Synthesis, crystal structure, sensitivity, and effect on thermal decomposition of ammonium perchlorate: an energetic compound Cu(HATZ)(PDA)(H2O)

Structure determination and Hirshfeld surface analysis of new cocrystal and salt forms of 5-aminotetrazole with hydroxy- and nitro-substituted carboxylic acids

Two new crystalline solids, namely, 5-aminotetrazole–3,5-dihydroxybenzoic acid–water (1/4/6), CH3N5·4C7H6O4·6H2O (I), and 5-aminotetrazolium 3,5-dinitrosalicylate, CH4N5 +·C7H3N2O7 − (II), have been synthesized and characterized by single-crystal X-ray diffraction and Hirshfeld surface analysis. The crystal packing arrangements of I and II are governed by N—H...O and O—H...O hydrogen-bonding interactions. In cocrystal I, adjacent acid molecules are linked through O—H...O hydrogen bonds, forming a dimer with an R 2 2(8) motif. In salt II, the tetrazolium cation and acid anion are linked through N—H...O hydrogen bonds to also form a dimer with an R 2 2(8) motif. Further N—H...O and O—H...O hydrogen bonds help to stabilize the crystal packing, along with aromatic π–π stacking interactions in I and carbonyl...π interactions in II. The Hirshfeld surface analysis and fingerprint plots reveal that O...H/H...O interactions contribute 34.4% of the total interactions in the crystal packing of cocrystal I and 36.7% in salt II.

Modulating energetic performance through decorating nitrogen-rich ligands in high-energy MOFs

In the presence of different nitrogen-rich ligands, two energetic MOFs with formulas [Ag(tza)]_n (1) and [Ag(atza)]_n (2) (Htza = tetrazole-1-acetic acid and Hatza = (5-amino-1H-tetrazole-1-yl) acetic acid) were successfully synthesized and characterized. X-ray single crystal structure analysis shows that both 1 and 2 have 2D layer-like topologies. The experimental and theoretical evaluations reveal the promising properties of both energetic compounds, such as prominent heats of detonation, high thermal stabilities, good sensitivities and excellent detonation performances. In contrast to 1, interestingly, the introduction of the amino group in 2 leads to various coordination modes of the ligands and different stacking patterns of the frameworks, resulting in the observation of the shorter Ag-O, Ag-Ag, C-N, N-N, and N[double bond, length as m-dash]N bond lengths in 2. Consequently, 2 features superior heats of detonation and thermostability compared to 1. The nonisothermal thermokinetic parameters are obtained by using the Kissinger and Ozawa methods, while the standard molar enthalpies of formation are calculated from the determination of constant volume combustion energies. In addition, both compounds were explored as practical additives to promote the thermal decomposition of ammonium perchlorate (AP). This work may provide an effective approach for manipulating the energetic properties and thermostability of high-energy compounds via the perturbation of energetic groups.

Two nitrogen-rich Ni(ii) coordination compounds based on 5,5′-azotetrazole: synthesis, characterization and effect on thermal decomposition for RDX, HMX and AP

Two novel efficient burning promoters of solid propellants based on Ni salt and azotetrazole have been successfully prepared and characterized.