Photonitration with nitrogen dioxide

Gorislavets [93] claimed that the nitration of benzene or nitrobenzene with nitrogen dioxide readily occurred on irradiation with rays of certain definite wavelengths, which activate nitrogen dioxide. 

benzene was nitrated quantitatively at the wavelengths 4000 - 7000 A at a temperature of 55-60°C. The highest yield of dinitrobenzene was obtained at wavelengths 1800 - 2900 A. The experiments of other workers did not confirm his results (Hastings and Matsen [94]). 

On the other hand Lippert and Vogel [95] assert that on irradiation with high intensity ultra-violet light nitro compounds undergo dissociation into free radicals  

On the basis of this statement it may be concluded that differences in the results of various authors may be due to the difference in intensity of applied irradiation. 

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Nitration with nitrogen dioxide in the presence of sulphuric acid Nitration with nitrogen dioxide in the presence of Friedcl-Crafts catalysts Nitration with nitrogen dioxide in the presence of activated silica Photonitration with nitrogen dioxide Nitrogen Pentoxide (Nitric anhydride)... 

Phenol transforms in the presence of nitrate and nitrite under UV irradiation. In all cases of oxidation/hydroxylation, nitrosation and nitration products have been detected. The oxidation and hydroxylation of phenol is initiated by reaction with hydroxyl, while nitrosation is probably due to reaction with N2O3. The formation of 2- and 4-nitrophenol from phenol is a consequence of the reaction of the substrate with nitrogen dioxide ( NO2/N2O4), although the details of the mechanism are still uncertain. It is, however, very doubtful that phenol photonitration involves phenoxyl as an intermediate, since nitra-... 

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