Among energetic materials, there are two significant challenges facing researchers: 1) to develop ionic CHNO explosives with higher densities than their parent nonionic molecules and (2) to achieve a fine balance between high detonation performance and low sensitivity. We report a surprising energetic salt, hydroxylammonium 3-dinitromethanide-1,2,4-triazolone, that exhibits exceptional properties, viz., higher density, superior detonation performance, and improved thermal, impact, and friction stabilities, then those of its precursor, 3-dinitromethyl-1,2,4-triazolone. The solid-state structure features of the new energetic salt were investigated with X-ray diffraction which showed π-stacking and hydrogen-bonding interactions that contribute to closer packing and higher density. According to the experimental results and theoretical analysis, the newly designed energetic salt also gives rise to a workable compromise in high detonation properties and desirable stabilities. These findings will enhance the future prospects for rational energetic materials design and commence a new chapter in this field.

Considerable work has been focused on developing replacements for ammonium perchlorate (AP), a primary choice for solid rocket and missile propellants, due to environmental concerns resulting from the release of perchlorate into groundwater systems [corrected]. Additionally, the generation of hydrochloric acid contributes to high concentrations of acid rain and to ozone layer depletion. En route to synthesizing salts that contain cationic FOX-7, a novel, high oxygen-containing oxidizer, tetranitroacetimidic acid (TNAA), has been synthesized and fully characterized. The properties of TNAA were found to be exceptional, with a calculated specific impulse exceeding that of AP, leading to its high potential as a replacement for AP. TNAA can be synthesized easily in a one-step process by the nitration of FOX-7 in high yield (>93%). The synthesis, properties, and chemical reactivity of TNAA have been examined.

The syntheses and full characterization of two new halogenated 1,1-diamino-2,2-dinitroethene (FOX-7) compounds and three halogenated azo-bridged FOX-7 derivatives are described. Some of these new structures demonstrate properties that approach those of the commonly used secondary explosive RDX (cyclo-1,3,5-trimethylene-2,4,6-trinitramine). All the compounds display hypergolic properties with common hydrazine-based fuels and primary aliphatic amines (ignition delay times of 2-53 ms). This is a new role that has yet to be reported for FOX-7 and its derivatives. Their physical and energetic properties have been investigated. All compounds were characterized by single-crystal X-ray crystallography, elemental analysis, infrared spectra, and differential scanning calorimetry. These new molecules as energetic materials and hypergolic oxidizers contribute to the expansion of the chemistry of FOX-7.

Synthesis, characterization, and thermolysis studies of 1-amino-1-hydrazino-2,2-dinitroethene (2) and salts thereof are reported. These compounds have been fully characterized by IR and NMR spectroscopy, elemental analysis, differential scanning calorimetry (DSC), density, and impact sensitivity measurements. Compound 2 decomposes at 124.5 °C (DSC) and the salts decompose over the range 138.6-181.6 °C, thus showing higher thermostability. The calculated detonation pressures (P) for these salts range from 27.2 to 37.8 GPa, and detonation velocities (vD) fall between 8424 to 9482 m s(-1); these properties make them competitive energetic materials.

1,1-Diamino-2,2-dinitroethene (FOX-7) reacts readily with copper nitrate in an aqueous solution of potassium hydroxide to form pea green Cu(FOX)(2)(H(2)O)(2) (5). FOX-7 complexes of copper and nickel supported by a variety of diamines including Cu(en)(2)(FOX)(2)(H(2)O) (1), Cu(pn)(2)(FOX)(2) (2), Cu(bipy)(FOX)(2)(H(2)O)(4) (3a), Cu(bipy)(2)(FOX)(2)(H(2)O)(2.5) (3b), Cu(bipy)(FOX)(2)(DMSO)(2)·2DMSO (3c), Cu(phen)(3)(FOX)(2)(H(2)O)(3) (4), (Ni)(2)(phen)(6)(FOX)(4)(NO(3))(3)(H(2)O)(2) (6), and Ni(bipy)(3)(FOX)(2)(H(2)O)(4) (7a) were obtained via metathesis reactions with potassium-FOX (K-FOX). Surprisingly FOX-7, in the presence of Ni(II) and bipyridyl in a mixed solvent of methanol and dimethyl sulfoxide, gave a chelated FOX carbamate anion resulting in the compound Ni(bipy)(2)(FOX-CO(2))·(DMSO) (7b). All metal salts were characterized by infrared, elemental analysis, and differential scanning calorimetry (DSC). Single-crystal X-ray diffraction structures were obtained for compounds 1, 2, 3c, 6, and 7b.

The exciting discovery of the first cations based on 1,1-diamino-2,2-dinitroethene (FOX-7) and its hydrazine derivative, 1-amino-1-hydrazino-2,2-dinitroethene (HFOX), along with their syntheses and full characterization is described.

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