Sulfur Chains Terminated by Sulfonate Groups The Polythionates

Sulfur Chains Terminated by Sulfonate Groups The Polythionates 

The history of the polythionates is a long one and fraught with problems as to structure and reactivity. Dalton in 1808 in his A New System of Chemical Philosophy commented on the chemical nature of the constituents of the liquid which later came to bear the name of Wackenrodor. The three lowest acids were discovered in 1840 to 1846, and Debus in 1888 from Wackenroder s liquid isolated a salt that analyzed for potassium hexa-thionate, but the existence of hexathionic acid was later doubted, and was not definitely established until the work of Weitz and Achterberg (220) in 1928. The literature on polythionates up to 1927 has been reviewed by Kurtenacker (158) a later review is by Goehring (131) in 1952. 

Two acids with mixed three-membered chains are known, namely selenopentathionic and telluropentathionic acid. They are derived from pentathionic acid by substitution of selenium or tellurium for the middle sulfur atom of the latter, and behave in reactions with nucleophilic reagents as thiosulfates of divalent selenium and tellurium. The first salts of scleno-pentathionic (84) and telluropentathionic (85) acid were isolated in 1949, although the formation reactions in aqueous solutions had been known earlier. Wood (229) has by paper electrophoresis shown that the preparative methods lead to pure products. 

The polythionic acids are strong, diprotic acids. The ions decompose in alkaline solutions and also, more or less readily, in strongly acid solutions, and free, unsolvated acids had not been prepared until quite recently Feh6r, Schotten, and Thomas (75) in 1958 announced the solvent-free synthesis of polythionic acids. Nothing was said about their stability at normal temperatures. 

Hertlein (US) in 1896 measured refraction, viscosity, and electrical conductivity of aqueous potassium tri-, tetra-, and pentathionates and decided in favor of uiibranched structures, and so did Martin and Metz (171) in 1924 on the basis of thermochemical measurements. Spacu and Popper (208) in 1939 reported the refraction of sodium tetrathionate Grinberg (186) has later commented on the ionic refraction of tetra thionate as indicating negative charge on the divalent sulfur atoms. However, from Hertlein s measurements the increments per sulfur atom, from tri-to tetra-thionate and tetra- to pentathionate, are about 9 cm3. This is the same as in other series, for example, in the polysulfur dichlorides (72) where the sulfur atoms are hardly negative. 

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VIII. Sulfur Chains Terminated by Sulfonate Groups The Polythionates. 254... 

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