Exploring the Maximum Potential of Initiating Ability in Metal-Free Primary Explosives.

Lead azide (LA) is a widely utilized primary explosive, serving as the initiating charge in blasting caps or detonators to start the detonation process of secondary explosives. The toxicity and environmental concerns associated with LA have led to regulatory restrictions and increased scrutiny, prompting the search for lead-free alternatives. LA is highly sensitive toward heat, shock, or friction, which poses safety challenges during manufacturing, handling, and storage.

Tailoring the Energetic Properties of Pyrazole Hybrids through Functionalization with Dinitromethyl and -Hydroxytetrazole.

The functionalization of pyrazole-based compounds with dinitromethyl and -hydroxytetrazole groups resulted in enhanced energetic properties. Two key compounds, 5-(dinitromethyl)-3,4-dinitro-1-pyrazole () and 5-(3,4-dinitro-1-pyrazol-5-yl)-1-tetrazol-1-ol (), along with their salts, were synthesized and evaluated for their energetic properties. Notably, the bishydroxylammonium salts (: 8778 m·s; : 33.

Thinking Outside the Energetic Box: Stabilizing and Greening High-Energy Materials with Reticular Chemistry.

ConspectusReticular chemistry has provided intriguing opportunities for systematically designing porous materials with different pores by adjusting the building blocks. Among them, framework materials have demonstrated outstanding performance for the design of new functional materials used in a broad range of fields, including energetic materials. Energetic materials are widely used for rockets, satellites, mining, and tunneling.

Energetic derivatives substituted with trinitrophenyl: improving the sensitivity of explosives.

The incorporation of trinitrophenyl-modified 1,3,4-oxadiazole fragments is commonly observed in high-energy molecules with heat-resistant properties. This study explores the strategy of developing heat-resistant energetic materials by incorporating trinitrophenyl and an azo group into 1,3,4-oxadiazole, which involved the synthesis and characterization of ()-1,2-bis(5-(2,4,6-trinitrophenyl)-1,3,4-oxadiazol-2-yl)diazene (2), -(5-(2,4,6-trinitrophenyl)-1,3,4-oxadiazol-2-yl)nitramide (3), and the energetic salts of 3. Characterization techniques employed included H and C NMR, IR and elemental analysis.

Understanding the Stability of Highly Nitrated Sensitive Pyrazole Isomers.

Two energetic isomers of chemically unstable 3,5-bis(dinitromethyl)-4-nitro-1-pyrazole (), namely, 4-methyl-3,5-dinitro-1-(trinitromethyl)-1-pyrazole () and 5-methyl-3,4-dinitro-1-(trinitromethyl)-1-pyrazole (), each containing five nitro groups and having the same chemical composition, exhibit major differences in their physiochemical properties. These include density, enthalpy of formation, temperature of decomposition, and sensitivity to impact and friction. Notably, both isomer and isomer demonstrate superior thermal stability compared to isomer , making them promising candidates as safer energetic materials.

Azidomethyl-bisoxadiazol-linked-1,2,3-triazole-(ABT)-based potential liquid propellant and energetic plasticizer.

A scalable synthesis of azidomethyl bisoxadiazol linked-1,2,3-triazole-(ABT) based potential liquid propellant and energetic plasticizer is obtained from commercially available diaminomaleonitrile in excellent yield. Newly synthesized compounds were fully characterized by various spectroscopic techniques. These materials exhibit good densities (1.

Pushing the Limit of Oxygen Balance on a Benzofuroxan Framework: KDNDP as an Extremely Dense and Thermally Stable Material as a Substitute for Lead Azide.

Because of environmental and health impacts, there is an ongoing necessity to develop sustainable primary explosives to replace existing lead-based analogues. Now we describe a potential primary explosive, dipotassium 4,6-dinitro-5,7-dioxidobenzo[c][1,2,5]oxadiazole 1-oxide (KDNDP), which exhibits an excellent thermal stability ( = 281 °C), positive oxygen balance (+4.79%), and a calculated crystal density of ρ = 2.

Host-Guest Technique for Designing Highly Energetic Compounds with the Nitroamino Group.

