Polythionic acid is an oxoacid which has a straight chain of sulfur atoms and has the chemical formula Sn(SO3H)2 (n > 2). Trithionic acid (H2S3O6), tetrathionic acid (H2S4O6) are simple examples. They are the conjugate acids of polythionates. The compounds of n < 80 are expected to exist, and those of n < 20 have already been synthesized. Dithionic acid (H2S2O6) does not belong to the polythionic acids due to strongly different properties.
All polythionates anion contains chains of sulfur atoms attached to the terminal SO3H-groups. Names of polythionic acids are determined by the number of atoms in the chain of sulfur atoms:
Numerous acids and salts of this group have a venerable history, and chemistry systems, where they exist, dates back to the studies John Dalton devoted to the behavior of hydrogen sulfide in aqueous solutions of sulfur dioxide (1808). This solution now has the name of Heinrich Wilhelm Ferdinand Wackenroder, who conducted a systematic study (1846). Over the next 60–80 years, numerous studies have shown the presence of ions, in particular tetrathionate and pentathionate anion (S 4O2− 6 and S 5O2− 6, respectively).
Preparation and propertiesedit
H 2S react with SO 3 or HSO 3Cl, forming thiosulfuric acid H 2S 2O 3, as the analogous reaction with H 2S 2 forms disulfonomonosulfonic acid HS 2SO 3H; similarly polysulfanes H2Sn (n = 2–6) give HSnSO3H. Reactions from both ends of the polysulfane chain lead to the formation of polysulfonodisulfonic acid HO3SSnSO3H.
Many methods exist for the synthesis of these acids, but the mechanism is unclear because of the large number of simultaneously occurring and competing reactions such as redox, chain transfer, and disproportionation. Typical examples are:
Interaction between hydrogen sulfide and sulfur dioxide in highly dilute aqueous solution. This yields a complex mixture of various oxyacids of sulfur of different structures, called Wackenroder solution. At temperatures above 20 °C solutes slowly decomposes with separation unit sulfur, sulfur dioxide, and sulfuric acid.[1]
H2S + H2SO3 → H2S2O2 + H2O
H2S2O2 + 2 H2SO3 → H2S4O6 + 2 H2O
H2S4O6 + H2SO3 → H2S3O6 + H2S2O3
Reactions of sulfur halides with HSO− 3 or HS 2O− 3, for example :
SCl2 + 2 HSO− 3 → [O3SSSO 3]2− + 2 HCl
S2Cl2 + 2 HSO− 3 → [O3SS2SO3]2− + 2 HCl
SCl2 + 2 HS 2O− 3 → [O3SS3SO3]2− + 2 HCl
Anhydrous polythionic acids can be formed in diethyl ether solution by the following three general ways:
Polythionic acids with a small number of sulfur atoms in the chain (n = 3, 4, 5, 6) are the most stable. Polythionic acids are stable only in aqueous solutions, and are rapidly destroyed at higher concentrations with the release of sulfur, sulfur dioxide and - sometimes - sulfuric acid. Acid salts of polythionic acids do not exist. Polythionate ions are significantly more stable than the corresponding acids.
^Sarkar, Ramaprasad (2012). General and inorganic chemistry. New Central Book Agency. p. 483. ISBN9788173817274.
^Takano, B. (1987). "Correlation of Volcanic Activity with Sulfur Oxyanion Speciation in a Crater Lake". Science. 235 (4796): 1633–1635. Bibcode:1987Sci...235.1633T. doi:10.1126/science.235.4796.1633. PMID 17795598. S2CID 19856265.
