Cyanuric acid

Cyanuric acid

Names
Preferred IUPAC name 1,3,5-Triazinane-2,4,6-trione
Other names 1,3,5-Triazine-2,4,6(1H,3H,5H)-trione 1,3,5-Triazinetriol s-Triazinetriol s-Triazinetrione Tricarbimide Isocyanuric acid Pseudocyanuric acid
Identifiers
CAS Number	108-80-5 Y
3D model (Jmol)	Interactive image
ChEBI	CHEBI:17696 Y
ChEMBL	ChEMBL243087 Y
ChemSpider	7668 Y
ECHA InfoCard	100.003.290
KEGG	C06554 Y
PubChem	7956
RTECS number	XZ1800000
InChI InChI=1S/C3H3N3O3/c7-1-4-2(8)6-3(9)5-1/h(H3,4,5,6,7,8,9) Y Key: ZFSLODLOARCGLH-UHFFFAOYSA-N Y InChI=1/C3H3N3O3/c7-1-4-2(8)6-3(9)5-1/h(H3,4,5,6,7,8,9) Key: ZFSLODLOARCGLH-UHFFFAOYAR
SMILES O=C1NC(=O)NC(=O)N1
Properties
Chemical formula	C3H3N3O3
Molar mass	129.07 g/mol
Appearance	white crystalline powder
Density	2.5 g/cm3
Melting point	320–360 °C (608–680 °F; 593–633 K) decomposes
Solubility in water	0.27 g/100 ml (25 °C)
Magnetic susceptibility (χ)	-61.5·10−6 cm3/mol
Hazards
Safety data sheet	ICSC 1313
Related compounds
Related triazines	Cyanuric fluoride Cyanuric chloride Cyanuric bromide
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Y  (what is YN ?)
Infobox references

Cyanuric acid or 1,3,5-triazine-2,4,6-triol is a chemical compound with the formula (CNOH)₃. Like many industrially useful chemicals, this triazine has many synonyms. This white, odorless solid finds use as a precursor or a component of bleaches, disinfectants, and herbicides. In 1997, worldwide production was 160 million kilograms.

Cyanuric acid is the cyclic trimer of the elusive species cyanic acid, HOCN. The two structures shown in the infobox readily interconvert; that is, they are tautomers. However, mixture with melamine forms melamine cyanurate, which locks cyanuric acid in the tri-keto tautomer and makes melamine cyanurate insoluble in water. The triol tautomer, which may have aromatic character, predominates in solution. The hydroxyl (-OH) groups assume phenolic character. Deprotonation with base affords a series of cyanurate salts:

Cyanuric acid (CYA) was first synthesized by Friedrich Wöhler in 1829 by the thermal decomposition of urea and uric acid. The current industrial route to CYA entails the thermal decomposition of urea, with release of ammonia. The conversion commences at approximately 175 °C:

CYA crystallizes from water as the dihydrate.

Cyanuric acid can be produced by hydrolysis of crude or waste melamine followed by crystallization. Acid waste streams from plants producing these materials contain cyanuric acid and on occasion, dissolved amino-substituted triazines, namely, ammeline, ammelide, and melamine. In one method, an ammonium sulfate solution is heated to the "boil" and treated with a stoichiometric amount of melamine, by which means the cyanuric acid present precipitates as melamine-cyanuric acid complex. The various waste streams containing cyanuric acid and amino-substituted triazines may be combined for disposal, and during upset conditions undissolved cyanuric acid may be present in the waste streams.