BAM Drophammer Research Articles

Energetic triazinium salts from N-amination of 3,5-diamino-6-nitro-1,2,4-triazine

The N-amination of 3,5-diamino-6-nitro-1,2,4-triazine via treatment with O-tosylhydroxylamine (THA) resulted in the formation of the 2,3,5-triamino-6-nitro-1,2,4-triazinium cation as the tosylate salt. The tosylate anion was easily exchanged using ion exchange resin to the chloride salt from which several energetic triazinium salts were synthesized via metathesis reaction. These energetic compounds were chemically and structurally characterized utilizing nuclear magnetic resonance (NMR), infrared spectroscopy (IR), and single-crystal X-ray crystallography. The thermal stabilities were determined by thermal gravimetric analysis (TGA) and energetic sensitivities (impact, friction) were experimentally determined with a BAM Drophammer and BAM friction tester. The energetic performances were calculated with Explo5v6 using Gaussian09 generated heats of formation. The energetic triazinium salts were found to be sensitive high performing energetic materials that have decomposition temperatures less than 200 ​°C. These salts possessed impact sensitivities ≤5 ​J and friction sensitivities generally between 40 ​N and 48 ​N, the exception being the 5,5′-bistetrazole-1,1′-diolate salt whose sensitivity was determined to be ​< ​5 ​N. The calculated detonation pressures range from 26 ​GPa to 34 ​GPa while the detonation velocities range from 8247 ​m·s−1 to 8774 ​m·s−1 similar to PETN (pCJ ​= ​30.8 ​GPa, vD ​= ​8429 ​m·s−1) and TATB (pCJ ​= ​32.4 ​GPa, vD ​= ​8114 ​m·s−1).

Salts of Picramic Acid – Nearly Forgotten Temperature‐Resistant Energetic Materials

AbstractThermally stable explosives are becoming more and more important nowadays due to their important role in the oil and mining industry. The requirements of these explosives are constantly changing. Picramate‐based compounds are poorly investigated towards their energetic properties as well as sensitivities. In this work, 13 different salts of picramic acid were synthesized as potential energetic materials with high thermal stability in a simple one‐step reaction and compared with commercially used lead picramate. The obtained compounds were extensively characterized by e. g. XRD, IR, EA, DTA, and TGA. In addition, the sensitivities towards impact and friction were determined with the BAM drop hammer and the BAM friction tester. Also, the electrostatic discharge sensitivity was explored. Calculations of the energetic performance of selected compounds were carried out with the current version of EXPLO5 code. Therefore, heats of formation were computed and X‐ray densities were converted to room temperature. Some of the synthesized salts show promising characteristics with high exothermic decomposition temperatures. Especially, the water‐free rubidium, cesium, and barium salts 5, 6 and 10 with decomposition temperatures of almost 300 °C could be promising candidates for future applications.

Synthesis and Properties of 3,6‐Dinitropyrazolo[4,3‐c]‐pyrazole (DNPP) Derivatives

AbstractA series of novel fused‐ring pyrazolo[4,3‐c]pyrazole derivatives featuring N‐dinitromethyl and N‐fluorodinitromethyl energetic groups (compounds 3–7) were synthesized using a nine‐step reaction. All these compounds were characterized using multinuclear nuclear magnetic resonance (NMR) spectroscopy, infra‐red (IR) spectroscopy, and elemental analysis. X‐ray diffraction analysis was performed, and the single‐crystal structures of compounds 3, 4, 6, and 7 were obtained. For these newly prepared energetic materials, the thermal stability was determined using differential scanning calorimetry (DSC), while the sensitivities were evaluated using BAM drop hammer and friction test. The calculated heat of formation values and the measured densities were used to determine the detonation parameters, including detonation velocity and pressure, using the EXPLO5 program. Of all the prepared compounds, dipotassium 1,4‐bis(dinitromethyl)‐3,6‐dinitro‐1,4‐dihydropyrazolo[4,3‐c]pyrazole (3) was crystallized as a three‐dimensional energetic metal‐organic framework (MOF) and showed outstanding detonation performances, which even outperformed the traditional primary explosive lead azide. Compound 7 exhibited a high crystal density of 1.939 g cm−3, the high decomposition temperature of 213 °C and desirable impact and friction sensitivities (IS: 12 J; FS: 240 N). These combined properties and performances make these novel fused‐ring energetic compounds suitable candidates for high‐performance energetic materials.

