Description

4,4'-Bis[(4-Hydroxyphenyl)Azo]Stilbene-2,2'-Disulphonic Acid is an important organic intermediate and functional dye, characterized by its azo-stilbene structure and disulphonic acid groups. This compound matters for its ability to impart specific optical properties and act as a key building block in the synthesis of more complex molecules. Industries that require high-performance colorants, optical brighteners, or specialized chemical intermediates, such as the dye, textile, and polymer sectors, are the primary users of this product.

Application

• As a key intermediate in the synthesis of direct dyes and reactive dyes for textiles, leather, and paper.
• Utilized in the production of optical brightening agents (OBAs) or fluorescent whitening agents (FWAs) for plastics, detergents, and paper.
• Acts as a functional monomer or additive in the manufacture of specialty polymers and liquid crystal materials.
• Used in research and development for creating novel photochromic or non-linear optical (NLO) materials.
• Potential application as a biological stain or analytical reagent in laboratory settings.
• Serves as a starting material for the synthesis of azo pigments with enhanced lightfastness and thermal stability.

Basic Information

Product Name	4,4'-Bis[(4-Hydroxyphenyl)Azo]Stilbene-2,2'-Disulphonic Acid
CAS No.	91-34-9
Molecular Formula	C26H18N4O8S2
Molecular Weight	578.57 g/mol
Synonyms	4,4'-Bis[(4-hydroxyphenyl)azo]stilbene-2,2'-disulfonic acid; Direct Yellow 11; C.I. 40000; Stilbene Yellow; 4,4'-Dihydroxy-2,2'-stilbenedisulfonic acid bis(azo) derivative; 2,2'-Stilbenedisulfonic acid, 4,4'-bis[(4-hydroxyphenyl)azo]-; 4,4'-[(1E,1'E)-1,2-Ethenediylbis(4,1-phenyleneazo)]bis[phenol]-2,2'-disulfonic acid
EINECS	202-062-9

Quality Control

Our 4,4'-Bis[(4-Hydroxyphenyl)Azo]Stilbene-2,2'-Disulphonic Acid is manufactured under a strict quality management system. Each batch undergoes rigorous analytical testing, including HPLC for purity and identity confirmation, to ensure it meets precise specifications for industrial and research applications. Certificates of Analysis (COA) detailing batch-specific results are available upon request to support your quality assurance protocols.

Storage

Preserve in a tightly closed container, protected from light. Store in a cool, dry, and well-ventilated area at room temperature (15-25°C). Due to its hygroscopic (moisture-sensitive) nature, the container must be kept tightly sealed to prevent absorption of atmospheric moisture, which could affect product performance.

Specification

Item	Specification
Appearance	Orange to reddish-brown powder
Identification (IR)	Conforms to structure
Assay (HPLC)	≥ 95.0%
Loss on Drying	≤ 5.0%
Sulfated Ash	≤ 0.5%
Heavy Metals (as Pb)	≤ 20 ppm
Solubility (1% in NaOH)	Clear, orange solution

Note: Specifications can be tailored. Please contact us for the detailed technical data sheet of a specific grade.