Phthalic acid

Phthalic acid
Phthalic acids
Ball-and-stick model of the phthalic acid molecule
Names
Preferred IUPAC name
Benzene-1,2-dicarboxylic acid
Other names
1,2-Benzenedioic acid
Phthalic acid
Benzene-1,2-dioic acid
ortho-Phthalic acid
Identifiers
3D model (JSmol)
ChEBI
ChemSpider
ECHA InfoCard 100.001.703 Edit this at Wikidata
EC Number
  • 201-873-2
UNII
  • InChI=1S/C8H6O4/c9-7(10)5-3-1-2-4-6(5)8(11)12/h1-4H,(H,9,10)(H,11,12) ☒N
    Key: XNGIFLGASWRNHJ-UHFFFAOYSA-N ☒N
  • InChI=1/C8H6O4/c9-7(10)5-3-1-2-4-6(5)8(11)12/h1-4H,(H,9,10)(H,11,12)
    Key: XNGIFLGASWRNHJ-UHFFFAOYAX
  • OC(=O)c1ccccc1C(=O)O
Properties
C8H6O4
Molar mass 166.132 g/mol
Appearance white solid
Density 1.593 g/cm3, solid
Melting point 207 °C (405 °F; 480 K)[3]
0.6 g / 100 mL [1]
Acidity (pKa) 2.89, 5.51[2]
-83.61·10−6 cm3/mol
Hazards
NFPA 704 (fire diamond)
NFPA 704 four-colored diamondHealth 2: Intense or continued but not chronic exposure could cause temporary incapacitation or possible residual injury. E.g. chloroformFlammability 0: Will not burn. E.g. waterInstability 0: Normally stable, even under fire exposure conditions, and is not reactive with water. E.g. liquid nitrogenSpecial hazards (white): no code
2
0
0
Related compounds
Isophthalic acid
Terephthalic acid
Related compounds
 Phthalic anhydride
Phthalimide
Phthalhydrazide
Phthaloyl chloride
Benzene-1,2-
dicarboxaldehyde
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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In organic chemistry, phthalic acid is an aromatic dicarboxylic acid, with formula C6H4(CO2H)2 and structure HO(O)C−C6H4−C(O)OH. Although phthalic acid is of modest commercial importance, the closely related derivative phthalic anhydride is a commodity chemical produced on a large scale.[4] Phthalic acid is one of three isomers of benzenedicarboxylic acid, the others being isophthalic acid and terephthalic acid.

  1. ^ "PHTHALIC ACID". hazard.com.
  2. ^ 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.
  3. ^ Several melting points are reported, for example: (i) 480. K (NIST website), (ii) 210−211 °C with decomposition (Sigma-Aldrich on-line), (iii) 191 °C in a sealed tube (Ullmann's Encyclopedia of Industrial Chemistry), (iv) 230 °C with conversion to phthalic anhydride and water (J.T.Baker MSDS).
  4. ^ Lorz, Peter M.; Towae, Friedrich K.; Enke, Walter; et al. (2007). "Phthalic Acid and Derivatives". Ullmann's Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH. doi:10.1002/14356007.a20_181.pub2. ISBN 978-3527306732.