naphthol

[ naf-thawl, -thol, nap- ]

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.

naphthol

/ 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

naphthol

/ 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.

Word History and Origins

Origin of naphthol¹

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

Word History and Origins

Origin of naphthol¹

C19: from naphtha + -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 Project Gutenberg

The phenols of naphthalene are called naphthols—they bear the same relationship to naphthalene that carbolic acid bears to benzene.

From Project Gutenberg

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

From Project Gutenberg

When this compound is combined with naphthol diazo-azo dyes are produced.

From Project Gutenberg

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

From Project Gutenberg