and Z = 4. The crystal structure contains triiodide ions I₃^? till now uniquely connected by iodine molecules I₂ in a trigonal planar way. Bipyridiniumheptaiodide C₁₀H₉N₂I₇ crystallizes at room temperature triclinically in P&1macr; with a = 713.1(3) pm, b = 1 007.9(3) pm, c = 1 464,8(4) pm, α = 81.07(3)°, β = 89.92(3)°, γ = 82.77(3)° and Z = 2. The crystal structure contains a V-shaped pentaiodide ion I₅^? completed by an iodine molecule I₂ to a trigonal pyramidally shaped heptaiodide ion I₇^? and at the same time connected to a zigzag chain.     

Synthese und Struktur von zwei- und dreikernigen Heterometallkomplexen mit Nitridobrücken zwischen Re und Mo

Synthesis and Structure of Two- and Threenuclear Heterometallic Complexes with Nitrido Bridges between Re and Mo The reaction of ReNCl₂(PMe₂Ph)₃ with MoCl₄(NCEt)₂ yields the heterometallic threenuclear complex [{(Me₂PhP)₃(EtCN)ClRe≡N–}₂MoCl₄][MoNCl₅]. The anion [MoNCl₅]^2– presumably results from a transfer of the nitrido ligand from the Re to the Mo atom. The air-sensitive compound is paramagnetic with μ_eff = 2.87 B. M. at room temperature. A reduction of the magnetic moment to 1.74 B.M at 20 K starts at 140 K. The complex crystallizes in the orthorhombic space group Pca2₁ with a = 2430(1), b = 1328(1), c = 2436.3(2) pm, Z = 4. With bond angles Re–N–Mo of 164° and 167° the nitrido bridges are almost linear. The distances Re–N of 169 and 170 pm can be interpreted with triple bonds. The Mo–N bond lengths of 210 and 211 pm correspond to single bonds. In the anion [MoNCl₅]^2– the distance Mo≡N is 167 pm. Hydrolysis of the threenuclear complex results in a cleavage of one of the nitrido bridges to yield (Me₂PhP)₃(EtCN)ClRe≡N–MoOCl₄. The compound is paramagnetic with μ_eff = 1.71 B.M. at room temperature. It crystallizes in the orthorhombic space group Pbca with a = 1718.5(4), b = 2037(1), c = 2041.1(7) pm, Z = 8. In the dinuclear complex the [MoOCl₄]^– unit is only weakly coordinated to the nitrido ligand with Mo–N = 246.5 pm, while the distance of the Re≡N bond of 168.1 pm is almost unchanged in comparison with a terminal bond. The bond angle Re≡N–Mo is 165.6°.     

Synthese und Kristallstruktur des μ-Dinitridosulfato(II)-Komplexes [Na-15-Krone-5]2[μ-(NSN)(MoF5)2]

Synthesis and Crystal Structure of the μ-Dinitridosulfate(II) Complex [Na-15-crown-5]₂[μ-(NSN)(MoF₅)₂] The title compound is formed at room temperature by the reaction of [MoCl₄(NSCl)]₂ with the equivalent amount NaF in acetonitrile in presence of the crown ether 15-crown-5. It forms black, moisture-sensitive crystals that were characterized by an X-ray structure determination (1 756 unique observed reflexions, R = 0.073). Crystal data (19°C): a = 965.5, b = 3 219, c = 1 161.1 pm, β = 95.42°; space group P2₁/n, Z = 4. The structure consists of ion triples in which the [Na-15-crown-5]⁺ ions are associated with the [μ-(NSN)(MoF₅)₂]^2? ions via Na…?F contacts of 215 to 265 pm length. Each of the two MoF₅ units of the anion is linked with one of the N atoms of the dinitridosulfate(II) group; bond angle NSN 103°, MoN bond lengths 172 pm.     

