Nitrogen energetics

The fact that the 3,5-dimethylpyrazol-l-yl moieties of 1,2,4,5-tetrazine 63 are good leaving groups in nucleophilic displacements has been used for the synthesis of azotetrazine 66, a novel high-nitrogen energetic material <00AG(E)1791>. 

Gilardi, 3,3 -Azobis(6-Amino-l,2,4,5-Tetrazine) A Novel High-Nitrogen Energetic Material, Angew. Chem. Int. Ed., 39 (2000) 1791-1793. 

Hiskey, M.A., Goldman, N., Stine, J.R. High-nitrogen energetic materials derived fiorn azotetrazolate. J. Energetic Mater. 16, 119-127 (1998)... 

Apnular tautomerism has been defined as the class of tautomeric rearrangements in which only annular nitrogen or carbon atoms are involved [76AHC(S1), p. 266], In azoles, the latter case is frequently energetically un-... 

Other Uses of Nitric Acid. As mentioned earlier, fuming nitric acid (FNA) when mixed with ale, toluene or acet anhydr will cause an expln. However, there are many other uses for FNA in energetic materials technology. As either red fuming nitric acid (RFNA) or as nitrogen tetrox-ide, it is used extensively as the oxidizer in pro-pint systemsnfor ram-jets, jet motors, space rockets and other missiles (Refs 37, 38 39). See also under Liquid Propellants in Vol 7, L24-Rff... 

Another extremely important application area for FNA and RFNA is to either directly nitrate or be used in mixed acids to nitrate raw materials to yield widely used expls and proplnt ingredients (Refs 29,31,33,38 39). Also see under Nitration in this Vol Analytical. Analysis and assay procedures for nitric acid may be found in Refs 1, 2,10,11,15, 17, 27, 29, 34, 35, and in this Vol under Nitrogen Determinations in Energetic Materials. 

The quantitative detn of combined nitrogen in energetic materials is of the greatest interest... 

Nitrogen tetroxide is formed as an undesirable product in several instances, eg, during the storage of some energetic materials, particularly NC, NG and mixts contg them, such as propints and Dynamite. In these Ihe nitric esters decomp at elevated temps. In some cases, even such stable nitrocompds as TNT can begin to evolve N02 when stored at higher than ambient temps. 

L34-R to L44-R Hypergolic Propellants in Vol 7, H254-L to H259-R Nitrogen Determination in Energetic Materials, and Mass Spectrometry in this Vol... 

Nonaqueous Titration Methods. See under Nitrogen Determination in Energetic Materials in this Vol... 

Simple mechanistic considerations easily explain why heterolytic dissociation of the C — N bond in a diazonium ion is likely to occur, as a nitrogen molecule is already preformed in a diazonium ion. On the other hand, homolytic dissociation of the C —N bond is very unlikely from an energetic point of view. In heterolysis N2, a very stable product, is formed in addition to the aryl cation (8.1), which is a metastable intermediate, whereas in homolysis two metastable primary products, the aryl radical (8.2) and the dinitrogen radical cation (8.3) would be formed. This event is unlikely indeed, and as discussed in Section 8.6, homolytic dediazoniation does not proceed by simple homolysis of a diazonium ion. 

The reaction with nitrite proceeds smoothly and with relatively high yields of the corresponding nitroarene (see Sec. 10.6). Obviously a major part of the driving force of this reaction is the formation of a stable, i. e., an energetically favorable, radical, nitrogen dioxide. With the hydroxide ion — a much stronger nucleophile than the nitrite ion — the reaction is expected to produce very unstable radicals, the hydroxy radical OH and the oxygen radical anion O, from the diazohydroxide (Ar - N2 — OH) and the diazoate (Ar-N20 ) respectively. Consequently, dediazoniation in alkaline aqueous solution does not follow the simple Scheme 8-41 with Yn = OH, but instead involves diazoanhydrides (Ar — N2 —O —N2 —Ar) as intermediates (see Sec. 8.8). 

This equation says that a nitrogen nucleus is composed of seven protons and seven neutrons. An alpha particle, which is identical to a helium ion, has two protons and two neutrons. A highly energetic collision fuses the two nuclei. The result is a rare isotope of oxygen with eight protons and nine neutrons. The leftover proton is ejected. And that proton is what Rutherford detected. 

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