Diazonium Salts

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diazonium salts

[‚dī·ə′zō·nē·əm ′sȯls]
(organic chemistry)
Compounds of the type R·X·N:N, where R represents an alkyl or aryl group and X represents an anion such as a halide.

Diazonium Salts


organic nitrogenous compounds of the general formula Diazonium Salts (where Ar is an aromatic or heterocyclic radical; X is the residue of a strong acid such as HSO4-, Cl-, or BF4-). Diazonium salts are usually produced by the diazotization reaction: NaNO2 acts on aromatic amines in an excess of strong acid, for example,

Almost all diazonium salts are solids; they are colorless or yellowish and readily soluble in water. They are highly reactive and therefore cannot be stored for long periods in aqueous solutions or as solids. In an acidic medium, diazonium salts break down (slowly in the cold and rapidly upon heating) into oxy compounds, nitrogen, and acid:

In solid form diazonium salts are explosive; they are usually processed in solution or suspension without isolation. Stable diazonium boron fluorides, Diazonium Salts, which are produced by the interaction of an alcohol solution of aromatic amine and fluoboric acid with nitrous acid esters (such as amyl nitrite), are an exception. Stable dry diazonium salts can be produced in the form of double salts (diazoles).

Nitrogen coupling, which is used to produce azo dyes, is the most important reaction of diazonium salts. Other reactions of diazonium salts, such as replacement of the diazo group with hydrogen, halogens, and other substances, are used in technology.


Vorozhtsov, N. N. Osnovy sinteza promezhutochnykh produktov i krasitelei, 4th ed. Moscow, 1955.
Zollinger, H. Khimiia azokrasitelei. Leningrad, 1960. (Translated from German.)


References in periodicals archive ?
In our study, we were interested in grafting tetrafluoroborate 4-methoxybenzene diazonium (C7H7N2O, BF4) on the surface of p-Si-H(111), were selected from aryl salts because of the simplicity of synthesis (reaction Quick and easy chemical in a single step from the corresponding amines [27-32] offering a wide choice of substituents in the para position of the diazonium cation on the aromatic ring (-COOH,-OH,- NO2,-NH2,-Br) the diazonium salts.
The presence of the functions aromatic primary amine is essential for conversion to diazonium salt by a diazotization reaction in acid medium allows the electrochemical grafting of the entity that these functions by reduction of diazonium salts as shown by the work of Finch and BACopyrightlanger [39].
The aromatic diazonium salts, stabilized by resonance, are more stable than aliphatic diazonium salts are very unstable or even non-existent.
The most diazonium salts are used as intermediates in organic synthesis.
The Modification of the hydrogenated silicon surface with aryl diazonium salts is generally carried out by dipping the material in the aqueous medium of aryl diazonium salts with a supporting electrolyte, and then applying a reducing potential of the surface [57].
Pinson, Immobilization of glucose oxidase on a carbon surface derivatized by electrochemical reduction of diazonium salts, J.
SavACopyrightant, Covalent modification of Carbon surfaces by Grafting of Functionalized aryl radicals produced from Electrochemical reduction of Diazonium salts, J.
Podvorica, Sterically Hindered Diazonium Salts for the Grafting of a Monolayer on Metals, J.
BACopyrightlanger, Electrochemical modification of glassy carbon electrode using aromatic diazonium salts.
A modification method for semiconductor surfaces consists in grafting an aromatic group derived from a diazonium salt carrying the said aromatic group.
In 1887, Fischer and Heppe found a method of introduction of the diazonium salt of an aromatic compound by the action of acid nitreux as shown in reaction (1.