The Molecular Composition of Hydrophilic Sulfur Sols Prepared by Acid Decomposition of Thiosulfate [1]
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چکیده
Hydrophilic sulfur sols prepared from sodium thiosulfate and concentrated sulfuric acid and purified by repeated NaCl precipitation and peptization in water have been studied by chemical analysis, vibrational spectroscopy, ion-pair chromatography and reversed-phase HPLC. The composition of the sol is Na1 6 4S2 8 .606 • 5.9In S„ • 1.0 NaCl. The elemental sulfur S„ (n = 6 1 4 ; mainly S8) accounts for 17% the total sulfur; 83% of the S are present as long-chain polythionates which form micelles in which the S„ molecules are dissolved. On aging of the sol at 20 °C the polythionate micelles decompose to give water-soluble short-chain polythionates and elemental sulfur which precipitates from the solution. The micelle structure of hydrophilic sulfur sols may serve as a model for the so-called sulfur globules (S°) formed intraor extracellularly by many sulfur bacteria which oxidize reduced sulfur compounds to S°. — Infrared and Raman spectra of K 2 S m 0 6 (m = 3—6) are reported. The photodecomposition of aqueous tetrathionate yields sulfite, thiosulfate, and polythionates with up to 9 sulfur atoms.
منابع مشابه
The Molecular Nature of the Hydrophilic Sulfur Prepared from Aqueous Sulfide and Sulfite (Selmi Sulfur Sol) [1]
Hydrophilic sulfur sols prepared by reaction of aqueous sulfide and sulfite at low pH have been studied by chemical analysis, ion-pair chromatography, and reversed-phase HPLC. The approxi mate composition of the sol is x (N a H S 0 4/N a;S 0 4) • vS„ • zN a2S,„Oh with n = 6 —10 and m = 4 —16. The elemental sulfur S„ accounts for 17% and the polythionate sulfur for 10% of the dry weight (sulfat...
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