Oxetane Monomers Based On the Powerful Explosive LLM-116: Improved Performance, Insensitivity, and Thermostability

3-Bromomethyl-3-hydroxymethyloxetane represents an inexpensive and versatile precursor for the synthesis of 3,3-disubstituted oxetane derivatives. In the present work, its synthesis was improved and energetic oxetanes based on the explosive LLM-116 (4-amino-3,5-dinitro-1H-pyrazole) prepared. Reaching detonation velocities and pressures of up to 7335 ms(-1) and 20.9 GPa in combination with a high thermostability and insensitivity, these surpass the prior art by far. Next to a symmetric LLM-116 derivative, three asymmetric compounds were prepared using azido-, nitrato- and tetrazolyl-moieties. All compounds were intensively characterized by vibrational-, mass- and multinuclear (H-1, C-13, N-14) NMR spectroscopy, differential scanning calorimetry and elemental analysis. The molecular structures were elucidated by single crystal X-ray diffraction. Hirshfeld analysis allowed to estimate their sensitivity next to a practical evaluation using BAM standard procedures. Their performance was calculated using the EXPLO5 V6.04 code and a small-scale shock reactivity test and initiation test demonstrated their insensitivity and performance

Nitrogen-Rich Oxetanes Based on the Combination of Azides and Tetrazoles

Literature known energetic oxetane derivatives have a nitrogen content of up to 49.98 %. Through the introduction of azide and tetrazole functionalities attached to an oxetane ring, energetic oxetanes with higher nitrogen contents than previously reported in the literature were obtained. The newly synthesized oxetane derivatives were extensively characterized via H-1 NMR, C-13{H-1} NMR, N-14 NMR, N-15 NMR, H-1-N-15 HMBC, FT-IR spectroscopy and/or DTA. Their crystal structures were elucidated using X-ray diffraction, their sensitivities towards impact, friction and electrostatic discharge were determined and their energetic properties were calculated using the EXPLO5 code

Energetic but insensitive spiro-tetrahydrotetrazines based on oxetane-3-one

Energetic oxetanes were first described in the 1970s, such as 3,3-bis(azidomethyl)oxetanes (BAMO) and 3-(nitratomethyl)-3-(methyl)oxetanes (NIMMO). Over the past few years, oxetanes were hardly available only as special-purpose chemicals for the pharmaceutical industry. Oxetan-3-one is condensed with energetic compounds with a hydrazino function such as amino-nitroguanidine and picryl hydrazine to form energetic Schiff bases. Hydrazinolysis of the guanidine derivatives lead to energetic spiro-tetrahydrotetrazines which are quite rare in literature. All products were characterized by their crystal structure using single-crystal X-ray diffraction. Furthermore, the new compounds were analyzed using IR, EA, DTA, and multinuclear NMR spectroscopy (H-1 and C-13). The sensitivities towards external stimuli such as friction and impact were determined according to BAM standards and the energetic performances were calculated using the EXPLO5 code

2-Hydrazonyl-Propandihydrazide - A Versatile Precursor for High-Energy Materials

In this work, 2-hydrazonyl-propandihydrazide (2), a new precursor for energetic materials based on diethyl 2,2-diazidomalonate (1) was investigated. Therefore, its versatility was shown by various secondary reactions, including formation of energetic salts (3-5), the synthesis of a nitrogen-rich bistriazole (10) and a highly instable diazido derivative (6). In addition, a Curtius degradation could be observed in detail. When possible, the compounds were analyzed by low temperature X-ray diffraction. All measurable compounds were analyzed by H-1 and C-13 NMR spectroscopy, elemental analysis, differential thermal analysis (DTA) and regarding their sensitivity towards impact and friction according to BAM standard techniques. All promising compounds were evaluated regarding their energetic behavior using the EXPLO5 code (V6.05) and compared to RDX and CL-20. In addition, compound 2 was investigated towards its aquatic toxicity, using the bioluminescent bacteria vibrio fischeri

Vertebral body stenting: a new method for vertebral augmentation versus kyphoplasty

Vertebroplasty and kyphoplasty are well-established minimally invasive treatment options for compression fractures of osteoporotic vertebral bodies. Possible procedural disadvantages, however, include incomplete fracture reduction or a significant loss of reduction after balloon tamp deflation, prior to cement injection. A new procedure called “vertebral body stenting” (VBS) was tested in vitro and compared to kyphoplasty. VBS uses a specially designed catheter-mounted stent which can be implanted and expanded inside the vertebral body. As much as 24 fresh frozen human cadaveric vertebral bodies (T11-L5) were utilized. After creating typical compression fractures, the vertebral bodies were reduced by kyphoplasty (n = 12) or by VBS (n = 12) and then stabilized with PMMA bone cement. Each step of the procedure was performed under fluoroscopic control and analysed quantitatively. Finally, static and dynamic biomechanical tests were performed. A complete initial reduction of the fractured vertebral body height was achieved by both systems. There was a significant loss of reduction after balloon deflation in kyphoplasty compared to VBS, and a significant total height gain by VBS (mean ± SD in %, p < 0.05, demonstrated by: anterior height loss after deflation in relation to preoperative height [kyphoplasty: 11.7 ± 6.2; VBS: 3.7 ± 3.8], and total anterior height gain [kyphoplasty: 8.0 ± 9.4; VBS: 13.3 ± 7.6]). Biomechanical tests showed no significant stiffness and failure load differences between systems. VBS is an innovative technique which allows for the possibly complete reduction of vertebral compression fractures and helps maintain the restored height by means of a stent. The height loss after balloon deflation is significantly decreased by using VBS compared to kyphoplasty, thus offering a new promising option for vertebral augmentation

1‑Amino-5-nitriminotetrazole: Effective Interaction of <i>N</i>‑Nitro and <i>N</i>‑Amino Functionalities for Outperforming and Applicable Energetic Materials

1-Amino-5-nitriminotetrazole is synthesized for the first time via acid-catalyzed protection of 1,5-diaminotetrazole with acetone followed by aprotic nitration using N2O5 and in situ deprotection. The salts of 1-amino-5-nitriminotetrazolate are synthesized by addition of the corresponding bases. Most of the nitrogen-rich salts show insane explosive properties and compete with the most powerful non-nuclear explosives. The implementation of a fused triazolium cation yields a promising secondary explosive, with high performance but also low sensitivity and high thermal stability. Metal salts (K and Ag) are successfully used to initiate pentaerythritol tetranitrate using a classical detonator setup