Synthesis and Characterization of Bis(triaminoguanidinium) 5,5′-Dinitrimino-3,3′-azo-1H-1,2,4-triazolate - A Novel Insensitive Energetic Material

Comparative Studies on Thermal Decompositions of Dinitropyrazole-Based Energetic Materials

Dinitropyrazole is an important structure for the design and synthesis of energetic materials. In this work, we reported the first comparative thermal studies of two representative dinitropyrazole-based energetic materials, 4-amino-3,5-dinitropyrazole (LLM-116) and its novel trimer derivative (LLM-226). Both the experimental and theoretical results proved the active aromatic N-H moiety would cause incredible variations in the physicochemical characteristics of the obtained energetic materials. Thermal behaviors and kinetic studies of the two related dinitropyrazole-based energetic structures showed that impressive thermal stabilization could be achieved after the trimerization, but also would result in a less concentrated heat-release process. Detailed analysis of condensed-phase systems and the gaseous products during the thermal decomposition processes, and simulation studies based on ReaxFF force field, indicated that the ring opening of LLM-116 was triggered by hydrogen transfer of the active aromatic N-H moiety. In contrast, the initial decomposition of LLM-226 was caused by the rupture of carbon-nitrogen bonds at the diazo moiety.

Selective Synthesis of Bis(3-(3-(trifluoromethyl)-1H-1,2,4-triazol-5-yl)-4,4'-azo- and -azoxyfurazan Derivatives

In this paper, we report the synthesis of two new derivatives, bis(3-(3-(trifluoromethyl)-1H-1,2,4-triazol-5-yl)-4,4'-azo- and -azoxyfurazans by selective oxidation of 4-(3-(trifluoromethyl)-1H-1,2,4-triazol-5-yl)-1,2,5-oxadiazol-3-amine. Ammonium salts of these derivatives were prepared, and all of them were fully characterized by multinuclear NMR, FTIR spectroscopy, elemental analysis, differential scanning calorimetry (DSC), and single-crystal X-ray diffraction. All of the new compounds have high measured crystal densities, and the energetic properties have been investigated.

Sandwich-like low-sensitive nitroamine explosives stabilized by hydrogen bonds and π–π stacking interactions

Sandwich-like low-sensitive nitroamine explosives were developed which expand the structural category of low-sensitive energetic materials and could give references to the design of new low-sensitive energetic materials.

Prediction of explosive properties of newly synthesized amino nitroguanidine-based energetic complexes via density functional theory

Density functional theory calculations were performed to explore four octahedral energetic complexes including [CoCl₂ (ANQ)₂], [Co (ANQ)₂(H2O)₂]²⁺, [CuCl₂ (ANQ)₂], and [Cu(NO3)₂ (ANQ)₂], (ANQ = amino nitroguanidine). In this work, an attempt has been made to present useful structural data in order to investigate and predict the explosive properties of these complexes. In this regard, interaction energy (IE), natural bond orbital (NBO), atoms in a molecule (AIM) as well as the three-dimensional Hirshfeld surface analysis and the two-dimensional fingerprint plots, charge transfers, HUMO-LUMO gap, oxygen balance (%OB) amounts, and molecular electrostatic potential (MEP) maps were utilized to assign intermolecular interactions, bond lengths, the nature of metal-ligand bonds, and energies in subject compounds. The results reveal that among the five applied levels of theory, interaction energies obtaining from M06-2X/Def2TZVP were in excellent compliance with the experiments. Additionally, the N⋯O interaction, oxygen balance, density, and HOMO-LUMO gap were the most contributing factors in assigning sensitivity and detonation properties. In general, the sensitivity and detonation properties are increased in the following order: ANQ < complex1 < complex3 < complex2 < complex4. Graphical abstract.

Tetrazolyl and dinitromethyl groups with 1,2,3-triazole lead to polyazole energetic materials

A class of polyazole energetic compounds (combination of tetrazolyl, dinitromethyl and triazole) was obtained from 4,5-dicyanotriazole.

