Synthesis of Heat-Resistant and Low-Sensitivity Energetic Materials Based on Hydrazine Bridge Linkage

Abstract

In this work, a combination of vicinal amino–nitro groups and the hydrazine bridge was developed to synthesize two insensitive and heat-resistant energetic compounds 2,2′-hydrazo-bis­(2-amino-3,5-dinitropyridine) (2) and 2,2′-hydrazo-bis­(4-amino-3,5-dinitropyridine) (4) through a simple method. The structures of compound 2 and 4 were adequately characterized by NMR (1H and 13C), elemental analysis, differential scanning calorimetry, and infrared spectroscopy. Notably, compound 2 possesses thermal stability (T d = 350 °C) higher than that of 2-bis­(2,4,6-trinitrophenyl) ethene (HNS) (T d = 318 °C) and comparable to that of 1,3,5-triamino-2,4,6-trinitrobenzene (TATB) (T d = 350 °C). Moreover, compound 2 possess a higher energy level (2: D = 8759 m s–1, P: 34.1 GPa) than HNS (7612 m s–1, P: 24.3 GPa) and TATB (8114 m s–1, P: 31.4 GPa). These consequences indicate that compound 2 has potential applications as an insensitive and heat-resistant explosive.

Constructing layered structure amidine-based pentazolate salts with low sensitivity

“…Generally, the safety performance and stability of high-energy salts depend on multiple factors, including physicochemical properties, molecular structure and crystal packing patterns. 14–21 As indicated in the literature, the reduced sensitivity of cyclo-N 5 − salts could potentially be attributed to the layered stacking patterns and face-to-face π–π interactions between these layers. 8,22–24 The coordination and interaction between molecules might facilitate the dissipation of kinetic energy from external stimuli through interlayer sliding mechanisms, subsequently enhancing stability and reducing sensitivity.…”

3-(3,5-Dinitrophenyl)-5-amino-1,2,4-oxadiazole: synthesis, structure and properties of a novel insensitive energetic material

“…Upon filtering and washing with methanol, 3 (0.257 g, yield 73%) was obtained as a grayish yellow solid. DSC (5 °C min −1 ): 164 °C (m. p.), 320 °C (dec.); 13…”

“…Generally, energetic materials with different properties are used in specific scenarios. [9][10][11][12] For instance, explosives used in exploiting oil and gas wells need to have good thermal stability, usually with a thermal decomposition temperature higher than 250 °C, 13 to ensure their reliability in hightemperature environments. Recently, heat-resistant energetic materials have been one of the hotspots for researchers in the field of energetic materials.…”

“…Upon filtering, washing with cold water and drying in air, 2 (0.594 g, yield 84%) was obtained as a white powder. DSC (5 °C min −1 ): 127 °C (m. p.), 320 °C (dec.);13 C NMR (101 MHz, DMSO-d 6 , 25 °C) δ = 175.17, 166.68, 149.22, 128.11, 127.75, 122.14, 82.73. 1 H NMR (400 MHz, DMSO-d 6 ) δ = 9.06, 9.…”

Elaborating NH-Bridged Nitrogen-Rich Energetic Materials via Base-Mediated Dimroth Rearrangement: Synthesis, Characterization, and Performance Study

“…Considering the outlined strategies, incorporating these building blocks with stabilized amino groups into the molecular structures of various energetic materials emerges as a promising approach to designing state-of-the-art energetic compounds. Moreover, employing diverse energy bridges, such as –NH– or –NHNH–, to interconnect two or more energetic rings enhances thermal stability through σ–π hyperconjugation, facilitated by the lone pair of electrons on a nitrogen atom and N-rich heterocyclic backbone. , Although the existing literature suggests limited exploration of NH-bridged energetic materials, a few reports have been published in this field. , In 2008, Klapötke and co-workers synthesized –NH– bridged energetic material, namely, 5,5′-bis­(1 H -tetrazolyl) amine monohydrate (H 2 bta.H 2 O), through an acid-catalyzed cycloaddition between sodium azide and sodium dicyanamide, as shown in Figure . Unfortunately, achieving its anhydrous form requires the reaction to be subjected to heating at 120 °C under elevated pressure.…”