Theoretical study on the thermal decomposition mechanism of 2-nitro-[1,2,4]triazolo[1,5-a][1,3,5]triazine-5,7-diamine.

Context: High nitrogen and high-density compounds have become popular research objects in the energetic materials in recent years. Among them, compounds composed of triazine and azole skeleton rings have received attention due to their good stability and nitrogen content. The triazine imidazole-based condensed ring energetic derivatives have good properties and lack research on the direction of thermal decomposition.

The molecular structure, electronic properties, and decomposition mechanism of FOX-7 under external electric field were calculated based on density functional theory.

Context: Based on the density functional theory (DFT), we analyzed the changes of the FOX-7 molecule under external electric field (EEF) from multiple perspectives, including molecular structure, electronic structure, decomposition mechanism, frontier molecular orbitals (FMOs), and density of states (DOS). The results revealed that as the intensity of the positive EEF increased, the detonation performance of the FOX-7 molecule was significantly enhanced, while its thermal stability was also improved. This discovery challenges the traditional concept that explosives are inherently dangerous under external electric fields and provides new insights for research in related fields.

Study on the regulation of ε-CL-20 by an external electric field.

Context: To explore the influence of the external electric field (EEF) on ε-CL-20. The molecular structure, frontier molecular orbitals (FMOs), global reactivity parameters (GRP), surface electrostatic potential, nitro charge, and UV-Vis spectra of ε-CL-20 under EEF were studied using density functional theory (DFT). The calculation results show that the electric field applied along N16-N24 has a significant effect on the structure of ε-CL-20.

Periodic DFT study of structural transformations of cocrystal CL-20/MMI under high pressure.

Context: The crystal and molecular structure, electronic properties, optical parameters, and elastic properties of a 1:2 hexanitrohexaazaisowurtzitane (CL-20)/2-mercapto-1-methylimidazole (MMI) cocrystal under 0 ~ 100 GPa hydrostatic pressure were calculated. The results show that the cocrystal CL-20/MMI undergoes three structural transitions at 72 GPa, 95 GPa, and 97 GPa, respectively, and the structural transition occurs in the part of the MMI compound. Structural mutations formed new bonds S1-S2, C2-C7, and N1C5 at 72GPa, 95 GPa, and 97 GPa, respectively.

Theoretical insight into different energetic groups on the performance of energetic materials 2,5,7,9-tetranitro-2,5,7,9-tetraazabicyclo[4,3,0]nonane-8-one.

Context: Energetic materials are a class of materials containing explosive groups or containing oxidants and combustibles. The optimization of energetic materials has a significant impact on the development of industry and national defense. For high-energy density compounds (HEDC) that have not been synthesized or are dangerous to experimental operation, it is of guiding significance to predict its energy level, physicochemical properties, and safety through molecular design and theoretical calculation.

Molecular design and theoretical study of oxadiazole-bifurazan derivatives.

Context: The design and synthesis of new high energy density materials is an important part of the research in the field of high energy materials. However, the synthesis of high-energy materials is very difficult and dangerous. Therefore, it is necessary to design the compounds in advance and evaluate the performance of the designed compounds, so as to screen the high-energy candidate compounds with excellent performance and provide reference for future synthesis and application.

Triazene-bridged energetic materials based on nitrotriazole: synthesis, characterization, and laser-ignited combustion performance.

Compared to the widely concerned azo bridges (-NN-), triazene bridges (-NN-NH-) with longer nitrogen chains are also favorable linking units leading to novel energetic materials. In this work, a new family of nitrogen-rich nitrotriazolate-based energetic compounds with a triazene bridge were synthesized and well characterized. The experimental results indicated that most of these new compounds have good thermal stabilities and low sensitivities.

Regulation of external electric field on sensitivity of ICM energetic materials.

Context: [2,2'-Bi(1,3,4-oxadiazole)]-5,5'-dinitramide (ICM-101), 2,4,6-triamino-5-nitropyrimidine-1,3-dioxide (ICM-102), and 6-nitro-7-azido-pyrazol[3,4-d][1,2,3]triazine-2-oxide (ICM-103) are excellent China-made explosives, but their performance under external electric fields (EEF) has never been explored, especially sensitivity. To study the induction effect of EEF on it, the chemical reactivity, electron localization function (ELF), spectrum, and other parameters were calculated by density functional theory. The results show that the increasing EEF can weaken the △E (△E = E-E) materials, making the stability worse and the sensitivity higher.

Regulation of external electric field on the high-energy polynitrogen compound 1,5-diaminotetrazole-4 N-oxide.

Background: The external electric field (EEF) tends to have a significant impact on chemicals, especially energetic materials.

Methods: Molecular structure, electrostatic potential (ESP), electron density difference, density of states (DOS), and frontier molecular orbitals (FMOs) of 1,5-diaminotetrazole-4N-oxide (SYX-9) are calculated by density functional theory (DFT) at B3LYP/6-311G+(d, p) and M062X/def2-TZVP under external electric field.

Results: Calculated results reveal that EEF has definite influence on the trigger bond of SYX-9, especially in positive direction, and the shortening of the trigger bond caused by it can effectively reduce the sensitive of SYX-9.

Structural transformation of methyl urotropine perchlorate under high pressure.

Based on the first-principles calculations of density functional theory (DFT), the crystal structure, molecular structure, electronic properties, and optical absorption properties of methyl urotropine perchlorate under hydrostatic compression in the range of 0 ~ 100 GPa were calculated. The results show that the crystal structure of methyl urotropine perchlorate undergoes two structural transformations under hydrostatic compression. The H1A-H1B bond breaks at 25 GPa, generating two new covalent bonds N3-H1A and O1-H1B.

Theoretical study on BTF-based cocrystals: effect of external electric field.

