Thiosulfuric acid

Thiosulfuric Acid.—Hyposulfurous acid——114—maybe considered as sulfuric acid, HaSOi, in which one atom of oxygen has been replaced by one of sulfur. The acid itself has. not been isolated, being decomposed, on liberation from the thiosulfates, into sulfur, water and sulfur dioxid HiSjOa = S-f-80, + H,0. 

Pyrosulfurio AciA—Fuming sxilfuric add—Nordhausen oil of vitriol—Disulfuric hydrate— B.SiOi—Molecular weight — 178— 8p. gr. =. Q—Boils at 52°.2 (126° F.). 

Preparation.—By distilling dry ferrous sulfate and purification of the product by repeated crystallizations and fusions, until a substance fusing at 35° (95° F.) is obtained. 

Properties.—The commercial Nordhausen acid, which is a mixture of HjSaO, with excess of SOa, or of H,SO , is a brown, oily liquid, which boils below 100° (212° F.) giving off SOs and is solid or liquid according to the temperature. It is used chiefly as a. solvent for indigo, and in the anilin industry. 

These are rare elements which form compounds similar to those of sulfur. Elementary selenium is used in some forms of electrical apparatus. 

Attempts to prepare thiosulfuric acid by acidification of stable thiosulfates are invariably thwarted by the ready decomposition of the free acid in the presence of water. The reaction is extremely complex and depends on the conditions used, being dominated by numerous redox interconversions amongst the products these can include sulfur (partly as cyclo-Sf,), SO2, H2S, HiS,. H2SO4 and various polythionates In the absence of water, however, these reactions are avoided and the parent acid is more stable it decomposes quantitatively below 0° according 

Combination of stoichiometric amounts of H2S and SO2 at low temperature yields the white crystalline adduct H2S.SO3 which is isomeric with thiosulfuric acid. 

In contrast to the free acid, stable thiosulfate salts can readily be prepared by reaction of HiS on aqueous solutions of sulfites  

The reaction appears 10 proceed first by the formation of elemental sulfur which then equilibrates with more HSO3 to form the product  

Consistent with this, experiments using HS labelled with radioactive (p. 661) show that acid hydrolysis of the 8203 produces elemental sulfur in which two-thirds of the activity is concentrated. Thiosulfates can also he made by boiling aqueous solutions of metal sulfites (or hydrogen sulfites) with elemental sulfur according to the stoichiometry 

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HIO4 periodic acid H2S2O3 thiosulfuric acid... 

H2Mn04 manganic acid H2S2O2 thiosulfurous acid... 

Sulfuric acid, H2SO4, the most important commercial sulfur compound (see Sulfuric acid and sulfur trioxide), and peroxymonosulfuric acid [7722-86-3] (Caro s acid), H2SO, are discussed elsewhere (see Peroxides and peroxide compounds, inorganic). The lower valent sulfur acids are not stable species at ordinary temperatures. Dithionous acid [15959-26-9] H2S2O4, sulfoxyHc acid [20196-46-7] H2SO2, and thiosulfuric acid [13686-28-7] H2S2O2 are unstable species. A discussion of efforts to isolate and characterize the unstable sulfur acids is given (330). 

Thiosulfuric Acid. Thiosulfuiic acid [14921 -76-7] is relatively unstable and thus cannot be recovered from aqueous solutions. In laboratory preparation, a lead thiosulfate [26265-65-6] solution is treated with H2S to precipitate PbS, or a concentrated solution of sodium thiosulfate [7772-98-7] is treated with HCl and cooled to — 10°C to crystalline NaCl. Aqueous solutions of thiosulfuric acid spontaneously decompose to yield sulfur, SO2, and polythionic acids, H2S O. Thiosulfuric acid is a strong acid comparable to sulfuric acid. Dissociation constants, = 0.25, = 0.018, have been... 

Sodium ethyl thiosulfate [26264-37-9] is also known as Bunte s salt after the name of its discoverer. Bunte salts may be thought of as esters of thiosulfuric acid (94—96). In essentially all of their chemical reactions, the cleavage is between the divalent and hexavalent sulfur atom. For example, acid hydrolysis produces a thiol and the acid sulfate ... 