A new energetic material, 2-azido-4,7-nitroamino-1-imidazo[4,5-]pyridazine () with a highly sensitive azido group and its host-guest compounds (/HO and /HO), and energetic salts were obtained. With the guest and protons in host molecules, an abundant hydrogen bond system can be formed. This results in high crystal density and good sensitivity, which suggests that the host-guest strategy is a promising way to balance the contradiction between energy and sensitivity and provides a new path to obtain a new generation of high energetic materials.

Nitroiminotriazole (NIT) based potential solid propellants: synthesis, characterization, and applications.

Nitroimino (R = N-NO) energetic material is a unique class of high energy density materials (HEDM). Synthesis and characterization of insensitive nitroimino compounds are a major challenge. Here triazole-based nitroimino compounds and their high-nitrogen green energetic salts in excellent yields are described.

A promising perovskite primary explosive.

A primary explosive is an ideal chemical substance for performing ignition in military and commercial applications. For over 150 years, nearly all of the developed primary explosives have suffered from various issues, such as troublesome syntheses, high toxicity, poor stability or/and weak ignition performance. Now we report an interesting example of a primary explosive with double perovskite framework, {(CHN)[Na(NH)(IO)]} (DPPE-1), which was synthesized using a simple green one-pot method in an aqueous solution at room temperature.

Manipulating nitration and stabilization to achieve high energy.

Nitro groups have played a central and decisive role in the development of the most powerful known energetic materials. Highly nitrated compounds are potential oxidizing agents, which could replace the environmentally hazardous used materials such as ammonium perchlorate. The scarcity of azole compounds with a large number of nitro groups is likely due to their inherent thermal instability and the limited number of ring sites available for bond formation.

Pushing the limits of the heat of detonation the construction of polynitro bipyrazole.

The trinitromethyl group is a highly oxidized group that is found as an active functionality in many high-energy-density materials. The most frequently used previous synthetic method for the introduction of the trinitromethyl group is the nitration of heterocyclic compounds containing an acetonyl/ethyl acetate/chloroxime group. Now a novel strategy for constructing a trinitromethyl group (5) nitration of an ethylene bridged compound, dipyrazolo[1,5-:5',1'-]pyrazine (2), is reported.

Polyiodo Azole-Based Metal-Organic Framework Energetic Biocidal Material for Synergetic Sterilization Applications.

Biological hazards caused by bacteria, viruses, and toxins have become a major survival and development issue facing the international community. However, the traditional method of disinfection and sterilization is helpless in dealing with viruses that spread quickly and are highly infectious. Metal-organic framework (MOF) biocidal materials hold promise as superior alternatives to traditional sterilization materials because of their stable framework structures and unique properties.

Energetic performance of trinitromethyl nitrotriazole (TNMNT) and its energetic salts.

Little is known about trinitromethyl nitrotriazole (TNMNT) since the crystal structure, density, energetic performance, and thermal properties have not been determined. A detailed characterization of TNMNT and its hydrazinium and potassium salts and their potential as solid propellants and oxidizers has been established. TNMNT exhibits a high density (1.

Trinitromethyl-triazolone (TNMTO): a highly dense oxidizer.

A scalable synthesis of 5-(trinitromethyl)-2,4-dihydro-3-1,2,4-triazol-3-one () is possible from commercially available 2-methylpyrimidine-4,6-diol. It exhibits high density (1.90 g cm) with comparably low thermal stability ( = 80 °C) and positive oxygen balance (OB = 20.

A Dihydrazone as a Remarkably Nitrogen-Rich Thermostable and Insensitive Energetic Material.

Hydrogen bonds (H-bonds) in energetic compounds have a very pronounced effect on physicochemical properties such as density, thermal stability, sensitivity, and solubility. Now a strategy to synthesize nitrogen-rich energetic materials with overall good properties, which stem from the synergetic effects of inter- or intramolecular H-bonds, is reported. 1,2-Dihydrazono-1,2-di(1-tetrazol-5-5-yl)ethane (), a new thermostable and insensitive material, is obtained from the reaction of dioxime () with hydrazine hydrate.

Design and Synthesis of High-Performance Planar Explosives and Solid Propellants with Tetrazole Moieties.

A straightforward synthetic strategy for newly designed nitrogen-rich planar explosives and solid propellants is reported. These materials exhibit high densities (1.69-1.