OZM Ball Drop Impact Tester (BIT‐132) vs. BAM Standard Method – a Comparative Investigation

AbstractSafety, performance, cost efficient synthesis and toxicity are the most important aspects of modern explosives. Sensitivity measurements are performed in accordance with different protocols all around the world. Sometimes the BAM drop hammer does not accurately reflect the sensitivity of an energetic material, in particular the sensitivity of primary explosives. Therefore, we present here preliminary results obtained using the novel ball drop tester (BIT‐132), manufactured by OZM research, following MIL‐STD‐1751 A (method 1016). The ball drop impact sensitivity tester is a device in which a free‐falling steel ball is dropped onto an unconfined sample, and is expected to produce more realistic results than the currently commonly used BAM method. The results obtained using the probit analysis were compared to those from the BAM drop hammer and friction tester. The following sensitive explosives were investigated: HMTD, TATP, TAT, Tetrazene, MTX‐1, KDNBF, KDNP, K2DNABT, Lead Styphnate Monohydrate, DBX‐1, Nickel(II) Hydrazine Nitrate, Silver Acetylide, AgN3, Pb(N3)2 RD‐1333, AgCNO, and Hg(CNO)2.

New Energetic Complex of Copper(II) Dinitramide Based Nitrogen‐rich Ligand Aminoguanidine(CH6N4): Synthesis, Structural and Energetic Properties

AbstractThe crystal structure of the energetic complex bis(aminoguanidine)copper(II) dinitramide [Cu(AG)2][DN]2 (I), has been determined at 298 K using single‐crystal X‐ray diffraction technique. The Cu(II) atom is four‐coordinated by two imine N atoms and two amine N atoms from two aminoguanidine ligands, forming a slightly distorted square‐planar coordination. In the crystal structure, molecules are linked through intermolecular N−H…O hydrogen bonds, forming a network. The infrared spectrum showed a sharp peaks at 1650 and 1010 cm−1 which are typical of the conjugated C=N stretching due to the coordination of the imine nitrogen and NNN stretching dinitramide counterion, respectively. The thermal decomposition process of this complex was investigated through differential scanning calorimetry (DSC) and the sensitivities toward impact and friction were assessed using a BAM drophammer and a BAM friction tester. In the measurement of I a violent explosion appeared destroying the setup. This may be a reason, due to the copper complex (I), which crystallizes water free. The power of powder and single crystal of I was measured by the Trauzl test are 425 and 427 cm−3 for 10 g I (142 % TNT and 88 % RDX).

Synthesis, Structural and Energetic Properties of Copper(II) Perchlorate Complex with Aminoguanidine

The complexation of copper(II) perchlorate with aminoguanidine hemesulfate (AGHS) yield related mononuclear complex bis(aminoguanidine)copper(II) perchlorate; [Cu(AG)2](ClO4)2 (I). The characterization of complex I was done by elemental analysis, electronic spectra, IR studies, and X‐ray diffraction. From analytical data, a stoichiometry of 1:2 of metal to ligand was determined for the complex. The structure consists of centrosymmetric square planar [Cu(AG)2]2+ cations and perchlorate counterions. The CuII atom is four‐coordinate by two imine N atoms and two amine N atoms from two aminoguanidine ligands, forming a slightly distorted square‐planar coordination. In the crystal structure, molecules are linked through intermolecular N–H···O hydrogen bonds, forming a network. The thermal decomposition process of this complex was investigated through differential scanning calorimetry (DSC) and the sensitivities toward impact and friction were assessed using a BAM drophammer and a BAM friction tester.

Potential Energetic Plasticizers on the Basis of 2,2‐Dinitropropane‐1,3‐diol and 2,2‐Bis(azidomethyl)propane‐1,3‐diol

AbstractDifferent carboxylic acid derivatives of 2,2‐dinitropropane‐1,3‐diol (DNPD) and 2,2‐bis(azidomethyl)propane‐1,3‐diol (BAMP) were synthesized to investigate their suitability as energetic plasticizers. The syntheses were carried out using acyl chlorides of acetic, propionic, and butyric acid. The obtained products were characterized by elemental analysis, NMR, and IR spectroscopy. The energetic properties of the synthesized compounds were calculated on the basis of the computed heats of formation at the CBS‐4M level of theory using the EXPLO5 version 6.02 computer code. Investigations of physical stabilities were carried out using BAM drop hammer and friction tester. Low and high temperature behavior was determined by differential scanning calorimetry (DSC). The energetic and physical properties of the synthesized compounds were compared to the literature known energetic plasticizers N‐butyl nitratoethylnitramine (BuNENA) and diethylene glycol bis(azidoacetate) ester (DEGBAA). For analyzing the plasticizing abilities, mixtures of glycidyl azide polymer (GAP) and poly(3‐nitratomethyl‐3‐methyloxetan) (polyNIMMO) were prepared with both propionyl based compounds in different ratios and investigated regarding their glass transition temperatures and viscosity. Both compounds showed plasticizing effects in the range of BuNENA.

