Name | Thymol Blue |
Synonyms | TB S NO 879 THYMOL BLUE Thymol Blue THYMOL BLUE TS THYMOLSULFONPHTHALEIN THYMOLSULFONEPHTHALEIN Thymolsulfonephthalein Thymolsulphonephthalein THYMOL BLUE ETHANOL (50) THYMOL BLUE INDICATOR SOLUTION 4,4'-(1,1-dioxido-3H-2,1-benzoxathiole-3,3-diyl)bis[5-methyl-2-(propan-2-yl)phenol] 2-{(E)-[4-hydroxy-2-methyl-5-(1-methylethyl)phenyl][2-methyl-5-(1-methylethyl)-4-oxocyclohexa-2,5-dien-1-ylidene]methyl}benzenesulfonic acid |
CAS | 76-61-9 |
EINECS | 200-973-3 |
InChI | InChI=1/C27H30O5S/c1-15(2)20-13-22(17(5)11-24(20)28)27(19-9-7-8-10-26(19)33(30,31)32)23-14-21(16(3)4)25(29)12-18(23)6/h7-16,28H,1-6H3,(H,30,31,32)/b27-23- |
Molecular Formula | C27H30O5S |
Molar Mass | 466.59 |
Density | 1.1413 (rough estimate) |
Melting Point | 221-224 °C (dec.) (lit.) |
Boling Point | 539.4°C (rough estimate) |
Flash Point | 36°C |
Water Solubility | Soluble in alcohol and dilute alkali solutions. Insoluble in water. |
Solubility | 0.11g/l |
Appearance | Green crystalline powder |
Color | Dark green to dark brown |
Odor | Characteristic odour |
Maximum wavelength(λmax) | ['594nm, 376nm, 544nm, 430nm'] |
Merck | 14,9400 |
BRN | 368036 |
pKa | Pka1:1.65(at 25℃)(PH=1.2 to 2.8) Pka2:8.9(at 25℃)(PH=8.0 to 9.6) |
Storage Condition | room temp |
Stability | Stable. Combustible. Dust may form an explosive mixture with air. Incompatible with strong oxidizing agents. |
Sensitive | Easily absorbing moisture |
Refractive Index | 1.5300 (estimate) |
MDL | MFCD00005869 |
Physical and Chemical Properties | Brown-green or red-purple crystalline powder. Decomposition at 200-220 °c, insoluble in water. Soluble in ethanol and yellow. Used as a pH indicator, there are two kinds of color range:(1) the acid range is pH 1.2-2.8, from red to yellow;(2) the alkali range is pH 8.0-9.6, from yellow to blue. |
Use | Clinical use as a diagnostic drug. |
Risk Codes | 10 - Flammable |
Safety Description | 24/25 - Avoid contact with skin and eyes. |
UN IDs | UN 1170 3/PG 3 |
WGK Germany | 3 |
RTECS | XP2575000 |
TSCA | Yes |
HS Code | 2934 99 90 |
Packing Group | II |
Reference Show more | 1. Liu Zhonghao, Zheng Zi, Chen Liang, Li Ning, Li Qianjun, Mu Shuqin, Yan Jun. Effects of carvacrol and thymol on colon microorganisms of weaned piglets [J]. Journal of Animal Science and Veterinary Medicine, 2020,47(12):3897-3908. 2. [IF = 9.381] Chao Yang et al."Chitosan and polyhexametene Guangxi dual-functionalized cotton gauze as a wide band for the management of chronic wounds." Carbohyd Polym. 2022 Apr;282:119130 |
brown-green crystalline powder. Soluble in ethanol and alkali solution, insoluble in water. Soluble in alkali is blue. PH 1.2~2.8 from red to yellow. 8.0~9.6 from yellow to blue.
benzenesulfonic anhydride, thymol, and anhydrous zinc chloride were mixed, heated, diluted with water, and then subjected to steam distillation to remove unreacted thymol. After cooling, Thymol Blue was obtained.
acid-base indicator, adsorption indicator.
pH range of acid-base indicator discoloration | 1.2(red)-2.8(yellow) 8(yellow)-9.6(blue) |
Main application | Display device, semiconductors, sensors, fuel cells, antimixing coding for glass, toys, multi-level alert system, correction fluid, textures, falsibility-proof security paper, packaging system, measurement of hydrogen concentration in swimming pool water, humity-invasive agent, biostatic materials, psychoactive drugs, antidepressant drugs, dental impression material |
NIST chemical information | information provided by: webbook.nist.gov (external link) |
EPA chemical substance information | information provided by: ofmpeb.epa.gov (external link) |
Use | clinical use as a diagnostic drug. acid-base indicator, pH1.2 (red) ~ 2.8 (yellow),8.0 (yellow) ~ 9.6 (blue) acid-base indicator. The pH discoloration ranges from 8.0 (yellow) to 9.6 (blue). Adsorption indicator. |
production method | 1. Obtained from the condensation of thymol with O-sulphobenzoic anhydride. 2. Mixing benzenesulfonic anhydride, thymol and anhydrous zinc chloride, heating, diluting with water, and then performing steam distillation to remove unreacted thymol, and obtaining Thymol blue after cooling. 3. The O-sulfonyl benzoyl anhydride, thymol, anhydrous zinc chloride mixed, heated to 105~110 ℃ with stirring, reaction: After the reaction is diluted with water and heated, the unreacted thymol was distilled off, the crystals were cooled and filtered. The crystals were washed with a small amount of ethanol, further removed of thymol, and then dried in air. |