Nitrogen pentoxide nitric anhydride

As is well known, nitrogen pentoxide is a solid, crystalline, colourless product, melting at 30°C. Nitrogen pentoxide was first used as a nitrating agent for the O-nitration of cellulose (Hoitsema [96] Berl and Klaye [97], and others (see Vol. II)). 

Titov [34] suggested in 1941 that nitrogen pentoxide undergoes a heterolytic dissociation  

It is the presence of the nitronium ion that accounts for the nitrating properties of nitrogen pentoxide. 

Ogg [98] studied the heat of dissolution of nitric anhydride is water, and on the basis of the results obtained came to the conclusion that the compound underwent the following reactions (a), (b), (c) and (d)  

The (a) reaction corresponds to the reaction (37). Reaction (c) proceeds slowly as compared with reaction (b), while, on the contrary, reaction (d) is a fast one. 

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

Nitrogen Pentoxid. Nitric anhydrid — NjOj—Molecular weight= m—Fuses at 80° (86° F.)—Foils at 47° (116°.6 F.). 

Nitrogen pentoxide (nitric acid anhydride) N2O5, is hexagonal with a bimolecular unit cell ... 

Salpetersaure. /. nitric acid, -anhydrid, n. nitric anhydride, (di)nitrogen pentoxide, nitrogen(V) oxide, -ather, m. nitric ether (ethyl nitrate), -bad, n. nitric acid bath, -dampf, m. nitric acid vapor or fume. 

Nitrogen pentoxide is an anhydride of nitric acid. It dissolves in water to form nitric acid ... 

Nitrogen trioxide and nitrogen pentoxide are the anhydrides of nitrous acid and of nitric acid. They are difficult to prepare and are unstable. 

Nitrogen pentoxide, NjO-, the anhydride of nitric acid, can be made, as white crystals, by carefully dehydrating nitric acid with phosphorus pentoxide or by oxidizing nitrogen dioxide with ozone. It is unstable, decomposing spontaneously at room temperature into nitrogen dioxide and oxygen. 

Nitration can be effected at low temperatures by mixed acids (sulfuric and nitric) by nitric acid of high concentration by nitric acid and acetic anhydride (acetyl nitrate is formed in such mixtures and they must not be concentrated) and by nitrogen pentoxide in halogenated hydrocarbon solvents with or without the addition of sodium fluoride to complex with the nitric acid formed 129) ... 

The paraffin chain shows high reactivity toward nitric anhydride [4]. The reaction of nitrogen pentoxide (N O ) with paraffins and cyclohexane occurs quickly even at 0 °C in a solution of CCl with the formation mainly of secondary alkyl nitrates and nitro compounds. This reaction is intensified by a very active NO3 radicals resulting from the homolytic dissociation ... 

The A-nitration of the furazan-based heterocycle (29) has been reported. The corresponding tetranitramine (30) is an unstable substance, but obtained on treating (29) with either trifluoroacetic anhydride (TFAA) in nitric acid or dinitrogen pentoxide in nitric acid. In this case the furazan rings stabilize the 1,4,5,8-tetraazadecalin structure and further reduce the basicity of the amidine amino groups. A number of other furazan and nitrogen-rich nitramines... 

The nitrolysis of hexamine is a direct route to the military high explosives 1,3,5-trinitro-1,3,5-triazacyclohexane (RDX) and l,3,5,7-tetranitro-13,5,7-tetraazacyclooctane (HMX). " The direct nitrolysis of hexamine with dinitrogen pentoxide in absolute ifitric acid provides RDX in 57 % yield. RDX prepared by this process is exceptionally pure, but other reagents, like ammonium nitrate-nitric acid-acetic anhydride, give much higher yields, partly because they use ammonium nitrate to supplement for ammonium nitrogen deficiency in the reaction. 

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