{{chembox | verifiedrevid = 400118162 | ImageFile=Indophenol.svg | ImageFile1 = Indophenol-3D-spacefill.png | ImageAlt1 = Indophenol molecule | ImageFile2 = Indophenol.jpg | ImageSize=220 | IUPACName=4-(4-hydroxyphenyl)iminocyclohexa-2,5-dien-1-one | OtherNames=Benzenoneindophenol, phenolindophenol<ref name=b1/> |Section1={{Chembox Identifiers | ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}} | ChemSpiderID = 9951 | InChI = 1/C12H9NO2/c14-11-5-1-9(2-6-11)13-10-3-7-12(15)8-4-10/h1-8,14H | InChIKey = RSAZYXZUJROYKR-UHFFFAOYAS | StdInChI_Ref = {{stdinchicite|correct|chemspider}} | StdInChI = 1S/C12H9NO2/c14-11-5-1-9(2-6-11)13-10-3-7-12(15)8-4-10/h1-8,14H | StdInChIKey_Ref = {{stdinchicite|correct|chemspider}} | StdInChIKey = RSAZYXZUJROYKR-UHFFFAOYSA-N | CASNo_Ref = {{cascite|correct|??}} | CASNo=500-85-6 | UNII_Ref = {{fdacite|correct|FDA}} | UNII = BW444H326B | PubChem=10379 | SMILES = O=C/2/C=C\C(=N\c1ccc(O)cc1)\C=C\2 }} |Section2={{Chembox Properties | C=12 | H=9 | N=1 | O=2 | Appearance=Reddish-blue powder<ref name=b1/> | Density= | MeltingPt= above 300 °C | MeltingPt_ref =<ref name=b1>{{cite book|author=Sabnis, R. W. |title=Handbook of Acid-Base Indicators|url=https://books.google.com/books?id=EzDbTL9Oah0C&pg=PA196|date=2007|publisher=CRC Press|isbn=978-0-8493-8219-2|page=196}}</ref> | BoilingPt= | Solubility= }} |Section3={{Chembox Hazards | MainHazards= | FlashPt= | AutoignitionPt = }} }}
'''Indophenol''' is an organic compound with the formula OC<sub>6</sub>H<sub>4</sub>NC<sub>6</sub>H<sub>4</sub>OH. It is deep blue dye that is the product of the Berthelot's reaction, a common test for ammonia.<ref>{{cite journal|doi=10.1021/ac50011a034|title=Spectrophotometric and kinetics investigation of the Berthelot reaction for the determination of ammonia|journal=Analytical Chemistry|volume=49|issue=3|pages=464–469|year=1977|last1=Patton|first1=Charles J.|last2=Crouch|first2=S. R.}}</ref> The indophenol group, with various substituents in place of O''H'' and various ring substitutions, is found in many dyes used in hair coloring and textiles.<ref>{{cite encyclopedia|author=Horst Berneth|encyclopedia=Ullmann's Encyclopedia of Industrial Chemistry|year=2002|publisher=Wiley-VCH|place=Weinheim|doi=10.1002/14356007.a03_213.pub2|isbn=978-3527306732|chapter=Azine Dyes}}</ref>
Indophenol is used in hair dyes, lubricants, redox materials, liquid crystal displays, fuel cells and chemical-mechanical polishing. It is an environmental pollutant and is toxic to fish.<ref name=b1/><ref>{{Cite web|title=Indophenol I5763|url=https://www.sigmaaldrich.com/catalog/product/sigma/i5763|access-date=2020-06-11|website=500-85-6}}</ref>
==Berthelot test== In the Berthelot test (1859), a sample suspected of containing ammonia is treated with sodium hypochlorite and phenol. The formation of indophenol is used to determine ammonia and paracetamol by spectrophotometry.<ref>{{cite journal|pmid=12400662|year=2002|last1=Tsuboi|first1=T.|title=Sensitivity improvement of ammonia determination based on flow-injection indophenol spectrophotometry with manganese(II) ion as a catalyst and analysis of exhaust gas of thermal power plant|journal=Analytical Sciences |volume=18|issue=10|pages=1141–4|last2=Hirano|first2=Y.|last3=Shibata|first3=Y.|last4=Motomizu|first4=S.}}</ref> Other phenols can be used. Dichlorophenol-indophenol (DCPIP), a form of indophenol, is often used to determine the presence of vitamin C (ascorbic acid).<ref>{{cite journal|doi=10.1002/jps.2600720208|title=Titrimetric Determination of Ascorbic Acid with 2,6-Dichlorophenol Indophenol in Commercial Liquid Diets|journal=Journal of Pharmaceutical Sciences|volume=72|issue=2|pages=126–129|year=1983|last1=Hughes|first1=David Emlyn}}</ref>
==Related compounds== Indophenol blue is a different compound with systematic name ''N-(p-dimethylaminophenyl)-1,4-naphthoquinoneimine''.<ref>{{cite journal|doi=10.1126/science.139.3557.835 |title=Indophenol Blue as a Chromogenic Agent for Identification of Halogenated Aromatic Hydrocarbons |journal=Science |volume=139 |issue=3557 |pages=835–836 |year=1963 |last1=Graham |first1=S. O. |bibcode=1963Sci...139..835G }}</ref> thumb|left|Indophenol blue{{clear-left}}
==References== {{Commons category|Indophenol}} <references/>
Category:Indophenol dyes Category:4-Hydroxyphenyl compounds