naphthol

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naphthol

(năf`thôl), C10H7OH, either of two crystalline monohydric alcohols. The naphthols are position isomersisomer
, in chemistry, one of two or more compounds having the same molecular formula but different structures (arrangements of atoms in the molecule). Isomerism is the occurrence of such compounds. Isomerism was first recognized by J. J. Berzelius in 1827.
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, differing in the location of the hydroxyl grouphydroxyl group
, in chemistry, functional group that consists of an oxygen atom joined by a single bond to a hydrogen atom. An alcohol is formed when a hydroxyl group is joined by a single bond to an alkyl group or aryl group.
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, -OH, on the carbon skeleton of naphthalenenaphthalene
, colorless, crystalline, solid aromatic hydrocarbon with a pungent odor. It melts at 80°C;, boils at 218°C;, and sublimes upon heating. It is insoluble in water, somewhat soluble in ethanol, soluble in benzene, and very soluble in ether, chloroform, or carbon
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; α-naphthol is 1-hydroxynaphthalene and β-naphthol is 2-hydroxynaphthalene: The naphthols have a number of similar properties. They melt at 95°C; and 122°C; and boil at 279°C; and 285°C;, respectively; both are soluble in alcohol and ether and slightly soluble in hot water. One way in which they differ is the form of their crystals—α-naphthol crystallizes in prisms and β-naphthol in plates. The naphthols are prepared by reacting naphthalene with sulfuric acid and hydrolyzing the resultant sulfate ester by heating it with sodium hydroxide solution. Both naphthols exhibit antiseptic properties. They are used in the synthesis of certain azo dyes and antioxidantsantioxidant,
substance that prevents or slows the breakdown of another substance by oxygen. Synthetic and natural antioxidants are used to slow the deterioration of gasoline and rubber, and such antioxidants as vitamin C (ascorbic acid), butylated hydroxytoluene (BHT), and
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 for rubbers. Naphthol solutions are used in chemical analysis to detect the ferric ion; dissolved ferric ion turns an α-naphthol solution violet and turns a β-naphthol solution green.
References in periodicals archive ?
Types of pigments: Blacks (carbon black, iron oxide dispersions), Blues (phthalo, alkali, Chinese dispersions), Greens (phthalo, chromium oxide dispersions), Iron Oxides (black iron oxide, red, yellow dispersions), Reds (iron oxide, quinacridone, napthol, toluidine), Yellow and Oranges (diansidine, diarylide, iron oxide, acrylide, ferrite, benzimidazolone dispersions), Whites (titanium dioxide dispersions)
Pigments Offered: Blues (phthalocyanine, indanthrone); Greens (phthalocyanine); Reds (metallized azo, monoazo, quinacridone, perylene, BON red, lithol rubine, napthol red, Red Lake C, rhodamine); Yellows and Oranges (metallized azo, diarylide yellow, monoazo, isoindolinone, hansa yellow, diazo/benzimidazolone).
Blacks (carbon black); Blues (indanthron blue, phthalocyanine blue); Greens (phthalocyanine green); Iron oxide pigments (yellow); Reds (BON red, lithol rubine, metallized azo red, napthol red, perylene maroon, perylene red, pigment scarlet, pyrazolone red, qainacridone red, quinacridone violet, red lake C, toluidine red); Yellow and Oranges (Diarylide orange toner, diarylide yellow toner, Hansa yellow, metallized azo yellow, orthonitraniline orange, dinitraniline orange).
Tenders are invited for Cloth Cotton Pugree Napthol Red Mull 81 Cms Wide Mill Made In 21 Meters And Above And Below 50 Meters Multiples Of 4-5 Meters To Is Specn 7119/1973 Reaffirmed With Relexation Of Parameters Colour Fastness To Washing 3 Or Better, Colour Fastness To Rubbing Both Dry And Wet 3 Or Better And Fabric Of Variety No.
Blue pigments (indanthrone, phthalocyanine blue); Green (phthalocyanine green); Red pigments (arylide red/maroon, BON red/maroon, lithol rubine, metallized azo red, napthol, perylene red/maroon, quinacridone red/violet, red lake C, toluidine red); Yellow and orange pigments (diarylide orange/yellow toner, hansa yellow, metallized azo yellow, orthonitraniline dinitraniline).
Pigment Red 2 is a napthol red that exhibits excellent gloss and transparency in both water and solvent systems.
HPPs encompass a wide variety of pigments, including specialty phthalocyanine (blue and green), indanthrone, quinacridone, perylene, DPP, specialty napthol, carbazole violet, benzimidazolone, azo condensations, metal complex pigments and isoindolinone.
This resulted in a rise in the price for naphthalene, which is the building block for tobias acid, beta napthol and BONA.