As energetic material

A discussion of nitrimines usage as energetic materials is part of the article entitled Amines Nitrated and Nitrited in Vol 1, A174-R to A178-R... 

Li and co-workers recognised the potential of cyclic IV-nitroureas as energetic materials and reported the synthesis of 2,4,6,8-tetranitro-2,4,6,8-tetraazabicyclo[3.3.0]octane-3-one (109) (K-55) from the nitration of 2,4,6,8-tetraazabicyclo[3.3.0]octane-3-one dihydrochloride (108) with absolute nitric acid in acetic anhydride at room temperature the latter obtained from the condensation of lV,lVL(iiformyl-4,5-dihydroxyimidazolidine (107) with urea in aqueous hydrochloric acid. Pagoria and co-workers " " reported the synthesis of 2,4,6-trinitro-2,4,6,8-tetraazabicyclo[3.3.0]octane-3-one (110) (HK-55) in 72% yield from the nitration of (108) with 90 % nitric acid in acetic anhydride at subambient temperature (Table 5.3). HK-55 has a relatively high density (1.905 g/cm ) coupled with a low sensitivity to shock. 

C. K. Lowe-Ma, R. A. Nissan and W. S. Wilson, Tetrazolo[l,5-a]pyridines and Eurazano[4,5-b]pyridine-l-oxides as Energetic Materials, NWC TP 6985 (1989), Naval Weapons Center, China Lake, CA. 

The essential question that we address in this section is How well can the various types of ab initio and density functional calculations predict heats of formation However an important caveat must be added Our eventual interest will not be in normal, typical molecules, but rather in those metastable ones that show potential as energetic materials. The present discussion will focus upon gas phase AHf we will return later to the conversion to liquid and solid phase values. 

Calculations of polynitrogens larger than N,2 have determined relative energetics and vibrational frequencies of possible isomers, but not activation barriers. Future work should explore the kinetic stabilities of these larger polynitrogens on their potential energy surfaces to validate their possible application as energetic materials. 

Covalently bound and ionic nitronium and nitrosonium oxalate were researched with respect to their potential use as energetic materials or oxidizers for solid rocket motors. None of these compounds can be expected to be a good high explosive. However, the covalent molecule oxalic acid dinitrate ester, 02N—02C—C02—N02, was identified to be a potentially interesting oxidizer. 

Two classes of unsaturated compounds that are of interest in the present context, as energetic materials, are trinitroaromatics and nitroheterocycles, e.g. imidazoles and triazoles. The electrostatic potential on the molecular surface of 1,3,5-trinitrobenzene, 11, which is the parent molecule for the trinitroaromatics that we shall consider, has local maxima above the ring and near each of the C-NO2 bonds [77], This pattern is modified somewhat when other substituents are introduced, but its basic features remain even under the influence of electron-donating groups, e.g. in 2,4-diamino-l,3,5-trinitrobenzene 12, although the maxima are now less positive [76]. The... 

Slurry explosives consist of saturated aqueous solutions of ammonium nitrate with sensitizing additives 1 31. Nitrates such as monomethylamine nitrate, ethylene glycol mononitrate, or ethanolamine mononitrate are used as sensitizers. Aluminum powders are also added as energetic materials. Table 4-19 shows a typical chemical composition of a slurry explosive. It is important to include so-called micro-bubbles in the explosives in order to give the initial detonation and produce the subsequent detonation wave. The micro-bubbles are made of glass or polymeric materials. 

Nitramide, 1, is the simplest possible nitramine and is included for that reason. However 2-5 are of practical interest as energetic materials. 2-4 are known, and efforts are underway to prepare 5. 

Traditionally, tetrazines attract attention as energetic materials in the development of explosives. This year, first members of a new class of electroactive explosives based on nitrate ester-functionalized 1,2,4,5-tetrazines... 

Triazoles are five-membered aromatic heterocycles that contain three nitrogen atoms located at the 1,2,3 or 1,2,4 positions in the ring. A large munber of ionic compounds that contain a triazole derivative are described as energetic materials. 

More recent propellant research has focused on the use of the nitramine explosives RDX and HMX as energetic materials. Like nitrocellulose, these materials will ignite and burn in a controlled manner from a flame stimnlns, and yet detonate when a shock of sufficient energy is applied. RDX (C3H6N6O6, Pyro Valence to COj = +6) and its chemical first-cousin HMX (C4H8N8O8, Pyro Valence to CO2 = -1-8) are both slightly fuel rich to produce carbon dioxide as a reaction product, but are oxygen... 

Ye C, Gard GL, Winter RW, Syvret RG, Twamley B, Shreeve JM (2007) Synthesis of penta-fluorosulfanylpyrazole and pentafluorosulfanyl-1,2,3-triazole and their derivatives as energetic materials by click chemistry. Org Lett 9 3841-3844... 

In 1968, a number of RP-based formulations with alternative non-oxygen-based oxidisers were investigated at Crane Naval Ammunition Depot/USA [27]. Both Mg/HC and Mg/PTFE were tested as energetic materials to vaporise RP. The compositional data and burn rates of consolidate strands at atmospheric pressure are given below. 

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