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

The most important of the naphthol colours is undoubtedly paranitroaniline red, produced by the combination of paranitroaniline and beta-naphthol.

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

So instead of phenol, other coal tar products such as cresol, naphthol or benzene itself may be used.

From Creative Chemistry Descriptive of Recent Achievements in the Chemical Industries by Slosson, Edwin E.

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.

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