Energetic Compounds Research Articles

Correction: Exploring high-energy and low-sensitivity energetic compounds based on experiments and DFT studies

Correction for ‘Exploring high-energy and low-sensitivity energetic compounds based on experiments and DFT studies’ by Qiaoli Li et al., New J. Chem., 2023, 47, 19523–19528, https://doi.org/10.1039/D3NJ03514J.

Preparation of novel heat-resistant and insensitive fused ring energetic materials

Compared with traditional polycyclic-based heterocyclic energetic compounds, the synthesis of fused ring compounds is more challenging since only a few substrates meet the structural requirements for a fused cyclization reaction.

Taming of 4-azido-3,5-dinitropyrazole based energetic materials

Energetic and physicochemical properties of 4-azido-3,5-dinitropyrazole based energetic compounds were fine-tuned by connecting it to 5-nitramino-1,2,4-oxadiazole moieties via N-methylene-C bridges and energetic salt formation strategy.

Harnessing triazole–oxadiazole–trinitromethyl moieties in the synthesis of insensitive energetic material with enhanced detonation performance

The nitrogen-and oxygen-rich azole-based high energetic compound 3,3′-(2-(trinitromethyl)-2H-1,2,3-triazole-4,5-diyl)-bis(1,2,4-oxadiazole) was synthesized from a readily accessible bis-cyano-substituted-azole in three steps with good yield.

Design of N-N ylide bond-based high energy density materials: a theoretical survey.

The generally encountered contradiction between large energy content and stability poses great difficulty in designing nitrogen-rich high-energy-density materials. Although N-N ylide bonds have been classified as the fourth type of homonuclear N-N bonds (besides >N-N<, -N[double bond, length as m-dash]N-, and N[triple bond, length as m-dash]N), accessible energetic molecules with N-N ylide bonds have rarely been explored. In this study, 225 molecules with six types of novel structures containing N-N ylide bonds were designed using density functional theory and CBS-QB3 methods. To guide future synthesis, the effects of substitution on the thermal stability, detonation velocity, and detonation pressure of the structures were evaluated under the premise that the N-N ylide skeleton remains stable. The calculations show that the bond dissociation energy values of the N-N ylide bonds of the designed 225 structures were in the range of 61.21-437.52 kJ mol-1, except for N-1NNH2. Many of the designed structures with N-N ylide bonds exhibit high detonation properties, which are superior to those of traditional energetic compounds. This study convincingly demonstrates the feasibility of the design strategy of introducing an N-N ylide bond to develop new types of energetic materials.

Structure and performance regulation of energetic complexes through multifunctional molecular self-assembly.

The design of novel energetic compounds constitutes a pivotal research direction within the field of energetic materials. However, exploring the intricate relationship between their molecular structure and properties, in order to uncover their potential applications, remains a challenging endeavor. Therefore, employing multi-molecule assembly techniques to modulate the structure and performance of energetic materials holds immense significance. This approach enables the creation of a new generation of energetic materials, fueling research and development efforts in this field. In this study, a series of coordination compounds are synthesized by utilizing tetranitroethide (TNE) as an anion, which possesses a high nitrogen and oxygen content. The synthesis involves the synergistic modification between metal ions and small molecule ligands. Characterization of the obtained compounds is carried out using various techniques, including single crystal X-ray diffraction, IR spectroscopy, elemental analysis, and simultaneous TG-DSC analysis. Additionally, the energy of formation for these compounds is calculated using bomb calorimetry, based on the heat of combustion. The detonation performances of the compounds are determined through calculations using the EXPLO 5 software, and their sensitivities to external stimuli are evaluated.

