Combination of 1,2,4‐Oxadiazole and 1,2,5‐Oxadiazole Moieties for the Generation of High‐Performance Energetic Materials

Abstract

Salts generated from linked 1,2,4-oxadiazole/1,2,5-oxadiazole precursors exhibit good to excellent thermal stability, density, and, in some cases, energetic performance. The design of these compounds was based on the assumption that by the combination of varying oxadiazole rings, it would be possible to profit from the positive aspects of each of the components. All of the new compounds were fully characterized by elemental analysis, IR spectroscopy, (1)H, (13)C, and (in some cases) (15)N NMR spectroscopy, and thermal analysis (DSC). The structures of 2-3 and 5-1⋅5 H2O were confirmed by single-crystal X-ray analysis. Theoretical performance calculations were carried out by using Gaussian 03 (Revision D.01). Compound 2-3, with its good density (1.85 g cm(-3)), acceptable sensitivity (14 J, 160 N), and superior detonation pressure (37.4 GPa) and velocity (9046 m s(-1)), exhibits performance properties superior to those of 1,3,5-trinitroperhydro-1,3,5-triazine (RDX).

Five-Membered Ring Systems With O and N Atoms

“…The combination of 1,2,4-oxadiazole and 1,2,5-oxadiazole moieties allowed the synthesis of salts, such as 166, that exhibit good thermal stability, relatively high density, and, in some cases, energetic performance (15AGE9367).…”

Bis(4‐nitraminofurazanyl‐3‐azoxy)azofurazan and Derivatives: 1,2,5‐Oxadiazole Structures and High‐Performance Energetic Materials

“…[2] To design new highperformance energetic materials,i ntroducing energy-rich functional groups such as -NO 2 ,-NHNO 2 ,-N =N-, and -N= N(O)-as substituents on azole frameworks is ar ecently emerging methodology. [4] Among the combinations between functional moiety and azole backbone,the family of nitramino-furazans has gained particular attention because of its high detonation properties. [4] Among the combinations between functional moiety and azole backbone,the family of nitramino-furazans has gained particular attention because of its high detonation properties.…”

“…[5] It can be easily attributed to the presence of al arger number of nitrogen atoms and -C=Nbonds in the two ring systems.Ina ddition, by comparing the heats of formation of the directly coupled furazans (4,4'dinitramino-3,3'-bifurazan), 4,4'-bis(nitramino)azofurazans (DNAF), and 4,4'-bis(nitramino)azoxyfurazans (DNAXF), it is found that azo and azoxy linkages also play an important role in increasing the heat of formation. [6] Given this background, we herein report that 1, as well as ten of its nitrogenrich ionic derivatives (2)(3)(4)(5)(6)(7)(8)(9)(10)(11), were efficiently synthesized and fully characterized (Scheme 1). [6] Given this background, we herein report that 1, as well as ten of its nitrogenrich ionic derivatives (2)(3)(4)(5)(6)(7)(8)(9)(10)(11), were efficiently synthesized and fully characterized (Scheme 1).…”

“…In general, the p delocalization in the furazan ring is the strongest and shows the biggest shielding space.I nc ontrast, the shielding space around the NÀNO 2 groups is much weaker,e specially for the NÀNO 2 group close to the N-oxide in DNAXF ( Figure 1b). Synthesis of bis(4-nitraminofurazanyl-3-azoxy)azofurazan (1)and its energetic salts (2)(3)(4)(5)(6)(7)(8)(9)(10)(11). The electron delocalization of NÀNO 2 groups of DNAF can also be visualized in Figure 1a,but judging by the size,the effect is lower than that of 1.S econd, the trigger bond dissociation enthalpies (TBDE), which are strongly related to the thermal decomposition in 1,w ere also calculated for DNAF and DNAXF as shown in Figure 1.…”

“…Subsequently,aseries of nitrogen-rich energetic salts (2)(3)(4)(5)(6)(7)(8)(9)(10)(11)w ere synthesized and fully characterized. Subsequently,aseries of nitrogen-rich energetic salts (2)(3)(4)(5)(6)(7)(8)(9)(10)(11)w ere synthesized and fully characterized.…”