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

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 process of dyeing cotton with a naphthol colour takes place in two stages, the first being the grounding or preparing with the naphthol, the second the developing with the diazotised base.

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

It is, chemically speaking, dinitro-alpha-naphthol; but it was not at first made from naphthol, as the latter was not at the time a technical product.

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

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

Alpha-Naphthylamine Claret.—This is a very fine and fairly fast red, and next to the paranitroaniline red may be considered the most important of the naphthol colours.

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