Transformation of vegetation under the conditions of the impact of military actions on the natural environment in Ukraine: A review

The negative consequences of various types of military activity on physical disturbances and chemical pollution of the environment are systematized. Factors of chemical pollution include potentially toxic elements, energetic compounds (explosives, fuels) and chemical warfare agents. According to the systematization of the available data on the long-term impact of military exercises and military actions on the territories of different countries on soil pollution, metal compounds dominate among potentially toxic elements, and organic pollutants dominate among energetic compounds. The combination of physical violations with multicomponent chemical pollution creates a specificity of the negative impact of the consequences of military activity on the natural environment compared to other anthropogenic factors. The following directions of research into the problem were noted: detection, distribution and ecotoxicology of chemical pollutants in natural environments, impact on biodiversity and vegetation dynamics, phytoremediation to reduce the level of chemical pollution, ecological and physiological factors of plant tolerance, degradation and detoxification of organic pollutants in plants. The tolerance of plants to the residues of explosive substances of various classes occurs due to the general pathways of biochemical transformation, which ensure the detoxification of organic xenobiotics. Taking into account the current state of the problem, literary data on the directions of research into the impact of military actions in Ukraine on the environment and the transformation of vegetation are summarized. Among these areas, the following were noted: assessment of damage caused by armed aggression to the natural environment; environmental monitoring of combat action; analysis of pollution of the natural environment; transformation of vegetation. Destructions of the natural environment as a result of combat action led to significant changes in vegetation, which are associated with ruderalization and adventization. The role of ruderal (including invasive) plants common in the flora of Ukraine under conditions of chemical pollution of habitats is analyzed. Increased tolerance of invasive plant species to high levels of metals and organic pollutants can be used for phytoremediation of disturbed areas, but will create a competitive advantage for more intensive spread compared to native species and new risks to phytodiversity.

Amine and nitramine functionalization of imidazole‐triazine and triazole‐triazine skeletons: Exploring for potential multipurpose energetic materials

AbstractA 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.

Torrefaction of kraft pulp mills sludges

Torrefaction emerges as an industrial process that increases the energy content of conventional biomass. Primary and secondary sludge are the main solid residues generated in the Effluent Treatment Plants of bleached kraft pulp mills, and can be considered as biomass. Typically, these wastes are sent to industrial landfills. The present study aimed to evaluate the technical feasibility of transforming the primary sludge (PS), secondary sludge (SS) and mixed sludges (MIX) into torrefied biomass for energy generation. Three temperatures (260, 290 and 320 °C) and three residence times (20, 40 and 60′) were used in the sludge torrefaction process. Increasing the torrefaction temperature and residence time of the sludges produced several benefits on their physical and chemical properties. They promoted an increase in the heating value, due to the elimination of less energetic compounds and the concentration of the fixed carbon content; caused a reduction of moisture, with a consequent increase in the lower heating value of the sludges; and led to a high energy yield and an increased energy density, important parameters in sludges energy generation. The treatment at 320 °C for 60′ obtained increases of 76%, 27% and 41% over the reference, for PS, SS and MIX, respectively.

3,5‐difluoro‐2,4,6‐trinitrophenol: A high‐energy compound born under the “NO2FNO2” construction strategy

Abstract3,5‐Difluoro‐2,4,6‐trinitrophenol (DFTNP) was designed as energetic compounds, based on the “NO2FNO2” strategy. Its structure was fully characterized by IR, NMR, elemental analysis, and single‐crystal X‐ray diffraction. Physico‐chemical characterization of this compound was investigated based on several theoretical techniques. The result indicated that DFTNP is less sensitive to external stimuli, with a thermal sensitivity of 213 °C, impact and friction sensitivity of 15 J and 240 N. It also shows particularly high density (ρ=1.949 g cm−3) and detonation performance (D=8440 m s−1, P=32.60 GPa), which far exceeds the performance of picric acid. Its crystal packing and the intermolecular interaction of DFTNP play an important role inreducing localized heating. In addition, this compound also has great potential for building ionic salts, and its ammonium salt performance exhibits better performance. Good performance not only highlight this compound as a suitable replacement for picric acid, but also suggests that “NO2FNO2” may be a good choice in designing energetic compounds.

