Indigo dye

Indigo

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
CAS Number	64784-13-0 Y
3D model (JSmol)	Interactive image
ChEMBL	ChEMBL599552 Y
ChemSpider	4477009 Y
ECHA InfoCard	100.006.898
PubChem CID	10215
RTECS number	DU2988400
UNII	1G5BK41P4F Y
CompTox Dashboard (EPA)	DTXSID3026279
InChI 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+ Y Key: COHYTHOBJLSHDF-BUHFOSPRSA-N Y 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
SMILES c1ccc2c(c1)C(=O)/C(=C\3/C(=O)c4ccccc4N3)/N2
Properties
Chemical formula	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
Solubility in water	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). Y verify (what is YN ?) Infobox references

Indigo dye is an organic compound with a distinctive blue color. Indigo is a natural dye obtained from the leaves of some plants of the Indigofera genus, in particular Indigofera tinctoria. Dye-bearing Indigofera plants were once common throughout the world. It is now produced via chemical routes. Blue colorants are rare. Since indigo is insoluble, it is also referred to as a pigment (C.I. Pigment Blue 66, C.I.).^[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.