Bromocresol purple

Bromocresol purple
Skeletal formula of bromocresol purple in cyclic form
Ball-and-stick model of the bromocresol purple molecule in cyclic form
Names
Preferred IUPAC name
3,3-Bis(3-bromo-4-hydroxy-5-methylphenyl)-2,1λ6-benzoxathiole-1,1(3H)-dione
Other names
5′,5′′-Dibromo-o-cresolsulfonephthalein
Bromcresol purple
Identifiers
3D model (JSmol)
ChEBI
ChemSpider
ECHA InfoCard 100.003.716 Edit this at Wikidata
EC Number
  • 204-087-8
UNII
  • InChI=1S/C21H16Br2O5S/c1-11-7-13(9-16(22)19(11)24)21(14-8-12(2)20(25)17(23)10-14)15-5-3-4-6-18(15)29(26,27)28-21/h3-10,24-25H,1-2H3 checkY
    Key: ABIUHPWEYMSGSR-UHFFFAOYSA-N checkY
  • InChI=1/C21H16Br2O5S/c1-11-7-13(9-16(22)19(11)24)21(14-8-12(2)20(25)17(23)10-14)15-5-3-4-6-18(15)29(26,27)28-21/h3-10,24-25H,1-2H3
    Key: ABIUHPWEYMSGSR-UHFFFAOYAH
  • InChI=1/C21H17BrO5S/c1-12-9-14(7-8-18(12)23)21(15-10-13(2)20(24)17(22)11-15)16-5-3-4-6-19(16)28(25,26)27-21/h3-11,23-24H,1-2H3
  • Brc1c(O)c(cc(c1)C3(OS(=O)(=O)c2ccccc23)c4cc(c(O)c(Br)c4)C)C
Properties
C21H16Br2O5S
Molar mass 540.22 g·mol−1
Appearance Purple powder
Melting point 241 to 242 °C (466 to 468 °F; 514 to 515 K) (decomposition)
< 0.1 %
Hazards
GHS labelling:
GHS07: Exclamation mark
Warning
H315, H319, H335
P261, P264, P271, P280, P302+P352, P304+P340, P305+P351+P338, P312, P321, P332+P313, P337+P313, P362, P403+P233, P405, P501
NFPA 704 (fire diamond)
NFPA 704 four-colored diamondHealth 1: Exposure would cause irritation but only minor residual injury. E.g. turpentineFlammability 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
1
0
0
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
☒N verify (what is checkY☒N ?)

Bromocresol purple (BCP) or 5′,5″-dibromo-o-cresolsulfophthalein, is a dye of the triphenylmethane family (triarylmethane dyes) and a pH indicator. It is colored yellow below pH 5.2, and violet above pH 6.8. In its cyclic sulfonate ester form, it has a pKa value of 6.3, and is usually prepared as a 0.04% aqueous solution.[1]

  1. ^ "Bromocresol Purple". NCBI PubChem. National Center for Biotechnology Information.