Initiation Step in the Condensed Phase Decomposition Process of Ammonium Perchlorate

AbstractAmmonium perchlorate (AP) is a commonly used oxidizer in solid propellant compositions. As a result, numerous experimental and theoretical studies have been carried out in order to better understand the behavior of its decomposition in both the liquid and gas phases. In this work, the first step of Ammonium perchlorate (AP) decomposition in the condensed phase has been investigated using quantum mechanics‐based calculations. The process of proton transfer from ammonium ion (NH4+) to perchlorate ion (ClO4−) was investigated in‐depth as it is thought to be the preferred reaction for the initiation of AP decomposition in the condensed phase. The calculations were carried out using density functional theory (DFT) at the B3LYP level in conjunction with the 6‐311G++(d,p) basis set. The current study revealed that proton transfer from ammonium cation to perchlorate anion takes place in two steps. The first step involves the decomposition of ClO4− to ClO2− and O2 followed by the second step which is H+ transfer from NH4+ to ClO2− giving NH3 and HClO2. In order to better understand protonation and deprotonation, it is essential to know the proton affinity (PA) of the involved species. In this study, the CBS‐QB3 method is used to determine the PA of various energetic ionic compounds. These compounds include guanidinium azotetrazolate, triaminoguanidinium azotetrazolate, guanidinium nitrate, ammonium nitrate, and ammonium perchlorate. Based on the results of the calculations, it is concluded that direct proton transfer process does not occur in the condensed phase because the proton affinities of all cations are significantly higher than those of the corresponding anions. In conjunction with experimental studies, this modelling study can help in the development of a better understanding of AP decomposition in the condensed phase.

Preparation of Highly Energetic Coordination Compounds with Rich Oxidants and Lower Sensitivity Based on Methyl Groups.

Revamping the structure of energy storage is an efficient strategy for striking a balance between the performance and sensitivity of energetic materials to achieve high energy and reduced sensitivity. In continuation of prior research, this study utilized the ligand 3,5-dimethyl-1H-pyrazole-4-carbonhydrazide (DMPZCA) and innovatively designed and synthesized the compound ECCs [Cu(HDMPZCA)2(ClO4)2](ClO4)2·2H2O (ECCs-1·2H2O). Compared with the former research, solvent-free compound ECCs-1 refers to an innovative material characterized by a dual structure involving ionic salts and coordination compounds. Due to these unique structures, ECCs-1 exhibits an increased [ClO4-] content, a higher oxygen balance constant (OB = -7.9%), and improved mechanical sensitivity (IS = 8 J, FS = 32 N). Theoretical calculations support the superior detonation performance of ECCs-1. Additionally, experimental results confirm its ignition capability through lower-threshold lasers and highlight the outstanding initiation potential and explosive power, making it a suitable candidate for primary explosives.

Structure property correlation study of energetic solid XeO3

In the realm of material science, xenon trioxide (XeO3) is characterized by an significant degree of shock sensitivity, resembling characteristics associated with primary explosives. To determine the underlying principles and quantify such behaviour we present a comprehensive computational study addressing the structural, vibrational, electronic and optical behaviour of energetic XeO3 by employing DFT calculations (Density Functional Theory). Our study demonstrates a good agreement between our computed structural parameters at equilibrium and experimental findings, particularly after incorporating vdW (van der Waals) interactions. Also, the mechanical stability of XeO3 is assessed by computing the Cij (elastic constants) and the B (bulk modulus). The evaluation of elastic constants in various directions indicates that (C33 > C22 > C11) XeO3 is highly shock sensitive along crystallographic a-axis. The computed (B) bulk modulus is determined to be 12.98 GPa, aligning closely with the values observed in other primary explosives. The phonon dispersion spectra computed within the harmonic approximation confirms the dynamical stability of XeO3 in P212121 structure. The spectra also reveal a notable interaction between the acoustic and optical branch, resulting in low thermal conductivity which is a trait for the energetic materials. The precise measurement of the energy band gap is crucial for establishing potential correlations with the photodecomposition process of energetic materials. To support this, we have conducted band structure calculations using the TB-mBJ (Tran-Blaha modified Becke-Johnson) potential, alongside the conventional GGA/LDA methods, generally known to underestimate band gaps. Our TB-mBJ based calculations yielded an energy band gap around 2.5 eV, which can also be compared with other energetic compounds. The rapid fluctuations of the optical constants suggest photodecomposition nature of XeO3 in the near UV region. The insights gained from our study would be of high interest for the study of other xenon (Xe) compounds and their oxides, delivering direction for potential applications across diverse fields.

