Rosolic Acid is a synthetic phenolic dye and pH indicator, also known as Aurin or Corallin, with the molecular formula C₁₉H₁₄O₃ and a molecular weight of 290.32 g/mol. It generally appears as a deep red crystalline solid with a metallic luster or as dark greenish-brown flakes. Rosolic Acid is almost insoluble in water but dissolves in alcohol and alkaline solutions, producing characteristic color changes. It shows a reported color transition from yellow to red at approximately pH 5.0–6.8, which makes it useful as a pH indicator in analytical chemistry.
CAS No.: 603-45-2
Synonyms: Aurin, Corallin, p-Rosolic acid.
| Physical Properties | |
| Chemical formula | C19H14O3 |
| IUPAC Name | 4-[Bis(4-hydroxyphenyl)methylidene]cyclohexa-2,5-dien-1-one |
| Molecular weight | 290.318 g/mol |
| Solubility | Insoluble in water, freely soluble in ethanol |
| Ph | 5.0- 6.8, yellow to pink |
| Density | 1.283 g/cm3 |
| Storage | Store at room temperature |
| Chemical Properties | |
| Color | Red-brown to brownish-red |
| Physical State | Solid |
| Melting Point | 308 °C |
| Boiling Point | 542.96 °C |
| λmax | 482 nm |
| Odor | Odorless |
| Pictograms : |  |
| Hazard Statements : | H315: Causes skin irritation. H319: Causes serious eye irritation. H335: May cause respiratory irritation. |
| Precautionary Statements: | P261: Avoid breathing dust/ fume/ gas/ mist/ vapours/ spray. P305 + P351 + P338: IF IN EYES: Rinse cautiously with water for several minutes. Remove contact lenses, if present and easy to do. Continue rinsing. |
Rosolic Acid is a synthetic phenolic dye and pH indicator, also known as Aurin or Corallin, with the molecular formula C₁₉H₁₄O₃ and a molecular weight of 290.32 g/mol. It generally appears as a deep red crystalline solid with a metallic luster or as dark greenish-brown flakes. Rosolic Acid is almost insoluble in water but dissolves in alcohol and alkaline solutions, producing characteristic color changes. It shows a reported color transition from yellow to red at approximately pH 5.0–6.8, which makes it useful as a pH indicator in analytical chemistry.
CAS No.: 603-45-2
Synonyms: Aurin, Corallin, p-Rosolic acid.
| Physical Properties | |
| Chemical formula | C19H14O3 |
| IUPAC Name | 4-[Bis(4-hydroxyphenyl)methylidene]cyclohexa-2,5-dien-1-one |
| Molecular weight | 290.318 g/mol |
| Solubility | Insoluble in water, freely soluble in ethanol |
| Ph | 5.0- 6.8, yellow to pink |
| Density | 1.283 g/cm3 |
| Storage | Store at room temperature |
| Chemical Properties | |
| Color | Red-brown to brownish-red |
| Physical State | Solid |
| Melting Point | 308 °C |
| Boiling Point | 542.96 °C |
| λmax | 482 nm |
| Odor | Odorless |
| Pictograms : | |
| Hazard Statements : | H315: Causes skin irritation. H319: Causes serious eye irritation. H335: May cause respiratory irritation. |
| Precautionary Statements: | P261: Avoid breathing dust/ fume/ gas/ mist/ vapours/ spray. P305 + P351 + P338: IF IN EYES: Rinse cautiously with water for several minutes. Remove contact lenses, if present and easy to do. Continue rinsing. |
Rosolic Acid, also known as Aurin or Corallin, is mainly used as a synthetic organic dye and pH indicator. It is specifically used as a pH indicator in the 5.0–6.8 range and is also used for the selective isolation of coliform bacteria in microbiological studies.
Rosolic Acid has a reported pH transition range of about 5.0–6.8, with a color change from yellow to pink or red.
Rosolic Acid indicator solution can be prepared by dissolving the dye in 90–95% ethanol or a dilute sodium hydroxide solution, depending on the intended application.
