In this study, a novel multi-nitro asymmetric energetic framework, 5-(dinitromethyl)-5 '-nitroamino-2H,2 ' H-3,3 '- bis(1,2,4-triazole), was constructed, and two related energetic ionic compounds, hydroxylamine salt 4 and ammonium salt 5, were prepared. The molecular configuration of the ammonium salt (5) was determined by single-crystal X-ray diffraction analysis. DSC and BAM tests show that both energetic ionic salts exhibit good thermal stability (T-d>186 degrees C) and relatively low mechanical sensitivity (IS>36 J, FS=360 N). The detonation performances were assessed using the EXPLO5, which is based on calculated enthalpy of formations and densities. The results show that the detonation velocities (vD>8875 m s-1) of the two energetic salts are both higher than those of FOX 7 (vD=8870 m s(-1)) and the conventional explosive RDX (vD=8748 m s(-1)). Consequently, the incorporation of nitrogen-rich cations improves the integrated properties of polynitro-based energetic materials, offering enhanced safety and promising potential for practical applications.

The incorporation of trinitromethyl or dinitromethyl moieties into nitrogen-rich heterocycles represents an effective strategy for the development of high-energy-density materials (HEDMs). In this work, we report the synthesis of a highly oxygen-balanced energetic compound, 2-trinitromethyl-4-(tetrazol-5-yl)-5-nitro-1,2,3-tria-zole (2), characterized by four nitro groups and a high oxygen balance (OBCO2) of-2.4 %. Subsequently, a series of energetic salts based on trinitromethyl-and dinitromethyl-functionalized 1,2,3-triazoles were derived from compound 2. All the newly synthesized energetic compounds were fully characterized via infrared (IR) spectroscopy, multinuclear NMR (1H, and 13C) spectroscopy, and elemental analysis. With the exception of the aminoguanidinium salt 5 (Td =115 degrees C), the salt derivatives exhibit notable thermal stability with decomposition temperatures exceeding 142 degrees C. Furthermore, these compounds display favorable densities (rho = 1.62 g cm-3-1.85 g cm-3) and superior detonation performances (vD = 7880-9256 m s-1, P = 22.8-37.2 GPa). Notably, compound 2 possesses excellent oxygen balance and detonation properties (rho = 1.87 g cm-3, vD = 9256 m s-1, P = 37.2 GPa) that surpass those of RDX. These findings suggest that compound 2 and its energetic salts are promising candidates for application as secondary explosives.

The synthesis and characterization of a heat-resistant and low mechanical sensitivity fused ring tetrazole compound was presented, utilizing IR, multinuclear NMR spectroscopy, thermal analysis, and elemental analysis. It was further analyzed through single crystal X-ray diffraction. The extensive non-covalent interactions (hydrogen bonding and it-it interactions) confer upon compound 3 excellent thermal stability (Td(onest)=312 degrees C) and outstanding mechanical stability (IS=40 J, FS=360 N), highlighting its potential as a new heat-resistant and insensitive energetic material for future application.

The safety of polynitro 1,2,3-triazole energetic materials is improved by introducing hydrogen-rich cation and Namino group to strengthen the intermolecular hydrogen bond network. 2-Amino-4-nitro-5-dinitromethyl-1H1,2,3-triazole and its corresponding energetic salts were successfully prepared, and they exhibit excellent properties compared to 4-nitro-5-dinitromethyl-1H-1,2,3-triazole compounds. Among them, Hydroxylaminium 2-amino-4-nitro-5-dinitromethyl-1H-1,2,3-triazole (7) showed the best detonation performances (Dv = 9389 m center dot s-1, p = 39.6 GPa), which are compatible with that of HMX (Dv = 9320 m center dot s-1, p = 39.5 GPa) and it also show acceptable sensitivities (IS = 7 J, FS = 80 N).

