Chemistry:Thymol blue
From HandWiki
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| Names | |
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| Preferred IUPAC name
3,3-Bis[4-hydroxy-2-methyl-5-(propan-2-yl)phenyl]-2,1λ6-benzoxathiole-1,1(3H)-dione | |
| Other names
α-hydroxy-α,α-bis(5-hydroxycarvacryl)- o-toluenesulfonic acid γ-sultone; thymolsulfonephthalein
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| Identifiers | |
3D model (JSmol)
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PubChem CID
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| Properties | |
| C27H30O5S | |
| Molar mass | 466.59 g·mol−1 |
| Appearance | Brownish-green crystal powder |
| Melting point | 221–224 °C (430–435 °F; 494–497 K) decomposes[1] |
| Insoluble | |
| UV-vis (λmax) | 594 nm (1st) 376 nm (2nd)[1] |
| Hazards | |
| Main hazards | Harmful |
| GHS pictograms | 
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| GHS Signal word | Warning |
| H302 | |
| P264, P270, P301+312, P330, P501 | |
| NFPA 704 (fire diamond) | |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). | |
 verify (what is   ?)
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| Infobox references | |
Tracking categories (test):
Thymol blue (thymolsulfonephthalein) is a brownish-green or reddish-brown crystalline powder that is used as a pH indicator. It is insoluble in water but soluble in alcohol and dilute alkali solutions.
| Thymol blue (pH indicator) | ||
| below pH 8.0 | above pH 9.6 | |
| 8.0 | ⇌ | 9.6 |
| Thymol blue (pH indicator) | ||
| below pH 1.2 | above pH 2.8 | |
| 1.2 | ⇌ | 2.8 |
It transitions from red to yellow at pH 1.2–2.8 and from yellow to blue at pH 8.0–9.6. It is usually a component of Universal indicator.
At wavelength (378 - 382) nm, extinction coefficient > 8000 and at wavelength (298 - 302) nm, the extinction coefficient > 12000.[3]
Structures
Thymol blue has different structures at different pH.
- 450pxthymol blue.
Safety
It may cause irritation. Its toxicological properties have not been fully investigated.[4] Harmful if swallowed, Acute Toxicity. Only Hazardous when percent values are above 10%.[5]
Bibliography
- Merck. "Thymol Blue." The Merck Index. 14th ed. 2006. Accessed via web on 2007-02-25.
References
- ↑ 1.0 1.1 Thymol Blue
- ↑ "Thymol blue" (in en). https://pubchem.ncbi.nlm.nih.gov/compound/65565#section=Safety-and-Hazards.
- ↑ "Product Specification: Thymol Blue- ACS reagent". Sigma-Aldrich. 9 October 2017. pp. 1. http://www.sigmaaldrich.com/Graphics/COfAInfo/SigmaSAPQM/SPEC/11/114545/114545-BULK_______SIAL_____.pdf.
- ↑ "Thymol Blue MSDS". https://fscimage.fishersci.com/msds/60620.htm#:~:text=Eye:%20May%20cause%20eye%20irritation,irritation%20of%20the%20digestive%20tract..
- ↑ "Thymol blue" (in en). PubChem. https://pubchem.ncbi.nlm.nih.gov/compound/Thymol_blue#section=GHS-Classification.
External links
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