620-45-1

Basic information

• Product Name: 2,6-Dichloroindophenol sodium salt
• Synonyms: 2,6-DICHLOROINDOPHENOL, SODIUM DERIVATIVE;2,6-DICHLOROINDOPHENOL, SODIUM SALT;2,6-DICHLOROPHENALINDEPHENOL SODIUM SALT;2,6-DICHLOROPHENOLINDOPHENOL NA-SALT;2,6-DICHLOROPHENOL-INDOPHENOL SODIUM;2,6-DICHLOROPHENOLINDOPHENOL SODIUM SALT;LABOTEST-BB LT00159816;PHENOLINDO-2,6-DICHLOROPHENOL
• CAS NO: 620-45-1
• Molecular Formula: C₁₂H₆Cl₂NO₂*Na
• Molecular Weight: 290.08
• EINECS: 210-640-4
• Mol File: 620-45-1.mol
• Article Data: 1

Chemical Properties

• Melting Point: >300°C
• Appearance: Dark green/Powder/Solid
• Vapor Density: 11.2 (vs air)
• Storage Temp.: Store at room temperature.
• Water Solubility: Soluble in water.
• Sensitive: Light Sensitive
• Stability: Stable. Incompatible with strong oxidizing agents, strong reducing agents. Air and moisture sensitive. Hygroscopic.
• Merck: 14,3068
• BRN: 3641229
• CAS DataBase Reference: 2,6-Dichloroindophenol sodium salt(CAS DataBase Reference)
• NIST Chemistry Reference: 2,6-Dichloroindophenol sodium salt(620-45-1)
• EPA Substance Registry System: 2,6-Dichloroindophenol sodium salt(620-45-1)

Safety Data

• Hazard Codes: Xi
• Statements: 36/37/38
• Safety Statements: 22-24/25-36-26
• WGK Germany: 3
• RTECS: GU5495000
• F: 8
• TSCA: Yes
• Hazardous Substances Data: 620-45-1(Hazardous Substances Data)

Usage

Chemical Properties

dark green powder

Uses

A redox indicator dye.

Application

2,6-Dichloroindophenol sodium can be used for the determination of ascorbic acid, and redox indicator and chromatographic analysis reagent.

Purification Methods

Dissolve it in 0.001M phosphate buffer, pH 7.5 (alternatively, about 2g of the dye is dissolved in 80mL of M HCl), and extracted into diethyl ether. The extract is washed with water, extracted with aqueous 2% NaHCO3, and the sodium salt of the dye is precipitated by adding NaCl (30g/100mL of NaHCO3 solution), then filtered off, washed with dilute NaCl solution and dried. It has max at 605nm. [Hiromi et al. Anal Biochem 101 421 1980.] The acetate M 310.1 has m 101-103o (from Et2O/pet ether) and 99.5-100.5o (from Et2O). [Beilstein 13 IV 1078-1079.]

InChI:InChI=1/C12H7Cl2NO2.Na/c13-10-5-8(6-11(14)12(10)17)15-7-1-3-9(16)4-2-7;/h1-6,16H;/q;+1/p-1

Upstream product

• 101-38-2 2,6-dichloroquinone-4-chloroimide 
• 2564-83-2 2,2,6,6-Tetramethyl-1-piperidinyloxy free radical 
• 108-95-2 phenol 

Downstream Products

• 122078-53-9 phenolindo-3',5'-dichlorophenyl 2,3,4,6-tetra-O-acetyl-β-D-glucopyranoside 

Relevant articles and documents

Mechanism of the Gibbs reaction. Part 4. Indophenol formation via N- chlorobenzoquinone imine radical anions. The aza-S(RN)2 chain reaction mechanism. Chain initiation with 1,4-benzoquinones and cyanide ion

The mechanism of the Gibbs reaction, a colorimetric phenol assay that applies N-chlorobenzoquinone imines 1 in an aqueous basic medium, was investigated. It is concluded that N-chloroimine radical anion 7 generated in a single electron transfer (SET) from the anion of phenol 4 to N-chloroimine 1 can produce indophenol dye 3 in three distinct routes. For more reactive reagent-substrate pairs, a route is proposed that involves a fast combination of the radical pair in the solvent cage and, consequently, the total rate of which exhibits a pH-independent second-order kinetics, as does the preceding SET itself. For less reactive reagents, a route is proposed in which the N- chloroimine radical anion 7 escapes from the solvent cage to initiate a chain reaction, evidenced by its characteristic kinetics. It has been found in the kinetic experiments that during propagation the chlorine of the chain carrier N-chloroimine radical anion 7 is substituted by the anion of 4 in a bimolecular rate-determining step. Therefore, the mechanism of the chain reaction is termed S(RN)2. In the case when the anion of 4 is less active, a competitive reaction along a third route can proceed in which the N-haloimine radical anion 7 yields benzoquinone imine 6 by the elimination of halogenide and the abstraction of an H-atom from the medium. Compound 6 is also known to give indophenol 3 with a second-order but pH-dependent rate that is considerably faster than the rate in the first route. On the basis of the different kinetic characteristics outlined above a clear distinction can be made among these three pathways. In this paper, evidence is also presented for the initiating SET. Furthermore, it is of high importance that the N- haloimine radical anion 7 can also be generated from reagent 1 using external electron donors and, independently of its origin, it can be spin trapped with 2,2,6,6-tetramethylpiperidine-N-oxyl.