Bromocresol Green is a dye from the triphenylmethane family that belongs to the sulfonephthaleins class. In an aqueous solution, it oxidizes to form a yellow monoanionic form and a blue dianionic form at higher pH levels. It exhibits an isosbestic point at 515 nm in its UV-visible spectrum, where both forms have the same absorbance. Further, it is synthesized by brominating Cresol Purple.
CAS No.: 76-60-8
Synonyms: Bromocresolgreen; Tetrabromo-m-cresolphthalein sulfone; 3′,3”,5′,5”-Tetrabromo-m-cresolsulfonephthalein; 3,3 -B is(3,5-dibromo-4-hydroxy-2-methylpheny)-3H-benzo[c][1,2]oxathiole 1,1-dioxide
| Physical Properties | |
| Chemical formula | C21H14Br4O5S |
| IUPAC Name | 3,3-Bis(3,5-dibromo-4-hydroxy-2-methylphenyl)-2,1λ6-benzoxathiole-1,1(3H)-dione |
| Molecular weight | 698.0 g/mol |
| Solubility | Soluble in Water, Benzene, Ethanol and Diethyl ether |
| Flash Point | 332.4±31.5 °C |
| Density | 2.1±0.1 g/cm³ |
| Chemical Properties | |
| Colour | Yellow-green to Blue-green |
| State | Crystalline powder |
| Melting point | 217 – 218 °C |
| LogP | 4.90 |
| Loss on drying (110°C) | NMT 3.0% |
| Pictograms : |
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| Hazard Statements : | H225: Highly flammable liquid and vapor. |
| Precautionary statements : | P210: Keep away from heat, hot surfaces, sparks, open flames, and other ignition sources. No smoking. |
Bromocresol Green is a dye from the triphenylmethane family that belongs to the sulfonephthaleins class. In an aqueous solution, it oxidizes to form a yellow monoanionic form and a blue dianionic form at higher pH levels. It exhibits an isosbestic point at 515 nm in its UV-visible spectrum, where both forms have the same absorbance. Further, it is synthesized by brominating Cresol Purple.
CAS No.: 76-60-8
Synonyms: Bromocresolgreen; Tetrabromo-m-cresolphthalein sulfone; 3′,3”,5′,5”-Tetrabromo-m-cresolsulfonephthalein; 3,3 -B is(3,5-dibromo-4-hydroxy-2-methylpheny)-3H-benzo[c][1,2]oxathiole 1,1-dioxide
| Physical Properties | |
| Chemical formula | C21H14Br4O5S |
| IUPAC Name | 3,3-Bis(3,5-dibromo-4-hydroxy-2-methylphenyl)-2,1λ6-benzoxathiole-1,1(3H)-dione |
| Molecular weight | 698.0 g/mol |
| Solubility | Soluble in Water, Benzene, Ethanol and Diethyl ether |
| Flash Point | 332.4±31.5 °C |
| Density | 2.1±0.1 g/cm³ |
| Chemical Properties | |
| Colour | Yellow-green to Blue-green |
| State | Crystalline powder |
| Melting point | 217 – 218 °C |
| LogP | 4.90 |
| Loss on drying (110°C) | NMT 3.0% |
| Pictograms : |
|
| Hazard Statements : | H225: Highly flammable liquid and vapor. |
| Precautionary statements : | P210: Keep away from heat, hot surfaces, sparks, open flames, and other ignition sources. No smoking. |
Bromocresol Green functions as a pH indicator by changing color based on the acidity or basicity of a solution. It turns yellow in acidic conditions and blue in basic conditions.
Dissolve Bromocresol Green dye in distilled water to a 0.04% concentration. Adjust the pH to the appropriate level, Stir well and store in a sealed container.
Bromocresol Green is a weak acid. It has a pKa of about 4.8, meaning it partially dissociates in solution.
Bromocresol Green changes color around a pH range of 3.8 to 5.4. Below pH 3.8, it appears yellow, and above pH 5.4, it turns blue.
Bromocresol Green is used in a dye-binding procedure to evaluate albumin levels in blood. It makes a complex with albumin, and the color intensity of the complex associates with the albumin concentration, which is then calculated using spectrophotometry.