The green chemistry paradigm in modern organic synthesis

After the appearance of the green chemistry concept, which was introduced in the chemistry vocabulary in the early 1990s, its main statements have been continuously developed and modified. Currently, there are 10–12 cornerstones that should form the basis for an ideal chemical process. This review analyzes the accumulated experience and achievements towards the design of chemical products and processes that reduce or eliminate the use or generation of hazardous substances. The review presents the views of leading Russian scientists specializing in various fields of this subject, including homogeneous and heterogeneous catalysis, fine and basic organic synthesis, electrochemistry, polymer chemistry, chemistry based on bio-renewable feedstocks and chemistry of energetic compounds and materials. A new approach to the quantitative evaluation of the environmental friendliness of processes developed by Russian authors is described. &lt;br&gt; The bibliography includes 1761.

Trinitromethyl groups-driven fused high energy compound featuring superior comprehensive performances

Balancing the inherent contradiction between energy and stability (especially for thermal stability) is particularly challenging in the design and synthesis of novel trinitromethyl energetic compounds. In this study, the stable trinitromethyl derivatives of TNFH and 8 were synthesized with three or four steps, and further structurally characterized by NMR, elemental analysis, infrared (IR) and single crystal X-ray diffraction. It is worth mentioning that the TNFH exhibit highest decomposition temperature (onset, 205 °C) among those trinitromethyl based high explosives to date. Since the existing contradiction between energy and safety, there are rarely trinitromethyl derivatives with similar detonation performance and insensitivity compared with the currently used strongest military explosive HMX. Thanks to the stable vicinal amino-nitro group of fused polycyclic motifs, TNFH exhibits excellent comprehensive performance over HMX (ρ: 1.905 g cm−3, D: 9144 m s−1, P: 39.3 GPa, IS: 7.5 J, FS: 120 N), including a high density of 1.947 g cm−3, superior detonation velocity and pressure (D: 9492 m s−1, P: 41.0 GPa), lower impact and friction sensitivity (IS: 12 J, FS: 192 N), thereby demonstrating great practical application potential as a substitute for HMX.

Isomerism of nitratoalkylazoles

In the field of energetic materials, traditional materials with high toxicity or other disadvantages are mostly used. There is an urgent need for trinitrotoluene replacements (TNT), which itself is toxic and its production is problematic due to red wastewater. New materials should be safe to handle, have good performance, and be inexpensive to synthesize. Nitratoalkylazoles are known to have low melting points and good energetic properties compared to TNT. In this paper, seven energetic compounds are synthesized starting from 5-methyltetrazole, 5-hydroxymethyltetrazole and 4,5-bishydroxymethyltriazole. The nitrates are characterized in terms of their physical, chemical, and energetic properties. Of those seven compounds, five are solid, melting between 27 °C and 110 °C, and two are liquid. Methylation and hydroxyalkylation were performed and discussed extensively. The organic nitrate is introduced in the last step so that the synthesis remains safe and scalable. Correlations between the molecular geometry and the melting points are explained. Calculations indicate detonation velocities that are 6%–11% higher than those of TNT. A discussion of the effect of isomerism on the properties leads to surprising insights and should help focus and accelerate research on the replacement of TNT.

Deciphering melting behaviors of energetic compounds using interpretable Machine learning for melt-castable applications

Melting behaviors of energetic compounds determine their thermo-responsive properties, which affects the manufacturing operations and structural stabilities. However, the decisive physicochemical mechanisms for melting behaviors of energetic compounds are absent, which hurdles the acceptancy and generalization of prediction models for rational molecular design. Herein, an interpretable machine learning (IML) approach was proposed to construct accurate prediction models for melting point values and melt-castable potentials of energetic compounds. A high-quality melting-point dataset comprising 239 neutral CHNO compounds was obtained, and the data was collected with strict criteria involving chemical formulations, crystal structures and experimental measurement operations. Tailored descriptors, which involve the priori insights for melting behaviors, were adopted for IML algorithms. The extreme gradient boosting model presents the best prediction accuracy (85 %) for the classification of melting point values between 273 K and 650 K; while 87 % accuracy is achieved for the classification of melt-castable property. Importantly, model interpretation assists to reveal that the close contacts between OC and NC, dipole, oxygen balance and the cohesive energy are decisive features for melting point prediction; while enthalpy of sublimation and polar surface area are paramount for the identification of melt-castable property. The ability to determine melting behaviors using IML will broaden the high-throughput screening of energetic compounds and offer valuable guidance towards molecular design.

