Two nitrogen-rich energetic salts based on 5,5′-dinitramino-3,3′-methylene-1 H -1,2,4-bistriazolate, were designed and synthesized. Their structures were characterized by IR spectroscopy, elemental analysis, and single-crystal X-ray diffraction.

Composites of metal complexes have catalytic effects on the thermal decomposition of ammonium perchlorate (AP), while the kinetics and mechanism studies of the processes are seldom mentioned. Here, composite microspheres of cupric 3,5-dinitrobenzoate and cobalt 3,5-dinitrobenzoate [(3,5-DNB)Cox center dot Cuy] were synthesized and employed to research the kinetics and mechanism of AP catalytic decomposition. The decomposition peak temperature of AP in the presence of the (3,5-DNB)Cox center dot Cuy microspheres decreased from 403 degrees C (pure AP) to 288 degrees C, and the released heat increased by 384.5-745.6 J/g. Notably, the (3,5-DNB)Cox center dot Cuy microspheres significantly improved the kinetic rate constant by 1.83-37.75 times. The (3,5-DNB)Cox center dot Cuy microspheres exhibited higher activity than their corresponding single components for the thermal decomposition of AP, indicating excellent synergistic effects and proposing a possible mechanism. Understanding the kinetics and mechanism of the catalytic process developed in this study could further improve the decomposition performance of AP.

Exploration of advanced lead-free primary explosives is a challenging issue in the field of energetic materials. Herein, we designed and synthesized a novel N-rich copper bromate energetic coordination compound (ECC) [Cu(ATRZ)(BrO3)2]n (BLG-1, ATRZ: 4,4'-azo-1,2,4-triazole) by a simple one-step reaction. BLG-1 is the first reported three-dimensional (3D) N-rich copper bromate ECC. Its interesting 3D reticular architecture contributed to its highest thermal decomposition temperature (Td: 226 °C) and crystal density (ρ: 2.69 g cm-3) among N-rich copper bromate ECCs. More importantly, a primary charge of BLG-1 as little as 3 mg could reliably detonate compressed RDX, and 1 mg could detonate CL-20. These incredible values indicated that BLG-1 had an ultra-powerful initiating ability far superior to that of previously reported primary explosives. BLG-1 had improved mechanical sensitivities (IS: 13 J; FS: 1 N) and electrostatic sensitivity (EDS: 240 mJ) compared with those of the typical lead-based primary explosive, lead azide (IS: 4J; FS: 0.75N; EDS: 5 mJ). In particular, BLG-1 had a low laser-initiation threshold of 13 mJ at 808 nm, suggesting that it could serve as a laser-ignitable primary explosive. This work suggests that BLG-1 is a promising candidate with engreat practical application prospects for lead-free primary explosives.

An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

利用动态测压热分析法(DPTA)、差式扫描量热法(DSC)、热重分析法(TG)、热烤法研究了低熔点含能材料DNAN/RDX的热行为和分解机理.研究得到结论:1)DPTA法测试结果表明DNAN/RDX的热安定性较好;在固相分解阶段,运用Satava-Sestak法得出20～100℃时非等温固相分解阶段机理函数为G(α)=[(1-α)-1/3-1]2,ES=85.64 kJ/mol,lgAs=11.57;等温阶段的等温分解动力学机理函数为G(α)=[(1-α)1/3,反应速率常数k=1.51532×10-4.2)DSC法和TG法研究结果表明RDX主要为熔融液相形式分解,DNAN主要为气相形式分解;混合体系中RDX促进了DNAN的分解过程,DNAN/RDX的受热质量损失过程主要为DNAN的挥发过程和RDX的热分解过程.运用DSC法研究升温速率为5℃/min时DNAN/RDX的热分解过程,普适积分法得出在224～320℃范围内的分解过程机理函数为G(α)=[-ln(1-α)]2,E=101.7 kJ/mol,lgA=6.676;不同升温速率下的热分解过程活化能为E=89.94 kJ/mol,lgA=6.489.3)热烤爆法研究结果表明DNAN/RDX混合体系的τ5s为592.1 K,热安全性较好.运用数值微分法、麦克劳林展开式等方法得出Tb=534.84 K,与DSC法计算出的结果较为接近.

