Phenolphthalein

• CAT Number: R045102
• CAS Number: 77-09-8
• Molecular Formula: C20H14O4
• Molecular Weight: 318.32
• Purity: ≥95%
• Synonyms: 3,3-Bis(4-hydroxyphenyl)-1(3H)-isobenzofuranone; 3,3-Bis(4-hydroxyphenyl)phthalide; 3,3-Bis(p-hydroxyphenyl)phthalide; Euchessina; Koprol; Laxogen; Lilo; NSC 10464; NSC 215214; Phthalimetten; Phthalin; Purga; Purgen; Purgophen; Spulmako-lax; TY 9; Tr
• Target: Immunology and Inflammatory Disease Models
• Storage: Store at -20°C
• IUPAC Name: 3,3-bis(4-hydroxyphenyl)-2-benzofuran-1-one
• InChI: InChI=1S/C20H14O4/c21-15-9-5-13(6-10-15)20(14-7-11-16(22)12-8-14)18-4-2-1-3-17(18)19(23)24-20/h1-12,21-22H
• InChIKey: KJFMBFZCATUALV-UHFFFAOYSA-N
• SMILES: C1=CC=C2C(=C1)C(=O)OC2(C3=CC=C(C=C3)O)C4=CC=C(C=C4)O

Phenolphthalein（Cat No.:R045102）is a synthetic organic compound widely used as a pH indicator in acid-base titrations. It appears colorless in acidic solutions and turns pink to deep fuchsia in basic conditions, typically between pH 8.2 and 10. Its sharp color change makes it ideal for laboratory and educational applications. Chemically, it belongs to the class of phthalein dyes, formed through the condensation of phthalic anhydride and phenol. Beyond analytical chemistry, phenolphthalein has been used in forensic science and historically as a laxative, although its medicinal use has declined due to safety concerns.

Reference

1.Lo, Y., and H. M. Lee. "Curing effects on carbonation of concrete using a phenolphthalein indicator and Fourier-transform infrared spectroscopy." Building and environment 37.5 (2002): 507-514.
2.Liu, Zhihong, Faliang Luo, and Tianlu Chen. "Phenolphthalein immobilized membrane for an optical pH sensor." Analytica chimica acta 510.2 (2004): 189-194.