How are diazonium salts used to make the bright dyes in clothes?
A primary aromatic amine treated with nitrous acid at low temperature (0–5°C) forms a diazonium salt.
A primary aromatic amine treated with nitrous acid at low temperature (0–5°C) forms a diazonium salt. This reactive intermediate couples with electron-rich aromatics (like phenols or amines) to form azo compounds, which contain the –N=N– group. The extended conjugation of azo dyes absorbs visible light strongly, giving the vivid, fast colours used in textiles.
Key point
Diazonium salts couple with aromatics to form coloured azo (–N=N–) dyes.
Common mistake
thinking diazonium salts are stable at room temperature.
Memory tip
keep diazonium cold (0–5°C), then couple it to make azo dyes.
Tap to watch or see it right here — the app stays open (it only opens a quick search if nothing embeddable is found).