Oxyacids of sulfur

M. Schmidt and W. Siebert. Oxyacids of sulfur, Seclian 2.4 in Comprehensive Inorganic Chemistry, Vol. 2, Chapter 23, pp. 868-98, Pergamon Press, Oxford, I973. 

The activation of persulfates by various reductant viz. metals, oxidizable metals, metal complexes, salts of various oxyacid of sulfur, hydroxylamine, hydrazine, thiol, polyhydric phenols, etc. has been reported [36-38]. Bertlett and Colman [39] investigated the effect of methanol on the decomposition of persulfates and proposed the following mechanism. 

The most common oxyacid of sulfur is H2S04, sulfuric acid. In dilute aqueous solutions this substance is almost completely dissociated into ions according to the equation... 

Therefore we see that the oxyacids of sulfur continue the trend of increasing acidity which... 

It would be possible to write an entire book on the oxyacids of sulfur alone. In fact an entire book... 

One of the unstable oxyacids of sulfur is dithionous acid, H2S204, which contains sulfur in the +3... 

This is another of the unstable oxyacids of sulfur that appears to contain sulfur +5. The structure of the dithionate anion is... 

By looking at Table 15.6, tell which of the oxyacids of sulfur are strong acids. 

Mechanisms and Reactivity in Reactions of Organic Oxyacids of Sulfur and their Anhydrides... 

Among the oxyacids of sulfur the predilection to form an anhydride with a sulfur-sulfur bond, rather than one with an oxygen bridge between the two sulfurs, is not restricted to sulfenic acids. We will see in a subsequent section that sulfinic acids also do this. Their anhydrides have the sulfinyl sulfone structure. RS(0)S02R, rather than RS(0)0S(0)R. What is unique about the sulfenic acid-thiolsulfinate system, however, is the fact that the anhydride (thiolsulfinate) is strongly preferred thermodynamically over the acid at equilibrium. With any other type of common acid the reverse is true, of course. The uniqueness of the sulfenic acid-thiolsulfinate situation can perhaps best be appreciated by realizing that, if the same stability relationship between acid and anhydride were to exist for carboxylic acids, acetic acid would spontaneously dehydrate to acetic anhydride ... 

Sulfonic acids, RS03H, particularly in the form of their salts RS03 M+, are far and away the most frequently encountered of the organic oxyacids of sulfur. They are strong acids, ionizing completely in water to RSO and H30+. 

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