114553

Thymolphthalein

ACS reagent, Dye content 95 %

• Synonym(s): 5′,5′′-Diisopropyl-2′,2′′-dimethylphenolphthalein
• Empirical Formula (Hill Notation): C₂₈H₃₀O₄
• CAS Number: 125-20-2
• Molecular Weight: 430.54
• Beilstein/REAXYS Number: 359413
• EC Number: 204-729-7
• MDL number: MFCD00005909
• UNSPSC Code: 12171500
• PubChem Substance ID: 24847182
• NACRES: NA.47

Properties

• grade: ACS reagent
• Quality Level: 200
• form: solid
• composition: Dye content, 95%
• clarity of soln: passes test
• technique(s): titration: suitable
• visual transition interval: 8.8-10.5, colorless to blue
• mp: 251-253 °C (lit.)
• λmax: 396 nm (2nd); 592 nm
• SMILES string: CC(C)c1cc(c(C)cc1O)C2(OC(=O)c3ccccc23)c4cc(C(C)C)c(O)cc4C
• InChI: 1S/C28H30O4/c1-15(2)20-13-23(17(5)11-25(20)29)28(22-10-8-7-9-19(22)27(31)32-28)24-14-21(16(3)4)26(30)12-18(24)6/h7-16,29-30H,1-6H3
• InChI key: LDKDGDIWEUUXSH-UHFFFAOYSA-N

Description

General description

Thymolphthalein (5′, 5′′-Diisopropyl-2′, 2′′-dimethylphenolphthalein) is an acid-base indicator which is colorless in solutions with a pH below 8.5 and blue in solutions with a pH above 9.5. Thymolphthalein has been used as an indicator in periodate-thiosulfate reaction.[1][2]

Application

Thymolphthalein has been used as a pH indicator[3] in [¹⁴C] urea breath test to determine when the CO₂ trap is full.[4][5][6]

Safety Information

• Storage Class: 11 - Combustible Solids
• wgk_germany: WGK 3
• flash_point_f: Not applicable
• flash_point_c: Not applicable
• ppe: Eyeshields, Gloves, type N95 (US)