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

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

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

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)

Copper(II) Dicyanamide Complexes with N ‐Substituted Tetrazole Ligands – Energetic Coordination Polymers with Moderate Sensitivities

Following the useful concept of energetic coordination compounds (ECC), copper(II) dicyanamide was used as a building block for the synthesis of eight new complexes. As ligands, six different N ‐substituted tetrazoles were applied, leading to the formation of high‐nitrogen containing complexes. The obtained compounds were characterized in detail by single crystal as well as powder XRD, IR, EA, DTA, and TGA. In addition, the sensitivities towards impact and friction were determined with BAM standard techniques as well as the sensitivity towards electrostatic discharges. All compounds show moderate sensitivities (IS >6, FS >80 N) and energetic properties but differ in their polymeric structures forming polymeric chains or layers up to 3D networks

Crystal Structures of Furazanes

Several nitrogen-rich salts of 3-nitramino-4-nitrofurazane and dinitraminoazoxyfurazane were synthesized and characterized by various spectroscopic methods. The crystal structures were determined by low temperature single crystal X-ray diffraction. Moreover the sensitivities toward thermal and mechanical stimuli were determined by differential thermal analysis (DTA) and BAM (Bundesanstalt fur Materialforschung und -prufung) methods. The standard enthalpies of formation were calculated for all compounds at the CBS-4M level of theory, and the energetic performance was predicted with the EXPLO5 V6.02 computer code

Alkyl‐Bridged Nitropyrazoles – Adjustment of Performance and Sensitivity Parameters

Starting from 3,5-dinitro-4-methylaminopyrazole (2), six different energetic salts and three new derivatives of methylene bridged nitropyrazoles were synthesized. The derivatives bear a methylamino (4), methylnitramino (5), and azido group (7). All compounds were intensively characterized using single crystal X-ray diffraction, multinuclear NMR spectroscopy, IR spectroscopy, mass spectrometry, elemental analysis and DTA/TGA measurements. The sensitivities were determined according to BAM standard methods and the energetic properties calculated using the EXPLO5 code. The energetic salts were compared with each other and with ANTA in terms of their energetic properties. On the basis of the methyl- and ethyl bridged derivatives, it was shown how the introduction of methylamino (4) and methylnitramino (5) groups in an alkyl-bridged nitropyrazole system modify its properties (performance & sensitivities). In addition, azido compound 7 was contrasted with its literature-known constitutional isomer and investigated for its suitability as a potential metal-free primary explosive

Tuning the Properties of 5-Azido and 5-Nitramino-tetrazoles by Diverse Functionalization - General Concepts for Future Energetic Materials

5-Azido and 5-nitraminotetrazole backbones are established heterocyclic motifs in the research field of energetic materials synthesis. Despite the high energy content of the compounds, the problem with many derivatives is that their sensitivities are far too high. Functionalization of one of the ring nitrogen atoms is the aim of this study to adjust the sensitivity by inserting nitratoethyl, azidoethyl and methyl groups. In this context, derivatives of 2-(2-azidoethyl)-5-nitraminotetrazoles (2, 2a-2d), as well as 1-nitrato and 1-azidoethyl substituted 5-azidotetrazole (7 and 10) and the methylation products of 5-azidotetrazole (5-azido-1-methyl-tetrazole, 11 and 5-azido-2-methyl-tetrazole, 12) were prepared. The obtained nitrogen-rich compounds were extensively characterized through multinuclear NMR spectroscopy and IR spectroscopy. The structural confinement was checked by X-ray diffraction experiments. The pure samples (verified by elemental analysis) were investigated regarding their behavior toward friction, impact (BAM methods) and electrostatic discharge as well as heating (DTA and DSC). For all metal-free compounds the detonation properties were computed with the EXPLO5 code using their density and heat of formation, calculated based on CBS-4 M level of theory