Description

2,2'-(1,2-Ethenediyl)Bis[5-[(2,3,4-Trihydroxyphenyl)Azo]Benzenesulfonic Acid] is a high-purity azo dye intermediate and analytical reagent with the CAS registry number 3937-33-5. This compound is valued for its strong chelating properties and distinct chromogenic response to specific metal ions, making it a critical component in precise detection and coloration processes. It is primarily required by manufacturers and R&D laboratories in the chemical synthesis, analytical chemistry, and specialty materials sectors.

Application

• Metal Ion Indicator & Chelating Agent: Used in analytical chemistry for the colorimetric detection and complexometric titration of transition metals like iron, aluminum, and copper.
• Specialty Dye Intermediate: Serves as a key precursor in the synthesis of complex azo dyes and pigments for niche industrial applications.
• Research & Development: Employed in biochemical and environmental research labs for developing novel assays and sensor materials.
• Photometric Analysis: Functions as a chromogenic reagent in spectrophotometric methods for quantitative analysis.
• Catalyst and Ligand Synthesis: Utilized in the preparation of specialized ligands for catalytic systems.

Basic Information

Product Name	2,2'-(1,2-Ethenediyl)Bis[5-[(2,3,4-Trihydroxyphenyl)Azo]Benzenesulfonic Acid]
CAS No.	3937-33-5
Molecular Formula	C26H20N4O12S2
Molecular Weight	644.59 g/mol
Synonyms	Eriochrome Cyanine R; Solochrome Cyanine R; Chrome Cyanine R; Mordant Blue 3; C.I. 43820; NSC 403697; 2,2'-[1,2-Ethenediylbis[(3-sulfo-4,1-phenylene)azo]]bis(1,3,4-benzenetriol); 1,1'-(1,2-Ethenediyl)bis[2-(2,3,4-trihydroxyphenyl)diazenyl]-4-sulfobenzene
EINECS	223-519-7

Quality Control

Our production of 2,2'-(1,2-Ethenediyl)Bis[5-[(2,3,4-Trihydroxyphenyl)Azo]Benzenesulfonic Acid] adheres to stringent quality management protocols. Every batch undergoes comprehensive analytical testing, including HPLC for purity and identity confirmation, to ensure it meets precise specifications for critical applications. A Certificate of Analysis (COA) detailing all test results is provided with each shipment to guarantee traceability and compliance.

Storage

Preserve in a tightly closed container, protected from light. Store in a cool, dry, and well-ventilated area at a controlled room temperature (15-25°C). Keep away from incompatible materials such as strong acids and organic solvents. For long-term stability, maintain the original packaging under these conditions.

Specification

Item	Specification
Appearance	Dark brown to reddish-brown powder
Identification (IR)	Conforms to structure
Assay (HPLC)	≥ 95.0%
Loss on Drying	≤ 2.0%
Residue on Ignition (Sulfated Ash)	≤ 0.5%
Heavy Metals (as Pb)	≤ 20 ppm
Solubility (in Water)	Clear, red solution

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