NaNb6Cl15 – Preparation,Structure, Ionic Conduction

NaNb₆Cl₁₅ is prepared by heating Nb₃Cl₈, NaCl and Nb under Ar at 1 170 < T [K] < 1 270 forming black regular dodecahedra. It crystallizes in the cubic space group Ia3 d (a = 2 041.7(2) pm at room temperature) and transforms to a tetragonal structure below 150 K (probably I4₁/acd, a = 2 037.2(6), c = 2 028.2(2) pm at 80 K). The Na⁺ ions are at room temperature dynamically disordered in a split position. Their mobility is investigated by IR spectroscopy and electrochemical methods.     

Untersuchungen an Polyhalogeniden. XXVI [1]. Über N-Propylurotropiniumpolyiodide UrPrIx mit x = 5 und 7: Strukturelle Charakterisierung eines Pentaiodids und eines Heptaiodids

Studies on Polyhalides. 26. On N-Propylurotropinium Polyiodides UrPrI_x with x = 5 and 7: Crystal Structures of a Pentaiodide and a Heptaiodide The salts UrPrI_x with x = 5 and 7 are formed by the reaction of N-propylurotropinium iodide UrPrI with excess iodine I₂ at room temperature from aqueous solution. N-propylurotropinium pentaiodide C₉H₁₉N₄I₅ crystallizes monoclinically in P2₁/n with a = 1007.6(3) pm, b = 1362.5(3) pm, c = 2899.0(9) pm, β = 91.49(3)º and Z = 8. The crystal structure is built up from parallel chains of cations UrPr⁺ and pairs of V-shaped pentaiodide anions I₅^? along [0 1 0]. N-propylurotropinium heptaiodide C₉H₁₉N₄I₇ crystallizes triclinically in P1 with a = 970.4(1) pm, b = 971.1(1) pm, c = 1357.8(2) pm, α = 106.83(1)º, β = 92.28(1)º, γ = 105.17(1)º and Z = 2. The crystal structure is stacked by alternating cationic and anionic double layers along [0 0 1]. The heptaiodide layer shows a two-dimensional network.     

Die Kristallstrukturen von α- und β-K3OCl

The Crystal Structures of α- and β-K₃OCl The orange coloured compound K₃OCl has been prepared. It exists in a low temperature modification (α-K₃OCl) and a high temperature modification (β-K₃OCl). The transition temperature is 364 ± 5 K. The crystal structures were determined by x-ray diffraction. α-K₃OCl crystallizes at room temperature in the orthorhombic space group Pbnm (Z = 4) with the cell parameters a = b = 723.9(2) pm and c = 1 027.7(2) pm in the anti-GdFeO₃-structure type. The high temperature modification β-K₃OCl crystallizes (Z = 1) in the cubic space group Pm3m in the β-Ag₃SI-structure type with a = 516.2(2) pm (T = 393 K).     

Synthesis and Structure of Ba12F19Cl5

A new member belonging to the binary phase diagram of BaF₂ and BaCl₂ was synthesized. The single domain crystals of Ba₁₂F₁₉Cl₅ can be prepared from a nonstoichiometric flux with molar ratio of 1 : 1 between BaFCl and BaF₂. The compound crystallizes at room temperature in the non-centrosymmetric hexagonal space group P6 2m with a = b = 1408.48(14) and c = 427.33(5) pm. Three different barium environements with coordination number of nine are found. The barium fluorine distances vary between 250.59(6) – a short distance compared to other Ba? F distances – and 302.7(1) pm and barium chlorine distances between 331.55(3) and 336.19(15) pm. This compound is further characterized using Raman spectroscopy.     

Struktur,Verzwillingung und Eigenschaften von Ce4Br3C4

Structure, Twinning, and Properties of Ce₄Br₃C₄ The new compound Ce₄Br₃C₄ can be prepared from Ce metal, CeBr₃ and C (3 : 3 : 2) at 1020 °C. It crystallizes in P 1 with a = 422.7(1) pm, b = 1103.4(3) pm, c = 1126.8(2) pm, α = 77.15(3)°, β = 90.13(2)° and γ = 84.42(3)°. The crystals are characteristically twinned, the twin law being (1 0 0, ¹/₂ –1 0, 0 0 –1). The crystal structure contains puckered layers of edge sharing Ce₆C₂ octahedra. The mean C–C distance in the C₂ units is 133(5) pm. Ce₄Br₃C₄ has at room temperature a specific resistivity of 100 mΩ cm and an effective magnetic moment of 2.55(3) μ_B (Ce³⁺).     

