Molekulare Zusammensetzung von flüssigem Schwefel. Teil: 3 Quantitative Analyse im Bereich 115–350°C

Molecular Composition of Liquid Sulfur. Part 3: Quantitative Analysis in the Temperature Region 115–350°C Relative concentrations of S₆, S₇, S₈, S_x (x > 8) and S_μ (insoluble sulfur) in equilibrium melts of elemental sulfur have been determined from i. r. and Raman spectra. At the freezing point (115°C) the melt consists of 0.6% S₆, 2.8% S₇, 1.5% S_x, and 95.1% S₈. – The solubility of S₇ in CS₂ has been determined at −77 to −26°C; the solubilities of both S₇ and S₈ in CS₂ are considerably enhanced by the presence of S_x. The thermal decomposition of S₈ and S_μ formation from S₆, S₇, and S_x has been investigated.     

Vibrational spectroscopic investigations of snse8-n molecules

The fundamental vibrations of 13 cyclic S_nSe_8-n (n = 7—2) molecules have been calculated using a modified Urey—Bradley force field with 9–14 independent force constants whose values have been adapted from those of Se₈ and S₈. Calculated wavenumbers are compared to those obtained by Raman spectroscopy for sulfur—selenium phases prepared by recrystallizing quenched molten mixtures of the elements as previously described. Agreement between the observed spectra and calculated wavenumbers is closest by assuming the existence of selenium—selenium bonds and the absence of isolated selenium atoms in S_nSe_8-n molecules. It is assumed that sulfur—selenium phases are mixed crystals with the following components in varying concentrations: 1,2-S₆Se₂, 1,2,3-S₅Se₃, 1,2,3,4-S₄Se₄, 1,2,5,6-S₄Se₄, 1,2,3-S₃Se₅ and 1,2-S₂Se₆. The presence of S₈ and Se₈ in some of the phases is indicated by the Raman spectra.     

Die Molekulare Zusammensetzung von erstarrten Phosphor-Schwefel-Schmelzen und die Kristallstruktur von β-P4S6

The Molecular Composition of Solidified Phosphorus-Sulfur Melts and the Crystal Structure of β-P₄S₆ Phosphorus sulfur melts were annealed for one week at 673 K and then quenched in ice water. The solids were dissolved in CS₂ and the concentrations of phosphorus sulfides were determined by ³¹P NMR spectroscopy. Samples containing between 44 and 70 mol% sulfur dissolved completely in CS₂. Between 0 and 42 mol% remains an insoluble residue of red phosphorus. Above 72 mol% it consisted of sulfur chains linked by phosphorus atoms. The solutions contained mainly the congruently melting compounds P₄S₃, P₄S₇, and P₄S₁₀ having maximum concentrations at their stoichiometric compositions. Other compounds P₄S_n (n = 4–9) which decompose on heating, according to the phase diagram, were also found in surprisingly high concentrations. One of these was β-P₄S₆ which crystallizes in the monoclinic space group P2₁/c with the lattice parameters a = 702.4(2), b = 1 205.6(2), c = 1 148.9(6) pm and β = 103.4(2)°. Reaction of white phosphorus with sulfur was also investigated. In contrast to the results of previous authors, who described the system P₄–S₈ below 373 K as eutectic, we found that the elements reacted below this temperature.     

Darstellung und Kristallstrukturen von Li4−2xSr2+xB10S19 (x ≈ 0,27) und Na6B10S18. Zwei neue Thioborate mit hochpolymeren Makrotetraeder-Netzwerken

Synthesis and Crystal Structures of Li_4?2xSr_2+xB₁₀S₁₉ (x ≈ 0.27) and Na₆B₁₀S₁₈. Two Novel Thioborates with Highly Polymeric Macro-tetrahedral Networks Li_4?2xSr_2+xB₁₀S₁₉ (x ≈ 0.27) and Na₆B₁₀S₁₈ were prepared from the reaction of strontium sulfide and lithium sulfide (sodium sulfide) with boron and sulfur at 700°C in graphitized silica tubes. Li_4?2xSr_2+xB₁₀S₁₉ (x ≈ 0.27) crystallizes in the monoclinic space group P2₁/c with a = 10.919(2) Å, b = 13.590(3) Å, c = 16.423(4) Å, and β = 90.48(2)°, Na₆B₁₀S₁₈ in the tetragonal space group I4₁/acd with a = 14.415(3) Å, c = 26.137(4) Å. Both structures contain supertetrahedral B₁₀S₂₀ units which are linked through tetrahedral corners to form a three-dimensional polymeric network in the case of Na₆B₁₀S₁₈ and one-dimensional chains in the case of Li_4?2xSr_2+xB₁₀S₁₉ (x ≈ 0.27). All boron atoms are in tetrahedral BS₄ coordination (B? S bond lengths vary from 1.879(5) to 1.951(5) Å (1.875(10) to 1.987(9) Å)). The strontium and lithium (sodium) cations are located within large channels formed by the anions.     

