2,7-Naphthalenedisulfonic acid,4,5-dihydroxy-3-[(2-hydroxy-5-sulfophenyl)azo]-, trisodium salt(CAS: 3270-25-5)

The compound is a trisodium salt of a dianionic dye, with a molecular weight of approximately 713.3 g/mol. It has a crystalline form and is soluble in water, with a solubility of about 20 g/L at 25°C. It is a strong acid and exhibits high reactivity towards bases and certain organic compounds. It is often used in analytical chemistry for its unique spectral properties.

The compound is typically synthesized by the coupling of 4,5-dihydroxy-3-[(2-hydroxy-5-sulfophenyl)azo]-2,7-naphthalenedisulfonic acid with sodium hydroxide. The synthesis involves diazotization and coupling reactions, with sodium carbonate as a common catalyst. High yield and selectivity are achieved under controlled pH and temperature conditions.

This compound is primarily used in the pharmaceutical industry for dyeing and colorimetric assays. It is also utilized in the polymer industry for dyeing and as a pH indicator. Additionally, it finds applications in the semiconductor industry as a dopant and in the production of sensors for detecting specific chemical species.

Proper personal protective equipment (PPE) should be worn when handling this compound, including gloves, goggles, and a lab coat. It should be handled in a fume hood to avoid inhalation and skin contact. Spills should be cleaned up using appropriate absorbent materials and the area should be ventilated. Safety data sheets (SDS) should be consulted for detailed handling and disposal information.