147 research outputs found
Research output software for energetic materials based on observational modelling 2.1 (RoseBoom2.1 (c))
There is huge scope for the implementation of sustainable methods in the research of new energetic materials and there are a number of ways this can be achieved. With the development of the program Research output software for energetic materials based on observational modelling(RoseBoom (c)), it is hoped that the development of new modern energetic materials will be advanced, since it aims to provide access to quick and easy prediction methods which will indicate performance parameters (e.g. the detonation velocity and pressure, the key indicator for the power of an explosive) - before they have been synthesized
2,6-Diazidotoluene
The structure of the title compound, C7H6N6, consists of almost planar molecules with C—N distances of 1.429 (2) and 1.428 (2) Å. The H atoms of the methyl group are disordered over two sites with occupancy factors of 0.69 and 0.31. The azide groups show typical geometry for covalently bound azides
Synthesis and reactivity of an unexpected highly sensitive 1-carboxymethyl-3-diazonio-5-nitrimino-1,2,4-triazole
During the synthesis of functionalized energetic triazole derivatives for biosensor detection devices 1-carboxymethyl-3-diazonio-5-nitrimino-1,2,4-triazole (2) was obtained by nitration of sodium 1-carboxymethyl-3,5-diamino-1,2,4-triazole (1). Zwitterionic (2) behaves like a diazonium cation which was proved from its reaction with sodium azide by the formation of 3-azido-5-nitrimino-1,2,4-triazole (3). Compounds 1-3 were fully characterized by low temperature single crystal X-ray diffraction, vibrational (IR/Raman) spectroscopy, NMR spectroscopy, mass spectrometry, elemental analysis and DSC measurements. The sensitivities were determined by the BAM drop hammer, BAM friction tester and an electrostatic discharge device. The extremely high impact sensitivity of the diazonio compound in comparison to its azido analogue is explained by the use of electrostatic potentials
Spectroscopic, Structural and Energetic Properties of Pentanitroaniline
Although pentanitroaniline (PNA) has been known for almost 100 years, as well as with an optimized synthesis, it is still not fully characterized. In this contribution, the crystal structure of PNA is reported for the first time without any adducts or solvents, allowing a view of the crystal packing, as well as the exact positioning of the nitro groups relative to each other. In addition, based on the crystal structure, a Hirshfeld analysis was performed, which determines the distances and types of interactions of the outer atoms. The compound was also studied in detail by NMR, especially with respect to C-13 and N-14, making this a challenge due to sensitivity in solution. Furthermore, the compound was fully characterized by IR spectroscopy and TGA, as well as the sensitivities, were measured. Using the density obtained from X-ray crystallography, as well as the heat of formation calculated with the gaussian program package, the energetic parameters were calculated using explo5 computer code. The performance data were compared to the commonly used RDX and oxidizer ammonium perchlorate, as well as the structurally similar triaminotrinitro (TATB) and pentanitro (PNB) benzene
Linear Correlation Between Confined Explosive Quantity and Dent Volume of an Underlying Aluminium Block Using the SSRT Setup
The SSRT setup gives smart access to test various properties of explosive materials and requires only little substance quantities. Unlike the standardized SSRT, we studied the bulge development from the blast of different amounts of PETN (200-1300 mg). The bulge of the corresponding aluminum blocks was evaluated with the help of a profilometer (Keyence VR-5200). This device, which measures the volume of the dents using the offset of structured light projected on the object, has allowed us to analyze the differences precisely. Despite the experimental limitations and the resulting undirected explosion direction, a throughout linear correlation between the respective amounts of PETN and the resulting dent depth could be determined. Our study thus forms an illustrative development of how the explosion behavior, represented by the dent of an aluminum block, of compressed energetic materials behaves in with increasing filling quantity, which is transferable to larger experimental setups as well as to other explosives
Preparation and Crystal Structure of Diaqua(μ-5,5'-bistetrazolato-κ4N1,N2,N5,N6)copper(II)
