Vinylsulfonic acid is the organosulfur compound with the

chemical formula In chemistry, a chemical formula is a way of presenting information about the chemical proportions of atoms that constitute a particular chemical compound or molecule, using chemical element symbols, numbers, and sometimes also other symbol ...

CH₂=CHSO₃H. It is the simplest unsaturated sulfonic acid. The C=C

double bond In chemistry, a double bond is a covalent bond between two atoms involving four bonding electrons as opposed to two in a single bond. Double bonds occur most commonly between two carbon atoms, for example in alkenes. Many double bonds exist betwee ...

is a site of high reactivity.

Polymerization In polymer chemistry, polymerization (American English), or polymerisation (British English), is a process of reacting monomer molecules together in a chemical reaction to form polymer chains or three-dimensional networks. There are many fo ...

gives polyvinylsulfonic acid, especially when used as a comonomer with functionalized vinyl and (meth)acrylic acid compounds. It is a colorless, water-soluble liquid, although commercial samples can appear yellow or even red.

Preparation

Vinylsulfonic acid is produced industrially by the

alkaline hydrolysis Alkaline hydrolysis, in organic chemistry, usually refers to types of nucleophilic substitution reactions in which the attacking nucleophile is a hydroxide ion. Example In the alkaline hydrolysis of esters and amides the hydroxide ion nucleophi ...

carbyl sulfate Carbyl sulfate is an organosulfur compound. The white solid is the product of the reaction of sulfur trioxide and ethylene. It is used in preparation of some dyes and other organosulfur compounds. Carbyl sulfate is a colorless, crystalline, hygr ...

with subsequent acidification of the resulting vinyl sulfonate salt: : Vinylsulfonsäure aus Carbylsulfat

The reaction is highly exothermic (reaction enthalpy: 1,675 kJ/kg) and requires exact maintenance of temperature and pH during the hydrolysis. When calcium hydroxide is used as the hydrolysis medium, a solution of calcium vinyl sulfonate is obtained. Acidification of this hydrolysis mixture with sulfuric acid gives vinylsulfonic acid, together with the poorly soluble

calcium sulfate Calcium sulfate (or calcium sulphate) is the inorganic compound with the formula CaSO4 and related hydrates. In the form of γ-anhydrite (the anhydrous form), it is used as a desiccant. One particular hydrate is better known as plaster of Paris ...

. Vinylsulfonic acid also can be prepared by dehydration of

isethionic acid Isethionic acid is an organosulfur compound containing an alkylsulfonic acid located beta to a hydroxy group. Its discovery is generally attributed to Heinrich Gustav Magnus, who prepared it by the action of solid sulfur trioxide on ethanol in 18 ...

with

phosphorus pentoxide Phosphorus pentoxide is a chemical compound with molecular formula P4 O10 (with its common name derived from its empirical formula, P2O5). This white crystalline solid is the anhydride of phosphoric acid. It is a powerful desiccant and dehydra ...

: :

Vinylsulfonic acid can also be prepared by

sulfochlorination The Reed reaction is a chemical reaction that utilizes light to oxidize hydrocarbons to alkyl sulfonyl chlorides. This reaction is employed in modifying polyethylene to give chlorosulfonated polyethylene (CSPE), which noted for its toughness. Com ...

of chloroethane,

dehydrohalogenation In chemistry, dehydrohalogenation is an elimination reaction which removes a hydrogen halide from a substrate. The reaction is usually associated with the synthesis of alkenes, but it has wider applications. Dehydrohalogenation from alkyl halid ...

to vinylsulfonyl chloride and subsequent hydrolysis of the acid chloride. :: ::= ::

Use

The activated C=C double bond of vinylsulfonic acid reacts readily with nucleophiles in an addition reaction. 2-Aminoethanesulfonic acid is formed with

ammonia Ammonia is an inorganic compound of nitrogen and hydrogen with the formula . A stable binary hydride, and the simplest pnictogen hydride, ammonia is a colourless gas with a distinct pungent smell. Biologically, it is a common nitrogenous wa ...

and 2-methylaminoethanesulfonic acid with methylamine. Vinylsulfonic acid is the monomer in the preparation of highly acidic or anionic homopolymers and copolymers. These polymers are used in the electronic industry as photoresists, as ion-conductive polymer electrolyte membranes (PEM) for fuel cells. For example, transparent membranes with high ion exchange capacity and proton conductivity can be produced from polyvinylsulfonic acid.

Research

Vinylsulfonic acid may also be grafted to polymeric supports (e.g. polystyrene) to give highly acidic ion exchangers, which used as catalysts for

esterification In chemistry, an ester is a compound derived from an oxoacid (organic or inorganic) in which at least one hydroxyl group () is replaced by an alkoxy group (), as in the substitution reaction of a carboxylic acid and an alcohol. Glycerides ar ...

and Friedel-Crafts acylations.T. Okayasu, K. Saito, H. Nishide, M.T W. Hearn: ''Poly(vinylsulfonic acid)-grafted solid catalysts: new materials for acid-catalysed organic synthetic reactions''. In: ''

Green Chem ''Green Chemistry'' is a monthly peer-reviewed scientific journal covering every aspect of sustainable chemistry and its implementation in chemical engineering. It is published by the Royal Society of Chemistry and was established in 1999 by J ...

''. 12 (2010) 1981–1989, {{doi, 10.1039/C0GC00241K. Where the sulfonic acid functionality is not essential, the much more usable alkaline aqueous solution of sodium vinylsulfonate is used, which is obtained directly in the alkaline hydrolysis of the carbyl sulfate and is commercially supplied as an aqueous solution..

References

Sulfonic acids Monomers Vinyl compounds