Synthesis and Study of Steering of Azido-tetrazole Behavior in Tetrazolo[1,5-c]pyrimidin-5-amine-Based Energetic Materials.

Tetrazoles and their derivatives are essential for compound synthesis due to their versatility, effectiveness, stability in air, and cost-efficiency. This has stimulated interest in developing techniques for their production. In this work, four compounds, tetrazolo[1,5-c]pyrimidin-5-amine (1), N-(4-azidopyrimidin-2-yl)nitramide (2), tetrazolo[1,5-c]pyrimidin-5(6H)-one (3), and tetrazolo[1,5-a]pyrimidin-5-amine (4), were obtained from commercially available reagents and straightforward synthetic methodologies. These new compounds were characterized by infrared (IR), 13C, and 1H NMR spectroscopy, differential scanning calorimetry (DSC), and single-crystal X-ray diffraction. The solvent, temperature, and electron-donating group (EDG) factors that were responsible for the steering of azido-tetrazole equilibrium in all compounds were also studied. In addition, the detonation performance of the target compounds was calculated by using heats of formation (HOFs) and crystal densities. Hirshfeld surface analysis was used to examine the intermolecular interactions of the four synthesized compounds. The results show that the excellent properties of 1-4 are triggered by ionic bonds, hydrogen bonds, and π-π stacking interactions, indicating that these compounds have the potential to be used in the development of high-performance energetic materials. Additionally, DFT analysis is in support of experimental results, which proved the effect of different factors that can influence the azido-tetrazole equilibrium in the synthesized pyrimidine derivatives in the solution.

Synthesis, biological and molecular docking studies of pyrimidine-derived bioactive Schiff bases.

Pyrimidine which is an important constituent of the genetic material of deoxyribonucleic acid, is identified with a large number of biological activities. Based on this, pyrimidine-derived Schiff bases (1-6) of hydroxy-1-naphthaldehyde were synthesized by using the condensation method. In addition, the molecular docking studies against topoisomerase II DNA gyrase, human hematopoietic cell kinase, urate oxidase from Aspergillus flavus, and cyclin-dependent kinase 8 to explore the antibacterial, antioxidant, antifungal, and anticancer properties respectively and binding affinities through bioinformatics approaches to determine the interaction among active molecules with the receptor. Hence, the computational docking analyses identified that all synthesized pyrimidine Schiff bases (1-6) are active and exhibited better binding affinities as compared to the standard drugs. Furthermore, all the prepared materials were characterized by using nuclear magnetic resonance, infrared, and elemental analysis. Additionally, the phase-transition and thermal decomposition temperatures were determined by differential scanning calorimetry and thermo-gravimetric analysis measurements. Moreover, the structures of pyrimidine-derived Schiff bases 1, 2, 3, 4, and 5 were also confirmed by the X-ray single-crystal diffraction technique. The pyrimidine-derived Schiff bases 5 possess significant antibacterial, antioxidant, antifungal, and anticancer agent properties which confirms its promising biological activities over standard drugs.

Metal Salts of 4-Chloro-3,5-dinitropyrazole for Promising Eco-Friendly Primary Colors Pyrotechnics.

The construction and design of pyrotechnics with superior performance is not only a task of great significance but also a tremendous challenge. In this regard, we present the syntheses of novel green primary colors pyrotechnics (red, green, and blue light-generating pyrotechnics) by employing 4-chloro-3,5-dinitropyrazole (CDNP) as a multifunctional raw material. CDNP contains a flame enhancer, oxygen-rich functional group, and nitrogen heterocyclic combustibles, which contribute to the high performance of the pyrotechnics. The characteristic elements (strontium, barium, and copper) that impart color to the flame are combined with the CDNP to synthesize the primary colors pyrotechnics by an "all-in-one" strategy. The structures of three energetic metal salts (EMS-1, EMS-2, and EMS-3) are completely characterized, and their thermal stability, sensitivity, ignition performance, and color purity are systematically evaluated. All EMSs show excellent thermal stability and low mechanical sensitivities (>330 °C, >40 J, >360 N). Moreover, the EMSs demonstrate successful ignition and combustion under laser conditions and roasting test conditions, producing bright characteristic flames. Chromaticity analysis reveals that the three EMSs possess good color purities of 91, 80, and 70%, respectively. Consequently, the three integrated pyrotechnics exhibit exceptional combustion properties, highlighting their potential for use in various pyrotechnic applications.

Synthesis, Crystal Structure, and Characterization of Energetic Salts Based on 3,5-Diamino-4H-Pyrazol-4-One Oxime.

