Definition of diazonium in English:

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Pronunciation: /ˌdīəˈzōnēəm/


[as modifier] Chemistry
An organic cation containing the group —2+ bonded to an organic group. Aromatic diazonium compounds are typically intensely colored and include many synthetic dyes.
Example sentences
  • Phenol can be produced from aniline by reacting aniline with a mixture of sodium nitrite and hydrochloric acid to give benzene diazonium chloride, that when heated gently, gives off nitrogen to leave phenol.
  • The manufacture of PY74 would most likely occur through diazotization of 2-amino - 5-nitroanisole to the corresponding diazonium salt and condensation of the diazonium salt with o-acetoacetanisidide.
  • These nitrites then react to form a diazonium salt which in turn reacts with a chromogen to produce the final color.


Late 19th century: coined in German from diazo- (indicating the presence of two nitrogen atoms) + the suffix -onium (from ammonium).

For editors and proofreaders

Syllabification: di·a·zo·ni·um

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