9400. Thymol Blue

Nomenclature

CAS number: 76-61-9
4,4′-(1,1-Dioxido-3H-2,1-benzoxathiol-3-ylidene)bis[5-methyl-2-(1-methylethyl)phenol]; 4,4′-(3H-2,1-benzoxathiol-3-ylidene)bis[5-methyl-2-(1-methylethyl)phenol] S,S-dioxide; α-hydroxy-α,α-bis(5-hydroxycarvacryl)-o-toluenesulfonic acid γ-sultone; thymolsulfonephthalein.
C27H30O5S; mol wt 466.59.
C 69.50%, H 6.48%, O 17.15%, S 6.87%.
Chemical structure

Properties

Brownish-green, cryst powder; characteristic odor. Insol in water. Sol in alcohol, dil alkali solns.

Use

As as acid-base indicator; pH: red 1.2 to yellow 2.8; also yellow 8.0 to blue 9.6.