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  • 1
    ISSN: 0044-2313
    Keywords: Bis(fluorosulfonyl)difluoromethane ; gas-phase structure ; conformation ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Die Gasphasen-Struktur von Bis(fluorosulfonyl)difluormethan, (SO2F)2CF2Es wird über neue Syntheseverfahren und das Infrarotspektrum von Bis(fluorsulfonyl) Difluormethan, (SO2F)2CF2 berichtet. Die geometrische Struktur und die Konformationseigenschaften dieser Verbindung wurden mittels der Elektronenbeugung an Gasen untersucht. Je nach Stellung der zwei SO2F Gruppen können vier Konformere mit unterschiedlichen Symmetrien auftreten: C2v Symmetrie, falls beide S—F Bindungen auf Lücke zu CF2 stehen, C2 oder Cs Symmetrie, falls eine S=O Bindung jeder SO2F Gruppe auf Lücke zu CF2 steht und C1 Symmetrie, falls eine S—F und eine S=O Bindung auf Lücke zu CF2 stehen. Die experimentellen Elektronenbeugungsintensitäten können mit einem C1 Konformeren oder mit einem Gemisch aus C2v, C2 und Cs Konformeren im Verhältnis 3:2:5 nahezu gleich gut angepaßt werden. Die folgenden geometrischen Parameter (ra Abstände und ∠α Winkel mit 3σ Fehlergrenzen) wurden erhalten: C—F = 1,340(6) Å, S=O = 1,412(2) Å, S—F = 1,550(3) Å, C—S = 1,848(4) Å, S—C—S = 113,6(7)°, F—C—F = 110,0(10)°, O=S=O = 124,6(18)°, C—S—F = 96,5(16)° und C—S=O = 108,4(14)°.
    Notes: New synthetic pathways and the infrared spectrum of bis(fluorosulfonyl)difluoromethane, (SO2F)2CF2, are reported. The geometric structure and conformational properties of the title compound have been studied by gas electron diffraction. Depending on the rotational position of the two SO2F groups, four conformers with different symmetries can occur in this compound: C2v symmetry, if both S—F bonds stagger the CF2 group. C2 or Cs symmetry, if one S=O bond of each group staggers the CF2 group. The experimental electron diffraction intensities can be fitted equally well with a C1 conformer or with a mixture of C2v, C2 and Cs conformers, in a ratio of 3:2:5. The following geometric parameters (ra distances, ∠α angles with 3σ uncertainties) were derived: C—F = 1.340(6) Å, S=O = 1.412(2) Å, S—F = 1.550(3) Å, C—S = 1.848(4) Å, S—C—S = 113.6(7)°, F—C—F = 110.0(10)°, O=S=O = 124.6(18)°, C—S—F = 96.5(16)° and C—S=O = 108.4(14)°.
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  • 2
    ISSN: 0044-2313
    Keywords: Trifluoroethylene Sultone ; 3,4,4-Trifluoro-1,2-oxathietane-2,2-dioxide ; Gas Electron Diffraction ; Structure ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Trifluorethylensulton: Struktur und ChemieDie Struktur des Trifluorethylensultons (1) (3,4,4-Trifluor-1,2-oxathietan-2,2-dioxid) wurde durch Elektronenbeugung in der Gasphase bestimmt. Der viergliedrige Ring ist planar. Folgende Parameter (ra Abstände und ∠α-Winkel mit der Fehlergrenze von 3σ) wurden erhalten: C—O = 1,41 Å (ass), C—C = 1,541(18) Å, S—O = 1,652(5) Å, S—C = 1,822(8) Å, S—C—C = 86,2(15)°, C—C—O = 97,1(28)°, C—O—S = 97,5(21)° und O—S—C = 79,1(8)°. Neue spektroskopische Daten (IR, NMR) für 1, sein acyclisches Isomer FSO2CFHC(O)F (2), und das Anhydrid FSO2OSO2CFHC(O)F (3) werden mitgeteilt. Neue Ester mit der Fluorsulfonyl-Funktion, FSO2CFHC(O)OCH2CF3 (4), FSO2CFHC(O)OCH2CH = CH2 (5), und (FSO2CFHC(O)OCH2CH—CH2—)n (6) wurden dargestellt und charakterisiert.
    Notes: The gas phase structure of trifluoroethylene sultone, (1) (3,4,4-trifluoro-1,2-oxathietane-2,2-dioxide) was determined by gas electron diffraction, and the four-membered ring was found to be planar. The following ring parameters (ra distances and ∠α angles with 3σ uncertainties) were derived in the electron diffraction analysis: C—O = 1.41 Å (ass.), C—C = 1.541(18) Å, S—O = 1.652(5) Å, S—C = 1.822(8) Å, S—C—C = 86.2(15)°, C—C—O = 97.1(28)°, C—O—S = 97.5(21)°, and O—S—C = 79.1(8)°. New spectral data (IR, NMR) of 1, its acyclic isomer FSO2CFHC(O)F (2), and the related anhydride, FSO2OSO2CFHC(O)F (3), are reported. New esters containing the fluorosulfonyl function, FSO2CFHC(O)OCH2CF3 (4), FSO2CFHC(O)OCH2CH = CH2 (5), and (FSO2CFHC(O)OCH2CH—CH2—)n (6) have been prepared and characterized.