Untersuchungen an Polyhalogeniden. XI. Darstellung und Kristallstruktur des Diethylmethylphenylammoniumtriiodids,Et2MePhNI3

Studies on Polyhalides. 11 Preparation and Crystal Structure of Diethylmethylphenylammoniumtriiodide, Et₂MePhNI₃ Diethylmethylphenylammoniumtriiodide C₁₁H₁₈NI₃ crystallizes at room temperature monoclinically with a = 824.1(2) pm, b = 1 428.5(2) pm, c = 1 430.0(2) pm, β = 103.17(3)° and Z = 4. The crystal structure is build up from layers of the quarternary ammonium ions Et₂MePhN⁺ and of the triiodide ions I₃^?, which alternate with each other along [1 0 0]. The packing of these layers and of the groups within each layer seems to be particularly effective without forming noticeable short contact distances.     

Existiert eine Wurtzit‐Modifikation von Lithiumbromid? — Untersuchungen im System LiBr/LiI —

Is there a Wurtzite‐Modification of Lithium Bromide? — Studies on the System LiBr/LiI — Deposition of mixtures of LiBr/LiI (ratio: LiBr/LiI = 3:1, 2:1, 1:1, 1:2, 1:3, 1:4) and of pure LiI and LiBr from the gas phase onto a sapphire substrate at ‐196 °C in a high vacuum chamber were investigated by means of temperature‐dependent X‐ray diffraction. Below 0 °C LiI crystallizes in the hexagonal Wurtzite‐modification (β‐LiI) with a = 451.4(1) und c = 731.1(2) pm, which transforms into the cubic rock salt modification (α‐LiI, a = 602.57(3) pm) by heating up to room temperature. Co‐depositions of LiBr/LiI formed solid LiBr_1‐xI_x solutions that also crystallize in the Wurtzite‐modification, below room temperature. Compared to β‐LiI, these solid solutions are more stable and transform into the cubic phase at the significantly higher temperature of 80 °C. The lattice constants of LiBr_1‐xI_x with x ≈ 0.7 are a = 445.48(7), c = 719.1(1) pm and with x ≈ 0.4 are a = 431.50(5), c = 691.7(1) pm. The hexagonal phase LiBr_1‐xI_x is observed for the complete series of mixed crystals with 0.25 ≤ x ≤ 0.8. Both cubic phases, α‐LiI and LiBr, show solubilities of up to ca. 10 % of the respective other compound. In case of pure LiBr only the cubic modification (a = 551.54(2) pm, 25 °C) was observed in the complete temperature range (‐196 °C to 25 °C).     

(Meta)stabiles CaC2

(Meta)stable CaC₂ One out of four modifications of CaC₂ is the so‐called metastable Calcium Carbide, CaC₂‐III, which was synthesized as pure material. It forms by heating monoclinic CaC₂‐II (C2/c) above 150 °C and remains stable after cooling down to room temperature. The structure was refined from X‐ray powder patterns (C2/m, Z = 4, a = 722.6(1) pm, b = 385.26(7) pm, c = 737.6(1) pm, β = 107.345(2)°). After grinding CaC₂‐III transforms back into CaC₂‐II. Heating CaC₂‐III induces a reversible phase transition into the cubic modification (CaC₂‐IV) at 460 °C. Differences between the three different structures of CaC₂ I–III, being stable at ambient conditions are also shown by ¹³C‐MAS‐NMR measurements, especially the presence of two distinct types of carbon atoms in the structure of the title compound.     

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.     