Sulfur Compounds. 164 Thermal Polymerization of the Cyclic Seleniumsulfide 1,2-Se2S5 Studied by DSC,HPLC, Raman Spectroscopy,and X-Ray Diffraction

Solid 1,2-Se₂S₅ polymerizes endothermically at 47°C to give a linear polymer which after stretching and extraction consists of helical molecules similar to those of polymeric sulfur. Heating of the polymer results in slow exothermic depolymerization at 84°C to give a mixture of seven cyclic Se_nS_8–n molecules which melts at 111°C. When the polymeric Se₂S₅ is refluxed with CS₂ the initial depolymerization Products are 1,2-Se₂S₅, SeS₅ and 1,2,3-Se₃S₅ but in addition SeS₇ and 1,2-Se₂S₆ are formed. These results indicate the atomic sequence –Se? S₅? Se– in the polymer. The powder x-ray diffraction pattern and Raman spectrum of the polymer as well as its lattice parameters are reported and the Probable mechanism of its depolymerization is discussed.     

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.     

Darstellung und Kristallstruktur von Cyclooktadekaschwefel,S18, und Cycloikosaschwefel,S20

Preparation and Crystal Structure of Cyclooctadecasulphur, S₁₈, and Cycloikosasulphur, S₂₀ Starting with mixtures of sulfanes and chlorosulfanes new sulfur rings S₁₈ and S₂₀. are synthesized according to The new compounds are remarkable stable. Preparation of the starting materials as well as the structure determinations by X-rays are reported.     

Thermal Polymerization and Depolymerization Reactions of 10 Sulfur Allotropes Studied by HPLC and DSC [1]

The thermal decomposition (polymerization, depolymerization, ring interconversion) of a number of sulfur allotropes (S₆, S₇, S₈, S₁₀, S₁₂, S₁₃, S₂₀, polymeric sulfur) has been investigated theoretically (on the basis of Gee's theory) and experimentally by differential scanning calorimetry (DSC) and high-pressure liquid chromatography (HPLC) in the temperature region of 30–250°C. While the polymerization of liquid S₈ is endothermic and endentropic (ΔS > 0), liquid S₇ polymerizes exothermically and endentropically, and liquid S₆ exothermically but exentropically (ΔS > 0). Therefore, a floor temperature exists for the polymerization of S₈ and a hypothetical very high ceiling temperature for the polymerization of S₆, while S₇ is unstable with respect to polymerization over the whole temperature region. Excepting S₈, all investigated cyclic sulfur allotropes yield polymeric sulfur on heating to 60–150°C followed by depolymerization to the equilibrium sulfur melt consisting mainly of S₈, some S₇, and traces of S₆, S₉, S₁₂ and other rings. Polymeric sulfur (S_μ) slowly dissolves in CS₂ at 20°C to give S₈, S₇ and traces of other rings (mainly S₆, S₉, S₁₂). On heating of the S_μ/CS₂ mixture in sealed ampoules to 80–100°C complete dissolution takes place within several hours or days and the rings S₈ and S₇ are the main products.     

Die Kristallstruktur und das Raman-Spektrum von SbCl3 · S8

Crystal Structure and Raman Spectrum of SbCl₃ · S₈ Contrary to literature data, the reaction of SbCl₅ with CS₂ at 5°C does not yield SbSCl₃ but SbCl₃ · S₈. At room temperature it already decomposes slowly to SbCl₃ and sulphur. The crystalline compound is built up from pyramidal SbCl₃ molecules and S₈ rings; pairs of SbCl₃ molecules form loosely associated dimeric units, furthermore there exist some relatively short Sb…?S contact distances. SbCl₃ · S₈ crystallizes in the space group P1 with the lattice constants a = 805, b = 867, c = 1073 pm, α = 94.9, β = 107.1 und γ = 111.6° (bei ?5°C). The crystal structure was determined with 2032 X-ray reflexions and was refined to a residual index of R = 0.028. The Raman spectrum is reported.     

