291099

α-Naphtholbenzein

indicator grade

• Synonym(s): 4,4′-(α-Hydroxybenzylidene)di-1-naphthol, p-naphtholbenzein
• Empirical Formula (Hill Notation): C₂₇H₁₈O₂
• CAS Number: 145-50-6
• Molecular Weight: 374.43
• Beilstein/REAXYS Number: 2628063
• EC Number: 205-656-3
• UNSPSC Code: 12171500
• PubChem Substance ID: 24857510
• NACRES: NA.47

Properties

• grade: indicator grade
• form: powder
• color: faintly Faint Brown to Very Dark Brown to Very Dark Red and Black
• pH: 0.0, green; 0.8, yellow; 10.0, blue-green; 8.2, yellow
• mp: 230-235 °C (lit.)
• ε (extinction coefficient): ≥50000 at 207-213 nm in methanol at 0.01 g/L
• application(s): diagnostic assay manufacturing; hematology; histology
• storage temp.: room temp
• SMILES string: Oc1ccc(\C(c2ccccc2)=C3\C=CC(=O)c4ccccc34)c5ccccc15
• InChI: 1S/C27H18O2/c28-25-16-14-23(19-10-4-6-12-21(19)25)27(18-8-2-1-3-9-18)24-15-17-26(29)22-13-7-5-11-20(22)24/h1-17,28H/b27-24-
• InChI key: VDDWRTZCUJCDJM-PNHLSOANSA-N

Description

General description

α-Naphtholbenzein is a dye belonging to the Benzein family insoluble in water and soluble in alcohol. α-Naphtholbenzein is primarily used as an indicator for pH range 8.2-10.0 (mostly in acid-base titrations), causing a color change for the neutral solutions turning alkaline. Its applications include detection of bacterial growth in packed food, viable cells, enzymes, ammonia odors in patients with bacterial infection, and many more.

Application

α-Naphtholbenzein has been used as an indicator during sequential injection analysis technique done for acid-base titrations.

Safety Information

• hcodes: H413
• pcodes: P273 - P501
• Hazard Classifications: Aquatic Chronic 4
• Storage Class: 11 - Combustible Solids
• wgk_germany: WGK 2
• flash_point_f: Not applicable
• flash_point_c: Not applicable
• ppe: dust mask type N95 (US), Eyeshields, Gloves