To seek new high energetic materials, N-methylene-C-bridged nitrogen-rich heterocycle 1-((4,5-diamino-4H-1,2,4-triazol-3-yl)methyl)-1H-1,2,4-triazol-3,5-diamine (DATMTDA) (2) was first synthesized, and two copper coordination compounds ([Cu12(OH)4(ClO4)4(H2O)4(DATMTDA)12](ClO4)16·12H2O (3) and [Cu3(OH)(ClO4)(DATMTDA)3](ClO4)3(NO3) (4)) based on 2 were formed by introducing different anions. These compounds were characterized by elemental analysis, IR spectroscopy and single-crystal X-ray diffraction analysis. The crystal structures of compounds 3 and 4 are similar and crystallize in monoclinic systems with the P21/c space group, while the central copper atoms show different coordination behaviors. However, the structure of compounds 3 and 4 is analogous to a three dimensional structure owing to the O atom of OH-, forming coordinate bonds with three copper cations. The NBO charge of 2 was calculated using density functional theory to understand its coordination modes. The Hirshfeld surface calculation reveals that 3 and 4 have strong intermolecular interactions. The thermal decomposition processes, non-isothermal kinetics, and enthalpies of formation and sensitivities of these compounds were investigated. By introducing one NO3- of compound 4 to replace one ClO4- in compound 3, compound 4 shows lower density and lower decomposition peak temperature but lower sensitivity and a higher formation enthalpy than compound 3. The complex 4 possesses an outstanding catalytic effect for the decomposition of AP than that of complex 3. The results illustrate the possibility of introducing various anions into energetic coordination compounds for the regulation of energetic materials.

With the development of aerospace science and technology, requirements for propellants are increasingly high. The thermal decomposition behavior of ammonium perchlorate (AP) directly influences the combustion performance of composite solid propellants. Catalysts play an important role in improving the thermal decomposition behavior of AP. In this study, three novel metal-organic frameworks (MOFs) were prepared using a straightforward method, namely Co[N(CN)2]2 (1; nitrogen content: 43.5%), Cu[N(CN)2]2 (2; nitrogen content: 43.0%), and Pb[N(CN)2]2 (3; nitrogen content: 24.8%). Their crystal structures were characterized and analyzed through single-crystal X-ray diffraction, forming interesting three-dimensional architectures. Moreover, derived composite catalysts under air (4, 6, and 8) or nitrogen (5, 7, and 9) atmosphere were generated by heating MOFs 1, 2, and 3–500 ​°C at a heating rate of 5 ​°C·min−1. The derived catalyst 4 exhibited the best performance. It reduced the decomposition peak temperature of AP by 81.9 ​°C, increased the heat release from 785 ​kJ·g−1 to 1232 ​kJ·g−1, and decreased the apparent activation energy (Ea) of AP from 223 ​kJ·mol−1 to 145 ​kJ·mol−1.

A sub-band k -means clustering method was used for laser-induced plasma spectral analysis to achieve accurate identification and classification of high explosives and organic materials.

Nitrogen-rich energetic salts have attracted considerable interest recently, due to their fascinating thermal stability and energetic performance. In this work, N-methylene-C-bridged nitrogen-rich heterocycle (5-((5-amino-tetrazol-1-yl)methyl)-1,2,4-triazole-3,4-diamine (ATMTDA) (1)) were synthesized and its nitrogen-rich energetic salts ((ATMTDA) 2 [(HATMTDA)(DCNM)] 2 H 2 O (2), (HATMTDA)NO 3 (3), (H 2 ATMTDA)(NO 3 ) 2 (4), (HATMTDA)ClO 4 (5), (HATMTDA)NTO (6), and (H 2 ATMTDA)(PA) 2 (H 2 O) 2 (7)) were prepared. These energetic compounds were fully characterized by elemental analysis, FTIR spectroscopy and single-crystal X-ray diffraction analysis. The NBO charge of 1 was calculated by density functional theory, to understand which N atoms was more vulnerable to attack by H protons to become cations. And the thermal stability of these compounds was studied by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) with acceptable results ( T dec > 190 degrees C). All of the studied compounds except for compound 5 (FS = 216 N, IS = 3 J) exhibited less sensitivities than RDX ((FS = 120 N, IS = 7.4 J), and compound 1 (8.62 km/s, 25.71 GPa) showed good detonation performance. All of the results illustrated the potential application of the compounds as energetic materials.(c) 2023 Elsevier B.V. All rights reserved.

A bimetallic MOF, CoNi(EIM)2(DCA)2 (1), containing an energetic 1-ethylimidazole (EIM) ligand and a hypergolic linker, dicyandiamide (DCA), was synthesized via a facile method. A fascinating three-dimensional reticular architecture was observed by single-crystal X-ray diffraction in this bimetallic MOF, whereas the corresponding monometallic compounds Co(EIM)4(DCA)2 (2) and Ni(EIM)4(DCA)2 (3) were in the mononuclear coordination mode. Uniformly distributed Co and Ni were observed in the bimetallic MOF crystals by SEM-EDS elemental mapping. Bimetallic MOF 1 was thermally stable and insensitive to mechanical stimuli and possessed an excellent energetic density (22.37 kJ·g-1). Using 1 as a hypergolic promoter, the ignition delay time of 1-butyl-3-methylimidazolium dicyanamide (BMIM DCA) was reduced from 53 to 37 ms, better than that of 2 and 3 as promoters, due to the synergistic catalysis of the bimetal. Furthermore, the thermal decomposition mechanisms of BMIM DCA with 1, 2, and 3 were studied by differential scanning calorimetry (DSC). 1 had the best catalytic performance in BMIM DCA thermolysis with a decrease in the decomposition temperature from 314.5 to 308.0 °C and a decrease in the activation energy by 16.3%. All results shed light on the better catalytic effect of the bimetallic MOF on ionic liquid hypergolic ignition than monometallic coordination compounds.

