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

They are also called naphthol colours from the use of beta-and alpha-naphthol in their production.

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

Among these are thymol, naphthol, oil of eucalyptus, carbolates, and salicylates.

From Scientific American Supplement, No. 561, October 2, 1886 by Various

There are two varieties of naphthol, called alpha- and beta-naphthol, but only one phenol, namely, carbolic acid.

From The Chemistry of Hat Manufacturing Lectures Delivered Before the Hat Manufacturers' Association by Shonk, Albert

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.

The azo-blacks are obtained by combining diazotised sulpho-acids of amidoazo-compounds of the benzene or naphthalene series with naphthol sulpho-acids or other naphthalene derivatives.

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