The external electric field plays an important role in the sensitivity of cocrystal energetic materials. To reveal the influence of external electric field on benzotrifuroxan/2,4,6-trinitroaniline (BTF/TNA), benzotrifuroxan/trinitroazetidine (BTF/TNAZ), benzotrifuroxan/1,3,5-trinitrobenzene (BTF/TNB), and benzotrifuroxan/trinitrotoluene (BTF/TNT) cocrystals' sensitivity, atoms in molecules (AIM), frontier molecular orbitals, nitro group charges (Q), electron density values (ρ), electrostatic surface potentials (ESPs), bond dissociation energy (E), and interaction energy (E) of the C-NO bond were calculated by density functional theory at M062X-D3/ma-def2 TZVPP and B3LYP-D3/6-311 + G (d, p) levels in this article. The results indicate that both negative and positive electric fields reduce the energy gap of the BTF-based cocrystals, and BTF/TNAZ is the most sensitive cocrystal among the four cocrystals.

Study on regulation effect of external electric field on energetic material 1-methyl-2,4,5-Trinitroimidazole.

In this work, in order to explore the regulation effect of external electric field (EEF) on various properties of 1-methyl-2,4,5-trinitroimidazole (MTNI), density functional theory (DFT) was used to investigate the molecular structure, electronic structure, frontier molecular orbital (FMO) and ultraviolet-visible (UV-Vis) spectroscopy of MTNI under EEF. The results show that: (1) EEF significantly affects the geometric and electronic structure of MTNI, which in turn affects the sensitivity of MTNI. (2) When the EEF in the positive direction increases, the energy gap of MTNI decreases significantly and the total density of states (TDOS) turns to be dominated by the nitro groups.

Thermodynamic properties, decomposition kinetics of 2-(5-amino-2H-tetrazol-1-yl)-4-amine-3,5-dinitropyridine.

A novel energetic material 2-(5-amino-2H-tetrazol-1-yl)-4-amine-3,5-dinitropyridine (ATDP) was synthesized and characterized by H NMR, C NMR, mass spectroscopy, and elemental analysis. The research by differential scanning calorimetry (DSC) shows that ATDP decomposed about 290 °C. The calculating results of kinetic parameters using Ozawa method, Kissinger method, and Starink method were quite consistent.

Theoretical studies of novel high energy density materials based on oxadiazoles.

In this study, 32 energetic compounds were designed using oxadiazoles (1,2,5-oxadiazole, 1,3,4-oxadiazole) as the parent by inserting different groups as well as changing the bridge between the parent. These compounds had high density and excellent detonation properties. The electrostatic potentials of the designed compounds were analyzed using density functional theory (DFT).

Theoretical Studies on the Performance of HMX with Different Energetic Groups.

Forty nitramines by incorporating -C=O, -NH, -N, -NF, -NHNO, -NHNH, -NO, -ONO, -C(NO), and -CH(NO) groups based on a 1,3,5,7-tetranitro-1,3,5,7-tetraazacyclooctane (HMX) framework were designed. Their electronic structures, heats of formation (HOFs), detonation properties, thermal stabilities, electrostatic potential, and thermodynamic properties were systematically investigated by density functional theory. The comprehensive relationships between the structures and performance of different substituents were studied.

Theoretical Study on CL-20-Based Cocrystal Energetic Compounds in an External Electric Field.

An external electric field has great effects on the sensitivity of cocrystal energetic materials. In order to find out the relationship between the external electric field and sensitivity of cocrystals 2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane/benzotrifuroxan (CL-20/BTF), 2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane/3,4-dinitropyrazole (CL-20/DNP), and 2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane/1-methyl-3,5-dinitro-1,2,4-triazole (CL-20/MDNT), density functional theory at B3LYP-D3/6-311+G(d,p) and M062X-D3/ma-def2 TZVPP levels was employed to calculate frontier molecular orbitals, atoms in molecules (AIM) electron density values, bond dissociation energies (BDEs) of the N-NO bond, impact sensitivity ( ), electrostatic potentials (ESPs), and nitro group charges ( ) in this work. The results show that a smaller highest occupied molecular orbital-lowest unoccupied molecular orbital gap and the BDEs, as well as , tend to have a larger sensitivity along with the positive directions in the external electric field.

Pressure induced structural behavior of energetic cocrystal TNT/TNB: a density functional theory study.

In order to find out the relationship between external pressures and properties of energetic materials, we used the density functional theory (DFT) method to investigate the structural, electronic, and absorption properties of crystalline 2,4,6-trinitrotoluene (TNT)/2,4,6-trinitrotoluene (TNB) under hydrostatic compression of 0-100 GPa. By analyzing the change of lattice constants (a, b, and c) of TNT/TNB under compression conditions, we found that variation tendency of the lattice constants was anisotropic. The b-axis is much stiffer than that along the a- and c-axes, which indicates that the TNT/TNB crystal is anisotropic within a certain pressure region.

Molecular design and properties of bridged energetic pyridines derivatives.

A series of bridged pyridine-based energetic derivatives were designed and their geometrical structures, electronic structures, heats of formation, detonation properties, thermal stabilities, thermodynamic properties and electrostatic potential were fully investigated using density functional theory. The results show that the steric hindrance effect is a decisive factor for structural stability, and the formation of intramolecular or intermolecular hydrogen bonds doesn't provide advantages to stabilize molecular structure, which was demonstrated by insertion of 3,4,5-trinitro-1-pyrazole, 3,4-dinitro-1-pyrazol-5-amine, 3,5-dinitro-1-pyrazol-4-amine and 3-nitro-1-1,2,4-triazol-5-amine. The azide group and azo bridge play an important role in improving the heats of formation of energetic pyridine-based materials.