Pyrocatechol Violet is a triphenylmethane-based complexometric indicator dye. It is characterized by its strong color response to changes in pH and interaction with metal ions. It is soluble in water and water-containing alcohol but has limited solubility in cold ethanol and is insoluble in nonpolar organic solvents. Its aqueous solution can display colors ranging from red and yellow to violet depending on the pH. A key chemical property of Pyrocatechol Violet is its capacity to chelate metal ions and form blue to blue-violet complexes. The dye is more stable near neutral pH and becomes less stable under alkaline conditions. These characteristics make the compound important as a colorimetric reagent and complexometric indicator for metal-ion analysis.
CAS No.: 115-41-3
Synonyms: Catechol violet, pyrocatechol sulfonephthalein.
| Physical Properties | |
| Chemical formula | C19H14O7S |
| IUPAC Name | 4-[3-(3,4-dihydroxyphenyl)-1,1-dioxo- 2,1λ6-benzoxathiol-3-yl]benzene-1,2-diol |
| Molecular weight | 386.4 g/mol |
| Solubility | Soluble in water |
| Appearance | Dark green to Dark red to Black powder to crystal. |
| Storage | Store at room temperature |
| Chemical Properties | |
| Color | Yellow to pink |
| Physical State | Solid |
| Melting Point | 170 °C |
| λmax | 444 nm |
| Odor | Odorless |
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| Pictograms : |  |
| Hazard Statements : | H315: Causes skin irritation. H319: Causes serious eye irritation. |
| Precautionary Statements: | P264: Wash thoroughly after handling. P280: Wear protective gloves/protective clothing/eye protection/face protection. P332+P313: If skin irritation occurs: Get medical advice/attention. P337+P313: If eye irritation persists: Get medical advice/attention. P321: Specific treatment (see on this label). P305+P351+P338: IF IN EYES: Rinse cautiously with water for several minutes. Remove contact lenses, if present and easy to do. Continue rinsing. |
Pyrocatechol Violet is a triphenylmethane-based complexometric indicator dye. It is characterized by its strong color response to changes in pH and interaction with metal ions. It is soluble in water and water-containing alcohol but has limited solubility in cold ethanol and is insoluble in nonpolar organic solvents. Its aqueous solution can display colors ranging from red and yellow to violet depending on the pH. A key chemical property of Pyrocatechol Violet is its capacity to chelate metal ions and form blue to blue-violet complexes. The dye is more stable near neutral pH and becomes less stable under alkaline conditions. These characteristics make the compound important as a colorimetric reagent and complexometric indicator for metal-ion analysis.
CAS No.: 115-41-3
Synonyms: Catechol violet, pyrocatechol sulfonephthalein.
| Physical Properties | |
| Chemical formula | C19H14O7S |
| IUPAC Name | 4-[3-(3,4-dihydroxyphenyl)-1,1-dioxo- 2,1λ6-benzoxathiol-3-yl]benzene-1,2-diol |
| Molecular weight | 386.4 g/mol |
| Solubility | Soluble in water |
| Appearance | Dark green to Dark red to Black powder to crystal. |
| Storage | Store at room temperature |
| Chemical Properties | |
| Color | Yellow to pink |
| Physical State | Solid |
| Melting Point | 170 °C |
| λmax | 444 nm |
| Odor | Odorless |
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| Pictograms : | |
| Hazard Statements : | H315: Causes skin irritation. H319: Causes serious eye irritation. |
| Precautionary Statements: | P264: Wash thoroughly after handling. P280: Wear protective gloves/protective clothing/eye protection/face protection. P332+P313: If skin irritation occurs: Get medical advice/attention. P337+P313: If eye irritation persists: Get medical advice/attention. P321: Specific treatment (see on this label). P305+P351+P338: IF IN EYES: Rinse cautiously with water for several minutes. Remove contact lenses, if present and easy to do. Continue rinsing. |
Pyrocatechol Violet is primarily used as a complexometric and colorimetric reagent for metal-ion analysis. It can also serve as a pH indicator and has been investigated in biochemical studies involving protein synthesis.
The color of Pyrocatechol Violet depends on solution conditions and pH. Its aqueous solution may appear yellow between approximately pH 2–7 and shifts toward cyan-purple or violet shades as the pH increases. It can also produce blue to blue-violet complexes after binding certain metal ions.
Pyrocatechol Violet is soluble in water and in alcohol-water mixtures. It is slightly soluble in cold ethanol and essentially insoluble in nonpolar solvents such as ether, benzene, and xylene.
