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In an attempt to cultivate energy‐stability balance, a series of nitrogen and oxygen‐rich high energy density materials were synthesized based on N‐substituted 4‐hydroxy‐3,5‐dinitropyrazole and methylene‐linked N‐amino‐1,2,4‐bridges. The hydroxy substituent contributed to oxygen content, hydrogen bonding, and tunability via salt formation. On the other hand, the triazole bridge delivered high nitrogen content and thermal stability. All the synthesized compounds were characterized with multinuclear NMR, FTIR, HRMS, and elemental analysis, and their physicochemical and energetic properties were analyzed. Energetic materials 1–5 showed high detonation performance and adequate overall stabilities. Compound 1 exhibited higher density (1.84 g/cm3) and detonation performance (Dv = 8103 m/s, P = 26.9 GPa) in comparison to its reported amino derivative. [ABSTRACT FROM AUTHOR]

Heat‐resistant explosives play a vital role in indispensable applications. For this, we have synthesized a novel, three‐dimensional, solvent‐free energetic metal−organic framework (EMOF) potassium 3,5‐dinitro‐6‐oxo‐1,6‐dihydropyrazin‐2‐olate (KDNODP) straightforwardly. The synthesized EMOF was characterized through IR, NMR spectroscopy, elemental analysis, and differential scanning calorimetry studies. Furthermore, single‐crystal X‐ray diffraction provided a complete description of KDNODP. It exhibits a three‐dimensional EMOF structure with remarkably balanced properties such as high density (2.11 g cm−3), excellent thermal stability (291 °C), good detonation performance (8127 m s−1 and 26.94 GPa) and low mechanical sensitivity (IS=35 J; FS=360 N) than the commonly used heat‐resistant explosives HNS (density=1.74 g cm−3; VOD=7164 m s−1, DP=21.65 GPa, IS=5 J) as well as the similar reported energetic potassium MOFs. To gain insights into the packing and intermolecular interactions, the Hirshfeld surface and a 2D fingerprint analysis were examined. Additionally, scanning electron microscopy was used to investigate the particle size and morphological characteristics of KDNODP. These outcomes highlight a successful method for creating 3D EMOF based on a six‐membered heterocycle as a potential heat‐resistant energetic material. [ABSTRACT FROM AUTHOR]

A series of five and six‐membered C‐C bonded energetic materials (2–7) based on a combination of imidazole‐triazine and triazole‐triazine backbones were designed, synthesized, and characterized using NMR, IR, Mass spectrometry, and TGA‐DSC studies. Further, the structure of compound 4 was supported by single‐crystal X‐ray analysis. All the newly synthesized energetic compounds exhibit good density, excellent thermal stability, good detonation performance, and low mechanical sensitivity toward impact and friction. Among all, the nitrate salt 4 exhibits balanced properties, including high density (1.80 g cm−3), excellent thermal stability (254°C), good detonation velocity (8178 m s−1), and low sensitivity towards impact and friction. The facile synthetic feasibility, thermal stability, energetic performance, and insensitivity of all the molecules suggest they can be used as an insensitive secondary explosive in various defense and civilian applications. [ABSTRACT FROM AUTHOR]

A series of nitrogen-rich fused energetic materials were synthesized from commercially available inexpensive starting materials and fully characterized using 1H and 13C NMR, IR spectroscopy, elemental analysis, and DSC. The structure of zwitterionic compound 2 was supported by SCXRD data. Among all, 3 and 4 possess excellent detonation velocity (8956 and 9163 m s−1) and are insensitive towards friction (>360 N) and impact (10 J), having moderate to excellent thermal stability (171–262 °C). It is worth mentioning that the zwitterionic fused pyrazolo-triazole compound 2 and its energetic salts offer remarkable performance as new-generation thermally stable energetic materials. [ABSTRACT FROM AUTHOR]

In energetic materials research, energetic coordination compounds (ECCs) have received much attention due to their high thermal stability and insensitivity to mechanical stimuli. The energetic characteristics of ECCs can be modified by combining various metal cations, potent anions, and ligands. In this study, we have synthesized two energetic ligands, 5-(4-nitro-1H-pyrazol-3-yl)-1H-1,2,4-triazol-3-amine (NPTA) and (Z)-N-(5-(4-nitro-1H-pyrazol-3-yl)-2,4-dihydro-3H-1,2,4-triazol-3-ylidene)nitramide (NPTN), from a commercially viable starting material and reacted them with nitrate salts of various 3d metals (e.g., Ni, Co, Zn) to obtain six new ECCs, [Ni(NPTA)(H2O)3]2·2NO3 (1), [Co(NPTA)(H2O)3]2·2NO3 (2), [Zn(NPTA)(H2O)3]2·2NO3 (3), [Ni(NPTN)(H2O)3]2 (4), [Co(NPTN)(H2O)3]2 (5), and [Zn(NPTN)(H2O)3]2 (6) under ambient conditions. All the newly prepared ECCs were characterised through PXRD, IR, SEM, and TGA-DSC analysis. Furthermore, single crystal analysis proved that 1–6 are dimeric complexes. Moreover, 1–6 show excellent density ranges from 1.94 to 2.06 g cm−3 and remarkable thermal stability (216–352 °C), and are highly insensitive towards impact (>40 J) and friction (>360 N), describing their potential as high performing energetic materials. All the ECCs revealed good enthalpy of combustion (−6.3 to −9.94 kJ g−1). Additionally, the Hirshfeld surface and 2D fingerprint analysis were used to understand the close contact of atoms within the molecules. High crystal densities, thermal stabilities and low sensitivities make the synthesized ECCs interesting for further studies and potential applications as safe high-energy dense materials. [ABSTRACT FROM AUTHOR]

