Aurin

For the French commune, see Aurin, Haute-Garonne.
Aurin
Skeletal formula of aurin
Ball-and-stick model
Names
Preferred IUPAC name
4-[Bis(4-hydroxyphenyl)methylidene]cyclohexa-2,5-dien-1-one
Other names
Aurin, corallin, p-rosolic acid, C.I. 43800
Identifiers
3D model (JSmol)
2055205
ChEMBL
ChemSpider
ECHA InfoCard 100.009.129 Edit this at Wikidata
EC Number
  • 210-041-8
UNII
  • InChI=1S/C19H14O3/c20-16-7-1-13(2-8-16)19(14-3-9-17(21)10-4-14)15-5-11-18(22)12-6-15/h1-12,20-21H checkY
    Key: FYEHYMARPSSOBO-UHFFFAOYSA-N checkY
  • InChI=1/C19H14O3/c20-16-7-1-13(2-8-16)19(14-3-9-17(21)10-4-14)15-5-11-18(22)12-6-15/h1-12,20-21H
    Key: FYEHYMARPSSOBO-UHFFFAOYAG
  • C1=CC(=O)C=CC1=C(C2=CC=C(C=C2)O)C3=CC=C(C=C3)O
Properties
C19H14O3
Molar mass 290.318 g·mol−1
Appearance see text
Density 1.283 g/cm3
Melting point 308 °C (586 °F; 581 K) (decomposes)
Insoluble
UV-vis (λmax) 482 nm[1]
-161.4·10−6 cm3/mol
Hazards
GHS labelling:
GHS07: Exclamation mark[1]
Danger
H315, H319, H335[1]
P261, P305+P351+P338[1]
NFPA 704 (fire diamond)
NFPA 704 four-colored diamondHealth 1: Exposure would cause irritation but only minor residual injury. E.g. turpentineFlammability 1: Must be pre-heated before ignition can occur. Flash point over 93 °C (200 °F). E.g. canola oilInstability 0: Normally stable, even under fire exposure conditions, and is not reactive with water. E.g. liquid nitrogenSpecial hazards (white): no code
1
1
0
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
checkY verify (what is checkY☒N ?)

Aurin (C.I. 43800), sometimes named rosolic acid or corallin is an organic compound, forming yellowish or deep-red crystals with greenish metallic luster. It is practically insoluble in water, freely soluble in alcohol. It is soluble in strong acids to form yellow solution, or in aqueous alkalis to form carmine red solutions.

Aurin (pH indicator)
below pH 5.0 above pH 6.8
5.0 ⇌ 6.8

Due to this behaviour it can be used as pH indicator with pH transition range 5.0 - 6.8. It is used as an intermediate in manufacturing of dyes.

  1. ^ a b c d Sigma-Aldrich Co., p-Rosolic acid. Retrieved on 2014-05-06.