- Synthesis and structure of W3S4Cl4
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The synthesis of W3S4Cl4, a layered tungsten thiohalide with a basic structure similar to TiS3 is described. W3S4Cl4 was synthesized from WCl2 and sulfur at 350°C. The X-ray powder diffraction pattern was completely indexed on a small hexagonal unit cell with a = 3.336(1) A and c = 5.907(1) A. Electron diffraction studies revealed a 4 × 4 × 8 supercell, giving the compound a superstructure with a = 13.356 A and c = 47.29 A. An ordering of the tungsten vacancies which can account for this superstructure is discussed in light of the electron diffraction patterns.
- Rauch,DiSalvo,Zhou,Tang,Edwards
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- A gravimetric procedure for determination of sulphur in disulphur dichloride
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A rapid gravimetric procedure has been developed for the determination of sulphur in S2Cl2 based on the reaction of S2Cl2 with pyridine in acetonitrile.Disulphur dichloride (neat) or in an inert solvent like acetonitrile, when treated with pyridine in acetonitrile at the refluxing temperature of the latter for 3-4 hr undergoes chloride cleavage with quantitative precipitation of sulphur.The reaction is found to cleave elemental sulphur from disulphur dichloride quantitatively.Such determination of entire sulphur in S2Cl2 has not been reported so far.
- Veena, S.,Padma, D. K.
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- Synthesis, Crystal Structure, and Phase Transition of Se4(MoOCl4)2
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Dark green, very air sensitive crystals of Se4(MoOCl4)2 are formed from selenium and MoOCl4 at 190°C in a sealed, evacuated glass ampoulein quantitative yield. The structure is built of nearly square planar Se4(2+) ions and centrosymmetric dimeric MoOCl4(1-) ions which are linke d by bridging Cl atoms. At -21°C Se4(MoOCl4)2 undergoes a reversible solid state phase transition of first order. Structure determinations at -70°C and 23°C show that during the phase transition the structures of the ions remain unchanged, while the orientations of the ions with respect to each other change in such a way that in the low temperature form the Se4(2+) ions obtain a higher coordination number byCl ona O atoms of neighboring MoOCl4(1-) ions.
- Beck, J.
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- Preparation, Crystal Structure, and Vibrational Spectra of cyclo-Undecasulfur (S11) and of cyclo-Tridecasulfur (S13)
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The homocyclic S11 and S13 molecules have been synthesized from titanocenepentasulfide and S6Cl2 or S8Cl2, respectively, and obtained as yellow crystals which are metastable for several days at 20 deg C.X-Ray structural analyses of single crystals at -105+/-5 deg C exhibited molecules of approximately C2 symmetry with bond distances (d), bond angles (α) and torsional angles (τ) in the following ranges: S11: d = 203.2-211.0 pm, α = 103.3-108.6 deg, τ = 69.3-140.5 deg; S13: d = 197.8-211.3 pm, α = 102.8-111.1 deg, τ = 29.5-116.3 deg.Infrared and Raman spectra of S11 and S13 are reported.In addition, the synthesis of S6Cl2 and S8Cl2 from S6 or S8, respectively, and chlorine is described. - Key words: Elemental Sulfur, Sulfur Rings, Crystal Structure, Raman Spectra, IR Spectra
- Steudel, Ralf,Steidel, Juergen,Sandow, Torsten
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p. 958 - 970
(2007/10/02)
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- Crystal Structures of Compounds A2X2 (A = S, Se; X = Cl, Br)
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The crystal structures of compounds A2X2 (A = S, Se; X = Cl, Br) contain molecules X-A-A-X with dihedral angles between 83.9 deg and 87.4 deg.Three different types of molecular packing are realized: S2Cl2, S2Br2 (α-Se2Br2) and β-Se2Br2(Se2Cl2).Details of molecular geometries as well as crystal structures are discussed. - Keywords: Sulfur(I) Halides, Selenium(I) Halides, Crystal Structure
- Kniep, Ruediger,Korte, Lutz,Mootz, Dietrich
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- Preparation, X-ray crystal structures, and vibrational spectra of some salts of the As3S4+ and As3Se4+ cations
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The reactions of α- and β-As4S4 and some arsenic-selenium melts with various oxidants in SO2 as solvent are reported. It is shown by X-ray crystallography that the reactions of As4S4 and a 1:1 As-Se melt with the Lewis acids AsF5 and SbF5 in a 1:3 molar ratio in SO2 give the hexafluoroarsenate and hexafluoroantimonate salts of the novel arsenic chalcogen cations As3S4+ and As3Se4+. Crystals of (As3S4)(SbF6) are yellow plates which crystallize in the orthorhombic space group Pcam with a = 20.453 (4) A?, b = 5.990 (1) A?, c = 9.609 (2) A?, U = 1177.3 (4) A?3, and dc = 3.32 g cm-3 for Z = 4. Crystals of the isomorphous (As3S4)(AsF6) are dark yellow prisms and rhombs with cell dimensions a = 19.962 (4) A?, b = 5.930 (1) A?, c - 9.441 (3) A?, U = 1115.8 (5) A?3, and dc = 3.22 g cm-3 for Z = 4. The compound (As3Se4)(SbF6) forms orange diamond-shaped plates which crystallize in the monoclinic space group P21/m with a = 6.224 (3) A?, b = 9.564 (5) A?, c = 10.643 (5) A?, β = 92.65 (4)°, U = 632.9 (5) A?3, and dc = 4.07 g cm-3 for Z = 2. The structure of the compound (As3S4)(SbF6) was solved by using the Patterson function and refined by least-squares methods to final agreement indices R1 = 0.036 and R2 = 0.043 for 699 observed data. The isomorphous compound (As3S4)(AsF6) has similarly been refined by least-squares methods to final agreement indices R1 = 0.043 and R2 = 0.052 for 546 observed data. The structure of the compound (As3Se4)(SbF6) was solved by using direct methods and has been refined by least-squares to final agreement indices R1 = 0.064 and R2 = 0.082 for 620 observed reflections. The two cations As3S4+ and As3Se4+ are isostructural with crystallographic mirror symmetry and an overall symmetry of Cs. The cage structure of the two cations can be derived by bridging three edges of a tetrahedron of three arsenic and one sulfur or selenium atoms by the remaining sulfur or selenium atoms. Bond distances, bond angles and some significant interionic contact distances in these compounds are discussed. In addition, the Raman and IR spectra of these cations as well as the Raman spectrum of As4S3 and an improved Raman spectrum of the compound α-As4S4 are reported.
- Christian, Beverley H.,Gillespie, Ronald J.,Sawyer, Jeffery F.
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p. 3410 - 3420
(2008/10/08)
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- 2,5-Dichloro-thiazolo[4,5-d]thiazole and process for making same
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2,5-Dichloro-thiazolo[4,5-d]thiazole, which is useful as a fungicide, is prepared by reacting compounds having the formula EQU1 wherein X1 is Cl, and X2 is H or Cl or X1 and X2 together form a C-C bond In the te
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