naphthol

American  

[naf-thawl, -thol, nap-] / ˈnæf θɔl, -θɒl, ˈnæp- /

noun

Chemistry.

1. either of two isomeric hydroxyl derivatives, C 1 0 H 7 OH, of naphthalene alpha-naphthol, or 1-naphthol, and beta-naphthol, or 2-naphthol, white or yellowish crystals, with a phenolic odor, that darken on exposure to light: used chiefly in dyes, drugs, perfumes, and insecticides.

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naphthol British  

/ ˈnæfθɒl, ˈnæp- /

noun

1. a white crystalline solid having two isomeric forms, alpha-naphthol, used in dyes, and beta-naphthol, used in dyes and as an antioxidant. Formula: C 10 H 7 OH

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naphthol Scientific  

/ năf′thôl′,-thōl′,năp′- /

1. A poisonous organic compound occurring in two isomeric forms. Both isomers are important in the manufacture of dyes, and also in making antiseptics, insecticides, and tanning agents. Naphthol consists of a hydroxyl group (OH) attached to naphthalene. Chemical formula: C ₁₀ H ₈ O.

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Etymology

Origin of naphthol

First recorded in 1840–50; naphth- + -ol ¹

Example Sentences

Or, with naphthylamine and naphthol, thus:— C10H7N:NCl + C10H7OH + NaOH = NaCl    +    C10H7N:NC10H6OH    +  H2O Naphthalene azo-naphthol.

From The Dyeing of Cotton Fabrics A Practical Handbook for the Dyer and Student by Beech, Franklin

This compound is rendered insoluble when precipitated directly on barytes, by acting on it with an alkaline solution of beta naphthol.

From Paint Technology and Tests by Gardner, Henry A.

Coal Tar.—These soaps contain, in addition to carbolic acid and its homologues, naphthalene and other hydrocarbons derived from coal, naphthol, bases, etc.

From The Handbook of Soap Manufacture by Simmons, W. H.

This was discovered in 1879 by Caro, and introduced as “acid naphthol yellow.”

From Coal and What We Get from It by Meldola, Raphael

Resorcine, like naphthol, is insoluble in water, but it can be dissolved by using either soda ash or caustic soda.

From The Dyeing of Cotton Fabrics A Practical Handbook for the Dyer and Student by Beech, Franklin