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  • 3
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Contributions to the Chemistry of Sulfur Halides. 8. Trifluoromethylbromosulfan - Gas Phase Structure and Normal Coordinate AnalysisAn improved method to prepare CF3SBr is reported. An electron-diffraction measurement has been carried out and the following molecular parameter are obtained (rα° values in Å and degree): C—F = 1.331(3), C—S = 1.814(6), S—Br = 2.162(6), CSBr = 99.4(3), FCF = 108.7(9), Tilt = 5.5(5).A reassignment of the vibrational frequencies based on IR-matrix and Raman measurements is given and the valence force constants of CF3SBr are calculated.
    Notes: Es wird über ein verbessertes Verfahren zur Darstellung von CF3SB1 und die Bestimmung der Molekülstruktur durch Elektronenbeugung berichtet. Folgende Parameter werden erhalten (rα°-Werte in Å und Grad): C—F = 1,331(3), C—S = 1,814(6), S—Br = 2,162(6), CSBr = 99,4(3), FCF = 108,7(9), Tilt = 5,5(5).Auf Grund von IR-Matrix- und Raman-Messungen erfolgt eine Neuzuordnung der Schwingungsfrequenzen, die durch eine Normalkoordinatenanalyse unterstützt wird.
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  • 4
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Perhalogenated 1,2,3,5-Dithiadiazolium Salts and 1,2,3,5-DithiadiazolesSyntheses of the perhalogenated 1,2,3,5-dithiadiazolium salts FCN2S2+Cl- (5) (by methathesis from ClCN2S2+Cl- with AgF2), FCN2S2+AsF6- (5a) (from 5 and AgAsF6), CF3CN2S2+Cl (11) (from CF3CN and S3N3Cl3 in liquid SO2 (in this reaction the by-products S5N5+Cl4- (9), S4N4O2 (10), CF3CN3S2Cl2 (11a), and CF3CN4S3+S3N3O4- (12) are isolated, too), and BrCN2S2+Cl- (15) (from 13c and SO2Cl2) are reported. By reduction of XCN2S2+ (Cl, Br)- with Zn in liquid SO2 the corresponding radicals XCN2S2· (13a - d, X = F, Cl, Br, CF3) are formed in high yields. These radicals are diamagnetic in the solid state. From 13b and d and their corresponding chlorides distinct compounds of the composition (XCN2S2)3Cl (16a, b, X = Cl, CF3) are obtained, while in the reaction of 13b with ClCN2S2+SbCl6 only reduction of the anion under formation of (ClCN2S2+)2SbCl52- (17) occurs. Structures of 13d and 16b were determined by X-ray-, of 13d also by electron-diffraction in the vapour phase. In order to understand the observed structures and ESR spectra of 13, model calculations by the MNDO method were performed for the RCN2S2-system and also for possible dimers there of.
    Notes: Synthesen der perhalogenierten 1,2,3,5-Dithiadiazolium-Salze FCN2S2+Cl- (5) (durch Metathese aus ClCN2S2+Cl- mit AgF2), FCN2S2+AsF6- (5a) (aus 5 und AgAsF6), CF3CN2S2+Cl- (11) (aus CF3CN und S3N3Cl3 in fl. SO2 (bei dieser Reaktion werden als Nebenprodukte u.a. S5N5+FeCl4- (9), S4N4O2 (10), CF3CN3S2Cl2 (11a) und CF3CN4S3+S3N3O4- (12) isoliert) und BrCN2S2+Cl- (15) (aus 13c und SO2Cl2) werden mitgeteilt. Durch Reduktion von XCN2S2+(Cl, Br)- mit Zn in fl. SO2 entstehen die entsprechenden Radikale XCN2S2· (13a-d, X = F, Cl, Br, CF3) in hohen Ausbeuten. Diese Radikale sind im festen Zustand diamagnetisch. Durch Umsetzung von 13b und d mit den ihnen zugrunde liegenden Chloriden lassen sich definierte Verbindungen der Zusammensetzung (XCN2S2)3Cl (16a, b, X = Cl, CF3) erhalten. Bei der Umsetzung von ClCN2S2+SbCl6- mit 13b erfolgt dagegen Reduktion des Anions unter Bildung von (ClCN2S2+)2 SbCl52- (17). Die Strukturen von 13d und 16b wurden durch Röntgen-, die von 13d außerdem durch Elektronenbeugung in der Gasphase bestimmt. Zum Verständnis der gefundenen Strukturen und der gemessenen ESR-Spektren von 13 wurden Modellrechnungen nach der MNDO-Methode an dem RCN2S2-System sowie an den möglichen Dimeren von 13 durchgeführt.
