SO3Hryhmä
The SO3H ryhmä, commonly written as the sulfonic acid group, is a functional group in organic chemistry represented by the formula R-SO3H. It consists of a sulfur atom in the oxidation state +6 bonded to three oxygens, one of which bears a hydrogen atom. When attached to a carbon framework, the group is often written as R-SO3H, forming sulfonic acids such as benzenesulfonic acid or p-toluenesulfonic acid.
The sulfonic acid group is a strong Brønsted acid. In water, most aryl and alkyl sulfonic acids
Synthesis and occurrence: the SO3H group is commonly introduced into substrates by sulfonation using sulfur trioxide
Applications: sulfonic acids and their salts are widely used in detergents (alkylbenzene sulfonates), in organic synthesis