Untersuchungen an Polyhalogeniden. XXIII. Kristallstrukturen der N-Alkylurotropiniumtriiodide UrRI3 mit R = Methyl,Ethyl, n-Propyl und n-Butyl

Studies on Polyhalides. 23. Crystal Structures of N-Alkylurotropinium Triiodides UrRI₃ with R = Methyl, Ethyl, n-Propyl, and n-Butyl The salts UrRI₃ may be prepared by the reaction of N-alkylurotropinium iodides UrRI with iodine I₂ at room temperature from aqueous solution. N-methylurotropinium triiodide C₇H₁₅N₄I₃ crystallizes monoclinically in P2₁/c with a = 1300.8(2) pm, b = 1276.0(3) pm, c = 859.3(2) pm, β = 94.75(2)° and Z = 4. The crystal structure is built up from layers of cations UrMe⁺ and of linear symmetric triiodide ions I₃^? alternating along [100]. N-ethylurotropinium triiodide C₈H₁₇N₄I₃ crystallizes orthorhombically in Pnma with a = 1397.3(5) pm, b = 1221.3(2) pm, c = 886.2(2) pm and Z = 4. The cationic (UrEt⁺) and anionic (I₃^?) layers alternate along [0 10]. N-propylurotropinium triiodide C₉H₁₉N₄I₃ crystallizes monoclinically in P2₁/c with a = 1885.7(5) pm, b = 1657.1(5) pm, c = 1700.5(4) pm, β = 112.39(2)° and Z = 12. The three independent cations and anions are slightly, but differently distorted. N-butylurotropinium triiodide C₁₀H₂₁N₄I₃ crystallizes monoclinically in P2₁/m with a = 991.8(3) pm, b = 757.8(2) pm, c = 1128.2(2) pm, β = 90.73(2)° and Z = 2. The crystal structure is stacked by alternating cationic and anionic layers along [001]. The triiodide ion is asymmetric and linear.     

Untersuchungen an Polyhalogeniden. XVII. Darstellung und Kristallstruktur von Urotropiniumtriiodid,UrHI3

Studies on Polyhalides. 17. Preparation and Crystal Structure of Urotropinium Triiodide, UrHI₃ Urotropinium triiodide C₆H₁₃N₄I₃ is formed by the reaction of equimolar amounts of urotropinium iodide and iodine in ^tBuOH as red-brown cube-like crystals melting at 402 K under decomposition. The compound crystallizes monoclinically in the space group P2₁/c with a = 952.0(3) pm, b = 1 160.2(6) pm, c = 1 149.9(4) pm, β = 92.22(3)° and Z = 4. The till now not described crystal structure (R = 0.027 for 1 860 observed reflexes) contains urotropinium ions UrH⁺ and slightly distorted triiodide ions I₃^?(d(I—I) = 292.3(1), 294.1(1) pm, φ(I—I—I) = 178.27(2)°) which are linked to ion pairs by a rather short contact (d(I …? I) = 389.0(1) pm, φ(I—I …? I) = 149.12(2)°).     

LiSr2[ReN4] und LiBa2[ReN4] – isotype Nitridorhenate(VII)

LiSr₂[ReN₄] and LiBa₂[ReN₄] – isotypic Nitridorhenates(VII) The quaternary nitridorhenates(VII) LiAE₂[ReN₄] (AE = Sr, Ba) were synthesized by reaction of the metals with molecular nitrogen at 850–900 °C. The plate‐like, nearly colourless crystals were investigated by X‐ray single crystal methods and were identified as isotypic phases: LiSr₂[ReN₄] (LiBa₂[ReN₄]); monoclinic, P2₁/m; a = 614.64(8) pm (651.04(12) pm), b = 585.97(6) pm (b = 598.86(9) pm), c = 689.70(17) pm (737.43(5) pm), β = 106.375(4)° (108.535(2)°); Z = 2. Crystals of the strontium compound were systematically twinned along [001]. In the crystal structures of the quaternary compounds the alkaline earth‐ and nitride‐ ions are arranged in the motif of the InNi₂‐type structure. Strontium and barium are in a trigonal prismatic coordination by nitrogen (Sr–N: 261.0(7)–284.3(4) pm; Ba–N: 278.0(7)–303.0(6) pm). One half of the tetrahedral voids within the partial structure formed by stacking of trigonal prismatic rod layers is occupied by rhenium (formation of [Re^VIIN₄]^5–‐tetrahedra; Re–N: 181.0(6)–184.5(8) pm), lithium takes the positions of the remaining tetrahedral sites (Li–N: 2 × 198(1) pm, 224(2) pm and 228(2) pm for the strontium phase). In the barium compound the lithium positions show a larger shift from the tetrahedral centres towards a tetrahedral plane (Li–N: 2 × 195(1) pm, 213(2) pm and 304(2) pm).     