Influence of nitroamino−nitroimino tautomerism: A useful theoretical supplement for nitroamino-based energetic materials

Nitroamino is an ideal high-energy group for constructing energetic compounds. The skeletal isomerization of nitroamino to nitroimino forms intramolecular HBs, thus resulting in better density, thermal stability and sensitivity. However, it is difficult to find nitroamino and nitroimino in the same environment for comparative analysis. A new compound, 5-Nitroamino-8-nitroimino-1,4-dihydropyrazino [2,3-d]pyridazine-2,3-dione (3), was designed and synthesized. The symmetric skeleton of pyrazino [2,3-d]pyridazine provides the same environment for both nitroamino and nitroimino groups. By using a variety of computational and graphical methods, a theoretical support for nitroamino-based energetic materials was produced by thoroughly examining the influence between nitroamino and nitroimino.

Supplementation with Manihot esculenta Crantz (Cassava) leaves’ extract prevents recognition memory deficits and hippocampal antioxidant dysfunction induced by Amyloid-β

ABSTRACT Objective: The Manihot esculenta Crantz (Cassava) is a typical South American plant rich in nutrients and energetic compounds. Lately, our group has shown that non-pharmacological interventions with natural antioxidants present different neuroprotective effects on oxidative balance and memory deficits in AD-like animal models. Here, our objective was to evaluate the neuroprotective effects of Cassava leaves’ extract (CAS) in an AD-like model induced by amyloid-beta (Aβ) 25–35 peptide. Methods: Male Wistar rats (n = 40; 60 days old) were subjected to 10 days of CAS supplementation; then, we injected 2 μL Aβ 25–35 in the hippocampus by stereotaxic surgery. Ten days later, we evaluated object recognition (OR) memory. Cassavas’ total polyphenols, flavonoids, and condensed tannins content were measured, as well as hippocampal lipid peroxidation and total antioxidant capacity. Results: CAS protected against Aβ-induced OR memory deficits. In addition, Aβ promoted antioxidant capacity decrease, while CAS was able to prevent it, in addition to diminishing lipoperoxidation compared to Aβ. Discussion: We show that treatment with Cassava leaves’ extract before AD induction prevents recognition memory deficits related to Aβ hippocampal injection. At least part of these effects can be related to the Cassava leaves’ extract supplementation effects on diminishing lipid peroxidation and preventing a decrease in the hippocampal total antioxidant capacity in the hippocampus of AD-like animals without adverse effects. Once cassavais a plant of warm and dry ground that can adapt to growon various soil types and seems to resist several insects, our results enable Cassava to be considered asa potential preventive intervention to avoid or minimizeAD-induced memory deficits worldwide.

Insensitive energetic compounds based on regioisomeric nitro-substituted fused triazole

Two series of nitro-substituted fused triazole were prepared. All compounds have been fully characterized by IR, elemental analysis, 1H and 13C NMR, and DSC. Neutral compounds a1 and b1 exhibit quite different thermostabilities and this trend has extended to their energetic salts, which could be explained by the NBO analysis and hydrogen bonds based on the single-crystal parameters. The structures of salts a2, a3, and b3 were also confirmed by single-crystal X-ray diffraction. NCI and Hirshfeld surface analysis were performed to further understand the relationship between properties and regioisomeric structures. All new compounds show good densities varying within 1.66–1.83 g cm−3, detonation velocities varying within 7688-8461 m s−1, and detonation pressures varying within 22.1–26.7 Gpa, and are insensitive to friction and impact. High thermal stability (Td = 274 °C) combined with good detonation velocity (vD = 8238 m s−1) highlight the promising application for salt b2 as a high-energy insensitive compound.