/ben"zi deen', -din/, n. Chem.
a grayish, crystalline, slightly water-soluble, basic compound, C12H12N2, usually derived from nitrobenzene: used chiefly in the synthesis of certain azo dyes, esp. Congo red.
[1875-80; BENZ- + -ID3 + -INE2]

* * *

      an organic chemical belonging to the class of amines and used in making numerous dyestuffs. The azo dyes (azo dye) derived from benzidine are important because, unlike simpler classes of azo dyes, they become strongly fixed to cotton without a mordant.

      Benzidine is prepared from nitrobenzene by reduction in alkaline medium to hydrazobenzene (C6H5NHNHC6H5), which is converted to benzidine by treatment with strong acid. This process is the simplest case of a general reaction, the benzidine rearrangement.

      The chemical reactions of benzidine are typical of aromatic primary amines; with nitrous acid it yields the bisdiazonium salt, which may be coupled with aromatic amino or hydroxyl compounds to produce azo dyes.

      Benzidine, a colourless, crystalline solid, practically insoluble in water, is toxic, causing dermatitis and bladder tumours. It is used in forensics for the identification of bloodstains.

* * *

Universalium. 2010.

Игры ⚽ Нужно решить контрольную?

Look at other dictionaries:

  • Benzidine — IUPAC name 4,4 diaminobiphenyl …   Wikipedia

  • Benzidine — structure chimique Général Nom IUPAC 4,4 diaminobiphenyl …   Wikipédia en Français

  • benzidine — ● benzidine nom féminin Diamine aromatique dérivant du biphényle, qui sert à la préparation de colorants (chrysamine, jaune Congo, rouge Congo). benzidine [bɛ̃zidin] n. f. ÉTYM. 1854, Gerhardt, in T. L. F. (art. Benz(o) ); all. benzidin, de… …   Encyclopédie Universelle

  • benzidine — [ben′zə dēn΄] n. [< BENZENE] a white or reddish crystalline organic base, NH2C6H4C6H4NH2, used in the manufacture of dyes …   English World dictionary

  • Benzidine — A compound used mainly for dyeing textiles and paper that is a known human carcinogen (cancer causing agent). Benzidine was one of the first chemicals for which an association of occupational exposure and increased incidence of urinary bladder… …   Medical dictionary

  • benzidine — benzidinas statusas T sritis chemija formulė (H₂NC₆H₄)₂ atitikmenys: angl. benzidine rus. бензидин ryšiai: sinonimas – 4,4ˊ bifenilendiaminas …   Chemijos terminų aiškinamasis žodynas

  • benzidine test — n a test for blood (as in feces) based on its production of a blue color in a solution of benzidine, sodium peroxide, and glacial acetic acid * * * (for occult blood in urine or feces) benzidine, acetic acid, and hydrogen peroxide are added to… …   Medical dictionary

  • benzidine dyes — Congo group Con go group [From {Congo red}.] A group of artificial dyes with an affinity for vegetable fibers, so that no mordant is required. Most of them are azo compounds derived from benzidine or tolidine. Called also {benzidine dyes}.… …   The Collaborative International Dictionary of English

  • benzidine — noun Etymology: International Scientific Vocabulary benz + idine Date: circa 1855 a crystalline diamine base C12H12N2 prepared from nitrobenzene and used especially in making dyes …   New Collegiate Dictionary

  • benzidine — noun The aromatic diamine 4,4 diaminobiphenyl that is used in testing for cyanide, and for traces of blood …   Wiktionary

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”