Über die komplexen Hydroxide des Chroms: Na9[Cr(OH)6]2(OH)3 · 6 H2O und Na4[Cr(OH)6]X · H2O (X = Cl, (S2)1/2) – Synthese,Kristallstruktur und thermisches Verhalten

Complex Hydroxides of Chromium: Na₉[Cr(OH)₆]₂(OH)₃ · 6 H₂O and Na₄[Cr(OH)₆]X · H₂O (X = Cl, (S₂)_1/2) – Synthesis, Crystal Structure, and Thermal Behaviour Green plate‐like crystals of Na₉[Cr(OH)₆]₂(OH)₃ · 6 H₂O (triclinic, P1, a = 872.9(1) pm, b = 1142.0(1) pm, c = 1166.0(1) pm, α = 74.27(1)°, β = 87.54(1)°, γ = 70.69(1)°) are obtained upon slow cooling of a hot saturated solution of Cr^III in conc. NaOH (50 wt%) at room temperature. In the presence of chloride or disulfide the reaction yields green prismatic crystals of Na₄[Cr(OH)₆]Cl · H₂O (monoclinic, C2/c, a = 1138.8(2) pm, b = 1360.4(1) pm, c = 583.20(7) pm, β = 105.9(1)°) or green elongated plates of Na₄[Cr(OH)₆](S₂)_1/2 · H₂O (monoclinic, P2₁/c, a = 580.8(1) pm, b = 1366.5(3) pm, c = 1115.0(2) pm, β = 103.71(2)°), respectively. The latter compounds crystallize in related structures. All compounds can be described as distorted cubic closest packings of the anions and the crystal water molecules with the cations occupying octahedral sites in an ordered way. The thermal decomposition of the compounds was investigated by DSC/TG or DTA/TG and high temperature X‐ray powder diffraction measurements. In all cases the final decomposition product is NaCrO₂.     

Zur Chemie und Strukturchemie von Phosphiden und Polyphosphiden. 42. Trilithiumheptaphosphid Li3P7: Darstellung,Struktur und Eigenschaften

Chemistry and Structural Chemistry of Phosphides and Polyphosphides. 42. Trilithiumheptaphosphide Li₃P₇: Preparation, Structure, and Properties Trilithium heptaphosphide, Li₃P₇, has been prepared by reaction of the elements at 870 K in Nb and Ta ampoules, respectively. The bright yellow (solventfree) substance crystallizes in a new structure type (P2₁2₁2₁; a = 974.2(1) pm; b = 1053,5(1) pm; c = 759,6(1) pm; Z = 4). The structure is closely related to the plastically crystalline Rb₃P₇ type of structure (Li₃Bi variant). The heptaphosphanortricyclene anions P₇^3? are surrounded by 12 Li cations and connected one to each other in a complex manner. The anion exhibits a differentation of distances and angles typical for ionic nortricyclenes X₇^3? (P? P distances: d?(basis) = 224.9 pm; d?(basis-bridge) = 214.7 pm; d?(bridge-bridgehead) = 217.6 pm). The distances Li to P are in the range of 250 ≤ d(Li? (2b)P^?) ≤ 270 pm. The P? P and Li? P bond distances are equivalent to meaningful Pauling bond orders PBO. On heating in closed ampoules, Li₃P₇ shows an endothermic effect at 900 K, corresponding to a first order phase transition into a HT phase of unknown nature up to now. On thermal decomposition no congruent dissociative sublimation occurs in contrast to the other heptaphosphides M₃P₇, but LiP and Li₃P are formed, the latter evaporates congruently dissociative, Solutions of Li₃P₇ in en show valence fluctuation of the P₇^3? anions already at room temperature (δ ³¹P-NMR = ? 122.1). Further reactions of Li₃P₇ are reported as well as the structural differences between Li₃P₇ and the solvates Li₃P_7solv3 are discussed.     