Thio-schwefelsaure, /. thiosulfuric acid, -sul-fatlosung, /. ihiosulfate solution. -sulfo-saure, /. thiosulfonic acid, -verbindung, /. thio compound, -zinnsaure, /. thiostannic acid. 

The amount of unreacted iodine was determined by titration with sodium thiosulfate [Thiosulfuric acid (H2S203), disodium salt], and the amount of iodine initially present was determined by a separate blank titration.3... 

Singlet oxygen [Oxygen, singlet], 51 Sodium acetate [Acetic acid, sodium salt], 33,49,66 Sodium azide, 109 Sodium hydride, 20 Sodium thiosulfate (Thiosulfuric acid (HjSj03), disodium salt], 120 Squalene [2,6,10,14,18,22 Tetracosa-... 

Due to reduced hydrogen bonding, thiosulfuric acid should be less acidic and have a lower boiling point. 

The relative stabilities of RSSR and R2S=S for R=OH and SH have been determined by Steudel and co-workers [23, 24]. At the MP2/6-311G //HF/ 6-311G +ZPE level of theory, (HO)2S=S (thiosulfurous acid) is just 13 kj mol less stable than the chain-like isomer HOSSOH (dihydroxydisul-fane) [23]. For R=SH, (HS)2S=S is less stable than the corresponding trisul-fane HSSSH by 132 kJ mor (MP2/6-31G -//HF/4-31G) [24]. 

Thionyl chloride, 55, 27 Thiosulfuric acid (HjSjO,), disodium salt [7772-98-71,56,120 pentahydrate [10102-17-7], 58, 147,... 

AtgSH =tetra-0-2,3,4,6-acetyl-l-p-o-thioglucose TgSH = p-l-D-thioglucose H2S2O3 = thiosulfuric acid and TmSH =thiomalic... 

Thiosulfate-fixing solutions, 19 213 Thiosulfate titration, of iodine, 14 367, 368 Thiosulfuric acid, 23 669 Thiotungstates, 25 385 Thiourea, 12 690... 

This paper describes the synthesis and characterization of a new zwitterionic water-soluble thiosulfate polymer (Poly[7-(amino -thiosulfate) etheij-PATE) via chemical reaction of a diglicydyl ether of bisphenol A (DGEBA) with aminoethane thiosulfuric acid (AETSA) as a reactive... 

Materials. Reagent grade solvents, dimethyl formamide (DMF), dimethyl acetamide (DMAC), dimethyl sulfoxide (DMSO) and methanol were purchased from Baker, stored over molecular sieves once opened, and used without further purification. Aminoethane thiosulfuric acid (AETSA) purchased from Kodak, and Taurine, purchased from Alfa were purified by recrystallization. Each was thrice recrystallized from hot, deionized water. The crystalline precipitate was dried (48 hours at 40 °C) in-vacuo and subsequently stored in a desiccator. Benzophenone (BP) was purchased from Aldrich Chemical Company. QUANTACURE BTC (BTC), (4-benzolybenzyl) trimethylammonium chloride, was used as supplied by Aceto, Inc., Flushing, New York. Phenyl glycidyl ether (PGE) was purchased from MCB, distilled in-vacuo. and stored at -15 °C. Epon 828 was used as supplied bv Shell Chemical Company. The epoxy equivalent weight (EEW) for Epon 828 determined by an appropriate titration, was found to be 187.7. 

Synthesis of Polyh-famino l-thiosulfatel ether] (TATE). Polyfr-amino g-sulfonic acidl (PASE1, and Hvdroxv-3-aminoethane thiosulfuric acid fAETS APPEL Details of the synthesis of these three compounds are given elsewhere (2). 

The synthesis of hydroxy-3-aminoethane thiosulfuric acid (AETSAPPE) is shown in Scheme II. The same basic conditions used for the polymer synthesis were employed to synthesize the model compound (AETSAPPE) although the work-up conditions were less stringent. The structure was confirmed by carbon-13 NMR and elemental analysis. 

Sodium thiosulfate Thiosulfuric acid, disodium salt (8,9) (7772-98-7)... 

Sodium isopropylthiosulfate Thiosulfuric acid, S-isopropyl ester, sodium salt (8) Thiosulfuric acid, S-(1-methylethyl) ester, sodium salt (9) (26726-19-2)... 

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