Die Kristall- und MolekülStruktur von S4N4·2C7H8

Crystal and Molecular Structure, of S₄N₄ · 2C₇H₈ The structure of the title compound has been determined from threedimensional X-ray data. Crystals are monoclinic, with unit cell dimenions a = 16.532 Å, b = 8.563 Å, c = 10.880 Å, β = 103.2°, space group C? C2/c and Z = 4. Least squares refinement, by use of 1132 independent reflections measured on a diffractometer has reached 3.9%. In the S₄N₄·2C₇H₈ molecules the organic components are linked to two sulfur atoms of the S₄N₄, ring each.     

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 Reaktion von Thionylchlorid mit Polysulfanen: Darstellung und Eigenschaften von S8O

On the Reaction of Thionyl Chloride with Polysulfanes: Preparation and Properties of S₈O The reactions of H₂S₂, H₂S₅, and crude sulfane with thionyl chloride at low temperatures are reported. S₈O can be prepared from SOCl₂ and H₂S_x at ?40°C in CS₂/(CH₃)₂O. Solubility, density, stability, mass spectrum, and some simple reactions of S₈O are reported and discussed.     

A New Allotrope of Elemental Sulfur: Convenient Preparation of cyclo-S14 from S8

Three simple steps lead from S₈ to cyclo-S₁₄, which is stable at 20°C. The final synthetic step [Eq. (a)] provides the title compound, which was characterized spectroscopically and by X-ray structure analysis. Formally, the structure of S₁₄ is derived by insertion of an S₂ unit into S₁₂. tmeda=N,N,N′,N′-tetramethylethylenediamine.     

Darstellung,Eigenschaften, röntgenographische und spektroskopische Untersuchung von Tl4Nb2S11 und Tl4Ta2S11

On Polychalcogenides of Thallium with M₂Q₁₁ Groups as a Structural Building Block. I Preparation, Properties, X‐ray Diffractometry, and Spectroscopic Investigations of Tl₄Nb₂S₁₁ and Tl₄Ta₂S₁₁ The new ternary compounds Tl₄Nb₂S₁₁ and Tl₄Ta₂S₁₁ were prepared using Thallium polysulfide melts. Tl₄M₂S₁₁ crystallises isotypically to K₄Nb₂S_8.9Se_2.1 in the triclinic space group P 1 with a = 7.806(2) Å, b = 8.866(2) Å, c = 13.121(3) Å, α = 72.72(2)°, β = 88.80(3)°, and γ = 85.86(2)° for M = Nb and a = 7.837(1) Å, b = 8.902(1) Å, c = 13.176(1) Å, α = 72.69(1)°, β = 88.74(1)°, and γ = 85.67(1)° for M = Ta. The interatomic distances as well as angles within the [M₂S₁₁]^4– anions are similar to those of the previously reported data for analogous alkali metal polysulfides. Significant differences between Tl₄M₂S₁₁ and A₄M₂S₁₁ (A = K, Rb, Cs) are obvious for the shape of the polyhedra around the electropositive elements. The two title compounds melt congruently at 732 K (M = Nb) and 729 K (M = Ta). The optical band gaps were estimated as 1.26 eV for Tl₄Nb₂S₁₁ and as 1.80 eV for the Tantalum compound.     

Über Chalkogenolate. 118. Kristall- und Molekülstruktur von Oxovanadin(V)-ethylxanthat

On Chalcogenolates. 118. Crystal and Molecular Structure of Oxovanadium(V) Ethylxanthate VO[S₂C? OC₂H₅]₃ crystallizes with Z = 8 in the monoclinic space group P2₁/n with cell dimensions a = 15.065(7) Å, b = 18.540(48) Å, c = 12.824(7) Å, = 99.31(7)°. The crystal and molecular structure has been determined from single crystal X-ray data at 20°C and refined to a conventional R of 0.045.     

