Novel family of nitrogen-rich energetic (1,2,4-triazolyl) furoxan salts with balanced performance

Abstract

Nitrogen-rich energetic materials comprised of a combination of several heterocyclic subunits retain their leading position in the field of materials science. In this regard, a preparation of novel high-energy materials with balanced set of physicochemical properties is highly desired. Herein, we report the synthesis of a new series of energetic salts incorporating a (1,2,4-triazolyl) furoxan core and complete evaluation of their energetic properties. All target energetic materials were well characterized with IR and multinuclear NMR spectroscopy and elemental analysis, while compound 6 was further characterized by single-crystal X-ray diffraction study. Prepared nitrogen-rich salts have high thermal stability (up to 232°C), good experimental densities (up to 1.80 g cm−3) and high positive enthalpies of formation (344–1,095 kJ mol−1). As a result, synthesized energetic salts have good detonation performance (D = 7.0–8.4 km s−1; p = 22–32 GPa), while their sensitivities to impact and friction are quite low.

Enthalpies of Formation of Bistetrazole Dioxides in the Question: Computer Simulation for the Answer

“…Among nitrogen-rich heterocycles, the tetrazole ring is an attractive scaffold for the design of various energetic materials due to its high thermal stability, good detonation characteristics, and high resistance to various kinds of actions (both of mechanical and chemical nature). − An introduction of the N -oxide motif (or a hydroxyl group in the case of a neutral compound) into the structure of tetrazole salts enables further improvement of the properties of compounds by varying the structure and optimizing the desired characteristics. − In this connection, bistetrazole dioxides and their salts are considered as highly promising energetic materials due to their high enthalpies of formation and, in turn, high detonation characteristics. − Thus, in particular, for dihydroxylammonium bistetrazole 1,1-dioxide (TKX-50, 1b ), the enthalpy of formation was determined to be 107 kcal mol –1 . However, subsequent experimental tests showed that the enthalpy of formation is 50 kcal mol –1 lower than originally estimated. , …”

New energetic 1,2,4‐triazole‐nitrofuroxan hybrids

“…Previously, some interesting biheterocyclic energetic materials incorporating 1,2,4-triazole and furoxan (1,2,5-oxadiazole 2-oxide) motifs bearing cyano and azide functionalities were synthesized (Figure 1A) [17,18]. Despite moderate mechanical sensitivity, these energetic substances contain low amount of oxygen which restricts its potential practicability.…”

First Example of 1,2,5‐Oxadiazole‐Based Hypergolic Ionic Liquids: A New Class of Potential Energetic Fuels

“…Meanwhile, 1,2,5‐oxadiazole (furazan) and 1,2,5‐oxadiazole 2‐oxide (furoxan) scaffolds are valuable building blocks due to their high positive enthalpies of formation and huge nitrogen‐oxygen contents presented within the core. Moreover, the functionalization of the 1,2,5‐oxadiazole backbone enables the preparation of energetic materials with high densities and improved properties [23–34] . Considering these advantages and versatility of the 1,2,5‐oxadiazole ring in the preparation of explosives, we proposed that its incorporation into the structure of ILs would be a promising combination enroute to novel potential high‐performance energetic fuels.…”

“…Moreover, the functionalization of the 1,2,5-oxadiazole backbone enables the preparation of energetic materials with high densities and improved properties. [23][24][25][26][27][28][29][30][31][32][33][34] Considering these advantages and versatility of the 1,2,5-oxadiazole ring in the preparation of explosives, we proposed that its incorporation into the structure of ILs would be a promising combination enroute to novel potential high-performance energetic fuels.…”