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With the increase in the demand for high‐performance composite explosives, the search for advanced energetic melt‐castable compounds has attracted increasing attention in the field of energetic materials. Herein, two new energetic materials with nitromethyl and azidomethyl substituents (1‐(nitromethyl)‐3,4‐dinitro‐1H‐pyrazole (NMDNP) and 1‐(azidomethyl)‐3,4‐dinitro‐1H‐pyrazole (AMDNP) were prepared by the substituent modification of a potential melt‐castable molecule ((3,4‐dinitro‐1H‐pyrazol‐1‐yl) methyl nitrate, MC‐4), respectively. NMDNP exhibited a suitable melting point (90 °C), good thermal stability (Td: 185 °C) and excellent detonation performance (8484 m s−1) and impact sensitivity (25 J), thereby demonstrating promise as an energetic melt‐castable material. Simultaneously, compared with the nitrato‐methyl and azidomethyl substituents, the nitromethyl substituent exhibited greater advantages in regulating performance. [ABSTRACT FROM AUTHOR]

A series of novel fused‐ring pyrazolo[4,3‐c]pyrazole derivatives featuring N‐dinitromethyl and N‐fluorodinitromethyl energetic groups (compounds 3–7) were synthesized using a nine‐step reaction. All these compounds were characterized using multinuclear nuclear magnetic resonance (NMR) spectroscopy, infra‐red (IR) spectroscopy, and elemental analysis. X‐ray diffraction analysis was performed, and the single‐crystal structures of compounds 3, 4, 6, and 7 were obtained. For these newly prepared energetic materials, the thermal stability was determined using differential scanning calorimetry (DSC), while the sensitivities were evaluated using BAM drop hammer and friction test. The calculated heat of formation values and the measured densities were used to determine the detonation parameters, including detonation velocity and pressure, using the EXPLO5 program. Of all the prepared compounds, dipotassium 1,4‐bis(dinitromethyl)‐3,6‐dinitro‐1,4‐dihydropyrazolo[4,3‐c]pyrazole (3) was crystallized as a three‐dimensional energetic metal‐organic framework (MOF) and showed outstanding detonation performances, which even outperformed the traditional primary explosive lead azide. Compound 7 exhibited a high crystal density of 1.939 g cm−3, the high decomposition temperature of 213 °C and desirable impact and friction sensitivities (IS: 12 J; FS: 240 N). These combined properties and performances make these novel fused‐ring energetic compounds suitable candidates for high‐performance energetic materials. [ABSTRACT FROM AUTHOR]

Abstract: A novel family of hydrophobic triaminocyclopropenium cation based ionic liquids have been synthesized, and their structures and physicochemical properties characterized by NMR and IR spectroscopy, elemental analysis, differential scanning calorimetry, and hypergolic tests. The experimental results showed that all of these ionic liquids exhibited the expected hypergolic reactivity with the oxidizer white fuming nitric acid. Among them, the hypergolic ionic liquid based on the cyanoimidazolylborohydride anion showed excellent integrated properties, including high decomposition temperature (194 °C), high density (0.95 g cm−3), moderate viscosity (44 MPa s), ultrafast ignition delay time (6 ms), and high specific impulse (301.9 s); this demonstrates its potential as an environmentally friendly alternative to toxic hydrazine derivatives. [ABSTRACT FROM AUTHOR]

Abstract: The experimental detection and synthesis of pentazole (HN5) and its anion (cyclo‐N5−) have been actively pursued for the past hundred years. The synthesis of an aesthetic three‐dimensional metal–pentazolate framework (denoted as MPF‐1) is presented. It consists of sodium ions and cyclo‐N5− anions in which the isolated cyclo‐N5− anions are preternaturally stabilized in this inorganic open framework featuring two types of nanocages (Na20N60 and Na24N60) through strong metal coordination bonds. The compound MPF‐1 is indefinitely stable at room temperature and exhibits high thermal stability relative to the reported cyclo‐N5− salts. This finding offers a new approach to create metal–pentazolate frameworks (MPFs) and enables the future exploration of interesting pentazole chemistry and also related functional materials. [ABSTRACT FROM AUTHOR]

gem-Dinitromethylated and fluorodinitromethylated 5,5′-dinitro-3,3′-bis-1,2,4-triazole (DNBT) ( 2 and 3) along with seven ionic derivatives 4- 9, were synthesized and characterized by NMR and IR spectroscopies, elemental analysis, single-crystal X-ray diffraction (XRD), and differential scanning calorimetry (DSC). XRD revealed that compounds 2 and 3 crystallized in the monoclinic P21/ n space group and compound 5 crystallized in the monoclinic P21/ c space group. The physicochemical properties of the as-synthesized compounds 2- 9 were investigated and the results indicated that compounds 3, 6, and 7 exhibited a good balance between high energy and low sensitivity, demonstrating their potential as new high-energy-density materials (HEDMs). The proposed synthetic strategy for introducing gem-dinitromethyl and fluorodinitromethyl groups into the DNBT framework to prepare materials with high energy and low sensitivity suitable for HEDMs looks promising. [ABSTRACT FROM AUTHOR]