The crystal structure of the coordination polymer diaqua(μ-5,5'-bistetrazolato-κ4N1,N2,N5,N6)copper(II) was determined by X-ray diffraction. The copper atoms are connected to chains over the bridging 5,5'-bistetrazolato ligand. The energetic properties of the compound were investigated, such as thermal behavior and sensitivities (shock, friction, electrical spark)
1-Nitrimino-5-azidotetrazole: Extending Energetic Tetrazole Chemistry
Azide and nitrimino functions are among the most energetic substituents that can be introduced to the skeleton to enhance the energetic properties of a compound. In this study, we report the successful synthesis of a compound that combines both, azide and nitrimino substituents directly attached to one tetrazole scaffold. 1-Nitrimino-5-azidotetrazole is prepared by nitration of 1-amino-5-azidotetrazole. Subsequent salination with ammonia and guanidinium carbonate yields two highly energetic derivatives. All energetic compounds, as well as the intermediate steps of an alternatively developed synthesis strategy, were analysed and characterized in detail. In addition to multinuclear NMR and IR spectroscopy, crystal structures of all key compounds were measured. The sensitivities (friction, impact, electrostatic discharge and thermal) were determined accordingly. In addition, the detonation parameters of all energetic substances were calculated with the EXPLO5 code, which was fed with the enthalpy of formation (atomization method based on CBS-4M) and the crystallographic densities
A Theoretical and Experimental Study on the Lewis Acid−Base Adducts (P4E3)·(BX3) (E = S, Se; X = Br, I) and (P4Se3)·(NbCl5)
The Lewis acid−base adducts (P4E3)·(BX3) (E = S, Se; X = Br, I) and (P4Se3)·(NbCl5) have been prepared and characterized by Raman, IR, and solid-state 31P MAS NMR spectroscopy. Hybrid density functional calculations (B3LYP) have been carried out for both the apical and the basal (P4E3)·(BX3) (E = S, Se; X = Br, I) adducts. The thermodynamics of all considered species has been discussed. In accordance with solid-state 31P MAS NMR and vibrational data, the X-ray powder diffraction structures of (P4S3)·(BBr3) [monoclinic, space group P21/m (No. 11), a = 8.8854(1) Å, b = 10.6164(2) Å, c = 6.3682(1) Å, β = 108.912(1)°, V = 568.29(2) Å3, Z = 2] and (P4S3)·(BI3) [orthorhombic, space group Pnma (No. 62), a = 12.5039(5) Å, b = 11.3388(5) Å, c = 8.9298(4) Å, V = 1266.09(9) Å3, Z = 4] indicate the formation of an apical P4S3 complex in the reaction of P4S3 with BX3 (X = Br, I). Basal adducts are formed when P4Se3 is used as the donor species. Vibrational assignment for the normal modes of these adducts has been made on the basis of comparison between theoretically obtained and experimentally observed vibrational data
Tetranitratoethane
Tetranitratoethane (C2H2N4O12), which has an oxygen content of 70.1% was synthesized by nitration of monomeric glyoxal using N2O5 and purified by sublimation. Single crystals could be grown from CH2Cl2/pentane and were used to determine the structure by X-ray diffraction. Several energetic parameters and values were also established
Energetic Polymers: A Chance for Lightweight Reactive Structure Materials?
Today's ammunition still consists of about 70 wt% structure-providing materials such as metals providing no energetic contribution. Therefore, reactive structure materials (RSMs) offer tremendous room for improvement. While current research focuses on rather heavy, metal-based materials (e. g., alloys, thermites), energetic polymers appear as an under-recognized opportunity for very lightweight RSMs. Unfortunately, suitable polymers are unavailable as energetic polymer research has almost exclusively focused on elastic binders with the least possible glass transition temperature. An application as RSM, however, requires rigid polymers with a glass transition above operational temperatures. Accordingly, monomers with fundamentally different structures are required. The first step in this particular direction is 3-(2,4,6-trinitrophenoxy)oxetane (TNPO). Herein, we report the synthesis of its homopolymer and investigate its polymerization behavior by copolymerization with prior art energetic oxetanes. All polymers were intensively studied by vibrational and multinuclear (H-1, C-13, N-14) NMR spectroscopy, elemental analysis, gel permeation chromatography, and differential scanning calorimetry (DSC). Hereby, DSC revealed the high effect of the TNPO repeating unit on the glass transition temperature. The performance of all polymers was calculated using the EXPLO5 code to evaluate the potential performance range of polymeric RSMs. Further, their shock and friction sensitivity was determined by BAM standard procedures
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