This work focuses on the synthesis and application research of silicon-containing biferrocene derivatives grafted onto hydroxyl-terminated polybutadiene (HTPB), to address the issues of volatility and migration tendency of ferrocene combustion catalysts in solid rocket propellants, as well as the insufficient catalytic performance caused by low iron content in ferrocene-containing polymeric materials. Firstly, a template reaction was employed to optimize the hydrosilylation reaction conditions. In this part, 4-vinyl-1-cyclohexene was employed as substrate, and the ratio of substrate, solvent, reaction time, reaction temperature was optimized. Based on the optimized condition, ferrocene silane derivatives and HTPB were utilized as substrates to obtain HTPB grafted silicon-containing biferrocene compounds. Subsequently, the relationship of biferrocene silane loading and the iron contents as well as the grafting rate were investigated. As the result, three different HTPB grafted silicon-containing biferrocene combustion catalysts were obtained by grafting biferrocene silane derivatives on HTPB polymers through hydrosilylation reactions. The iron contents of above combustion catalysts were 10.7%, 11.9% and 14.1% respectively, which were higher than that of Butacene (8%). At the same time, its thermal stability and catalytic decomposition performance of ammonium perchlorate (AP) were tested. The combustion catalysts were mixed with ultrafine AP at a mass ratio of 5:95, then carefully ground it to uniformity. The solvent was evaporated during the grinding process. After grinding, a mixture of combustion catalyst and AP was obtained, and then differential scanning calorimetry (DSC) and thermogravimetric (TG) study were employed. The results demonstrated that the decomposition temperature of AP under catalytic conditions were reduced. The initial and final decomposition temperatures of AP were reduced after adding 5% biferrocene-containing HTPB, with the final decomposition temperature reduced by about 57 similar to 77 degrees C, and the high decomposition temperature reduced by 87.4 similar to 103.7 degrees C, which could catalyze the decomposition of AP efficiently. These above combustion catalysts might be utilized in HTPB solid rocket propellant in the future.

The development of single chiral source-derived ligands to fine-switch enantioselectivity has been a key aspect in asymmetric catalysis. Herein, in this study, using the same chiral source l-prolinamide as the starting material, we synthesize 14 new diphenyl ether bridged C2-symmetric rigid chiral tertiary amine-derived dioxide ligands (abberviated as BPE-2NO) and 9 new m-phenylene bridged C2-symmetric rigid chiral tertiary amine-derived dioxide ligands (abberviated as Phe-2NO); their effectiveness was demonstrated in the first switch of enantioselectivity in palladium(II)-catalyzed Friedel-Crafts alkylation. In the presence of palladium acetate as the Lewis acid, both enantiomers of indole derivatives can be prepared in good-to-excellent yields and enantioselectivities by using the single chiral source-derived Eagle-shaped BPE/Phe-2NO ligands. Control experiments and density functional theory calculations provide a rational explanation for the above observations. This study was the first switch of enantioselectivity in palladium(II)-catalyzed Friedel-Crafts alkylation by using the single chiral source-derived ligands.

Trinitromethyl and N-amino groups were innovatively incorporated into the framework of 1,2,4-triazole, resulting in 1-amino-5-nitro-3-(trinitromethyl)-1,2,4-triazole (2). Ammonium and hydrazinium salts of 1-amino-5-nitro-3-(dinitromethyl)-1,2,4-triazole were synthesized by acidification, extraction, and neutralization with bases from the potassium salt. All of the newly prepared energetic compounds were comprehensively characterized by using infrared spectroscopy, elemental analysis, nuclear magnetic resonance spectroscopy, and single crystal X-ray diffraction. Compound 2 exhibits favorable properties such as positive oxygen balance (OBCO2 = 5.8%), high density (1.88 g cm(-1)), good detonation performances (v(D) = 8937 m s(-1), P = 35.5 GPa), and appropriate friction sensitivity (FS = 144 N). The potassium salt 3 demonstrates good thermal decomposition temperature (181 degrees C) and high density (1.98 g cm(-1)), while the ammonium salt and hydrazinium salt also display good thermal decomposition temperatures of 183 and 176 degrees C, respectively. Among these compounds, the ammonium salt exhibits the lowest mechanical sensitivities (FS = 144 N, IS = 6 J).

Haifeng Huang is a professor at Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai, P.R. China. He received his Ph.D. in 2012 from Beijing Institute of Technology (BIT) under the guidance of Prof. Zhiming Zhou. Then, he joined Shanghai Institute of Organic Chemistry to start his academic career. His research interests mainly focus on the design and synthesis of new energetic materials. Jun Yang received his Ph.D. at Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences in 2005 under the supervision of Prof. Minzhi Deng. He is now a professor of the Shanghai Institute of Organic Chemistry, CAS. His research interests primarily include the synthesis of energetic materials and energy regulation materials for solid and liquid propellants.

2-Amino-5-nitro-4-(tetrazol-5-yl)-1,2,3-triazole (HANTT), its corresponding energetic salts and a dimeric azo compound are successfully synthesized. Compared to 5-nitro-4-(tetrazol-5-yl)-1,2,3-triazole (H2NTT), the neutral N-amino compound HANTT exhibits excellent properties in many aspects, including a higher density (rho = 1.86 g cm(-3)), a better detonation performance (D-v = 8931 m s(-1), P = 32.2 GPa) and a higher thermal decomposition temperature (T-d = 237 degree celsius). Among the prepared materials, the hydroxylammonium energetic salt exhibits the best detonation performance (D-v = 9096 m s(-1), P = 32.8 GPa) and an acceptable mechanical sensitivity (IS = 12 J, FS = 144 N). HANTT, the energetic salts and the azo compound are fully characterized by infrared spectroscopy, multinuclear NMR spectroscopy, elemental analysis and differential scanning calorimetry.

