Thiosulfurous acid
| Thiosulfurous acid | |
|---|---|
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| Identifiers | |
| CAS number | 15060-43-2 |
| ChemSpider | 7827575 |
| Jmol-3D images | Image 1 |
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| Properties | |
| Molecular formula | HS-S(=O)-OH |
| Molar mass | 98.14668 |
| Related compounds | |
| Related compounds | thiosulfuric acid SSO thiosulfinic acid |
| Except where noted otherwise, data are given for materials in their standard state (at 25 °C (77 °F), 100 kPa) | |
| Infobox references | |
Thiosulfurous acid (HS-S(=O)-OH) or sulfurothionous O,O acid is a low oxidation state (+1) sulfur acid. It is termed a disulfur(I) acid.[1] It is the equivalent acid for disulfur monoxide. Thiosulfurous acid is formed by reacting hydrogen sulfide and sulfur dioxide at room temperature.[2] The thiosulfurous acid molecule is unstable when condensed, reacting with itself.[3]
It decomposes to polysulfane oxide or polythionic acids in water which is termed Wakenroder's liquid.[1]
Other possible isomers are dihydroxydislfane or hypodithionous acid HOSSOH, a linear chain, and thiothionyl hydroxide (S=S(OH)2) a tautomer where the hydrogen has moved from a sulfur to an oxygen.[1] HOSSOH can have two different rotamers with symmetry C1 and C2. The isomer with one hydrogen on sulfur and one on oxygen is the most stable according to calculations.[4]
Reactions
Thiosulfurous acid can be formed during the hydrolysis of disulfur dichloride.
In alkaline conditions Thiosulfurous acid rapidly deteriorates forming a mixture of sulfide, sulfur, sulfite, and thiosulfate. In acidic conditions it will form hydrogen sulfide and sulfur dioxide as well. Some of these react to form pentathionate and other polythionates. Thiosulfurous acid reacts with sulfurous acid to give tetrathionate, and with thiosulfuric acid to make hexathionate.[5]
Salts
Salts of thiosulfurous acid are known as thiosulfites or sulfurothioites. The ion is S=SO22-. However they are unknown.
Esters
Thiosulfurous acid can form esters with alcohols, for example thiosulfurous acid dimethyl ester (dimethyl thiosulfite) or thiosulfurous acid O,O-diethyl ester. They can be made by reacting sodium methoxide or sodium ethoxide with disulfur dichloride and distilling the liquids at reduced pressure. They are immicible in water, but can dissolve in benzene or carbon tetrachloride.[5]
Cyclic esters can be formed by reacting disulfur dichloride with a 1,2 diol, making a compound with a CCOSO ring.[6]
References
- ↑ 1.0 1.1 1.2 Wiberg, Egon; Wiberg, Nils (2001). Inorganic Chemistry. Academic Press. p. 552. ISBN 9780123526519. Retrieved 3 November 2013.
- ↑ "Thioschweflige Säure - Chemgapedia". Retrieved 3 November 2013.
- ↑ Schmidt, Heinar; Ralf Steudel, Detlev Suelzle, Helmut Schwarz (1992). "Sulfur compounds. 148. Generation and characterization of dihydroxy disulfide, HOSSOH: the chainlike isomer of thiosulfurous acid". Inorganic Chemistry 31 (6): 941–944. doi:10.1021/ic00032a004. ISSN 0020-1669.
- ↑ Miaskiewicz, Karol; Ralf Steudel (1991). "Sulphur compounds. Part 140. Structures and relative stabilities of seven isomeric forms of H2S2O2". Journal of the Chemical Society, Dalton Transactions (9): 2395. doi:10.1039/DT9910002395. ISSN 0300-9246.
- ↑ 5.0 5.1 Nair, C. G. Ramachandran; A. R. Vasudeva Murthy (19 June 1961). "Hydrolytic Reactions of Esters and Amides of Thiosulfurous Acid". Proceedings of the Indian Academy of Sciences (Bangalore) 56 (3): 130–140.
- ↑ Zysman-Colman, Eli; Charles B. Abrams, David N. Harpp (2003). "Synthesis of New Cyclic Thionosulfites". The Journal of Organic Chemistry 68 (18): 7059–7062. doi:10.1021/jo0346306. ISSN 0022-3263.