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  • 1
    Electronic Resource
    Electronic Resource
    The Gas Phase Acidities of the Sulfanes H2Sn (n = 1-4) (1999)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 1999 (1999), S. 2057-2061 
    Details
    ISSN: 1434-1948
    Keywords: Sulfur ; Sulfanes ; Acidity ; Ab initio MO calculations ; Hyperconjugation ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The gas-phase acidities ΔGacid(298 K) of the sulfanes H2Sn (n = 1-4) have been calculated by ab initio molecular orbital theory using the G2 and G2(MP2) methods, which were applied to the geometries of lowest energy. The results show that the higher sulfanes are surprisingly strong proton donors. The acidities (in kJ mol-1) are as follows: H2S (1444), H2S2 (1406), H2S3 (1370), H2S4 (1347). The latter three values may be compared to those of other strong Brønsted acids like gaseous HNO2 (1396), HCl (1371), and HBr (1332). The monoanions HSn- exhibit an interesting bond length distribution as a consequence of the charge delocalization by hyperconjugation, which in turn may be responsible for the high acidities of the sulfanes.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Preparation of Organic Polysulfanes R2Sn (n = 5, 7, 8, 9) from Sulfenyl Chlorides, RSCl, and Transition Metal Polysulfido Complexes (2000)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 2000 (2000), S. 921-928 
    Details
    ISSN: 1434-1948
    Keywords: Sulfur ; Titanium ; Zinc ; Polysulfido complexes ; Sulfur heterocycles ; Polysulfides ; Polysulfanes ; Sulfenyl chlorides ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The preparation of seven novel organic polysulfanes is reported. Bis(n-octyl)heptasulfane R2S7 1 is formed upon reaction of RSCl with [Cp2TiS5], while the corresponding nonasulfane R2S9 2 is obtained by reaction of RSSCl with [Cp2TiS5]. The bis(n-octyl)pentasulfane R2S5 3 is obtained from RSCl and [(Cp′2TiCl)2S3] by transfer of the S3 ligand at 20 °C. The new alkyl polysulfanes 1-3 have been obtained in quantitative yields. They are liquids at 20 °C, having freezing points below -50 °C, but do not form mesogenic phases. Reactions of [Cp2TiS5] with 2-naphthyl- and 4-chlorophenyl sulfenyl chloride furnish the corresponding heptasulfanes 4 and 5, respectively, which are solids at 20 °C. 1,2-Benzodisulfenyl chloride C6H4(SCl)2 reacts with [(Cp′2TiCl)2S3] to give the known 1,2,3,4,5-benzopentathiepin C6H4S5 6, with [Cp2TiS5] to give the novel 1,2,3,4,5,6,7-benzoheptathionin C6H4S7 7, and with [(TMEDA)ZnS6] to give the novel 1,2,3,4,5,6,7,8-benzooctathiecin C6H4S8 8. The cyclic polysulfanes 6-8 are solids at 20 °C and have been recovered in yields of 60-83%. The orthorhombic structure of 1,2-C6H4S7 has been investigated by single-crystal X-ray diffraction analysis. The molecules are found to be located at sites of Cs symmetry and the motif of the C2S7 heterocycle is +-+-+-+-, with the torsion angle of zero at the carbon-carbon bond. The three internuclear SS distances measure 205.0(1), 203.7(1), and 205.7(1) pm.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Gas-Phase Acidities of Nine Sulfur Oxoacids of Composition [H2,S,On] (n = 1-4) (2000)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 2000 (2000), S. 617-624 
    Details
    ISSN: 1434-1948
    Keywords: Sulfur oxo acids ; Acidity ; Ab initio calculations ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The gas-phase acidities of the most stable conformations of nine sulfur oxo acids were determined by ab initio MO calculations at the CBS-Q, G2(MP2), and G2 levels of theory. The most accurate G2 results are as follows (ΔG°298 of the deprotonation reaction in kJ mol-1): H-S-O-H 1468, H-S-O-H 1449, (HO)2S 1426, H-S(=O)OH 1406, H2S/O 1394, H-S(=O)OH 1361, (HO)2S/O 1324, H2S(=O)2 1321, H2O→S 1294, H-S(=O)2OH 1287, H-S(=O)2OH 1279, (HO)2S(=O)2 1268. These values are in excellent agreement with the few experimental data that can be considered reliable. For molecules of analogous structure, the acidity increases with increasing oxidation number of the sulfur atom. While sulfenic acid, HSOH, is as weak an acid as HOCl, sulfurous acid, (HO)2SO, is as strong a proton donor as nitric acid, HNO3, and sulfonic acid, HS(O)2OH, is even stronger than hydrogen iodide, HI, surpassed only by sulfuric acid, H2SO4. These results are of relevance to phenomena such as acid rain and aerosol formation in the earth′s atmosphere.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    Sulfur Compounds, 199Part 198: R. Steudel, Y Drozdova, K. Miaskiewicz, R. H. Hertwig, W. Koch, J Am. Chem. Soc. 1997, 119, 1990.. Novel Titanocene Thiolato Complexes and Their Application in Preparing New Sulfur-Containing Heterocycles (1997)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 757-764 
    Details
    ISSN: 0009-2940
    Keywords: Titanocene complexes ; S ligands ; Organic polysulfanes ; Ligand transfer reactions ; Sulfur heterocycles ; Chalcogens ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Treatment of Cp2Ti(CO)2 (3) with the di- and polysulfanes 1,2,4-(CH2)2S3, C4S6 (9), C,7H10S3 (11), 1,2,4,6-(CH2)3S4 (16), C6H10S6(19), and S6 affords the titanocene chelate complexes Cp2TiS3(CH2)2 (8), (Cp2Ti)2C4S6 (10), Cp2TiS3C7H10 (13), Cp2TiS2C7H10 (14), Cp2TiS4(CH2)3 (17), Cp,2TiS6C6H6H10 (20), and Cp2TiS8 (23). 14 is also obtained from Cp2TiCl2 (1) and the geminal dithiol of norbornene. The analogous reaction with the dithiol of dicyclopentadiene yields Cp2TiS2C10H12 (15). In ligand transfer reactions, 8 reacts with SCl2 to give 1,2,3,5-tetrathiane (25), 10 provides 9 on reaction with Cl2, 13 when treated with S2Cl2 affords C7H10S5 (12), 15 reacts with S2Cl2Cl2 to give C10H12S4. 17 and SCl2 yield 1,2,3,5,7-pentathiepane (18), 20 is converted to C6H10S7 (22) on reaction with SCl2, and 23 yields S10 and 1,2,-C6H4(SCl)2, respectively. With phosgene, thiophosgene, and thionyl chloride, compound 15 yields the corresponding dithiocarbonate 26, the trithiocarbonate 27 and the trisulfane 2-oxide 28. The structure of 27 was determined by X-ray crystallography.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19971300614
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