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Thirteen tetranitro-diazinodiazines have been designed and investigated to find the importance of diazinodiazine fused-heterocyclic backbone for energetic materials. The positional influence of four nitrogen atoms in the diazinodiazine backbone on the heat of formation, performance, and stability has been investigated by density functional theory. It is observed that diazinodiazine is an efficient backbone to improve energy content in the designed derivatives. The energy contribution from the diazinodiazine backbone varies from 352–558 kJ/mol. Introducing four –NO2 groups into the diazinodiazine backbone resulted in new energetic molecules with acceptable detonation performance and stability. Their densities, detonation velocities, and detonation pressures were 1.87–1.89 g/cm3, 8.36–8.68 km/s, and 31.72–34.42 GPa, respectively. The bond dissociation energies for the longer C–NO2 bonds fall in the range of 207–233 kJ/mol, reveals the stable nature of tetranitro-diazinodiazines. Thus, diazinodiazine isomers may be regarded as promising aromatic heterocyclic backbone, and tetranitro-diazinodiazines appear to be potential candidates for energetic materials.

The oxadiazole ring is an essential nitrogen-containing heterocycle and a valuable building block that is used in developing numerous functionalized energetic compounds. To understand the effect of multiple oxadiazole rings on energetic performance and sensitivities, we investigated oxadiazole rings connected with C–C and NN bond-possessing –NO2 and –NHNO2 groups. The results show that skeletal energy can be increased by the incorporation of oxadiazoles. All the studied compounds have positive heat of formation (> 410 kJ mol−1) that are larger than those of 3,4-dinitrofurazan (O1, 219 kJ mol−1) and N,N′-1,2,5-oxadiazole-3,4-diyldinitramide (O7, 254 kJ mol−1). Even though various molecular combinations offer unlimited structural diversity options and energetic properties, the linear addition of oxadiazole rings efficiently reduces sensitivity but with decreased oxygen balance and detonation performance. To achieve a balance between sensitivity and detonation performance, incorporating oxadiazole rings in the molecular framework may be considered as an efficient scaffold and can significantly assist in the progress of developing new energetic compounds.

To develop environmentally friendly green energetic materials with excellent insensitivity, thermal stability, and detonation performance, a series of nitrogen-rich salts were synthesized from di(1H-tetrazol-5-yl)methane and N,N′-(methylenebis(1H-1,2,4-triazole-3,5-diyl))dinitramide using a simple and straightforward high-yield approach. The molecules were characterized using NMR, IR, elemental analysis, and differential scanning calorimetry. Single-crystal X-ray diffraction studies confirm the molecular structures of salts 4 and 15. Their key energetic parameters, viz., energy content, density, detonation performance, melting and decomposition temperatures, and impact/friction sensitivities, were assessed. All of these salts showed excellent thermal stability over 210 °C as measured using DSC. The crystal structures of compounds 4 and 15 show a strong intramolecular network of hydrogen bonding that is expected to stabilize the salts and induce a higher insensitivity to mechanical stimuli. All the newly synthesized derivatives exhibit a superior energetic performance over TNT, close to RDX. The salts 5, 6, 10–14, and 16 display properties better than TATB and are expected to serve as potential energetic materials.

A rapid practical process has been developed for synthesis of 2,4,5-trisubstituted-imidazoles in excellent yields up to 95% from readily available starting materials. In this CuI catalyzed synthesis, trisubstituted imidazoles were afforded in short reaction times, wherein the substrate scope is well explored with benzoin as well as benzil reacting with different aldehydes in the presence of ammonium acetate as the nitrogen source.

Various energetic salts (

Phenylalanine ammonia-lyase (PAL) has gained attention in recent years for the treatment of phenylketonuria (PKU), a genetic disorder that affects ∼1 in 15,000 individuals globally. However, the enzyme is easily degraded by proteases, unstable at room temperature, and is currently administered in PKU patients as daily subcutaneous injections. We report here the stabilization of the PAL from Anabaena variabilis, which is currently used to formulate pegvaliase, through incorporation in a silk fibroin matrix. The combination with silk stabilizes PAL at 37 °C. In addition, in vitro studies showed that inclusion in a silk matrix preserves the biological activity of the enzyme in simulated intestinal fluid, enabling the oral administration of pegvaliase for the treatment of PKU.

Background: The present research work is focused on the development of alternative antioxidant and anti-inflammatory agents. The review of the literature reveals that many benzofused thiazole analogues have been used as lead molecules for the design and development of therapeutic agent, including anticancer, anti-inflammatory, antioxidant and antiviral. The synthesized benzofused thiazole derivatives are evaluated for in vitro antioxidant, anti-inflammatory activities and molecular docking study. Thus, the present research work aims to synthesize benzofused thiazole derivatives and to test their antioxidant and antiinflammatory activities. Objective: To design and synthesize an alternative antioxidant and anti-inflammatory agents. Methods: The substituted benzofused thiazoles 3a-g were prepared by cyclocondensation reaction of appropriate carboxylic acid with 2-aminothiophenol in POCl3 and heated for about 2-3 h to offer benzofused thiazole derivatives 3a-g. All the newly synthesized compounds were in vitro screened for their anti-inflammatory and antioxidant activities by using a known literature method. Results: At the outset, the study of in vitro indicated that the compounds code 3c, 3d and 3e possessed distinct anti-inflammatory activity as compared to a standard reference. All the tested compounds show potential antioxidant activity against one or more reactive (H2O2, DPPH, SO and NO) radical scavenging species. Additionally, docking simulation is further performed to the position of compounds 3d & 3e into the anti-inflammatory active site to determine the probable binding model. Conclusion: New anti-inflammatory and antioxidant agents were needed; it has been proved that benzofused thiazole derivatives were 3c, 3d and 3e constituted as an interesting template for the evaluation of new anti-inflammatory agents and an antioxidant’s work also may provide an interesting template for further development.

A new series of 1-Thiazolyl-2-Pyrazolines 5a-g was accomplished by reacting pyrazolealdehyde with an appropriate aromatic ketone in the presence of PEG-300 as a solvent to yield chalcone. The chalc...

Eight new energetic salts combining N-bases (amines) with picrate ions were synthesized in high yields and characterized by NMR (1H and 13C), IR spectroscopy, elemental analysis, and differential thermal analysis. Single-crystal structural studies were performed to confirm the structures, packing, and various interactions in the salts. Interestingly, salts 1 and 7 exist in different polymorphic forms and the effect of solvent on polymorphism was examined (i.e. solvatomorphism). Thermal stability and impact and friction sensitivities were also determined to understand the relationship between their structures and properties. Salt 3 with hydrazinium cations showed higher performance (d = 1.82 g cm−3; Td = 255.2 °C; D = 7.95 km s−1; P = 28.2 GPa; IS ≥ 30 J; FS ≥ 350 N) towards energetic applications. However, salts 4, 7, and 8 also exhibit good performance parameters, which are marginally better as compared to TNT. The tuning of the physiochemical properties and performances was carried out with the modification of the cationic-amine molecules and the molar ratio of the reactants.

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.

An efficient protocol for the synthesis of symmetrical 3,3’-bis(indolyl)arylmethanes catalyzed by green and easily available ammonium iron(II) sulfate (Mohr’s salt) has been developed in “green” water solvent afforded in excellent yield.