5‐Amino‐3,4‐dinitropyrazole as a Promising Energetic Material

Abstract

The nitrogen‐rich energetic compound 5‐amino‐3,4‐dinitropyrazole (5‐ADP) was investigated using complementary experimental techniques. X‐ray diffraction indicates the strong intermolecular hydrogen bonding in 5‐ADP crystals. Compound exhibits low impact sensitivity (23 J) and insensitivity to friction. The activation energy of thermolysis determined to be 230±5 kJ mol−1 from DSC measurements. Accelerating rate calorimetry indicates the lower thermal stability (173 °C) of 5‐ADP than that of RDX, which is probably the main concern about using this compound. 5‐ADP also exhibits good compatibility with common energetic materials (viz. TNT, RDX, ammonium perchlorate), including an active binder. The burning rate of 5‐ADP monopropellant is higher than that of benchmark HMX, while the pressure exponent 0.51±0.04 is surprisingly low. Addition of ammonium perchlorate does not affect the pressure exponent of 5‐ADP, while the burning rate increases. The 5‐amino‐3,4‐dinitropyrazole exhibits a notable combination of combustion performance, low sensitivity, and good compatibility, which renders it as a promising energetic material.

Autocatalytic decomposition of energetic materials: interplay of theory and thermal analysis in the study of 5-amino-3,4-dinitropyrazole thermolysis

“…26,27 This energetic compound combines both the benefits of the polynitro derivatives of pyrazole (i.e., high formation enthalpy, thermal stability, and moderate sensitivity towards mechanical stimuli) 26,[28][29][30][31][32][33][34][35] and facile synthetic procedures of the introduction of amino group in the molecule bearing nitro groups. 36,37 E.g., the structural isomer of 5-ADP, namely, 4-amino-3,5-dinitro-1H-pyrazole (4-ADP, LLM-116) is a very promising insensitive explosive. [34][35][36] At the same time, the former species is more thermally stable and has even lower impact sensitivity.…”

“…36,37 E.g., the structural isomer of 5-ADP, namely, 4-amino-3,5-dinitro-1H-pyrazole (4-ADP, LLM-116) is a very promising insensitive explosive. [34][35][36] At the same time, the former species is more thermally stable and has even lower impact sensitivity. However, the thermal stability and the thermolysis mechanism of 5-ADP remain almost entirely unknown.…”

Comprehensive Study of the Interaction and Mechanism between Bistetrazole Ionic Salt and Ammonium Nitrate Explosive in Thermal Decomposition

“…TKX-50 and ABTOX were prepared according to the method described by Klapoẗke et al and then crystallized from the mother solution, isolated by suction filtration, and air dried. 5 The obtained samples were refined to >99% purity and characterized by 1 H and 13 C NMR spectroscopy.…”

“…Ever-changing weapon platforms have spurred the development of new robust explosives with high energy and low sensitivity, which has become an important area in the field of energetic materials. − Tetrazole-based compounds, such as bistetrazole and its derivatives, is a new class of insensitive energetic materials, triggering extensive research because of their high density, high enthalpy of formation, large ring tension, and good stability. − In 2012, Fischer et al synthesized a series of bistetrazole energetic salts bereft of typical nitro-detonating groups . Among the energetic ionic salts examined, dihydroxylammonium 5,5′-bistetrazole-1,1′-diolate (TKX-50) and diamino 5,5′-bistetrazole-1,1′-diolate (ABTOX) displayed optimal performance, with densities of 1.88 and 1.80 g cm –3 , theory of detonation velocities of 9698 and 8817 m s –1 , and decomposition peak temperatures of 525 and 565 K (heating rate of 5 K min –1 ), respectively.…”

Selecting Suitable Substituents for Energetic Materials Based on a Fused Triazolo-[1,2,4,5]tetrazine Ring

“…In addition to the selection of an appropriate energetic substituent(s), the formation of strong hydrogen bonds (HBs) is also a good approach to obtain compounds with high density and low sensitivity. 16 Typical energetic materials, like 1,3,5triamino-2,4,6-trinitrobenzene (TATB), 2,6-diamino-3,5-dinitropyrazine-1-oxide (LLM-105), 17 and 2,2-dinitroethylene-1,1diamino (FOX-7), 18 possess many NH 2 and NO 2 groups which are available to form strong HBs. These HBs not only reduce sensitivity but also help to form closer packing giving rise to higher density.…”