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

The substance has the characteristic appearance, odor and taste of naphthol.

From Project Gutenberg

This was observed when 6-amino-2-phenylbenzoselenazole was diazotized and coupled with B-naphthol, salicylic acid, etc.

From Project Gutenberg

The compounds formed are brilliant orange dyes, the latter being still largely consumed as “naphthol orange.”

From Project Gutenberg

Their discovery not only increased the consumption of beta-naphthol, but also that of the bases which were used for diazotising.

From Project Gutenberg

It is an amido-derivative of a sulpho-acid of beta-naphthol, so that naphthalene is the generating hydrocarbon of this substance.

From Project Gutenberg