Nitric esters structure

The structure of the nitro group present in nitric esters is the same as that in nitro compounds. 

The reactivity of nitric acid esters and in particular the complicated chemical composition of the products formed by their hydrolysis led some investigators [1, 37] to express the view that nitric esters may have the structure of peroxy-compounds (I) ... 

However there exists no evidence for this. Moreover, investigation of the absorption spectra of nitric acid, nitrous acid and aliphatic nitro compounds indicates that the peroxide structure hypothesis is incorrect, because nitric acid esters behave as compounds having the normal ester structure (II) (Crigee and Schnorrenberg [la], Matsushima [lb]) ... 

X-Ray investigations, electron diffraction, Raman and infra-red spectra, and dipole moment measurements of nitric esters also support the idea of a symmetrical structure for the nitrate group (in spite of certain discrepancies obtained by different authors) ... 

Klason and Carlson were of the opinion that the formation of nitrous acid takes place owing to the peroxy structure of nitric esters, as these, under the influence of a hydrolysing agent, would change their structure and be transformed into peroxy compounds. Simultaneously nitrous acid would be formed ... 

Now since the chemical structure of nitric esters has already been established, this hypothesis has been abandoned. 

PETN differs from other nitric esters in failing to produce a colloid solution with nitrocellulose. This is the result of the symmetrical structure of PETN, which has a zero dipole moment. PETN is completely non-hygroscopic. Its specific gravity in crystalline form is 1.77. On compression the following density values are obtained ... 

Due to its symmetrical structure, pentaerythritol tetranitrate is characterized by high resistance to many reagents. Thus PETN, differing from the majority of nitric esters, is not readily decomposed by sodium sulphide at 50°C. On the other hand, it is decomposed quite quickly by boiling in a ferrous chloride solution. Boiling with a 2.5% solution of sodium hydroxide causes very slow decomposition, whereas nitrocellulose rapidly decomposes under these conditions. 

Epoxides 72 may also act as starting materials for hybrid structures 77 containing an isohexide and a glyceryl moiety, with nitric ester functions at different positions.172 Additional monoethers of isosorbide 2- and 5-nitrate 78 were synthesized by reaction of the free hydroxyl group with any of several alkyl iodides in the presence of freshly prepared silver oxide. The yields were low, as usual.146 Amongst a larger series of different alcohol... 

The most widely used inorganic ester of cellulose is cellulose nitrate (CN), also called nitrocellulose or gun cotton. Celluloid is produced from a mixture of CN and camphor. It was first made in 1833 when cellulose-containing linen, paper, or sawdust was reacted with concentrated nitric acid. It was the first synthetic cellulose product that was recognized. Initially, CN was used as a military explosive and improvements allowed the manufacture of smokeless powder. A representation of CN is given in structure 9.7. 

Stabilizers. Compels which, when added in small amts to other chemical compds or mixts, impart stability to the latter. In propint chemistry, especially so in the case of NC contg powders, the stabilizers employed are compds which, owing to their chemical structure, prevent the acid-catalyzed decompn of NC, NG and similar nitric acid esters... 

Cellulose is esterified with certain inorganic acids such as nitric acid, sulfuric acid, and phosphoric acid. A prerequisite is that the acids used can bring about a strong swelling thus penetrating throughout the cellulose structure. The esterification can be considered as a typical equilibrium reaction in which an alcohol and acid react to form ester and water. Of the inorganic esters cellulose nitrate is the only important commercial product. 

Hyponitrous acid. In contrast to nitrous and nitric acids, hyponitrous acid crystallizes from ether as colourless crystals which easily decompose, explosively if heated. The detailed molecular structure of this acid has not been determined, but it is known that the molecular weights of the free acid and its esters correspond to the double formula, H2N2O2, that it is decomposed by sulphuric acid to N2O, and that it can be reduced to hydrazine, H2N-NH2. Infrared and Raman studies show conclusively that the hyponitrite ion has the trans configuration (a), but the N-N frequency suggests that the central bond has an order of rather less than two. ... 

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