- Structure of the fluorosulfite anion: Rotational disorder of SO2F- in the alkali metal fluorosulfites and crystal structures of α- and β-CsSO2F
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19F solid-state NMR spectra of the alkali metal fluorosulfites KSO2F, RbSO2F, α-CsSO2F, and β-CsSO2F show that the fluorosulfite anion is subjected to dynamical disorder at room temperature. This disorder can be modeled by 120° rotational jumps with respect to the C3-pseudoaxis of the anion. The exchange frequency of this disorder decreases with decreasing temperature. The calculated jump frequencies at room temperature are 5 x 105 Hz for KSO2F, 2 × 105 Hz for RbSO2F, 1 × 107 Hz for α-CsSO2F, and 5 × 105 Hz for β-CsSO2F, respectively. The crystal structures of α- and β-CsSO2F were determined for the first time (α: Pnma; Z = 4; a = 790.98(8), b = 666.07(7), c = 798.93(9) pm; T = 293 K. β: R3m; Z = 3; a= 659.22(6), c = 800.50(4) pm; T = 293 K). X-ray single-crystal data of KSO2,F RbSO2F, and α-CsSO2F taken at various temperatures were refined using the disorder model developed from the NMR results. It is shown that it is impossible to obtain reliable structural parameters of the SO2F- ion by refinement of X-ray data as long as rotational disorder persists. The preference of an ordered structure increases with decreasing temperature. The degree of disorder remaining in α-CsSO2F at 93 K is small. The structural parameters of the fluorosulfite anion as obtained by a routine refinement of this phase (S-F, 169.0(2) pm; S-O, 147.8(1) pm) are the best lower (S-F) and upper (S-O) limits of the true bond lengths determined experimentally. They comply with the values obtained from quantum chemical calculations.
- Kessler,Van Wuellen,Jansen
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- METHOD OF MAKING HALOSILOXANE
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A method of producing a halosiloxane, the method comprising: combining water, a halosilane, and first solvent, where the first solvent has a water solubility of > 1.5 grams in 100 ml of solvent, to form a reaction mixture having a temperature above the melting point temperature of the solvent, partially hydrolyzing and condensing the halosilane to form a reaction product mixture comprising the halosiloxane, the solvent, a hydrogen halide and unreacted halosilane, and, optionally, adding a second solvent with a boiling point the boiling point of the halosloxane to the reaction mixture or the reaction product mixture.
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Paragraph 0044-0046
(2019/01/06)
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- METHOD OF MAKING A HALOSILOXANE
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A method of producing a halosiloxane, the method comprising: i) combining water, a halosilane, and a first solvent to form a reaction mixture, ii) partially hydrolyzing and condensing the halosilane to form a reaction product mixture comprising the halosiloxane, the solvent, unreacted halosilane, and hydrogen halide, iii) adding a second solent, where the second solent has a boiling point the boiling point of the halosiloxane, to the reaction mixture in i) or to the reaction product mixture in ii), and iv) recovering the halosiloxane from the reaction product mixture.
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Paragraph 0041; 0051; 0052
(2019/01/06)
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- Thermolysis of Si2OCl6
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The thermolysis of gaseous Si2OCl6 leads to a mixture of higher chlorosiloxanes with up to 8 silicon atoms per molecule. The unexpected formation of larger molecules from smaller ones by high temperature pyrolysis is due to three basic reactions: a) Formation of highly reactive O=SiCl2 as an intermediate, b) insertion Of O=SiCl2 into Si-Cl bonds (growth reaction), and c) thermally induced elimination of SiCl4 from chlorosiloxanes formed in (b). Temperature and time dependencies of the thermolysis have been investigated and are discussed.
- Wilkening, Andreas,Binnewies, Michael
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- Crystal structures of monofluorosulfites MSO2F (M = K, Rb)
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Single crystals of potassium and rubidium fluorosulfite were obtained for the first time by reacting the alkali metal fluorides with sulfur dioxide in acetonitrile at 75 °C. According to the results of X-ray structure determinations they are isotypic (monoclinic, P21/m, Z = 2, KSO2F: a = 696.2(2), b = 566.3(2), c = 465.8(1) pm, β = 107.73(2)o, RbSO2F: a = 717.2(1), b = 586.7(1), c = 484.0(1) pm, β = 107.14(1)o) and structurally analogous to potassium chlorate. In contrast to potassium fluoroselenite in which the complex anions are polymerized to linear chains by unsymmetric fluorine bridges, the fluorosulfite anion is isolated. The S-F-distance of 159.1(2) pm (KSO2F) corresponds to a S-F single bond, the S-O-distance of 152.6(2) pm indicates a bond order of 1.5.
