3-Azido-N-nitro-1H-1,2,4-triazol-5-amine-Based Energetic Salts

Chemical Descriptors for a Large-Scale Study on Drop-Weight Impact Sensitivity of High Explosives

The drop-weight impact test is an experiment that has been used for nearly 80 years to evaluate handling sensitivity of high explosives. Although the results of this test are known to have large statistical uncertainties, it is one of the most common tests due to its accessibility and modest material requirements. In this paper, we compile a large data set of drop-weight impact sensitivity test results (mainly performed at Los Alamos National Laboratory), along with a compendium of molecular and chemical descriptors for the explosives under test. These data consist of over 500 unique explosives, over 1000 repeat tests, and over 100 descriptors, for a total of about 1500 observations. We use random forest methods to estimate a model of explosive handling sensitivity as a function of chemical and molecular properties of the explosives under test. Our model predicts well across a wide range of explosive types, spanning a broad range of explosive performance and sensitivity. We find that properties related to explosive performance, such as heat of explosion, oxygen balance, and functional group, are highly predictive of explosive handling sensitivity. Yet, models that omit many of these properties still perform well. Our results suggest that there is not one or even several factors that explain explosive handling sensitivity, but that there are many complex, interrelated effects at play.

Synthesis and characterization of promising insensitive energetic salts based on 3-amino-5-hydrazinopyrazole

The development of green energetic materials is based on environmental friendliness, safety and performance improvement. It is of great significance to design and synthesize new nitrogen rich salts for a new generation of green energetic materials. In the present work, a series of 3-amino-5-hydrazinopyrazole energetic salts comprising energetic anions were synthesized and were characterized using elemental analysis, IR spectroscopy and differential scanning calorimetry (DSC). Compounds 1-5 were further confirmed by single crystal X-ray diffraction and the sensitivities were measured by the standard BAM methods. Additionally, the structure-property relationship was elucidated from the experimental results and theoretical calculations. Energetic salts of 2 and 5 exhibited high heat of formation (5, 1160.06 kJ mol-1), high decomposition temperature (2, 172 °C; 5, 186 °C), excellent detonation performance (2, Dv, 9076 m s-1, P 34.1 GPa; 5, Dv, 8974 m s-1, P 31.9 GPa), moderate sensitivity towards outer stimuli and high nitrogen contents (2, 41.03%; 5, 63.84%). This work increases future prospects for the design of insensitive and novel high-energy green energetic material.

Amorphous polymerization of nitrogen in compressed cupric azide

Metal azides have attracted increasing attention as precursors for synthesizing polymeric nitrogen. In this article, we report the amorphous polymerization of nitrogen by compressing cupric azide. The ab initio molecular dynamics simulations show that crystalline cupric azide transforms into a disordered network composed of singly bonded nitrogen at a hydrostatic pressure of 40 GPa and room temperature. The transformation manifests the formation of a π delocalization along the disordered Cu-N network, thus resulting in a semiconductor-metal transition. The estimated heat of formation of the amorphous polymeric nitrogen system is comparable to conventional high-energy-density materials. The amorphization provides an alternative route to the polymerization of nitrogen under moderate conditions.

Exploration of low-melting energetic compounds: influence of substituents on melting points

The substituent effect of low melting point compounds reduces sensitivity and improves explosive performance.

A facile synthesis of energetic salts based on fully nitroamino-functionalized [1,2,4]triazolo[4,3-b][1,2,4]triazole

Promising high-energy-density materials: energetic salts based on fully nitroamino-functionalized [1,2,4]triazolo[4,3-b][1,2,4]triazole.

Preparation and characteristics of 1,2,4-oxadiazole-derived energetic ionic salts with nitrogen linkages

A new family of nitrogen-bridged energetic ionic salts were synthesized exhibiting good stabilities and low sensitivities.

Oxygen-rich anion based energetic salts with high detonation performances

Novel energetic salts based on 2,2,2-trinitroethyl nitrocarbamate anion were synthesized, which exhibited promising detonation performances (detonation pressure: 29.4 to 33.1 GPa; detonation velocity: 8213 to 8596 m s⁻¹).

Novel dinitromethyl-featured polynitro energetic salts

An unique and facile method was developed to synthesize a new class of energetic salts based on 2-amino-1,1,5,5-tetranitro-4-oxo-3-aza-pentene (ATNP) anion in one-pot reaction. These salts exhibited promising detonation performances (detonation pressure: 28.6 to 34.3 GPa; detonation velocity: 8037 to 8674 m s⁻¹) which were comparable to those of RDX.

Synthesis and characterization of a new family of energetic salts based on a guanidinium cation containing a picryl moiety

A series of energetic salts based on a guanidinium cation containing a picryl moiety was successfully synthesized and characterized.

Synthesis and characterization of a new family of energetic salts based on guanidinium cation containing furoxanyl functionality

A new family of energetic salts based on a guanidinium cation containing furoxanyl functionality was synthesized and well characterized.

Nitramines with varying sensitivities: functionalized dipyrazolyl-N-nitromethanamines as energetic materials

1,3-Dichloro-2-nitro-2-azapropane is an excellent precursor to dense energetic functionalized dipyrazolyl-N-nitromethanamines. This new family of energetic compounds was fully characterized by using (1)H, (13)C, and (15)N NMR and IR spectroscopy, differential scanning calorimetry, elemental analysis, and impact sensitivity tests. Additionally, single-crystal X-ray structuring was done for 3 and 5·CH3CN, which gave insight into structural characteristics. The experimentally determined densities of 2-9 fall between 1.69 and 1.90 g cm(-3). Heats of formation and detonation properties were calculated by using Gaussian 03 and EXPLO5 programs, respectively. The influence of different energetic moieties on the structural and energetic properties was established theoretically.