Indigo dye

Indigo
Lump of Indian indigo dye
Skeletal formula of indigo dye
Ball-and-stick model of the indigo dye molecule
Names
Preferred IUPAC name
[2(2')E]-[2,2'-Biindolylidene]-3,3'(1H,1'H)-dione
Other names
2,2'-Bis(2,3-dihydro-3-oxoindolyliden), Indigotin
Identifiers
3D model (JSmol)
ChEMBL
ChemSpider
ECHA InfoCard 100.006.898 Edit this at Wikidata
RTECS number
  • DU2988400
UNII
  • InChI=1S/C16H10N2O2/c19-15-9-5-1-3-7-11(9)17-13(15)14-16(20)10-6-2-4-8-12(10)18-14/h1-8,17-18H/b14-13+ checkY
    Key: COHYTHOBJLSHDF-BUHFOSPRSA-N checkY
  • InChI=1/C16H10N2O2/c19-15-9-5-1-3-7-11(9)17-13(15)14-16(20)10-6-2-4-8-12(10)18-14/h1-8,17-18H/b14-13+
    Key: COHYTHOBJLSHDF-BUHFOSPRBQ
  • c1ccc2c(c1)C(=O)/C(=C\3/C(=O)c4ccccc4N3)/N2
Properties
C16H10N2O2
Molar mass 262.27 g/mol
Appearance dark blue crystalline powder
Density 1.199 g/cm3
Melting point 390 to 392 °C (734 to 738 °F; 663 to 665 K)
Boiling point decomposes
990 µg/L (at 25 °C)
Related compounds
Related compounds
 Indoxyl
Tyrian purple
Indican
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Indigo dye is an organic compound with a distinctive blue color. Indigo is a natural dye extracted from the leaves of some plants of the Indigofera genus, in particular Indigofera tinctoria. Dye-bearing Indigofera plants were commonly grown and used throughout the world, particularly in Asia, with the production of indigo dyestuff economically important due to the historical rarity of other blue dyestuffs.[1]

Most indigo dye produced today is synthetic, constituting around 80,000 tonnes each year, as of 2023.[2] It is most commonly associated with the production of denim cloth and blue jeans, where its properties allow for effects such as stone washing and acid washing to be applied quickly.

  1. ^ Cite error: The named reference Ullmann was invoked but never defined (see the help page).
  2. ^ Linke, Julia A.; Rayat, Andrea; Ward, John M. (2023). "Production of indigo by recombinant bacteria". Bioresources and Bioprocessing. 10 (1): 20. doi:10.1186/s40643-023-00626-7. ISSN 2197-4365. PMC 10011309. PMID 36936720.