Studies of Novel Heterocyclic Insensitive High Explosive Compounds: Pyridines, Pyrimidines, Pyrazines and Their Bicyclic Analogues

Abstract

The rationale behind using heterocyclic compounds [1], particularly nitrogen heterocycles, as higher energy insensitive high explosives is discussed, including the potential advantages compared with carbocyclic compounds. The types of functional groups used to impart energy to heterocyclic nuclei, whilst maintaining insensitivity, and methodologies for their introduction, are covered. The latter include nitration (by conventional and clean synthetic methods), amination, and oxidation (on ring heteroatoms and of exocyclic amino groups). Strategies for maximising the energetic content of a given heterocyclic nucleus are also examined. The syntheses of specific examples at QinetiQ are described, based on the following nuclei: pyridine, pyrimidine, pyrazine, quinoxaline, quinazoline, pteridine and purine. Strategies for obtaining the desired amino-nitro derivatives and their heterocyclic N-oxides are outlined. Optimisation of the synthetic routes for several candidates is discussed. The physical, explosive and thermal properties of the more successful candidates are described, with suggestions for their potential application in military stores.

A DFT theoretical study of heats of formation and detonation properties of nitrogen-rich explosives

“…One promising approach to overcoming that challenge is to explore new energetic compounds with increased nitrogen content, which is the direction pursued by many recent research and development efforts, as reviewed in Refs. [1][2][3][4]. The characteristic feature of such high-nitrogen compounds is that, in contrast to traditional energetic molecules, their energy content comes primarily from the high heats of formation due to the large number of energetic N-N and C-N, rather than from the overall heat of combustion (oxidation of carbon backbone).…”

Review on Promising Insensitive Energetic Materials

“…The use of nitro compounds of different heterocycles such as pyridines, pyrimidines, pyrazines and their bicyclic analogues had been reported as insensitive explosives by Millar and coworkers [56]. Molecular modelling studies indicated that ANPZ-i would have a similar performance to RDX, with an anticipated greater insensitivity.…”

Thermal hazard assessment of 4,10-dinitro-2,6,8,12-tetraoxa-4,10-diazaisowutrzitane (TEX) by accelerating rate calorimeter (ARC)

“…Currently, explosives with superior detonation characteristics and/or decreased sensitivity to exterior stimuli [1][2][3][4][5][6][7][8][9][10][11][12] are of great concern. 4,10-dinitro-2,6,8,12-tetraoxa-4,10-diazaisowutrzitane, also called as TEX (Fig.…”