Sulfonic acid
Sulfonic acid is an hypothetical acid with formula H-S2-OH. This compound is a
tautomer of
sulfurous acid HO-S-OH, but less stable, and would likely convert to that very quickly if it were formed. Although this compound is unimportant, there are many derived compounds, with formula
R-S2-OH for various
R. These may then form
salts or
esters, called sulfonates.
Encyclopedia
Sulfonic acid is an hypothetical acid with formula H-S
2-OH. This compound is a
tautomer of
sulfurous acid HO-S-OH, but less stable, and would likely convert to that very quickly if it were formed. Although this compound is unimportant, there are many derived compounds, with formula
R-S
2-OH for various
R. These may then form
salts or
esters, called sulfonates.
Sulfonic acids
Sulfonic acids are a class of organic acids with the general formula
RSO3H, where
R is usually a
hydrocarbon side chain. Sulfonic acids are typically much stronger acids than their
carboxylic equivalents, and have the unique tendency to bind to
proteins and
carbohydrates tightly; most "washable"
dyes are sulfonic acids for this reason. They are also used as
catalysts and intermediates for a number of different products. Sulfonic acid salts are important as
detergents, and the antibacterial sulfa drugs are also sulfonic acid derivatives.
The simplest example is
methanesulfonic acid, CH
3SO
2OH, which is a reagent regularly used in
organic chemistry.
P-toluenesulfonic acid is also an important reagent.
Note that the sulfonic acids and sulfonates are analogous to
carboxylic acids and
carboxylates; in both cases, -C- is replaced by -S2-. Chemical properties are similar as well, although sulfonic acids are often even stronger acids than carboxylic acids, the hydrogen being easier to leave than in most compounds, and they readily form esters.
The sulfonic acid and sulfonate
functional groups, -SO
2OH and -SO
2O-, are found in many chemical compounds, e.g. certain
detergents and
dyes as well as in strongly acidic
cation exchange resins.
Sulfonic acid chlorides
Sulfonic acid chlorides are a class of
organic compounds with the general formula R-SO
2-Cl. These compounds react readily with
alcohols to sulfonic esters. Important acid chlorides are
tosyl chloride,
brosyl chloride,
nosyl chloride and mesyl chloride. One synthetic procedure to synthesize sulfonic acid chlorides is the
Reed reaction.
Sulfonic esters
Sulfonic esters are a class of
organic compounds with the general formula R-SO
2-OR. Sulfonic esters are considered good leaving groups in
nucleophilic aliphatic substitution.
See also
External links
