Diazonium derivatives

Forms diazonium derivative which can be coupled with 2-naphthol or with dimethylaniline to form azo-dyes. 

Diazotisation of the potentially explosive 2-chloro-4,6-dinitroaniline in the third batch of a new process (at a higher than usual concentration in 40% nitrosylsulfuric acid) led to a violent explosion soon after the temperature had been increased to 50°C. Subsequent DSC work showed that the temperature at which thermal decomposition of the diazonium sulfate solution or suspension sets in is inversely proportional to the concentration of amine, falling from 160°C at 0.3 mmol/g to 80°C at 2 mmol/g. Thermal stability of 17 other diazonium derivatives was similarly investigated. 

Anon., CISHC Chem. Safety Summ., 1978, 49, 53 An explosion in a poorly maintained and infrequently cleaned rubber lined vessel used for diazotisation of 2-amino-5-nitrophenol was attributed to decomposition of traces of a diazonium derivative (possibly 4-nitrobenzenediazonium-2-oxide) which had accumulated and dried out on the underside of the lid. 

The procedure for creating the diazonium derivative of p-aminobenzoyl biocytin and coupling to a protein or a nucleic acid is as follows. 

Dilute the diazonium derivative of p-aminobenzoyl biocytin with 0.2 M sodium borate, pH 8.4, to a concentration of 10 pg/ml. 

Insertion of mono- or bis(aryldiazonium) cations into the Re—bonds of the hydride complexes [ReH(CO)5 (PR3)J (PR3 = P(OEt)3, PPh(OEt)2, PPh2(OEt) =1 ) results in the formation of cationic aryldiazene complexes of the compositions [Re(HNNAr)(CO)5 (PR3) ]" or [ Re(CO)5 (PR3) 2(/r-HNNArNNH)] +. " Bifunctional diazene/diazonium derivatives which can be prepared in this way are excellent building blocks for heterobinuclear and heterotrinuclear compounds with bis(aryldiazene) bridging ligands as has been demonstrated for Re-Ru, Re-Os,... 

Several high production products for the dyeing of polyacrylonitrile textile fibres come from the azacarbocyanines class. Example in this class are the azacarbocyanine Basic Yellow 11 (2.27), synthesised from 2,4-dimethoxyaniline (2.26) and Fischer s aldehyde (2.25) the diazacarbocyanine Cl Basic Yellow 28 (2.30), synthesised from the diazonium derivative of (2.29) and Fischer s base (2.28) as shown in Figure 2.16. These dyes, although they are very bright, do tend to suffer from low fasteess to light. 

The formation of bonds to aromatic rings is the foundation of much of organic synthesis. There has been much excitement over the past several years around Pd- or Cu-mediated displacement of an aromatic halide or aryl sulfonate with an amine. Paul Knochel of the University of Munich reports (Angew. Chem. Int. Ed. 2004,43, 897) a complementary approach, the addition of an aryl halide-derived Grignard such as 2 to the diazonium derivative 3. Aryl triflates such as 4 are efficient partners for further coupling. 

Most diazo- and dlazonium compounds are described in this Encyclopedia, either as individual diazocompds or under the corresponding parent compd, such as Benzene Diazo-and Diazonium Derivatives (Vol 2, pp B54-R to B58-L)... 

Benzene diazo- and diazonium derivs 2 B54—B58 chemistry, definition and history 2 B54—B55 benzene diazonium chloride 2 BS5 benzenediazonium hydroxide and derivs 2 B55—BS6... 

Benzene diazo- and diazonium derivs (cont d) benzenediazonium sulfocyanate 2 BS7 benzenediazonium sulfonic acid and derivs 2 B57... 

Diazonium derivs of anilinobenzene see Anilinobenzene diazonium hydroxide and derivs 1 A421... 

Diazonium derivs of azobenzene see Azobenzenediazonium derivs 1 A650... 

---