- Dichlorphenolindophenol
Chembox new
Name = DCPIP
ImageFile1 = DCPIP-2D-skeletal.png
ImageSize1 = 150px
ImageFileL2 = Dichlorphenolindophenol-3D-balls.png
ImageSizeL2 = 100px
ImageFileR2 = Dichlorphenolindophenol-3D-vdW.png
ImageSizeR2 = 100px
IUPACName = 2,6-dichlorophenol-indophenol
OtherNames = 2,5-cyclohexadien-1-one;
dichloroindophenol;
2,6-dichloro-4- [(4-hydroxyphenyl)imino] -2,6-dichloroindophenol;
2,6-Dichloro-4-((4-hydroxyphenyl)imino) -2,5-cyclohexadien-1-one
Section1 = Chembox Identifiers
CASNo = 956-48-9
SMILES = O=C(C(Cl)=C2)C(Cl)=C/ C2=NC1=CC=C(O)C=C1
Section2 = Chembox Properties
Formula = C12H7NCl2O2
MolarMass = 268.1 g mol−1
Density =
MeltingPt =
BoilingPt =2,6-dichlorophenolindophenol, ( DCPIP ) is a blue
chemical compound used as a redox dye.Oxidized DCPIP is blue,reduced DCPIP is colorless.The rate of photosynthesis can be measured by the rate at which this dye is broken down (reduced) when exposed to light in a photosynthetic system. This reaction is reversible, as colorless DCPIP can be reoxidized to blue. It is often used in measurements of the
electron transport chain in plants because of its higher [affinity] for electrons thanferredoxin . For example, it is possible to compare rates ofphotosynthesis with DCPIP. Due to the reductions that occur during the light reactions, DCPIP can be substituted forNADPH , the final electron carrier in the light reactions. Thelight reactions will reduce the DPIP and turn it colorless. As DCPIP is reduced and becomes colorless, the following increase in light transmittance can be measured by aspectrophotometer .DCPIP
DCPIP is a redox dye commonly used as a monitor of the
light reactions inphotosynthesis because it is anelectron acceptor that is blue whenoxidized and colorless whenreduced . It is part of theHill reagent s family. DPIP is commonly used as a substitute for NADP+. The dye changescolor when it is reduced, due to itschemical structure . Thenitrogen atom in the center of the molecule is the atom that accepts electrons, and it changes the double N-C bond to a single bond, which forces bonds between carbons in the entire left ring to change. This microscopic shift in the DCPIP structure causes themacroscopic change in color, from dark blue to colorless.The rate of photosynthesis light-dependent reaction can be measured with this property of DCPIP, because one of the stages of the light reaction is an
electron transport chain that normally ends with the reduction of NADP+. When DCPIP is present, it also gets reduced by the light reaction. The amount of DCPIP reduced can be found by measuring the solution'slight transmittance with aspectrophotometer .Using DCPIP to determine the
concentration ofascorbic acid orVitamin C in a solution.DCPIP is commonly used as an indicator for
Vitamin C . If vitamin C, which is a good reducing agent is present , the blue dye, which turns pink in acid conditions and is reduced to a colorless compound by ascorbic acid.:DCPIP (blue) + H+ ----------> DCPIPH (pink):DCPIPH (pink) + VitC ----------> DCPIPH2 (colorless):C6H8O6 + C12H7NCl2O2 ----------> C6H6O6 + C12H9NCl2O2
In a titration, when all the ascorbic acid in the solution has been used up, there will not be any electrons available to reduce the DCPIPH and the solution will remain pink due to the DCPIPH. The end point is a pink color that persists for 10 seconds or more.
ee also
*
Indophenol
*Metachromasy References
* Derek Denby, "Chemistry Review", May 1996
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