Diazotisation and the first azo dyes
Diazotación y primeros tintes azoicos
- Date
- 1858-1863 · confidence medium
- Place
- Marburg, Hesse, Germany
- Credited to
- Peter Griess
- Field
- Matter & energy
What was discovered
In 1858 Griess described the reaction of aromatic amines with nitrous acid to give diazonium salts, which when coupled with phenols or amines yield coloured compounds. It opened the largest family of synthetic dyes: the azo dyes.
Griess discovered diazotisation in Marburg (1858) and the first industrial azo dyes were made by Martius and others in 1863 in Manchester; the milestone date summarises that arc. More than half of today's dyes are azo dyes.
What it led to
- aniline yellow (1861), Bismarck brown (1863) and Congo red (1884)
- cheap dyes in a wide range for cotton and wool
- basis of the BASF, Bayer and Hoechst dye industry