In this study, a high-nitrogen insensitive energetic material, 2-amino-4,5-bis(tetrazole-5-yl)-1,2,3-triazole (H(2)ABTT), was successfully synthesized by introducing the N-amino group on the 1,2,3-triazole ring. This compound exhibits excellent properties in many aspects. Compared to 4,5-bis(tetrazol-5-yl)-1,2,3-triazole (H3BTT), which has a decomposition temperature (T-d) of 277 degrees C, nitrogen content of 75.11 %, density of 1.69 g cm(-3), a detonation velocity of 8630 m s(-1), a detonation velocity of 26.3 GPa, an impact sensitivity (IS) of 2 J, and a friction sensitivity (FS) of 240 N, H(2)ABTT exhibits higher thermal stability of T-d:303 degrees C, higher nitrogen content of N%:76.35 %, higher density of 1.86 g cm(-3), more desirable detonation properties (detonation velocity Dv: 9185 m s(-1); detonation pressure p: 31.7 GPa), and lower mechanical sensitivities (IS > 100 J; FS > 360 N). Furthermore, H(2)ABTT outperforms insensitive explosive TATB (Dv = 8179 m s(-1); p = 30.5 GPa; IS = 50 J; FS > 360 N) in some properties, making it a potential high-performance insensitive explosive. Besides, energetic salts 4-6 were successfully synthesized based on H(2)ABTT. The calculated results show that some of these salts even possess higher detonation performance compared to H(2)ABTT.

Here, we report the nitration of NH on the 1,2,3-triazole ring and the synthesis of several nitrogen-rich energetic compounds based on key intermediate 4-azido-5-(chlorodinitromethyl)-2-nitro-2H-1,2,3-triazole (5). Starting from 4-amino-1H-1,2,3-triazole-5-carbonitrile (1), we successfully constructed compound 5 through four steps. Subsequently, the dechlorination of compound 5 gave potassium 4-azido-5-(dinitromethyl)-2H-1,2,3-triazole (6) (IS = 1 J, vD = 8802 m s-1). Additionally, diammonium (8) and dihydrazinium (9) salts based on 4-azido-5-(dinitromethyl)-2H-1,2,3-triazole were also successfully synthesized and characterized. A novel fused nitrogen-rich heterocycle, namely, 6H-[1,2,3]triazolo[4,5-d][1,2,3] triazine-6,7-diamine (10), was surprisingly obtained, which has a high nitrogen content of 73.66% and shows good thermal stability (Tdec = 203 °C) and insensitivity to mechanical stimuli, while the detonation velocity (vD) and detonation pressure (P) reach 8421 m s-1 and 26.0 GPa, respectively.

Ni catalysts are commonly used for important transformations in organic chemistry. However, they frequently attend the employment as Ni complexes. Herein, we design an efficient and environmentally compatible nanoscale Ni catalyst for debenzylation reactions via hydrogenative C–N bond cleavage. The Ni nanoparticles (NPs) can be in situ generated by pure H2 reduction based on the precursor Ni–Al hydrotalcite-like compound. The Ni nanocatalysts were systematically characterized with various technique approaches including physical adsorption, XRD, Raman, H2-TPR, TEM, and SEM. Two types of Ni species can be detected, i.e., NiO and Ni0. The latter was supposed to be the active sites. The ultra-small and highly dispersed active Ni0 NPs with average diameters of 5 nm can be formed on the surface of the Ni–Al2O3–H2–78 catalyst. Then the complete conversion and high yield (> 90

A MOF-on-MOF heterostructure is attractive in material science because of its potential combined effects in catalysis. However, precisely controlling the growth pattern at the metal-organic framework (MOF) nucleation stage to manipulate the metallic composition and structure dimensionality remain a challenge. Herein, we introduce a polyvinylpyrrolidone-assist kinetic-control strategy to achieve the "anti-epitaxial growth" pattern of a foreign MOF nucleus on the (111) facets of UiO-66-NH2 octahedron seeds, and construct diverse two-dimensional-on-three-dimensional (2D-on-3D) MOF heterostructures (2D-on-3D Cu, Zn, Cd, Co, and Ni). Notably, the 2D-on-3D Cu exhibits a unique "dimensionality-hybrid" effect in photocatalysis which led to a significant photoactivity enhancement over those of the traditional "dimensionality-identical" 2D, 3D and 3D-on-3D MOF structures.