Polyurethanes based on 2,2‐Dinitropropane‐1,3‐diol and 2,2‐bis(azidomethyl)propane‐1,3‐diol as potential energetic binders

ABSTRACTOn the base of 2,2‐bis(azidomethyl)propane‐1,3‐diol (BAMP) and 2,2‐dinitropropane‐1,3‐diol (DNPD) four different polyurethanes were synthesized in a polyaddition reaction using hexamethylene diisocyanate (HMDI) and diisocyanato ethane (DIE). The obtained prepolymers were mainly characterized using vibrational spectroscopy (IR) and elemental analysis. For determination of low and high temperature behavior, differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) were used. Investigations concerning friction and impact sensitivities were carried out using a BAM drop hammer and friction tester. The energetic properties of the polymers were determined using bomb calorimetric measurements and calculated with the EXPLO5 V6.02 computer code. The obtained values were compared with the glycidyl azide polymer (GAP). The compounds turned out to be insensitive toward friction (&gt;360 N) and less sensitive toward impact (40 J). The good physical stabilities, along with their sufficient thermal stability (170–210 °C) and moderate energetic properties renders these polymers into potential compounds for applications as binders in energetic formul;ations. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43991.

Studies on Energetic Salts Based on (2,4,6‐Trinitrophenyl)guanidine

Abstract(2,4,6‐Trinitrophenyl)guanidine was synthesized and its thermal and energetic properties were investigated. The reaction of (2,4,6‐trinitrophenyl)guanidine with different acids, such as nitric, picric, perchloric, and hydrochloric acid results in protonation of (2,4,6‐trinitrophenyl)guanidine and the formation of the corresponding salts (cation : anion ratio 1 : 1). The reactions are performed at ambient temperature in H2O or EtOH and produce qualitatively pure products with energetic properties, which are typical of those of secondary explosives. The compounds were characterized using multinuclear NMR spectroscopy, IR and Raman spectroscopy, as well as mass spectrometry. Single crystal X‐ray diffraction studies were performed and the structures of the four different salts at low temperatures were determined. The thermal stabilities were measured using differential scanning calorimetry (DSC). The sensitivities were determined using the BAM drophammer and friction tests. The heats of formation were calculated by the atomization method based on CBS‐4M enthalpies. Using these values as well as the X‐ray or pycnometric densities, several detonation parameters such as the detonation pressure, velocity, energy, and temperature were computed using the EXPLO5 code.

(Picrylamino)‐1,2,4‐triazole Derivatives – Thermally Stable Explosives

Abstract3‐(Picrylamino)‐1,2,4‐triazole (PATO) and 3‐amino‐5‐(picrylamino)‐1,2,4‐triazole (APATO) were synthesized and analyzed. During the syntheses of the compounds, two interesting side‐products were isolated. The reactions of PATO and APATO with different nitrogen‐rich bases, such as ammonia, hydrazine, triethylamine, and triaminoguanidine, resulted in the deprotonation of both triazole compounds and the formation of the corresponding salts (cation/anion ratio = 1:1). The compounds were obtained at ambient temperature in H2O or EtOH as qualitatively pure products with the characteristic properties of secondary explosives. The compounds were characterized by multinuclear NMR, IR, and Raman spectroscopy as well as mass spectrometry. The low‐temperature structures of two compounds were determined by single‐crystal X‐ray diffraction. The thermal stabilities were measured by differential scanning calorimetry (DSC). The sensitivities were determined through the BAM drophammer and friction tests. The heats of formation were calculated by the atomization method from the CBS‐4M enthalpies and the densities determined by X‐ray diffraction or pycnometry. Several detonation parameters including the detonation pressure, detonation velocity, detonation energy, and detonation temperature were computed with the EXPLO5 code.