Synthesis of high-performance insensitive energetic materials based on nitropyrazole and 1,2,4-triazole

A new family of symmetric nitropyrazole and 1,2,4-triazole derivatives and its energetic salts were obtained. The positive effect of ternary hydrogen bonds improve the performances of target compounds.

Theoretical study of a series of 4,4'-azo-1H-1,2,4-triazol-5-one based nitrogen-rich salts as potential energetic compounds

Density function theory has been employed to systemically study 4,4'-azo-1H-1,2,4-triazol-5-one (ZTO) and its six nitrogen-rich salts at two different calculated levels (B3LYP/6-31G(d,p) and B3PW91/6-31G(d,p)). Their optimized geometries, electronic structures and molecular electrostatic potentials were further studied. Based on the two computed methods, the results of the optimized geometries show that the calculated structure of each compound adopted at the two different levels are rather similar except salt 7 with some differences. The values of the energy gaps indicate that compound 3 has the highest reactivity among salts 2-7. The crystal densities were corrected using the Politzer approach based on these two optimized levels. The density values with slight deviation indicate that the two calculated levels are applicable and the results are convincible. Based on the isodesmic reactions and Born-Haber energy cycle, the solid-phase heats of formation (HOFs) were predicted. Detonation parameters were evaluated using the Kamlet-Jacobs equations on the foundations of the calculated densities and HOFs. The results manifest that salt 2 exhibits the best detonation performance due to its highest density (1.819 g cm^-3), followed by salt 6. Moreover, impact sensitivities of compounds 1-7 were assessed using the calculated Q values to correlate with h ₅₀. Combining the detonation performance with safety, 1-7 exhibit good comprehensive properties and might be screened as a composition of modern nitrogen-rich energetic compounds.

The synthesis, crystal structure and thermal properties of an energetic compound: the hydrated azanium salt of 3,6-bis[(1H-1,2,3,4-tetrazol-5-yl)amino]-1,2,4,5-tetrazine

The energetic ionic salt bis(1-aminoguanidin-2-ium) 5,5'-[1,2,4,5-tetrazine-3,6-diylbis(azanediyl)]bis(1H-1,2,3,4-tetrazol-1-ide) dihydrate, 2CH₇N₄⁺·C₄H₂N₁₄^2-·2H₂O, (I), with a high nitrogen content, has been synthesized and examined by elemental analysis, Fourier transform IR spectrometry, ¹H NMR spectroscopy and single-crystal X-ray crystallography. Compound (I) crystallizes in the monoclinic space group P2₁/c with two water molecules. However, the water molecules are disordered about an inversion centre and were modelled as half-occupancy molecules in the structure. The crystal structure reveals a three-dimensional network of molecules linked through N-H...N, N-H...O, O-H...N and O-H...O hydrogen bonds. Thermal decomposition was investigated by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The exothermic peak temperature is 509.72 K, which indicates that hydrated salt (I) exhibits good thermal stability. Non-isothermal reaction kinetic parameters were calculated via both the Kissinger and the Ozawa methods to yield activation energies of E_k = 239.07 kJ mol^-1, lgA_k = 22.79 s^-1 and E_O = 235.38 kJ mol^-1 for (I). Additionally, the thermal safety was evaluated by calculating critical temperatures and thermodynamic values, viz. T_SADT, T_TIT, T_b, ΔS^≠, ΔH^≠ and ΔG^≠. The results reveal that (I) exhibits good thermal safety compared to other ion salts of 3,6-bis[(1H-1,2,3,4-tetrazol-5-yl)amino]-1,2,4,5-tetrazine (BTATz).

Nitrogen-rich 4,4′-azo bis(1,2,4-triazolone) salts—the synthesis and promising properties of a new family of high-density insensitive materials

4,4′-Azo-bis(1,2,4-triazolone) (ZTO) based salts from alkaline (Li⁺, K⁺, Na⁺, and Cs⁺), alkaline earth metal salts (Mg²⁺, Ca²⁺, Sr²⁺, and Ba²⁺) and hydrazinium salt were synthesized in a simple, straightforward manner and were characterized by IR and NMR spectroscopy, elemental analysis.