Chemistry:Chloranilic acid

Chloranilic acid

Names
Preferred IUPAC name 2,5-Dichloro-3,6-dihydroxycyclohexa-2,5-diene-1,4-dione
Other names 2,5-Dichloro-3,6-dihydroxy-1,4-benzoquinone 2,5-Dichloro-3,6-dihydroxybenzoquinone
Identifiers
CAS Number	87-88-7
3D model (JSmol)	Interactive image
ChemSpider	59971
EC Number	201-780-7
PubChem CID	66604
UNII	YJ8L3BB7Y4
InChI InChI=1/C6H2Cl2O4/c7-1-3(9)5(11)2(8)6(12)4(1)10/h9,12H Key: IPPWILKGXFOXHO-UHFFFAOYAU
SMILES Cl\C1=C(/O)C(=O)C(\Cl)=C(\O)C1=O
Properties
Chemical formula	C6H2Cl2O4
Molar mass	208.98 g/mol
Appearance	orange or red crystals or powder
Density	1.96 g/cm3
Melting point	≥300 °C
Acidity (pKa)	2.95, 4.97
Hazards
GHS pictograms
GHS Signal word	Warning
GHS hazard statements	H315, H319, H335
GHS precautionary statements	P261, P264, P271, P280, P302+352, P304+340, P305+351+338, P312, P321, P332+313, P337+313, P362, P403+233, P405, P501
Flash point	135.4 °C (275.7 °F; 408.5 K)
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Infobox references

Tracking categories (test):

• SizeSet

Chloranilic acid is an organic compound with the chemical formula C
6Cl
2O
2(OH)
2. It is a red-orange solid. The compound is obtained by hydrolysis of chloranil:

C
6Cl
4O
2 + 2 H
2O → C
6Cl
2O
2(OH)
2 + 2 HCl

It is centrosymmetric, planar molecule. It also crystallizes as a dihydrate.

Chloranilic acid is a noteworthy hydroxyquinone that is somewhat acidic owing to the presence of the two chloride substituents. The conjugate base, C₆H₂Cl₂O₄]2- readily forms coordination complexes often linking pairs of many metal ions.

See also

• Chloranil