Hydrogen polysulfide

Sulfur combines directly with hydrogen at 150—200°C to form hydrogen sulfide. Molten sulfur reacts with hydrogen to form hydrogen polysulfides. At red heat, sulfur and carbon unite to form carbon disulfide. This is a commercially important reaction in Europe, although natural gas is used to produce carbon disulfide in the United States. In aqueous solutions of alkaU carbonates and alkaU and alkaline-earth hydroxides, sulfur reacts to form sulfides, polysulfides, thiosulfates, and sulfites. 

Interestingly, the sulfanes H2S are both proton acceptors and donors. In the first case sulfonium ions H3S are formed, in the second case hydrogen polysulfide anions HS are the result. While the latter have never been isolated in salts, several salts with sulfonium cations derived from the sulfanes with n = 1, 2, and 4 have been published. However, none of these salts has been structurally characterized by a diffraction technique. Therefore, the structures of the HsSn cations and HS anions are known from theoretical calculations only. 

Hydrogen pinch, applications of, 20 764 Hydrogen polysulfides, 23 568, 639-640 Hydrogen processing, 12 404 15 217 Hydrogen-producing reactions, 13 766-767 Hydrogen product oxidation, in styrene manufacture, 23 343... 

When the reaction medium is liquid sulfur, as in the Richard Process, the H2S reactant can readily form hydrogen polysulfide... 

The presence of the liquid sulfur phase in the Richard process may favor the formation of the product liquid sulfur by aiding the formation of the intermediate hydrogen polysulfide building block. The success of a 5LTD demonstration plant may well determine whether future sulfur recovery from H2S feed continues to be by... 

Not only is H2S2, the sulfur analog of hydrogen peroxide known, but hydrogen polysulfides having as many as eight atoms of sulfur per molecule have also been described. A mixture of such sulfides (represented as H2S where may be 1,2,3,4,5 or 6) results from acidification of a solution of... 

Thiobenzoylthioglycolic acid has been prepared by the interaction of potassium dithlobenzoate and alkali chloroacetate. " The required intermediate, dithiobenzoic acid, has been obtained from phenylmagnesium bromide and carbon disulfide, -or by the condensation of benzaldehyde and hydrogen polysulfides, or most conveniently by treatment of benzotrichloride with potassium hydrogen sulfide. - The last procedure has been adapted here to afford improved yields. 

Hydrogen disulfide, H2S2, analogous to hydrogen peroxide, can be made by careful treatment of a disulfide with acid it is a pale yellow oily liquid. The hydrogen polysulfides readily decompose to hydrogen sulfide and sulfur. 

Hydrogen disulfide provides appropriate S2 units and readily condenses with phenylpropynyl chloride to form 5-phenyl-l,2-dithiole-3-one (128). 1,3-Diketones or synthetic equivalents form 1,2-dithiolium salts (3) <57AG138, 62JCS5104). Hydrogen polysulfide or diacetyl disulfide can usefully replace the hydrogen disulfide (Scheme 18). 

The hydrogen polysulfides are yellow liquids, which from the tetra-sulfide upwards have no definite freezing points. They are labile with respect to change into sulfur and hydrogen sulfide, and decompose on contact with powdered quartz and glass, wood, or paper, or traces of basic substances the same applies to hydrogen disulfide. 

Further support for un branched structures in hydrogen polysulfides and polysulfur dichlorides comes from molar volumes, refractions, and viscosities these are discussed in Section V on organic disulfides and polysulfides. 

Structure determinations by X-ray and electron diffraction methods have demonstrated the presence of unbranched chains of up to six divalent sulfur atoms in inorganic polysulfides, four divalent ones in salts of polythionic acids, and three in disulfonyl, dialkyl, and cyanogen derivatives. The synthetic and Raman-spectroscopic work of Feh6r has established the presence of unbranched structures with up to five sulfur atoms in organic polysulfides, and eight in the cyanogen polysulfide, polysulfur dichloride, and hydrogen polysulfide series. The results are supported by extensive physicochemical evidence of less conclusive nature. 

Crude perhydrc en sulfide, crude hydrogen persulfide, hydrogen polysulfide, or just crude oil. For the nomenclature of chain compounds of sulfur, see F. Feher and W. Laue, Z. Naturforsch. 8b, 11 (1953). 

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