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 ?
para, lithols, lithol rubines, napthols, quinacridone, red lake C, rhodamine, toluidine): Yellow pigments (diarylide; hansas).
Comments: 1184 Napthol Red 184 has a bluish red hue and offers very good lightfastness and superior chemical resistance for use in paper coatings and especially for use as a process red in water flexo inks and solvent inks.
Comments: 1070 Napthol Red 170 is an improved quality version of our 1370 offering a slightly yellower, cleaner shade with a slight improvement in lightfastness.
13-3722 Permanent Rubine F8B P/C (PR 269 Napthol AS)
Comments: 13-3722 Permanent Rubine F8B P/C (PR 269 Napthol AS) is used for aqueous flexo, textile and flush.
is a medium shade high-performance napthol used for ink and paint applications, and is transparent grade.
Organic pigments include phthalo blues and greens, 2B red, napthols, Red Lake C, and carbazole violet.
Primaries are usually p-phenylenediamines or p-aminophenols while couplers are resorcinols, m-aminophenols, m-phenylenediamines, or napthols.