Beiträge zur Chemie des Schwefels. 108. Schmelzwärme und spezifische Wärme des flüssigen Schwefels. Einfluß von Verunreinigungen

Using an adiabatic calorimeter, the heat of transition S_α ? S_β, the heat of fusion of S_β and the specific heat of the liquid had been determined on sulfur samples refined by zone melting and samples doped with chlorine, bromine and iodine. The data obtained from pure sulfur (heat of fusion: 1608 ± 8 J/Tom, specific heat of the liquid at 120°C: 29,4 J/Tom.°C) are about 10% lower than comparable values of other authors. Apparently they represent heat of fusion and specific heat of the pure cyclooctasulfur. The measurements on doped samples (δH_S = 1736 ± 10 J/Tom) are in agreement with the data reported in literature and include a portion of enthalpy from the transition reaction of cycloocta-sulfur (S_λ) to catenaocta-sulfur (S_π), requiring extremly long equilibrium times in pure sulfur. The influence of impurity on the caloric properties of the liquid sulfur is also indicated by the increasing width and decreasing highness of the C_p-maximum at 159°C with increasing amount of halogens. For the heat of transition S_α → S_β, independent of the amount of impurity, the literature data could be confirmed. At the samples doped with iodine there was observed a previously unreported transition near 65,9°C.     

Über [Ag(S9)]−, ein symmetrisches zehngliedriges Ringsystem Darstellung,Struktur und spektroskopische Charakterisierung der schwefelreichen Verbindung [(PPh3)2N][Ag(S9)] · S8

About [Ag(S₉)]^?, a Symmetric Ten-Membered Ring System; Preparation, Structure, and Spectroscopic Characterization of the Sulfur Rich Compound [(PPh₃)₂N][Ag(S₉)] · S₈ Orange [(PPh₃)₂N][Ag(S₉)] · S₈ ( 1 ) could be obtained by reaction of a definite S_x^2?-solution with AgNO₃ and characterized by vibrational spectra (IR/Raman) and X-ray structure analysis. The anion [Ag(S₉)]^? shows a symmetric conformation of a ten-membered ring system. 1 crystallizes in the triclinic space group P1 (a = 1383.8(4), b = 1429.5(4), c = 1540.5(5) pm, α 62.38(2), β 68.05(2), γ 65.86(2)°, V = 2399.1 · 10⁶ pm³, Z = 2; R = 0.077 for 5433 independent reflections (F₀ > 3.92 σ(F₀))).     

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.     

Synthesis and Characterization of the Ternary Thiobismuthates A9Bi13S24 (A = K,Rb)

Ternary alkali metal thiobismuthates A₉Bi₁₃S₂₄ (A = K, Rb) were synthesized by direct combination reactions at 650 °C. The compounds crystallize in the monoclinic space group C2/m (no. 12) with cell parameters a = 30.919(1) Å, b = 4.1008(2) Å, c = 20.9072(9) Å, β = 105.826(3)° for K₉Bi₁₃S₂₄ ( 1 ) and a = 31.823(6) Å, b = 4.1177(8) Å, c = 21.086(4) Å, β = 105.62(3)° for Rb₉Bi₁₃S₂₄ ( 2 ). The crystal structure of 1 contains a 3D [K₂Bi₁₃S₂₄]^7– polyanionic framework, whereas 2 consists of 2D [RbBi₁₃S₂₄]^8– polyanionic slabs stacked along [201]. Both 1 and 2 are semiconductors with a band gap of 1.4 and 1.3 eV, respectively, which is supported by an electronic structure calculation. 1 melts congruently at 580 °C, while 2 melts incongruently at 575 °C. 1 and 2 are airstable and insoluble in water and organic solvents.     

Schwingungsspektren von β-P4S5 und P4S7

Vibrational Spectra of β-P₄S₅ and P₄S₇ The vibrational spectra of the solid and liquid cage compounds β-P₄S₅ and P₄S₇ have been recorded. The assignments of the frequencies are proposed mainly based on polarization data. β-P₄S₅ decomposes during melting into P₄S₃ α-P₄S₇ and β-P₄S₆. Molten α-P₄S₇ dissociates to some extent into β-P₄S₆ and sulphur. An association of β-P₄S₆ with α-P₄S₇ is discussed for the molten state. All reactions in molten P₄S₇ are reversible.