- Kessler, Ulrich,Jansen, Martin
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p. 385 - 388
(2008/10/08)
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- Vibrational Spectra and Structural Aspects of Fluorosulfites
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The Raman and infrared spectra of the fluorosulfites of K+, Rb+, Cs+, NH4+, and Me4N+ have been examined. Previous assignment of the fundamental vibrations is revised, and an ab initio study of the SO2F- anion is presented. For the pyramidal anion of symmetry Cs, distances of r(S-O) = 1.458 ? and r(S-F) = 1.698 ? have been calculated. The heat of formation of Me4NSO2F (-14.0 kcal/mol) was derived from the dissociation pressure of the salt. In addition, the lattice energy of Me4NF (159.2 kcal/mol) was calculated from a thermochemical cycle. The thermochemical data are discussed in terms of reactivity of the fluorides and stability of the fluorosulfites.
- Kornath, Andreas,Neumann, Frank,Ludwig, Ralf
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p. 5570 - 5573
(2008/10/09)
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- Gas-Phase Reaction of Hexachlorodisilane with Acetone
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Gas-phase reaction between hexachlorodisilane and acetone was studied at 520-560°C. Hexachlorodisiloxane, 1-allyl-1,1,3,3,3-pentachlorodisiloxane, 1,1,3,3,3-pentachloro-1-vinyldisiloxane, and 1,1,3,3,3-pentachloro-1-vinyloxydisiloxane were found to be major reaction products, and a mechanism of their formation was proposed.
- Chernyshev,Komalenkova,Kapitova,Bykovchenko,Khromykh,Bochkarev
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p. 753 - 755
(2007/10/03)
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- The SiO/PN Isoelectronic Pair, I Perchlorocyclosiloxanes and Perchlorocyclophosphazenes. Vibrational Spectra and X-Ray Structure Analysis of (Cl2SiO)3 and (Cl2SiO)4
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Hexachlorocyclotrisiloxane (2) and octachlorocyclotetrasiloxane (4) were prepared by reaction of SiCl4 with O2 at 955 deg C.Their mass spectra are compared with those of the isoelectronic cyclophosphazenes.The vibrational spectra of 2 and 4 are very similar and closely related to that of (PNCl2)3, but clearly different from that of the puckered (PNCl2)4 molecule.The X-ray examination of 2 and 4 reveals planarity of the (SiO)n, n = 3 and 4 ring systems, with d(Si-O) on average 1.619(4) and 1.584(3) Angstroem, respectively.
- Wannagat, Ulrich,Bogedain, Gabriele,Schervan, Adrian,Marsmann, Heinrich C.,Brauer, David J.,et al.
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p. 931 - 940
(2007/10/02)
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- DIRECT MASS SPECTROMETRIC IDENTIFICATION OF SILICON OXYCHLORIDE COMPOUNDS.
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Silicon oxychloride compounds formed during the high temperature reaction of Si and SiC with Cl//2/O//2 mixtures at 930 degree and 950 degree C have been directly observed with an atmospheric pressure mass spectrometer sampling system. Molecules with the formulas Si//2OCl//6 and Si//3OCl//8 have been identified. These compounds are very likely formed by a gas phase reaction between the oxygen gas in the system and silicon tetrachloride which is produced by chlorination of the silicon-based material.
- Marra,Kreidler,Jacobson,Fox
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p. 1571 - 1574
(2008/10/08)
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- Preparation of Hexafluorodisilane and Reactions of Hexafluorodisilane and Hexachlorodisilane with Sulfur Trioxide
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Hexafluorodisilane has been prepared by the fluorination of hexachlorodisilane or hexabromodisilane by potassium fluoride in boiling acetonitrile, in yields approximating 45 and 60percent respectively.Hexafluorodisilane has been characterised by infrared
- Suresh, Bettadapura Srinivasaiah,Padma, Doddaballapur Krishnamurthy
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p. 1867 - 1868
(2007/10/02)
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- Trimethyl- and trichlorosilylcobalt tetracarbonyls and the hydrosilation of ethylene
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The new compound (CH3)3SiCo(CO)4 was synthesized by the reaction of (CH3)3SiH with either Co2(CO)8 or HCo(CO)4. The interaction of Cl3SiH or CH3S
- Baay, Yvonne Louise,MacDiarmid, Alan G.
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p. 986 - 994
(2008/10/08)
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