The pyrazole ring has three modifiable carbon sites and one modifiable NH site.Based on the pyrazole ring, a variety of pyrazole energetic compounds can be designed by the introduction of nitro, nitramino, amino and hydroxyl group and the formation of fused rings.At the same time, compared with conventional energetic compounds such as 2,4,6-trinitrobenzene (TNT), hexahydro-1,3,5-trinitro-triazine (RDX) and 1,3,5,7-tetranitro-1,3,5,7-tetrazocane (HMX), energetic pyrazoles have the advantages of high nitrogen content, high enthalpy of formation and low sensitivities.In recent years, a large number of energetic salts based on pyrazole have been designed and synthesized around the world, including monocyclic energetic salts, bicyclic energetic salts and fused energetic salts based on pyrazole.Many of them exhibit the characteristics of high energy and low sensitivity.The synthesis and properties of recently reported energetic salts based on pyrazole are reviewed, and their applications in the field of energetic materials are prospected.

Three guanidinium salts based on high-oxygen-balanced 1,4-dinitramino-3,5-dinitropyrazolate anion were synthesized. And the structures of these salts were characterized by NMR ( 1 H and 13 C), IR spectroscopy, and elemental analysis, and single crystal X-ray diffraction. Furthermore, their thermal stabilities were analyzed by differential scanning calorimetric measurements (DSC) with the diaminoguandinium salt being thermal stable up to 153.1 o C. Their enthalpies of formation were calculated based on isomesdic reaction by using Gaussian 09 program to be between 193.4 and 613.2 kJ mol -1 . The results show that the densities of salts 8 - 10 are between 1.572 and 1.693 g·cm -3 , and their thermal decomposition temperatures are between 93.4 and 153.1°C. Their detonation velocities and detonation pressures are calculated according to Kamlet-Jacobs detonation equations to be between 7638-8227 m·s -1 and 23.8-28.8 GPa, respectively. Salts 9 and 10 have better detonation performance and high sensitivity, and can be used as primary explosives. Among them, salt 10 has the best detonation performances and the highest hydrogen content (3.5%), which makes it a potential energetic material to be used as air generating agent.

In this work, we successfully synthesized 3-(5-amino-1H-1,2,3-triazol-4-yl)-1,2,4-oxadiazol-5-amine (4) through four steps from 5-amino-1H-1,2,3-triazole-4-carbonitrile, and then applied different nitrification approaches to achieve its single-nitrated and full-nitrated products, namely N-(4-(5-amino-1,2,4-oxadiazol-3-yl)-1H-1,2,3-triazol-5-yl)nitramid (13) and N-(3-(5-(nitroamino)-1H-1,2,3-triazol-4-yl)-1,2,4-oxadiazol-5-yl) nitramide (14). By treating intermediates 13 and 14 with excess free bases, a serial of energetic salts 5-7 and 9-12 were readily obtained. Among these salts, the hydrazinium salt 9 and hydroxylammonium salt 11 possess the best detonation performances (9: P = 30.5 GPa; v(D) = 8493 m s(-1) and 11: P = 33.6 GPa; v(D) = 8682 m s(-1)), which are comparable with RDX. The heat of detonation data (Q) of these salts are distributed from 3077 (6) and 5787 J g(-1) (11). Among them, dihydroxylammonium salt (11) has the most outstanding heat of detonation data reaching 5787 J g(-1).

The synthesis of high-energy-density energetic materials usually suffers from the conflict between energy and stability. The preparation of a 3-nitramino-4-(1H-5-tetrazol-5-yl)furazan based composite energetic salt with mixed cations was successfully achieved. The newly prepared composite energetic salt was fully characterized by IR, NMR, elemental analysis and single-crystal X-ray diffraction. Additionally, its thermal stability and sensitivities were measured and its detonation performances were calculated. The results show that this new salt has more balanced safety and detonation performances compared to its parent salts. (C) 2020 Elsevier Ltd. All rights reserved.

Potassium 1,1,3,3-tetranitropropane-1,3-diide (K2TNP) was found to react readily with various (hetero)aryl amines (12 examples) to give corresponding N-(hetero)aryl-3,5-dinitropyrazoles in moderate to excellent yields. The reactions were performed at mild temperature, and most of the reactions completed in less than 4 h. Four potential energetic compounds show high enthalpy of formation, excellent thermal stability, and good sensitivity, with 3-(3,5-dinitropyrazol-1-yl)-1H-1,2,4-triazole (3j) being a potential 2,2',4,4',6,6'-hexanitrostibene (HNS) replacement.