Contributions to the Chemistry of N‐Methylnitramine: Crystal Structure, Synthesis of Nitrogen‐Rich Salts, and Reactions towards 2‐Nitro‐2‐azapropyl Derivatives

AbstractThis work compares the hitherto unknown crystal structure of N‐methylnitramine with its gas‐phase diffraction structure. A series of alkaline, alkaline earth and some transition‐metal salts were investigated. Furthermore, a series of new nitrogen‐rich salts was synthesized and characterized for the first time. The Mannich reaction of N‐methylnitramine with formaldehyde yields 2‐nitro‐2‐azapropanol, which was treated with 2‐nitro‐2‐azapropyl isocyanate to furnish new bis‐N,O‐(2‐nitro‐2‐azapropyl)carbamate. The analogue bis‐N,N′‐(2‐nitro‐2‐azapropyl)urea derivative is formed when 2‐nitro‐2‐azapropyl isocyanate is treated with water. Owing to the energetic nature of all compounds, their energetic properties were determined. The sensitivities towards impact, friction and electrostatic discharge were determined using the BAM drophammer and friction tester as well as a small‐scale electrical discharge device. Standard enthalpies of formation were calculated at the CBS‐4M level of theory. With these values and the experimental densities, several detonation parameters such as detonation pressure and velocity of the compounds were computed using the EXPLO5 (V6.01) computer code and compared to currently used explosives.

Fluorodinitroethyl Ortho-carbonate and -formate as Potential High Energy Dense Oxidizers

Tetrakis(2-fluoro-2,2-dinitroethyl) ortho-carbonate (1) and tris(2-fluoro-2,2-dinitroethyl) orthoformate (2) were synthesized by the reaction of carbon tetrachloride, respectively chloroform, with 2-fluoro-2,2-dinitroethanol and catalytic amounts of anhydrous iron(III) chloride. The compounds were characterized by single-crystal X-ray diffraction, vibrational spectroscopy (IR and Raman), multinuclear NMR spectroscopy, elemental analysis, and multi-temperature DSC measurements. The suitability of the compounds as potential oxidizers in energetic formulations has been investigated and discussed. The heats of formation of the products were determined experimentally using bomb calorimetric methods. With this value and the experimental (X-ray) density, several detonation parameters such as the detonation pressure, velocity, energy, and temperature were computed using the EXPLO5 code. The sensitivity towards impact, friction and electrostatic discharge was tested using the BAM drop hammer, a friction tester and a small-scale electrostatic discharge device.

Maximum Compaction of Ionic Organic Explosives: Bis(hydroxylammonium) 5,5′‐Dinitromethyl‐3,3′‐bis(1,2,4‐oxadiazolate) and its Derivatives

Within this contribution on bis(oxadiazoles) we report on bis-hydroxylammonium 5,5'-dinitro-methyl-3,3'-bis(1,2,4-oxadiazolate), which (to the best of our knowledge) shows the highest density (2.00 g cm(-3) at 92 K, 1.95 g cm(-3) at RT) ever reported for an ionic CHNO explosive. Also the corresponding bis(ammonium) salt shows an outstanding density of 1.95 g cm(-3) (173 K). The reaction of the 3,3'-bis(1,2,4-oxadiazolyl)-5,5'-bis(2,2'-dinitro)-diacetic acid diethyl ester with different nitrogen-rich bases, such as ammonia, hydrazine, hydroxylamine, and triaminoguanidine causes decarboxylation followed by the formation of the corresponding salts (cation/anion stoichiometry 2:1). The reactions are performed at ambient temperature in H2O/MeOH mixtures and furnish qualitatively pure products showing characteristics of typical secondary explosives. The obtained compounds were characterized by multinuclear NMR spectroscopy, IR and Raman spectroscopy, as well as mass spectrometry. Single-crystal X-ray diffraction studies were performed and the structures of all compounds were determined at low temperatures. The thermal stability was measured by differential scanning calorimetry (DSC). The sensitivities were explored by using the BAM drophammer and friction test. The heats of formation were calculated by the atomization method based on CBS-4M enthalpies. With these values and the X-ray densities, several detonation parameters such as the detonation pressure, velocity, energy, and temperature were computed using the EXPLO5 code.