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  • 5
    ISSN: 0009-2940
    Keywords: 1λ4,3λ4,5λ4-Trithiatriazines ; Anomeric effect ; Antiaromaticity ; Calculations, ab initio, MNDO ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The Structure of TrithiatriazinesMNDO and ab initio calculations have shown that the structure of trithiatriazines [(RSN)3, where R = F, Cl, {H}] is influenced by the anomeric effect and by antiaromaticity of the ring for electron pairs in axial positions. These calculations are supported by a joint electron diffraction and microwave structure determination of (NSF)3 in the gas phase.
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  • 6
    ISSN: 0009-2940
    Keywords: 1λ4,3λ4-Dithiatriazines ; Calculations, MNDO ; Anomeric effect ; Electron diffraction ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The Anomeric Effect in DithiatriazinesFrom (CF3CN3S2)n (1) and XeF2, Br2, or (CF3)2NO* the corresponding S,S-substituted dithiatriazines CF3CN3S2F2 (2), CF3CN3S2Br2 (3), and CF3CN3S2[ON(CF3)2]2 (4) are prepared. An electron diffraction study of 2 in the gas phase results in a slightly aplanar 6-membered ring with chair conformation and both S-F bonds in axial position. MNDO calculations show that the position of the substituents at the sulfur atoms is strongly dependent on these substituents and on the ring geometry. The cis preference is the result of an anomeric effect.
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  • 7
    ISSN: 0009-2940
    Keywords: Dithietanes, fluoro- and fluorooxo-; formation of, cleavage with halogen fluorides, gas phase structure ; Lewis acids, containing fluorine ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Fluoro- and Fluorooxodithietanes (1) was isolated from the reaction of 2,2,4,4-tetrafluoro-1,3-dithietane (3) with CIF in an unpassivated monelcylinder. The hydrolysis of 1 gives (2): the trans derivative (2b) and the cis isomer (2a) are formed in a 4:1 ratio. (7) is oxidized by CIF at room temperature to give the known (8) in 87% yield. At 50°C from 8 and (9) is formed besides the ring cleavage products CF3SO2CF2SF4Cl (10) and CF3SO2CF2SF5 (11). The gasphase structure of 9 (e.d.) is described. (5) and (13) coordinate by the oxygen of the SO group to AsF5, with an unstable sulfonium salt is formed, while from the reaction of AsF5 and SbF5 with 8 (15 a, b, M = As, Sb) are isolated.
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  • 8
    ISSN: 0009-2940
    Keywords: Trifluorotrifiuoromethylthioethene ; Gas-phase structure ; Electron diffraction ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The molecular structure of 1-trifluoromethylthio-1,2,2-trifluoroethene, CF3SC(F) = CF2, was determined by gas electron diffraction (GED) and ab initio calculations (HF/3-21G*). The S - CF3 bond is oriented nearly perpendicular to the ethene plane with Φ(C = C-S-C) = 96.9(12)°. This orientation implies that the p-shaped sulfur lone pair is perpendicular to the ethene π orbitals. The following skeletal bond lengths (ra in Å) and angles (χ α in °) were obtained (error limits are 30 values): C = C = 1.302(19) Å, C(sp2) - S = 1.719(9) Å, S—C(sp3) = 1.820(10) Å, C = C—S = 120.0(9)°, and C—S—C = 101.7(7)°. The experimental geometric parameters were reproduced reasonably well by the ab initio method.
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  • 9
    ISSN: 0009-2940
    Keywords: Trifluoromethyl vinyl sulfide ; Gas-phase structure ; Electron diffraction ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The geometric structure of trifluoromethyl vinyl sulfide, CF3SC(H)=CH2, was determined by gas electron diffraction and ab initio calculations (HF/3-21G* and MP2/6-31G*). A single conformer with a dihedral angle φ(C=C-S-C) = 129(4)° is present. The conformational properties are compared to those of the parent compound, CH3SC(H)=CH2, and of the perfluorinated species CF3SC(F)=CF2.
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  • 10
    ISSN: 0009-2940
    Keywords: 2-Isotetrasilanylsodium salt ; Trisilylgermyl(alkali metal) salt ; 2-Methylisotetrasilane ; Methyltrisilylgermane ; Electron diffraction ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Synthesis and Molecular Structure of CH3M(SiH3)3 (M=Si, Ge)A solution of 2-isotetrasilanylsodium (1a) was obtained in good yield from silane and sodium under special conditions. Methylation of 1a with methyl p1-toluenesulfonate yields 2-methylisotetrasilane (1b). The corresponding methyltrisilylgermane (2b) was synthesized via (K, Cs)Ge(SiH3)3 (2a) resulting from the reaction of cesium trichlorogermanide with KSiH3 followed by methylation. The molecular structures of 1a and 1b were determined by electron diffraction analyses.
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