Three anionic open frameworks, formulated as [Him]2Eu2(ox)4(H2O)2 ·2H2O ( 1), [Him]2Tb2(ox)4(H2O)2 ·2H2O ( 2), and [Hmim]2Eu2(ox)4(H2O)2 ·2H2O ( 3; ox = oxalate, im = imidazole, mim = methylimidazole), have been synthesized by a solvent-free method. In these solvent-free processes, in situ encapsulation of imidazolium in the channels of the anionic open frameworks was successfully achieved. These compounds show 1D channels with extensive hydrogen-bonding networks created between the guest molecules and adjacent oxalate oxygen atoms; the imidazolium or methylimidazolium cations are regularly arranged within the channels. Alternating current (AC) impedance measurements revealed that the three compounds display high proton conductivities (>10-3 S cm-1) at 298 K and 98 % relative humidity, with compound 2 showing the highest proton conductivity of 5.0 × 10-3 S cm-1 at 298 K. The high proton conductivities of compounds 1- 3 may be attributed to the extensive hydrogen-bonding networks existing in the open frameworks, which are constructed by water molecules, protonated imidazole or methylimidazole molecules, and adjacent oxalate oxygen atoms. This work provides an efficient synthetic strategy for the construction of high-performance solid proton conductors. [ABSTRACT FROM AUTHOR]

Over the past few decades, toxic and highly volatile hydrazine derivatives have been the main fuel choices for liquid bipropellants, especially in traditional hypergolic rocket engines. The search for new hypergolic fuels as replacements for hydrazine derivatives is of great interest to researchers. In this study, a series of N-alkylimidazole borane compounds has been synthesized and characterized. Interestingly, these compounds display promising applications as potential hypergolic fuels owing to their excellent physiochemical properties including low melting points, high thermal stability, low viscosities, and unique hypergolic reactivity. Compared with popular hypergolic ionic liquids, the cost-effective and scaling-up advantages of these materials highlight their promising potential as high-performance fuels in liquid bipropellant formulations. [ABSTRACT FROM AUTHOR]

Bis(4-nitraminofurazanyl-3-azoxy)azofurazan ( 1) and ten of its energetic salts were prepared and fully characterized. Computational analysis based on isochemical shielding surface and trigger bond dissociation enthalpy provide a better understanding of the thermal stabilities for nitramine-furazans. These energetic compounds exhibit good densities, high heats of formation, and excellent detonation velocity and pressure. Some representative compounds, for example, 1 ( vD: 9541 m s−1; P: 40.5 GPa), and 4 ( vD: 9256 m s−1; P: 38.0 GPa) exhibit excellent detonation performances, which are comparable with current high explosives such as RDX ( vD: 8724 m s−1; P: 35.2 GPa) and HMX ( vD: 9059 m s−1; P: 39.2 GPa). [ABSTRACT FROM AUTHOR]

Two microporous metal-organic frameworks (MOFs) based on zinc clusters, that is, [Zn3(BDC)2(HBDC)2] ·2DMA ·4CH3OH ·2H2O ( 1; H2BDC = 1,4-dicarboxybenzene, DMA = N, N-dimethylacetamide) and [(CH3)2NH2]2[Zn7(µ4-O)2(NDC)6] ·DMF ·H2O ( 2; H2NDC = 1,4-naphthalenedicarboxylic acid, DMF = N, N-dimethylformamide), were synthesized by a solvothermal method. Both compounds possess three-dimensional porous skeletons with square channels and exhibit interesting blue fluorescence. Compound 1 consists of trinuclear ZnII building units bridged by both BDC2- and HBDC- ligands, which results in the formation of a 2,8-connnected topological net (hex). Compound 2 features another 2,8-connected topological net (bcu) that is constructed by eight-connected Zn7(µ4-O)2 clusters and two-connected NDC2- ligands. The solid-state and solvent-dependent fluorescence of the two MOFs revealed that 1 and 2 showed fluorescence enhancement effects in the presence of acetone and chloroform, respectively, which thereby demonstrates their potential as fluorescent sensors for selective sensing towards acetone and chloroform. [ABSTRACT FROM AUTHOR]

Four beryllium hydrogen phosphates, Be2(Hea)(PO4)(HPO4) ( 1), Him ·Be3(OH)(HPO4)3 ( 2a), Hpy ·Be3(OH)(HPO4)3 ( 2b), and Hma ·Be1.5(HPO4)2 ·0.5H2O ( 3) in which ea = ethanolamine, im = imidazole, py = pyridine, and ma = methylamine, were synthesized under solvothermal conditions. All compounds have open-framework structures with (3,4)-connected networks. Compound 1 features a neutral inorganic-organic hybrid framework with an interrupted zeolitic GIS topology. The dual role of the amine molecules as charge-balancing agents and coordinating agents to the beryllium atoms is noteworthy. Compounds 2a and 2b are isostructural, and they have an AFI-related framework with elliptical 12-ring channels. Compound 3 has a 3D structure with 4.82 layers pillared by corner-sharing four-ring chains. It represents the first example of an open-framework beryllium hydrogen phosphate with 16-ring channels. [ABSTRACT FROM AUTHOR]

A new family of gem ‐ dinitromethylated and fluorodinitromethylated energetic compounds based on 5,5’ ‐ dinitro ‐ 3,3’ ‐ bis ‐ 1,2,4 ‐ triazole (DNBT) shows high energy density, good thermal stability, and excellent detonation properties. The proposed strategy of introducing gem ‐ dinitromethyl and fluorodinitromethyl groups into DNBT frameworks demonstrates a great promise for developing new ‐ generation high ‐ energy ‐ density materials (HEDMs) with high ‐ performing detonation level and low sensitivity. More information can be found in the Full Paper by Q. Zhang et al. on page 12787. [ABSTRACT FROM AUTHOR]