Engaging DBFO as a C1N1 “two-atom synthon” in [3 + 2] cycloaddition reaction: synthesis of the energetic material 5-azidotetrazolate 1N-oxide

Abstract

We reported an formal [3+2] annulation of dibromoformaloxime (DBFO) and sodium azide for the synthesis of tetrazole-based energetic materials. Several energetic salts were prepared and fully characterized by X-ray diffraction,...

1‐Nitrimino‐5‐azidotetrazole: Extending Energetic Tetrazole Chemistry

“…Similar observations were made recently for the reaction of dibromoformaldoxime with sodium azide. [20] The main goal in the synthesis of 1-ethoxycarbamate-5azidotetrazole was the better and easier accessibility of 1 and 2, respectively. However, we were not successful with the deprotection of 6.…”

“…Therefore, its density is about 0.05 g cm À 3 higher than for guanidinium 5-azidotetrazolate (1 = 1.610 g cm À 3 @298 K). [20] The nitro units of the nitramine groups are offset parallel to the planar guanidinium cations. Each guanidinium cation is saturated by four NAAT À anions, which follows a clear pattern.…”

“…[18] Using this tactic: Combining tetrazole-based explosives with suitable (high N and O content), energy contributing substituents, major research successes have already been achieved (Figure 1). [19][20][21] Groups composed exclusively of nitrogen and oxygen have proved to be particularly attractive for use as substituents. Particularly suitable in this context are covalently bonded azides (only possible as C-substituents at tetrazoles), which, in addition to an energy contribution of 256 kJ mol À 1 , also increase explosion properties and normally adjust sensitivities.…”

Nitrogen-rich ion salts of 1-hydroxytetrazole-5-hydrazide: a new series of energetic compounds that combine good stability and high energy performance

“…11–13 Fortunately, the high acidity brought by the hydroxyl group allows these hydroxytetrazole compounds to easily form high-energy ion salts (HEISs) and high-energy metal–organic frameworks (HEMOFs) to meet the need for energetic compounds in different fields, such as high-energy secondary explosives, primary explosives and high-energy catalysts. 14–18 Among them, the hydroxylamine salt dihydroxylammonium-5,5′-bistetrazolyl-1,1′-diolate (TKX-50) obtained from 1 H ,1′ H -[5,5′-bitetrazole]-1,1′-diol (BTO) shows a combination of characteristics of high energy ( D = 9698 m s −1 , P = 42.4 GPa) and good stability ( T d = 221 °C, IS = 20 J and FS = 120 N) and is a high-energy explosive that is expected to replace CL-20. However, the difficulty in synthesizing TKX-50 and the high risk in the synthesis process are still the key issues to be solved urgently.…”

Salt Formation, to Realize a Good Combination of High Energy and Low Sensitivity of Nitroform-Based Energetic Compounds

“…These characteristics make energetic ionic salts more environmentally and human-friendly than nonsalt energetic compounds. 17,18 Recently, to further realize the environmental friendliness of energetic compounds, a series of heterocyclic azoles have been used to prepare highenergy explosives. 19−25 Among these numerous heterocyclic energetic compounds, nitroform-substituted triazole derivatives are favored by energetic material researchers due to their high crystal density and positive oxygen balance.…”