Naphthalene-2-sulfonic acid
[CAS# 120-18-3]

Identification

• Classification: Organic raw materials >> Hydrocarbon compounds and their derivatives >> Hydrocarbon sulfonate
• Name: Naphthalene-2-sulfonic acid
• Synonyms: 2-Naphthalenesulfonic acid
• Molecular Formula: C₁₀H₈O₃S
• Molecular Weight: 208.23
• CAS Registry Number: 120-18-3
• EC Number: 204-375-3
• SMILES: C1=CC=C2C=C(C=CC2=C1)S(=O)(=O)O

Properties

• Melting Point: 124 ºC

Safety Data

• Hazard Symbols: GHS05;GHS07 Danger
• Hazard Statements: H302-H314-H318
• Precautionary Statements: P260-P264-P264+P265-P270-P280-P301+P317-P301+P330+P331-P302+P361+P354-P304+P340-P305+P351+P338-P305+P354+P338-P316-P317-P321-P330-P337+P317-P363-P405-P501

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Serious eye damage	Eye Dam.	1	H318
Skin corrosion	Skin Corr.	1C	H314
Acute toxicity	Acute Tox.	4	H302
Skin corrosion	Skin Corr.	1B	H314
Skin corrosion	Skin Corr.	1A	H314
Substances or mixtures corrosive to metals	Met. Corr.	1	H290

• Transport Information: UN 2583

Discovory and Applicatios

Naphthalene-2-sulfonic acid is an organic compound that belongs to the class of sulfonic acids, with the molecular formula C10H8O3S. This compound is derived from naphthalene, a polycyclic aromatic hydrocarbon, through the introduction of a sulfonic acid group at the second position of the naphthalene ring. The discovery of naphthalene-2-sulfonic acid dates back to the early developments in the chemical industry, particularly in the 19th century, when sulfonation reactions were widely explored to produce various useful chemicals for dyes and industrial processes.

One of the primary applications of naphthalene-2-sulfonic acid is in the dye industry. It serves as an intermediate in the production of azo dyes, which are widely used in textiles, plastics, and leather. The sulfonic acid group enhances the water solubility of the dyes, improving their applicability in aqueous dyeing processes. The ability of naphthalene-2-sulfonic acid to form strong bonds with fibers has made it an essential component in the synthesis of many direct and reactive dyes.

In addition to its role in the dye industry, naphthalene-2-sulfonic acid is used as a dispersing agent in a variety of industrial applications. It helps to stabilize suspensions and prevent particles from clumping together in formulations such as concrete mixtures, pesticides, and ceramics. This property is particularly valuable in the construction industry, where the compound improves the flow properties of cement, resulting in stronger and more durable concrete.

Naphthalene-2-sulfonic acid also finds use in the synthesis of other organic compounds. It is employed as a chemical intermediate in the production of surfactants, pharmaceuticals, and agricultural chemicals. Its sulfonic acid group makes it reactive in many organic transformations, providing a versatile platform for creating more complex chemical structures.

The environmental impact of naphthalene-2-sulfonic acid and its derivatives has been a subject of research, as the compound is persistent in water systems. Efforts are being made to reduce its environmental footprint through improved waste management and treatment processes.