Phosphaniminato-Komplexe des Schwefels. Synthese und Kristallstrukturen von [SO(Cl)(NPPh3)], [SO2(Cl)(NPPh3)] und [SCl(NPPh3)2]Cl

Phosphorane Iminato Complexes of Sulfur. Synthesis and Crystal Structures of [SO(Cl)(NPPh₃)], [SO₂(Cl)(NPPh₃)], and [SCl(NPPh₃)₂]Cl The title compounds have been prepared by the reaction of Me₃SiNPPh₃ with SOCl₂, SO₂Cl₂, and SCl₂, respectively. They form colourless, moisture sensitive crystals, which were characterized by IR spectroscopy and by crystal structure determinations. [SO(Cl)(NPPh₃)]: Space group P2₁/n, Z = 4, structure determination with 2 434 observed unique reflections, R = 0.047. Lattice dimensions at 19°C: a = 1 304.8, b = 996.5, c = 1 339.5 pm, β = 93.75°. The compound forms monomeric molecules with a remarkably long S? Cl bond of 234.2 pm and distances SN and PN of 154.6 and 161.6 pm, respectively, which agree with double bonds. [SO₂(Cl)(NPPh₃)]: Space group P2₁/n, Z = 4, structure solution with 2 872 observed, unique reflections, R = 0.047. Lattice dimensions at 20°C: a = 956.9, b = 1 909, c = 1 002.0 pm, β = 106.06°. The compound forms monomeric molecules with distances S? Cl of 207.1 pm, SN of 154.5 pm, and PN of 161.6 pm. [SCl(NPPh₃)₂]Cl: Space group P2₁/c, Z = 4, structure solution with 5 224 observed, unique reflections, R = 0.042. Lattice dimensions at 20°C: a = 1 108.6, b = 1 603.8, c = 1 840.5 pm, β = 99.98°. The compound forms ions [SCl(NPPh₃)₂]⁺ and Cl^?. In the cation the sulfur atom is φ-tetrahedrally coordinated with a long S? Cl distance of 248.5 pm and SN bond lengths of 154.5 and 156.0 pm.     

3-Chloro-1,2,3,4-tetraphenylcyclobutenyl-Ennea-chloro-μ-Oxo-di-Niobat(V),[C4Cl(Ph)4]⊕[Nb2OCl9]⊖ Synthese und Kristallstruktur

3-Chloro-1,2,3,4-tetraphenylcyclobutenyl-Ennea-chloro-μ-Oxo-di-Niobate(V), [C₄Cl(Ph)₄]^⊕[Nb₂OCl₉]^?. Synthesis and Crystal Structure The title compound yields from a one step reaction of niobium pentachloride and niobium oxide trichloride with diphenyl acetylene in dichloro methane, forming dark green crystals. The new complex is characterized by the i.r. spectrum and a crystal structure determination by X-ray methods. The compound crystallizes triclinic in the space group P1 with two formula units per unit cell (2253 independent observed reflexions, R = 4.7%). The lattice dimensions are a = 1199, b = 1034, c = 1453 pm; α = 87.0°, β = 108.6°, γ = 96.6°. The cyclobutenyl cation forms an almost planar C₄-ring with two pairs of neighbouring C? C bonds of 139 pm and 153 pm. The anion [Nb₂OCl₉]^? displays a nearly linear NbONb axis (bond angle 174°) in which the NbO bond lengths are 176 pm and 208 pm. Two anions are linked via asymmetric chloro bridges with Nb? Cl bond lengths of 248 pm and 270 pm to form a centrosymmetric dimer.