Polynitro Containing Energetic Materials based on Carbonyldiisocyanate and 2, 2‐Dinitropropane‐1, 3‐diol

AbstractNew polynitro compounds containing a carbonyl biscarbamate moiety derived from the precursor carbonyldiisocyanate were synthesized. In addition, 2, 2‐dinitropropane‐1, 3‐diyl bis(2, 2,2‐trinitroethylcarbamate) and 2, 2‐dinitropropane‐1, 3‐diyl bis(2, 2,2‐trinitroethyl) dicarbonate, were synthesized using 2, 2‐dinitropropane‐1, 3‐diol as starting material. The compounds were characterized by using the analytical methods, single‐crystal X‐ray diffraction, vibrational spectroscopy (IR and Raman), multinuclear NMR spectroscopy, elemental analysis, and mass spectrometry. The thermal behavior was investigated with DSC measurements. The suitability of the compounds as potential oxidizers in energetic formulations was determined. The heats of formation of the compounds were calculated with GAUSSIAN 09. The detonation parameters such as the detonation pressure, velocity, energy, and temperature were computed using the EXPLO5 code. For a secure handling of the materials, the sensitivity towards impact, friction, and electrical discharge was tested using the BAM drop hammer, BAM friction tester as well as a small‐scale electrical discharge device, respectively.

Transition Metal Complexes of 3-Amino-1-nitroguanidine as Laser Ignitible Primary Explosives: Structures and Properties

3-Amino-1-nitroguanidine (ANQ, 2) was synthesized via hydrazinolysis of nitroguanidine. By dissolving 2 in solutions containing transition metal salts, several complexes M(2+)(ANQ)2X2(H2O)y with M(2+) = Co, Ni, Cu, Zn as well as M(ANQ)2X(H2O)y with M = Ag could be isolated. In these cases, nitrate as well as perchlorate and chloride served as the respective anions X. Additionally, the ANQ complexes of Co, Ni, and Ag with dinitramide as the anion were synthesized from ANQ and silver dinitramide and by reacting the cobalt and nickel ANQ perchlorate complexes with ammonium dinitramide. The crystal structures of all described complexes were determined by low temperature single-crystal X-ray diffraction. Additionally, they were characterized using IR spectroscopy and elemental analysis. The decomposition temperatures were determined by differential scanning calorimetry and the sensitivities toward impact and friction were assessed using a BAM drophammer and a BAM friction tester (BAM = Bundesanstalt für Materialforschung und -prüfung). Additionally, the sensitivity toward electrostatic discharge was determined on a small-scale ESD device. The potential use of the nitrate, dinitramide and perchlorate containing species as primary explosives was investigated in a laser ignition test.

Asymmetric fluorodinitromethyl derivatives of 2,2,2-trinitroethyl N-(2,2,2-trinitroethyl)carbamate

The energetic polynitro compounds 2,2,2-trinitroethyl 2,2,2-trinitroethylcarbamate, 2-fluoro-2,2-dinitroethyl 2,2,2-trinitroethylcarbamate, 2,2,2-tinitroethyl 2-fluoro-2,2-dinitroethylcarbamate and 2-fluoro-2,2-dinitroethyl 2,2,2-trinitroethylcarbonate were synthesized and investigated as potential high energy dense oxidizers. Due to their structural similarity, the compounds have been compared with each other by using various analytical methods, like single-crystal X-ray diffraction, vibrational spectroscopy (IR and Raman), multinuclear NMR spectroscopy, elemental analysis, mass spectrometry and multi-temperature DSC measurements. The suitability of the compounds as potential oxidizers in energetic formulations has been investigated. In addition, the heats of formation of the products were calculated with the program package Gaussian 09. Several detonation parameters such as the detonation pressure, velocity, energy and temperature were computed using the EXPLO5 code. Furthermore, the sensitivity toward impact, friction and electrical discharge was tested using a BAM drop hammer, a friction tester as well as a small-scale electrical discharge device.

Nitrogen‐Rich Salts of 1H,1′H‐5,5′‐Bitetrazole‐1,1′‐diol: Energetic Materials with High Thermal Stability

