Thymolphthalein

(aka it's invisible ink!)
 * Thymolphthalein ** is an [|acid] - [|base] ( [|pH] ) [|indicator] . Its transition range is at approximately [|pH] 9.3-10.5. Below this pH, it is colorless; above this pH, it is [|blue] . The [|molar extinction coefficient] for the blue thymolphthalein [|dianion] is 38000 M -1 cm -1 at 595 nm. [|[1]]
 * **Thymolphthalein** ( [|pH indicator] ) ||
 * //below pH 9.3// ||  || //above pH 10.5// ||
 * **9.3** || ↔ || **10.5** ||

|| [|[show]]  || [|[show]]  ||
 * [|IUPAC name] [|[hide]] 3,3-bis(4-hydroxy-2-methyl- 5-propan-2-ylphenyl)- 2-benzofuran-1-one
 * ~ Identifiers ||
 * [|CAS number] || [|125-20-2]  [[image:http://upload.wikimedia.org/wikipedia/en/thumb/f/fb/Yes_check.svg/7px-Yes_check.svg.png width="7" height="7" caption="Yes"]] ||
 * [|PubChem] || [|31316]  ||
 * [|ChemSpider] || [|29054]  [[image:http://upload.wikimedia.org/wikipedia/en/thumb/f/fb/Yes_check.svg/7px-Yes_check.svg.png width="7" height="7" caption="Yes"]] ||
 * [|EC number] || [|204-729-7]  ||
 * [|ChEMBL] || [|CHEMBL587849]  [[image:http://upload.wikimedia.org/wikipedia/en/thumb/f/fb/Yes_check.svg/7px-Yes_check.svg.png width="7" height="7" caption="Yes"]] ||
 * [|Jmol] -3D images || [|Image 1] ||
 * [|SMILES]
 * [|InChI]
 * ~ Properties ||
 * [|Molecular formula] || C28H30O4 ||
 * [|Molar mass] || 430.53 g/mol ||
 * Appearance || White powder ||
 * [|Melting point] || 248 - 252 °C (decomp.) ||
 * ~ Hazards ||
 * [|R-phrases] || 4, 10 ||
 * [|S-phrases] || [|S22] [|S24/25] ||
 * [|NFPA 704] ||  ||