Diazonium Salts


Also found in: Medical.

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.

REFERENCES

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

E. S. LISITSYNA

References in periodicals archive ?
greatly diminished after the grafting of the diazonium salt on the gold
combining the diazonium salt chemistry and the photoiniferter method.
Due to the high efficiency of the azo-coupling reaction, the precursor PAZ was 100% reacted to form the azo polymers (PAZ-ET, PAZ-CN, PAZ-NT, and PAZ-TZ) by using excessive diazonium salts, which was confirmed by the [sup.1]H NMR spectra.
A diazonium salt of 4-aminobenzonitrile was prepared by adding an aqueous solution of sodium nitrite (0.37 g, 5.5 mmol in 3 mL of water) into a solution of 4-aminobenzonitrile (0.54 g, 4.5 mmol) in a homogeneous mixture of 1.3 mL of sulfuric acid and 18 mL of glacial acetic acid.
On the anodic current-voltage curve of iron nanoparticles coated with a layer of carbon and diazonium salts (sample 3), besides a peak (at potential -(0.12 [+ or -] 0.01)), there has been another additional anodic signal at the potential E = (0.45 [+ or -] 0.05) (Figure 2, curve 4) that is obviously related to electric transformations of diazonium salts.
As it was mentioned above, in addition to the development of methods for identifying and quantifying solid-phase iron-based nanoparticles, it is of great interest to study stability of nanoparticles with various coatings (carbon and diazonium salts) in the solution of gastric juice.
Choi, "One-step modification of various electrode surfaces using diazonium salt compounds and the application of this technology to electrochemical DNA (E-DNA) sensors," Electrochimica Acta, vol.
Yranzo, "New application of heterocyclic diazonium salts: synthesis of new pyrazolo[3,4-d][1,2,3]triazin- 4-ones," European Journal of Organic Chemistry, vol.
In order to introduce the conjugated aromatic polymer and carboxylic acid group onto the surface of MWNTs, 4-carboxyphenyl diazonium salts were first synthesized by the diazotization reaction of 4-aminobenzoic acid (5.0 mmol) and sodium nitrite (NaN[O.sub.2], 5.0 mmol) in 0.5 mol HCl solution (10 mL).
Among the commonly used procedures [18], these include the formation of aryl radicals by reduction of diazonium salts. For a decade, This procedure has had remarkable success thanks to its compatibility with variety of functional groups [19] Anodically and in Grignard reagents [20, 21].
Other topics include metal contacts to p- type diamond, structural analysis of detonation nanodiamonds, ternary boron and aluminum carbonitride thin films, aryl diazonium salts for functional diamond platforms, and carbon nanotube growth by DC plasma enhanced CVD.
To the best of our knowledge, the synthesis of 8-hydroxy-4-methyl- 2-phenylpyrido[2',3':4,5]thieno[2,3-d]pyrimidin-6- (5H)-one derivative in a simple single step from 5-cyano-1,6-dihydro-4-methyl-2-phenyl-6-thioxo- pyrimidine 1, which can be coupled with diazonium salts to afford the arylazo-pyrido[2,3:4,5]thieno- [2,3-d]pyrimidines dyes have not yet been reported.