Abstract1H,1′H‐5,5′‐Bitetrazole‐1,1′‐diol was synthesized starting from glyoxal, which is converted to glyoxime after treatment with hydroxylamine. Chlorination of glyoxime with Cl2 gas in ethanol and following chloro/azido exchange yields diazidoglyoxime, which is cyclized under acidic conditions (HCl gas in diethyl ether) to give 1H,1′H‐5,5′‐bitetrazole‐1,1′‐diol dihydrate (1). A large variety of nitrogen‐rich salts of 1 such as the diammonium (2), the dihydrazinium (3), the bis‐guanidinium (4), the bis(aminoguanidinium) (5), the diaminoguanidinium salt monohydrate (6), the triaminoguanidinium salt monohydrate (7), the 1‐amino‐3‐nitroguanidinium salt dihydrate (8), the diaminouronium salt monohydrate (9), the bis(oxalyldihydrazidinium) (10), the oxalyldihydrazidinium salt dihydrate (11), the 3,6‐dihydrazino‐1,2,4,5‐tetrazinium (12), the 5‐aminotetrazolium (13), the bis(5‐amino‐1‐methyl‐1H‐tetrazolium) salt (14), the bis(5‐amino‐2‐methyl‐2H‐tetrazole) adduct (15), and the 1,5‐diaminotetrazolium salt (16) were synthesized by means of Brønsted acid–base or metathesis reactions. All compounds were fully characterized by vibrational spectroscopy (IR and Raman), multinuclear NMR spectroscopy, elemental analysis, and differential scanning calorimetry (DSC) measurements. The crystal structures of 1–16 could be determined by using single‐crystal X‐ray diffraction. The heats of formation of 1–16 were calculated by using the atomization method on the basis of CBS‐4M enthalpies. With regard to their potential use as cyclotrimethylene trinitramine (RDX) or hexanitrostilbene (HNS) replacements, several detonation parameters such as the detonation pressure, detonation velocity, explosion energy, and explosion temperature were computed using the EXPLO5 code on the basis of the experimental (X‐ray) densities and calculated heats of formation. In addition, the sensitivities towards impact, friction, and electrical discharge were tested using the BAM drop hammer, a friction tester, as well as a small‐scale electrical discharge device.

1-Amino-3-nitroguanidine (ANQ) in High-performance Ionic Energetic Materials

Abstract 1-Amino-3-nitroguanidine (ANQ, 2) was synthesized via hydrazinolysis of nitroguanidine (1). An appropriate Lewis structure of ANQ is drawn based on VB calculations. Due to its basicity, it can be protonated by strong mineral acids or acidic heterocycles. In order to synthesize new energetic materials the nitrate (3) and perchlorate (4) salts of 1-amino-3-nitroguanidine were synthesized by protonation of 2 with 40% nitric acid and 60% perchloric acid, respectively. 5-Nitrimino-1,4H-tetrazole obtained by reacting 5-amino-1H-tetrazole with 100% HNO3 was used to synthesize the nitriminotetrazolate salt 5. Furthermore, the dinitramide salt 6 of 1-amino-3-nitroguanidine was synthesized by metathesis reaction of silver dinitramide and 1-amino-3-nitroguanidinium chloride. The dinitroguanidinate salt 7 was synthesized by protonation of 2 with 1,3-dinitroguanidine, which was prepared from nitroguanidine in anhydrous nitric acid/N2O5. All compounds were fully characterized by singlecrystal X-ray diffraction, vibrational spectroscopy (IR and Raman), multinuclear NMR spectroscopy, mass spectrometry, elemental analysis, and DSC measurements. The heats of formation of 2 - 7 were calculated using the atomization method based on CBS-4M enthalpies. With these values and the experimental (X-ray) densities several detonation parameters such as the detonation pressure, velocity, energy, and temperature were computed using the EXPLO5 code. In addition, the sensitivities towards impact, friction and electrical discharge were tested using the BAM drophammer, friction tester as well as a small-scale electrical discharge device. A Koenen test with 1-amino-3-nitroguanidinium nitrate (3) was carried out in order to evaluate its explosive performance and shipping classification.

Salts of Tetrazolone – Synthesis and Properties of Insensitive Energetic Materials

AbstractTetrazolone (5‐oxotetrazole, 1) is formed by diazotization of 5‐aminotetrazole in the presence of CuSO4. Nitrogen‐rich salts such as guanidinium (2), 1‐aminoguanidinium (3), 1,3‐diamino‐guanidinium (4), 1,3,5‐triamino‐guanidinium (5), ammonium (6), hydrazinium (7) and the hydroxylammonium (8) salts of tetrazolone were prepared by facile deprotonation or metathesis reactions. All compounds were characterized by single‐crystal X‐ray diffraction, vibrational spectroscopy (IR and Raman), multinuclear NMR spectroscopy, elemental analysis and DSC measurements. The heats of formation of 2–8 were calculated using the atomization method based on CBS‐4M enthalpies. With these values and the experimental (X‐ray) densities several detonation parameters such as the detonation pressure, velocity, energy and temperature were computed using the EXPLO5 code (V.5.04). In addition, the sensitivities towards impact, friction and electrical discharge were tested using the BAM drop hammer and friction tester as well as a small scale electrical discharge device.

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.