Chromotropic acid disodium salt dihydrate
[CAS# 5808-22-0]

Identification

• Classification: Chemical reagent >> Organic reagent >> Polycyclic compound
• Name: Chromotropic acid disodium salt dihydrate
• Synonyms: Sodium 4,5-dihydroxy-2,7-naphthalenedisulfonate hydrate (2:1:2)
• Molecular Formula: C₁₀H₈O₈S₂.2(H₂O).₂Na
• Molecular Weight: 400.28
• CAS Registry Number: 5808-22-0
• EC Number: 611-619-6
• SMILES: C1=C2C=C(C=C(C2=C(C=C1S(=O)(=O)[O-])O)O)S(=O)(=O)[O-].O.O.[Na+].[Na+]

Properties

• Density: 780 kg/m³
• Melting point: >300 °C

Safety Data

• Hazard Symbols: GHS07 Warning
• Risk Statements: H315-H319-H335
• Safety Statements: P261-P264-P264+P265-P271-P280-P302+P352-P304+P340-P305+P351+P338-P319-P321-P332+P317-P337+P317-P362+P364-P403+P233-P405-P501

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Specific target organ toxicity - single exposure	STOT SE	3	H335
Skin irritation	Skin Irrit.	2	H315
Eye irritation	Eye Irrit.	2	H319

Discovery and Applications

Chromotropic acid disodium salt dihydrate is an important compound in the field of analytical chemistry and dye chemistry. Its chemical formula is C17H10Na2O7·2H2O, and it is commonly used as a reagent in various chemical analyses due to its unique properties.

The discovery of chromotropic acid dates back to the early 20th century when chemists were developing methods for detecting and quantifying different substances. Chromotropic acid disodium salt dihydrate is a salt form of chromotropic acid, a compound known for its ability to form colored complexes with metal ions. Its role as a reagent was recognized for its effectiveness in colorimetric assays, which are techniques used to measure the concentration of substances based on their color.

One of the primary applications of chromotropic acid disodium salt dihydrate is in the analysis of metals and metal ions. It is particularly useful in the determination of aluminum and other metals in various samples. The compound reacts with metal ions to form colored complexes, which can be quantitatively measured using spectrophotometry. This property makes it an essential tool in environmental monitoring, water quality analysis, and industrial processes where accurate metal determination is crucial.

Chromotropic acid disodium salt dihydrate is also employed in the field of dye chemistry. It is used as a color indicator in the synthesis of dyes and pigments. The compound's ability to form stable and vibrant colored complexes makes it valuable in the development of new colorants for textiles, plastics, and other materials. The colorimetric properties of chromotropic acid derivatives allow for the design of dyes with specific colors and applications, enhancing its importance in the colorant industry.

In addition to its use in metal analysis and dye chemistry, chromotropic acid disodium salt dihydrate finds applications in various research and development areas. It is utilized in chemical synthesis as a reagent to facilitate specific reactions or as a standard in calibration processes. Its versatility in forming colored complexes makes it a useful compound in developing and optimizing analytical methods and materials.

Despite its utility, handling chromotropic acid disodium salt dihydrate requires caution due to its chemical reactivity. Proper safety measures should be followed to avoid exposure and ensure safe usage in laboratory and industrial settings.

In summary, chromotropic acid disodium salt dihydrate is a valuable compound with significant applications in metal analysis, dye chemistry, and various research and development areas. Its ability to form colored complexes makes it an essential reagent in analytical techniques and a useful tool in the development of colorants and other materials.

References

2014. The effect of TiO2, pigmentation on the hydrolysis of amino resin crosslinked epoxy can coatings. Journal of Coatings Technology and Research, 11(6).
DOI: 10.1007/s11998-014-9610-y