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  • 1
    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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  • 2
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 620 (1994), S. 121-126 
    ISSN: 0044-2313
    Keywords: Dithionite decomposition ; polythionate reduction ; thiosulfate decomposition ; ion-pair chromatography ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Die Zersetzung von Dithionit in Wasser und seine Reaktionen mit Polythionaten SnO2-6 (n = 3-5)  -  eine Untersuchung mittels IonenpaarchromatographieDithionit hydrolysiert in Wasser bei 20°C und pH-Werten nicht weit von 7,0 zu Thiosulfat und Sulfit, aus denen dann Trithionat entstehen kann. Zugabe von Thiosulfat beschleunigt die Hydrolysereaktion nur bei pH 〈 6. Diese pH-Abhängigkeit wird durch die Bildung des Ions HS2O3- erklärt, das durch Dithionit zu Sulfid und Sulfit reduziert wird. Sulfidionen zerstören Dithionit durch nucleophile Spaltung, wobei wahrscheinlich primär Sulfoxylat und Thiosulfit entstehen. Die Polythionate SnO62- (n = 3-5) werden von Dithionit bei 20°C und pH = 7,0 reduziert (Gleichung siehe Abstract), wobei die Reaktionsgeschwindigkeit mit der Kettenlänge n rasch ansteigt. In Sekundärreaktionen baut Sulfit die Polythionationen unter Bildung von Thiosulfat ab.
    Notes: Aqueous dithionite decomposes at 20°C and pH values not far from 7.0 to give thiosulfate and sulfite from which trithionate may form. Addition of thiosulfate accelerates this reaction only at pH 〈 6. The pH dependence is explained by formation of HS2O3- ions which are reduced by dithionite to HS- and SO2-3. Sulfide destroys dithionite by nucleophilic cleavage, probably with formation of sulfoxylate and thiosulfite ions. The polythionates SnO2-6 (n = 3-5) are reduced by dithionite at pH = 7.0 and 20°C according to SnO2-6 + S2O2-4 + 2 H2O→S2O32- + Sn-3SO32- + 4H1 + 2SO32- The reaction rate rapidly increases with the number n of sulfur atoms. In secondary reactions sulfite attacks SnO62- ions with thiosulfate formation.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
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