Mellitic acid
| |||
Names | |||
---|---|---|---|
Preferred IUPAC name
Benzenehexacarboxylic acid | |||
Other names
Graphitic acid
| |||
Identifiers | |||
3D model (
JSmol ) |
|||
ChEBI | |||
ChEMBL | |||
ChemSpider | |||
DrugBank | |||
ECHA InfoCard
|
100.007.495 | ||
PubChem CID
|
|||
UNII | |||
CompTox Dashboard (EPA)
|
|||
| |||
| |||
Properties | |||
C12H6O12 | |||
Molar mass | 342.16 g/mol | ||
Density | 1.68 g/cm3, 2.078 (calc.)[3] | ||
Melting point | > 300 °C (572 °F; 573 K) | ||
Boiling point | 678 °C (1,252 °F; 951 K) (calc.)[3] | ||
Acidity (pKa) | 5.0, 2.19, 3.31, 4.78, 5.89, 6.96[4] | ||
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
|
Mellitic acid, also called graphitic acid or benzenehexacarboxylic acid, is an acid first discovered in 1799 by Martin Heinrich Klaproth in the mineral mellite (honeystone), which is the aluminium salt of the acid.[5] It crystallizes in fine silky needles and is soluble in water and alcohol.
Structure
The stable conformation of this molecule has the carboxylic acid groups rotated out of the plane of the central benzene ring. The molecule adopts a propeller-like conformation in which the tilt of each carboxylic acid group relative to the central benzene ring varies due to intramolecular hydrogen bonding.[2]
Preparation
Mellitic acid may be prepared by warming mellite with
Reactions
It is a very stable compound;
6(CONHCO)
3), and ammonium euchroate
The high stability of mellitic acid salts and their presence as an endproduct of the oxidation of polycyclic aromatic hydrocarbons, which are present in the solar system, make them a possible organic substance in Martian soil.[7]
Mellitates (and salts of other benzene polycarboxylic acids) of iron and cobalt have interesting magnetic properties.[8]
See also
References
- ^ MSDS for mellitic acid[permanent dead link]
- ^ .
- ^ a b Curate Data: Predicted Properties: 2244. ChemSpider.com.
- ^ Brown, H.C., et al., in Baude, E.A. and Nachod, F.C., Determination of Organic Structures by Physical Methods, Academic Press, New York, 1955.
- ^ Klaproth (1802). Beiträge zur chemischen Kenntniss der Mineralkörper, Band 3 (in German). p. 114.
- ^ WebElements.com
- PMID 10706606.
- ^ Kurmoo M, Estournes C, Oka Y, Kumagai H, Inoue K (2005) Inorganic Chemistry volume 44, page 217
Further reading
Henry Enfield Roscoe, Carl Scholemmer, "Mellitene Group", "A Treatise on Chemistry: V.III: The Chemistry of the Hydrocarbons and their Derivatives on Organic Chemistry: P.V:529. D. Appleton and Co. (1889).
public domain: Chisholm, Hugh, ed. (1911). "Mellitic Acid". Encyclopædia Britannica. Vol. 18 (11th ed.). Cambridge University Press. p. 95.
This article incorporates text from a publication now in the