In order to broaden the study of energetic cations, a cation 3,5-diamino-4H-pyrazol-4-one oxime (DAPO) with good thermal stability was proposed, and its three salts were synthesized by a simple and efficient method. The structures of the three salts were verified by infrared spectroscopy, mass spectrometry, elemental analysis, and single crystal X-ray diffraction. The thermal stabilities of the three salts were verified by differential scanning calorimetry and thermos-gravimetric analysis. DAPO-based energetic salts are analysed using a variety of theoretical techniques, such as 2D fingerprint, Hirshfeld surface, and non-covalent interaction. Among them, the energy properties of perchlorate (DAPOP) and picrate (DAPOT) were determined by EXPLO5 program combined with the measured density and enthalpy of formation. These compounds have high density, acceptable detonation performance, good thermal stability, and satisfactory sensitivity. The intermolecular interactions of the four compounds were studied by Hirshfeld surface and non-covalent interactions, indicating that hydrogen bonds and π-π stacking interactions are the reasons for the extracellular properties of perchlorate (DAPOP) and picrate (DAPOT), indicating that DAPO is an optional nitrogen-rich cation for the design and synthesis of novel energetic materials with excellent properties.

Access to Green Pyrotechnic Compositions via Constructing Coordination Polymers: A New Approach to the Application of 3,4-Dinitropyrazole.

Alkali and alkaline-earth metal salts with 3,4-dinitropyrazole (DNP) were synthesized by the reaction of DNP with stoichiometric amounts of the corresponding metal hydroxide-, oxide-, or carbonate-based highly pure salts, and products were fully characterized. Determination of single-crystal structures of all new complexes except for the lithium and strontium salts was performed by X-ray diffraction techniques. The cesium salt crystallized no water among them. Differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) manifested that these salts have satisfactory thermal stabilities with decomposition temperatures above 210 °C. They also showed that there exists strong bonding of crystallized water among lattices, which disappeared at temperatures equal to or above 115 °C except for salts MES-3, MES-4, and MES-9. In addition, the percentage of water contents was confirmed by using DSC and TGA methods. The constant-volume combustion heats of these metal salts containing DNP anions were measured using an oxygen bomb calorimeter due to their expectant interest in energetic materials, and their standard molar formation enthalpies were obtained. The investigated salts were found to be insensitive toward friction and impact. Findings of burning tests performed with experimental formulations using MES-1, MES-7, MES-8, and MES-9 certify that these four salts might be more promising candidates for application in green pyrotechnics.

Energetic bimetallic complexes as catalysts affect the thermal decomposition of ammonium perchlorate.

Two bimetallic complexes of 4-hydroxy-3,5-dinitropyrazole, [K2Mn(DNPO)2(H2O)4]n·2H2O (BMEP-1) and [K2Zn(DNPO)2(H2O)6]n (BMEP-2), were synthesized and characterized by IR spectroscopy and elemental analysis. The crystal structures of BMEP-1 and BMEP-2 were determined by single-crystal X-ray diffraction. It is noteworthy that these complexes presented different metal-organic frameworks. The thermal behaviors of BMEP-1 and BMEP-2 were investigated by differential scanning calorimetry and thermogravimetric analysis measurements. These bimetallic complexes exhibited high thermal stability (348.0 °C and 331.0 °C) due to their large coordination bonds and three-dimensional interconnected structure. The catalytic performances of BMEP-1 and BMEP-2 on the thermal decomposition of ammonium perchlorate were investigated by TGA-DSC, TGA-FTIR, and non-isothermal kinetic analyses. The results showed that BMEP-1 and BMEP-2 exhibited excellent catalytic performance in the thermal decomposition of ammonium perchlorate. Notably, there was only a single exothermic peak at 302.6 °C and 318.6 °C, and the activation energy values of ammonium perchlorate decreased to 123.88 kJ mol-1 and 128.43 kJ mol-1, respectively. TGA-FTIR results showed that BMEP-1 and BMEP-2, as effective components of catalysis, will promote the production of H2O, N2O, NO2, and HCl in advance, during the thermal decomposition of ammonium perchlorate. BMEP-1 and BMEP-2 are expected to be two candidate additives for the catalytic decomposition of ammonium perchlorate in composite solid propellants.

Xanthenone-based hydrazones as potent α-glucosidase inhibitors: Synthesis, solid state self-assembly and in silico studies.

Xanthenone based hydrazone derivatives (5a-n) have been synthesized as potential α-glucosidase inhibitors. All synthesized compounds (5a-n) are characterized by their FTIR, 1H NMR, 13C NMR and HRMS, and in case of 5g also by X-ray crystallographic technique. The compounds unveiled a varying degree of α-glucosidase inhibitory activity when compared with standard acarbose (IC50 = 375.38 ±â€¯0.12 µM). Amongst the series, compound 5l (IC50 = 62.25 ±â€¯0.11 µM) bearing a trifluoromethyl phenyl group is found to be the most active compound. Molecular modelling is performed to establish the binding pattern of the more active compound 5l, which revealed the significance of substitution pattern. The pharmacological properties of molecules are also calculated by MedChem Designer which determines the ADME (absorption, distribution, metabolism, excretion) properties of molecules. The solid state self-assembly of compound 5g is discussed to show the conformation and role of iminoamide moiety in the molecular packing.