Bromothymol blue

Not to be confused with Bromophenol blue.
Bromothymol blue
Names
Preferred IUPAC name
3,3-Bis[3-bromo-4-hydroxy-2-methyl-5-(propan-2-yl)phenyl]-2,1λ6-benzoxathiole-1,1(3H)-dione
Identifiers
3D model (JSmol)
ChEBI
ChEMBL
ChemSpider
ECHA InfoCard 100.000.884 Edit this at Wikidata
EC Number
  • 200-971-2
UNII
  • InChI=1S/C27H28Br2O5S/c1-13(2)17-11-20(15(5)23(28)25(17)30)27(19-9-7-8-10-22(19)35(32,33)34-27)21-12-18(14(3)4)26(31)24(29)16(21)6/h7-14,30-31H,1-6H3 checkY
    Key: NUHCTOLBWMJMLX-UHFFFAOYSA-N checkY
  • InChI=1/C27H28Br2O5S/c1-13(2)17-11-20(15(5)23(28)25(17)30)27(19-9-7-8-10-22(19)35(32,33)34-27)21-12-18(14(3)4)26(31)24(29)16(21)6/h7-14,30-31H,1-6H3
    Key: NUHCTOLBWMJMLX-UHFFFAOYAD
  • Brc1c(O)c(cc(c1C)C3(OS(=O)(=O)c2ccccc23)c4cc(c(O)c(Br)c4C)C(C)C)C(C)C
Properties
C27H28Br2O5S
Molar mass 624.38 g·mol−1
Density 1.25 g/cm3
Melting point 202 °C (396 °F; 475 K)
Sparingly soluble in water[1]
Acidity (pKa) 7.0
Hazards
GHS labelling:
GHS07: Exclamation mark
Warning
H302, H315, H319
P264, P270, P280, P301+P312, P302+P352, P305+P351+P338, P321, P330, P332+P313, P337+P313, P362, P501
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 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
2
1
0
Safety data sheet (SDS) ThermoFisher Scientific
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 ?)

Bromothymol blue (also known as bromothymol sulfone phthalein and BTB) is a pH indicator. It is mostly used in applications that require measuring substances that would have a relatively neutral pH (near 7). A common use is for measuring the presence of carbonic acid in a liquid. It is typically sold in solid form as the sodium salt of the acid indicator.

  1. ^ "Archived copy". Archived from the original on 2015-11-26. Retrieved 2015-12-11.{{cite web}}: CS1 maint: archived copy as title (link)