Determination of macroscale detonation parameters of energetic materials (EMs) in a safe and rapid way is highly desirable. However, traditional experimental methods suffer from tedious operation, safety hazards and high cost. Herein, we present a micro-scale approach for high-precision diagnosis of explosion parameters based on radiation spectra and dynamic analysis during the interaction between laser and EMs. The intrinsic natures of micro-explosion dynamics covering nanosecond to millisecond and chemical reactions in laser-induced plasma are revealed, which reveal a tight correlation between micro-detonation and macroscopic detonation based on laser-induced plasma spectra and dynamics combined with statistic ways. As hundreds to thousands of laser pulses ablate on seven typical tetrazole-based high-nitrogen compounds and ten single-compound explosives, macroscale detonation performance can be well estimated with a high-speed and high-accuracy way. Thereby, the detonation pressure and enthalpies of formation can be quantitatively determined by the laser ablation processes for the first time to our knowledge. These results enable us to diagnose the performance of EMs in macroscale domain from microscale domain with small-dose, low-cost and multiple parameters.

The development of high-performance initiating explosives through energetic complexes is considered a feasible way to satisfy military and civilian applications. Compared with other reported initiating explosives, copper(II)azide is a more promising candidate due to its stronger initiation ability and green nature. However, its instability towards mechanical and electrostatic stimulation hinders its application. This study aimed to propose an effective strategy for stabilizing highly sensitive and explosive copper(II)-azide via hydrogen bonding with NH2 substituted ligands. Using this method, two highly energetic polymers, [Cu(MAT)(N-3)(2)](n) (CMA-1) and [Cu-4(MAT)(2)(N-3)(8)(H2O)](n) (CMA-2), based on 1-methyl-5-aminotetrazole (MAT), were synthesized and confirmed by single-crystal x-ray diffraction. The experimental results showed that both CMA-1 and CMA-2 had improved thermal stability and reduced mechanical and electrostatic sensitivities to meet practical applications, demonstrating the feasibility of stabilizing the copper(II)-azide system through hydrogen bonds. Especially, combining a series of advantages, including nontoxic metal (Cu), high nitrogen content (62.5%), high thermal decomposition temperature (223.3 degrees C), good sensitivities (impact sensitivity = 1.0 J; friction sensitivity = 30 N; electrostatic spark sensitivity = 201.6 mJ), powerful ignition capability (minimum primary charge = 10 mg), and simple synthesis, CMA-2 exhibited comprehensive performance beyond those of all other initiating substances to date. In particular, the electrostatic spark sensitivity (201.6 mJ) is at least 720 times higher than that of the original CA powder (<0.28 mJ), making it a promising candidate for new-generation initiating explosive.

为探索金属氢化物在固体火箭推进剂中的应用可能性,通过差示扫描量热法(DSC)、热烤爆法、动态测压热分析法(DPTA)研究了 AlH3与MgH2对高氯酸铵(AP)热分解性能的影响规律.DSC结果表明,AlH3与MgH2对AP的高温放热分解过程有显著的促进作用,使AP的分解温度提前近50℃;热烤爆法研究AlH3/AP和MgH2/AP混合体系的热感度发现,AlH3和MgH2的引入使得混合体系的热感度升高,AlH3/AP、MgH2/AP和AP的5s爆发点温度分别为:582.63、644.17和662.65 K;DPTA法研究发现,MgH2/AP的放气量仅为0.2mL/g,热安定性好;而AlH3/AP测试过程的放气量为3.2mL/g,安定性较差.金属氢化物AlH3和MgH2对AP热分解表现出良好的催化效果,在AP体系的复合固体火箭推进剂中有潜在应用价值.