4H,8H-bis[1,2,5]oxadiazolo[3,4-b:3',4'-e]pyrazine (bis-oxadiazolo-pyrazine) represents a versatile CHNO backbone for the design of energetic materials. In this paper, we report a comprehensive computational study using density functional theory to improve detonation properties of this CHNO backbone by introducing pyrazine rings, nitro groups, and N-oxide functionalities. The heat of formation, oxygen balance, density, and detonation properties of a series of furazan-pyrazine fused ring derivatives are computed. Their sensitivity and stability has been correlated with bandgap (ΔELUMO-HOMO), maximum heat of detonation (Q), and impact energy (h50). Introduction of –NO2 and N–oxide on the parent furazan-pyrazine fused ring derivatives is favorable for improving the heat of formation, oxygen balance and density. The heat of formation varies between 464.46 and 1043.57 kJ/mol, and the densities range from 1.75 to 2.01 g/cm3. The positive heat of formation and high densities achieved good detonation velocities (6.74 to 9.61 km/s) and pressures (19.96–43.65 GPa). Among the bis-oxadiazolo-pyrazine derivatives, P5, P6, Q5, Q6, R4, R5, and R6 are fascinating due to their high detonation performances, have calculated detonation velocities and pressures above 9.30 km/s and 40.0 GPa, respectively. Some furazan-pyrazine fused ring derivatives reveal good performance parameters with reasonable stability, confirming them as potential energetic compounds relative to RDX and HMX. [ABSTRACT FROM AUTHOR]

A series of gem-dinitromethyl substituted zwitterionic C – C bonded azole based energetic materials (3–8) were designed, synthesized, and characterized through NMR, IR, EA, and DSC studies. Further, the structure of 5 was confirmed with SCXRD and those of 6 and 8 with 15N NMR. All the newly synthesized energetic molecules exhibited higher density, good thermal stability, excellent detonation performance, and low mechanical sensitivity to external stimuli such as impact and friction. Among all, compounds 6 and 7 may serve as ideal secondary high energy density materials due to their remarkable thermal decomposition (200 °C and 186 °C), insensitivity to impact (>30 J), velocity of detonation (9248 m s−1 and 8861 m s−1) and pressure (32.7 GPa and 32.1 GPa). Additionally, the melting and decomposition temperatures of 3 (Tm = 92 °C, Td = 242 °C) indicate that it can be used as a melt-cast explosive. The novelty, synthetic feasibility, and energetic performance of all the molecules suggest that they can be used as potential secondary explosives in defence and civilian fields. [ABSTRACT FROM AUTHOR]

Abstract: Based on the backbone of the nitrogen-rich triazole and tetrazole structure, their N-OH derivatives were designed to improve the properties of energetic materials. This work introduces five novel nitrogen-rich [...]

A carbamate-linked-bistriazole (5) was prepared by click reaction of diethynyl 1,3-phenylenedicarbamate (2) and phenyl azide derivative (4) in DMF/H2O using copper sulfate and sodium ascorbate as a catalyst at room temperature for fluoride ion sensing. The structural analysis of synthesized compound was done by using 1HNMR, 13C NMR, FTIR and HRMS. The sensing behavior of carbamate-linked-bistriazole (5) was examined by 1HNMR, UV–vis and fluorescence study. NMR titration study suggested the participation of triazole, amide and aromatic protons in binding of fluoride ion. UV–visible study established the 1:1 complexation ratio between sensor 5 and F– ion with stability constant K of 2.64 × 104 M−1 and detection limit in µM range (9.372 µM). Further, fluorescence titration for 5 (9.2 × 10−6 M) with fluoride ions exhibited an emission quenching at 424 nm along with small bathochromic shift. Density functional theory (DFT) calculations also confirmed interaction mechanism in 5a-F– complex established by, UV–visible, 1H NMR and fluorescence studies. [ABSTRACT FROM AUTHOR]