Vinylsulfonic acid

Vinylsulfonic acid
Names

IUPAC name ethenesulfonic acid
Identifiers
CAS Number	1184-84-5 3039-83-6 (sodium salt)
3D model (JSmol)	Interactive image
ChemSpider	56254
ECHA InfoCard	100.013.342
PubChem CID	62474
InChI InChI=1S/C2H4O3S/c1-2-6(3,4)5/h2H,1H2,(H,3,4,5) Key: NLVXSWCKKBEXTG-UHFFFAOYSA-N InChI=1/C2H4O3S/c1-2-6(3,4)5/h2H,1H2,(H,3,4,5) Key: NLVXSWCKKBEXTG-UHFFFAOYAA
SMILES C=CS(=O)(=O)O
Properties
Chemical formula	C₂H₄O₃S
Molar mass	108.11 g·mol⁻¹
Appearance	colouless liquid
Boiling point	128 °C (1,29 hPa) * 95 °C
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Infobox references

Vinylsulfonic acid is the organosulfur compound with the formula CH₂=CHSO₃H. It is simplest unsaturated sulfonic acid. The C=C double bond is a site of high reactivity. polymerize 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.

Vinylsulfonic acid is produced industrially by the alkaline hydrolysis of carbyl sulfate with subsequent acidification of the resulting vinyl sulfonate salt:

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.

Vinylsulfonic acid also can be prepared by dehydration of isethionic acid with phosphorus pentoxide:

...
Wikipedia