Resorcinolnaphthalein

• CAT Number: I011004
• CAS Number: 41307-63-5
• Molecular Formula: C24H14O5
• Molecular Weight: 382.36
• Purity: ≥95%
• Synonyms: 3′,6′-dihydroxyspiro[3-oxatricyclo[7.3.1.05,13]trideca-1(12),5,7,9(13),10-pentaene-4,9′-xanthene]-2-one
• IUPAC Name: 3',6'-dihydroxyspiro[3-oxatricyclo[7.3.1.05,13]trideca-1(12),5,7,9(13),10-pentaene-4,9'-xanthene]-2-one
• InChI: InChI=1S/C24H14O5/c25-14-7-9-17-20(11-14)28-21-12-15(26)8-10-18(21)24(17)19-6-2-4-13-3-1-5-16(22(13)19)23(27)29-24/h1-12,25-26H
• InChIKey: FTUOFHGOGJGQAB-UHFFFAOYSA-N
• SMILES: C1=CC2=C3C(=C1)C(=O)OC4(C3=CC=C2)C5=C(C=C(C=C5)O)OC6=C4C=CC(=C6)O

Resorcinolnaphthalein(CAT: I011004) is a synthetic organic dye belonging to the triarylmethane and naphthalein family of colorants. It is widely used as a pH indicator, displaying distinct color changes in acidic and alkaline environments due to its ionizable hydroxyl groups and extended conjugated system. Its strong chromophore properties also make it useful as a tracer dye and analytical reagent in chemical and biochemical studies. Beyond its role in analytical chemistry, Resorcinolnaphthalein is employed in teaching laboratories to demonstrate acid–base equilibria and dye chemistry. Its defined optical characteristics support applications in spectroscopy, titrations, and material science research.