Bisnitramide-Bridged -Substituted Tetrazoles with Balanced Sensitivity and High Performance.

In this study, a simple synthetic strategy for bridged bis(nitramide)-based -substituted tetrazoles is described. All new compounds were isolated and fully characterized by sophisticated analytical techniques. The structures of the intermediate derivative and two final compounds were determined by single-crystal X-ray data.

Design and synthesis of phenylene-bridged isoxazole and tetrazole-1-ol based energetic materials of low sensitivity.

A variety of phenylene-bridged isoxazole and tetrazole-1-ol based green energetic materials was synthesized, for the first time, in good to excellent yields. The structures of the newly synthesized compounds were confirmed by spectroscopic techniques, elemental analysis, and single-crystal X-ray analysis. The value of the present work is that all newly synthesized compounds have good thermal stabilities ranging between 167-340 °C and acceptable densities between 1.

Balancing Energy and Stability of Nitroamino-1,2,4-Oxadiazoles through a Planar Bridge.

By integrating two approaches─an ethene bridge to enhance safety and planarity to support good density─we have achieved new high-energy-density materials -. Compounds - show good detonation performance ( = 8037-9305 m s and = 24.7-33.

Size-matched hydrogen bonded hydroxylammonium frameworks for regulation of energetic materials.

Size matching molecular design utilizing host-guest chemistry is a general, promising strategy for seeking new functional materials. With the growing trend of multidisciplinary investigations, taming the metastable high-energy guest moiety in well-matched frameworks is a new pathway leading to innovative energetic materials. Presented is a selective encapsulation in hydrogen-bonded hydroxylammonium frameworks (HHF) by screening different sized nitrogen-rich azoles.

Effects of nitric acid concentration for nitration of fused [1,2,5]oxadiazolo[3,4-]pyrimidine-5,7-diamine.

Nitration reactions are very often used for the selective synthesis of novel, high performing nitramine-based materials. Now nitration reactions of the fused 5,7-diamino pyrimidine derivative 1, under different nitric acid concentrations were examined. Concentrated nitric acid gave selectively -(5-amino-4,5-dihydro-[1,2,5]oxadiazolo[3,4-]pyrimidin-7-yl)nitramide, 2, while the fused ring nitrate salt, 4, and ring open nitrate salt, 3 were obtained using low concentrations of nitric acid (<70%).

Highly Selective Nitroamino Isomerization Guided by Proton Transport Dynamics: Full-Nitroamino Imidazole[4,5-]pyridazine Fused-Ring System.

Due to the advantage of the hydrogen bond system formed by nitroamino isomerization, by the calculations of hydrogen transfer in reported nitroamino explosives, the proton transport dynamics was first proposed to predict the nitroamino isomerization of energetic materials. With the calculated results of zero-point energy, the full-nitroamino fused energetic materials, 2,4-nitroamino-7-nitroimino-1,5-dihydro--imidazolo[4,5-]pyridazine () and 2,2',7,7'-tetranitromino-4,4'-azo-imidazolo[4,5-]pyridazine () were designed and successfully synthesized. The highly selective nitroamino isomerization of neutral compound is shown by X-ray diffraction.

Toward Advanced High-Performance Insensitive FOX-7-like Energetic Materials via Positional Isomerization.

For an energetic molecule with a definite elemental composition, the substituent type and position are the most important factors to influence its detonation performance and mechanical sensitivities. In this work, two pairs of FOX-7-like energetic isomers based on ( and ; and ) were synthesized and characterized. Through positional isomerization, advanced high-performance insensitive explosives were obtained.

Construction of Highly Thermostable and Insensitive Three-Dimensional Energetic Salts Based on [1,2,5]Oxadiazolo[3,4-]pyrimidine.

A novel method for accessing energetic salts of a fused-ring skeleton based on [1,2,5]oxadiazolo[3,4-]pyrimidine and three alkali metals, sodium (Na), potassium (K), and cesium (Cs), was developed. All three compounds were fully characterized, and their structures were confirmed by single-crystal X-ray analysis. They were highly thermally stable (>290 °C) and had high density, good detonation properties, and insensitive properties, which suggested possible heat-resistant explosive applications.