目的 研究环四亚甲基四硝胺(HMX)与2,4,6-三硝基甲苯(TNT)、2,4-二硝基苯甲醚(DNAN)、3,4-二硝基呋咱基氧化呋咱(DNTF)3种低熔点、高挥发性含能材料混合后的热安定性及相关性质.方法 将HMX与3种低熔点含能材料按照质量比1:1进行混合,采用动态测压热分析法(DPTA)、差示扫描量热法(DSC)研究混合炸药的相容性、热安定性等性能.结果 DPTA研究表明,HMX与TNT/DNAN/DNTF均相容,结合净分解放气量、反应速率常数的热安定性顺序为HMX/DNTF>HMX/TNT>HMX/DNAN.HMX与TNT、DNAN具有一定的相互作用,使得HMX与TNT、DNAN组成的混合物的热安定性变低.用密封坩埚的DSC法研究表明,根据分解峰温,判断出单质的热安定性顺序为DNTF<TNT<DNAN,混合物的热安定性顺序为HMX/TNT<HMX/DNAN<HMX/DNTF,这与DPTA判定方法得出的结果一致.HMX与DNTF具有良好的相容性,但在高温高压环境下,HMX与TNT、DNAN变得不相容.结论 HMX/DNTF的热安定性较好,在高温高压环境下具有较好的相容性.当熔铸基炸药主装药为HMX时,更适合用DNTF作为熔融物.HMX/TNT、HMX/DNAN在100℃时的热安定性和相容性均较好,在高温高压环境下的相容性差,热安定性也相应较差.

Six new coordination complexes were obtained and fully characterized; complexes 4 and 5 exhibit good catalytic performances on AP.

The thermal decomposition process of GAP in a vacuum confined space was measured by Dynamic Pressure-measuring Thermal Analysis(DPTA). In order to avoid the test error, the test process was improved: the method of liquid nitrogen condensation was used to prevent GAP volatilization in the process of vacuum pumping in the reaction test tube, and the vapor pressure at different temperatures was measured by thermogravimetric analysis. The results show that at 80°C to 120°C, the mechanism function of GAP non-isothermal decomposition reaction is Jander equation, the apparent activation energy is 159.8kJ·mol-1, and the pre-exponential factor lnA is 25.8. At the GAP isothermal reaction stage, the mechanism function changes with the temperature. When the temperature increases, the thermal decomposition reaction changes from diffusion reaction to activation reaction. The decomposition rate constant K increases exponentially with increasing temperature. When T=80°C, K=1.27×10-6; when T=120°C, K=36.93×10-6. According to the data of the decomposition time of 0.1% in the temperature range of 80~120 °C, the Semenov equation is lntT = 19039.90/T- 43.012. The storage life is 35.96 years at 25°C.

In this study, three energetic complexes, namely Cu(1-MIM)(2)(N-3)(2) (1) (1-MIM=1-methylimidazole), [Cu(1-VIM)(2)(N-3)(2)](n) (2) (1-VIM=1-vinylimidazole), and Cu(2-MIM)(3)(N-3)(2) (3) (2-MIM=2-methylimidazole), were synthesized via a simple and mild method. The complexes were characterized by single-crystal X-Ray diffraction, Fourier transform infrared (FTIR) spectroscopy, and elemental analysis. The thermal behavior and sensitivity of the complexes were analyzed by DSC, TG, and BAM methods, and their catalytic performances with respect to AP (ammonium perchlorate), CL-20 (hexanitrohexaazaisowurtzitane), and BNFFO (3,4-dinitrofurazanfuroxan) thermal decomposition were studied by differential scanning calorimetry (DSC). The obtained results indicate that complex 1 exhibits the best catalytic performance for AP thermal decomposition, as it reduces the decomposition (high-temperature) peak temperature by 101.0 degrees C compared to pure AP. Moreover, this complex alters the shape of the decomposition peak, which suggests that it speeds up the decomposition process and renders it more intense. In terms of CL-20 and BNFFO thermal decomposition, complex 3 shows the best catalytic performance, and it reduces the peak decomposition temperatures by 18.4 and 108.2 degrees C, respectively, compared to the pure samples. The activation energies of the AP/complex, CL-20/complex, and BNFFO/complex mixtures were calculated using the Kissinger and Ozawa equations. Considering that the calculated values are lower than those corresponding to the pure substrates, the complexes can be employed as combustion catalysts for composite propellants.

N-nitropyrazole, as a kind of important intermediate, is used to synthesize the novel energetic material. Therefore, it is necessary to get an insight into the isomerization mechanism. Herein, we propose three reaction pathways. Quantum chemistry theory was used to calculate the structure, energy, and thermal parameter. Pathway A is the main path with the lowest energy barrier. The theoretical rate constant is 0.022 min(-1) which has a good agreement with the experimental result of 0.021 min(-1). The proton shift was also studied to confirm that 2H-3-nitropyrazole is the final production.

A type of all-in-one hypergolic MOF has been described, in which CTB ligands as triggers impart active sites for the ignition reaction and imidazole ligands with different substituent groups as bandgap mediators could optimize the hypergolicity.