1,2,4‐Triazolium‐Cation‐Based Energetic Salts

Abstract

3,4,5-Triamino-1,2,4-triazole (guanazine, 1) can be readily methylated with methyl iodide yielding methylguanazinium iodide (2). Salts containing the novel methylguanazinium cation with energetic anions were synthesised by metathesis reactions with silver azide (3), silver nitrate (4), silver perchlorate (5), sodium 5,5'-azotetrazolate (6), silver 5-nitrotetrazolate (7) and silver dinitramide (8), yielding a new family of heterocycle-based salts, which were fully characterised by analytical (mass spectrometry and elemental analysis) and spectroscopic methods (IR, Raman and NMR). In addition, the molecular structures of all compounds were confirmed by X-ray analysis, revealing extensive hydrogen-bonding in the solid state and densities between 1.399 (3) and 1.669 g cm(-3) (5). The hydrogen-bonded ring motifs are discussed in the formalism of graph-set analysis for hydrogen-bond patterns and compared to each other. Preliminary sensitivity testing of the crystalline compounds indicate surprisingly low sensitivities to both friction and impact, the highest friction and shock sensitivity being found for the perchlorate (5, 220 N) and the dinitramide (8, 20 J) salts, respectively. In addition, DSC analysis was used to assess the thermal stabilities of the compounds: 3-6 melt above 200 degrees C with concomitant decomposition, whereas 7 and 8 have clearly defined melting points at 162 and 129 degrees C, respectively, and with decomposition occurring about 30 degrees C above the melting point. Lastly all compounds have positive calculated heats of formation between 336 (4) and 4070 kJ kg(-1) (6) and calculated detonation velocities in the range between 8330 (7) and 8922 m s(-1) (6) making them of interest as new highly energetic materials with low sensitivity.

Crystal structure of bis(1,3-diaminoimidazolium) 5,5’-azotetrazolate, (C3H7N4)2 (C2N10), C8H14N18

“…It is another example of nitrogen-rich 'energetic salts' which have received much attention [4,5]. Crystal structuresofother 5,5'-azotetrazolate salts [6][7][8][9] including aseries of metal salts [10][11][12] have been reported. The salt consists of two cations and one dianion (Figure, top iii (2.52 Åand 3.408(2) Å, 159°).…”

Synthesis, Structure and Energetic Properties of a Catenated N6, Polynitro Compound: 1,1'-Azobis(3,5-Dinitropyrazole)

“…Both of these parameters are governed by the compound's molecular structure. A higher density, heat of formation and nitrogen content are all directly related to the performance of a compound [34].…”

Structures and Energetic Properties of Two New Salts Comprising the 5,5'-Azotetrazolate Dianion

“…Both the 1 H and 13 C NMR spectra were in good agreement with the expected structure. For example, the 1 H NMR spectrum showed a multiplet at δ 7.95 ppm for the phenyl hydrogens in para-position and a broad multiplet at δ 7.83-7.67 ppm can be assigned to the asymmetric N-C=N stretching vibration of the tetrazole ring, while a strong band at 724 cm −1 is characteristic for the asymmetric C-N=N stretching vibration of the azotetrazolate dianion [19][20][21][22][23][24][25][26][27][28][29][30][31][32][33].…”