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.

---

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

---

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.

---

Etymology

Origin of naphthol

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

Example Sentences

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

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

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

Naphthol Yellow is of course a naphthol colour, whilst Vermilline Scarlet is a dye containing both naphthylamine and naphthol.

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

Various additions have been made from time to time to the naphthol bath.

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