Synthesis of 5‐(1H‐Tetrazolyl)‐1‐hydroxy‐tetrazole and Energetically Relevant Nitrogen‐Rich Ionic Derivatives

Abstract

Sodium 5‐cyanotetrazolate sesquihydrate (1) was prepared from sodium azide and two equivalents of sodium cyanide under acidic conditions. Sodium 5‐cyanotetrazolate sesquihydrate (1) reacts with hydroxylammonium chloride to form 5‐aminohydroximoyl tetrazole (2). 5‐Aminohydroximoyl tetrazole (2) is treated with sodium nitrite and hydrochloric acid to form 5‐chlorohydroximoyl‐tetrazole (3). The chloride azide exchange yields 5‐azidohydroximoyl‐tetrazole monohydrate (4). When compound 4 is treated with hydrochloric acid, 5‐(1H‐tetrazolyl)‐1‐hydroxytetrazole (5) is obtained in good yield. Compound 5 can be deprotonated twice by various bases. Different ionic derivatives such as bis(hydroxylammonium) (6), bis(hydrazinium) (7), bis(guanidinium) (8), bis(aminoguanidinium) (9), bis(ammonium) (10), and diaminouronium (11) 5‐(1‐oxidotetrazolyl)‐tetrazolate were synthesized and characterized. With respect to energetic use salts 6 and 7 are most relevant. Compounds 3–9 and 11 were characterized using low temperature single‐crystal X‐ray diffraction. All compounds were investigated by NMR and vibrational (IR, Raman) spectroscopy, mass spectrometry and elemental analysis. The thermal properties were determined by differential scanning calorimetry (DSC). The sensitivities towards impact (4: 4 J, 5: 40 J, 6: 12 J, 7: 40 J), friction: (4: 60 N, 5: 240 N, 6: 216 N, 7: 240 N), and electrical discharge (5: 0.40 J, 6: 0.75 J, 7: 0.75 J), were investigated using BAM standards and a small scale electrostatic discharge tester. The detonation parameters of 5–7 were calculated using the EXPLO5.06 code and calculated (CBS‐4 M) enthalpy of formation values.

Synthesis and Investigation of 2,3,5,6‐Tetra‐(1H‐tetrazol‐5‐yl)pyrazine Based Energetic Materials

“…The guanidine carbon atom signal can be found at δ =158.4 ppm and 159.3 ppm for the guanidinium ( 12 ) and aminoguanidinium ( 13 ) derivatives, respectively. The assignments are in agreement to those previously reported in the literature for known structures such as H 4 TTP, 5,5′‐bistetrazolates, 5‐(1 H ‐tetrazolyl)‐1‐hydroxytetrazoles, and TKX‐50 . In the proton NMR spectra of all obtained salts, we do not observe signals consistent with the non‐deprotonated tetrazole moieties which indicate that we obtained only the tetra‐cationic derivatives of H 4 TTP.…”

The Crystal Structure of Guanidinium Sulphate Hemiperoxosolvate

“…Herein we suggest the usage of small guanidinium cation that is able to form up to six charge-assisted hydrogen bonds. The advantage of this route is based on the fact that guanidinium cations are widely used for the synthesis of nitrogen-rich insensitive explosives [5][6][7].…”

Synthesis, Characterization, and Thermal Decomposition of a New Energetic Salt of 1H,1′H-5,5′-Bistetrazole-1,1′-diol

“…The tetrazole ring and its derivatives have attracted extensive interest because of their unique and excellent properties, such as high nitrogen content, high formation enthalpy, and good stability [8]. Among all of the strategies used to improve the detonation performance of energetic materials, the use of N-oxides is a special approach that facilitates the achievement of oxygen balance [8][9][10][11][12][13][14][15]. Fischer and his coworkers synthesized a series of 1H,1′H-5,5′-bistetrazole-1,1′-diolate (BTO) salts [8,16] and showed that the excellent performance of dihydroxylammonium 1H,1′H-5,5′-bistetrazole-1,1′diolate (TKX-50) is comparable with that of CL-20.…”