Dichlorophenolindophenol

• 2,6-dichloro- N-(4 -hydroxyphenyl) - 1,4- benzoquinone imine, sodium salt
• Dichlorophenolindophenol ( DCPIP, DPIP )
• Dichloroindophenol ( DCIP )
• Tillmans reagent

Dark green solid

Fixed

Soluble in water and ethanol

Attention

Template: Infobox chemical / molecular formula search available

2,6- dichlorophenol indophenol - sodium (sodium salt of 2,6- dichlorophenol indophenol - ) is an indophenol dye. After the German chemist Joseph Tillman, the salt is also called Tillmans reagent.

Properties

The sodium salt of dichlorophenol indophenol is a dark - green solid. Aqueous solutions of the salt are deep blue. In acidic solutions of the dye assumes a red color. Dichlorophenol indophenol itself is not soluble in water and can be, for example, by entering into a heated sodium in the soluble form (sodium salt) are transferred.

Dichlorophenol indophenol is an oxidizing agent and can be used as a redox indicator. The color change occurs by a redox reaction: In the oxidized quinone form is dichlorophenol indophenol - blue and red, respectively, in the reduced - form Aminodiphenol colorless ( leuco dye). The transfer into the leuco can be reached by reducing agents: If you specify to the blue solution of dichlorophenol indophenol - eg, sodium dithionite, then the solution changes color to yellow. This process is reversible with an oxidizing agent ( eg hydrogen peroxide). Also on prolonged standing of the solution with the leuco form in the air it is blue by oxidation with oxygen in the air again. These reversible reactions correspond to the procedures in the vat dyeing ( textile dyeing ).

Use

One application is the quantitative determination of ascorbic acid ( vitamin C). The ascorbic acid is oxidized in the process and in turn the colored dichlorophenol indophenol - solution is reduced and decolorized. Also cholinesterase can be determined. The consumption of the reagent in redox reactions can be determined photometrically. Dichlorophenol indophenol Hill can be used as reagent.