April 17, 2024
polythionic, acid, oxoacid, which, straight, chain, sulfur, atoms, chemical, formula, so3h, trithionic, acid, h2s3o6, tetrathionic, acid, h2s4o6, simple, examples, they, conjugate, acids, polythionates, compounds, expected, exist, those, have, already, been, s. Polythionic acid is an oxoacid which has a straight chain of sulfur atoms and has the chemical formula Sn SO3H 2 n gt 2 Trithionic acid H2S3O6 tetrathionic acid H2S4O6 are simple examples They are the conjugate acids of polythionates The compounds of n lt 80 are expected to exist and those of n lt 20 have already been synthesized Dithionic acid H2S2O6 does not belong to the polythionic acids due to strongly different properties Skeletal formula of polythionic acid Contents 1 Nomenclature 2 History 3 Preparation and properties 4 Occurrence 5 ReferencesNomenclature editAll polythionates anion contains chains of sulfur atoms attached to the terminal SO3H groups Names of polythionic acids are determined by the number of atoms in the chain of sulfur atoms H2 S2 O6 dithionic acid H2 S3 O6 trithionic acid H2 S4 O6 tetrathionic acid eo H2 S5 O6 pentathionic acid eo etc History editNumerous acids and salts of this group have a venerable history and chemistry systems where they exist dates back to the studies John Dalton devoted to the behavior of hydrogen sulfide in aqueous solutions of sulfur dioxide 1808 This solution now has the name of Heinrich Wilhelm Ferdinand Wackenroder who conducted a systematic study 1846 Over the next 60 80 years numerous studies have shown the presence of ions in particular tetrathionate and pentathionate anion S4 O2 6 and S5 O2 6 respectively Preparation and properties editH2 S react with SO3 or HSO3 Cl forming thiosulfuric acid H2 S2 O3 as the analogous reaction with H2 S2 forms disulfonomonosulfonic acid HS2 SO3 H similarly polysulfanes H2Sn n 2 6 give HSnSO3H Reactions from both ends of the polysulfane chain lead to the formation of polysulfonodisulfonic acid HO3SSnSO3H Many methods exist for the synthesis of these acids but the mechanism is unclear because of the large number of simultaneously occurring and competing reactions such as redox chain transfer and disproportionation Typical examples are Interaction between hydrogen sulfide and sulfur dioxide in highly dilute aqueous solution This yields a complex mixture of various oxyacids of sulfur of different structures called Wackenroder solution At temperatures above 20 C solutes slowly decomposes with separation unit sulfur sulfur dioxide and sulfuric acid 1 H2S H2SO3 H2S2O2 H2O H2S2O2 2 H2SO3 H2S4O6 2 H2O H2S4O6 H2SO3 H2S3O6 H2S2O3 dd Reactions of sulfur halides with HSO 3 or HS2 O 3 for example SCl2 2 HSO 3 O3SSSO 3 2 2 HCl S2Cl2 2 HSO 3 O3SS2SO3 2 2 HCl SCl2 2 HS2 O 3 O3SS3SO3 2 2 HCl dd Anhydrous polythionic acids can be formed in diethyl ether solution by the following three general ways HSnSO3H SO3 H2Sn 2O6 n 1 2 8 H2Sn 2 SO3 H2Sn 2O6 n 1 2 8 2 HSnSO3H I2 H2S2n 2O6 2 HI n 1 2 6 Polythionic acids with a small number of sulfur atoms in the chain n 3 4 5 6 are the most stable Polythionic acids are stable only in aqueous solutions and are rapidly destroyed at higher concentrations with the release of sulfur sulfur dioxide and sometimes sulfuric acid Acid salts of polythionic acids do not exist Polythionate ions are significantly more stable than the corresponding acids Under the action of oxidants potassium permanganate potassium dichromate polythionic acids and their salts are oxidized to sulfate and the interaction with strong reducing agents amalgam of sodium converts them into sulfites and dithionites Occurrence editPolythionic acids are rarely encountered but polythionates are common and important Polythionic acids have been identified in crater lakes 2 The phenomenon may be useful to predict volcanic activity References edit Sarkar Ramaprasad 2012 General and inorganic chemistry New Central Book Agency p 483 ISBN 9788173817274 Takano B 1987 Correlation of Volcanic Activity with Sulfur Oxyanion Speciation in a Crater Lake Science 235 4796 1633 1635 Bibcode 1987Sci 235 1633T doi 10 1126 science 235 4796 1633 PMID 17795598 S2CID 19856265 Retrieved from https en wikipedia org w index php title Polythionic acid amp oldid 1077927399 Wackenroder solution, wikipedia, wiki, book, books, library,
