Synthesis and characterization of a new class of energetic compounds - Ammonium nitriminotetrazolates

Abstract

1-Methyl-5-nitriminotetrazole (1) and 2-methyl-5-nitraminotetrazole (2) obtained by nitration of 1-methyl-5-aminotetrazole (3) and 2-methyl-5- aminotetrazole (4) were deprotonated using aqueous ammonia solution yielding the energetic compounds, ammonium 1-methyl-5-nitriminotetrazolate (5) and ammonium 2-methyl-5-nitriminotetrazolate (6). The nitrogen-rich salts were tested and characterized comprehensively using vibrational spectroscopy (Infrared (IR) and Raman), multinuclear (1H, 13C, 14N, and 15N) NMR spectroscopy, and elemental analysis. The molecular structures in the crystalline state were determined using low temperature single crystal X-ray diffraction. The thermal behavior and the decompositions were investigated using differential scanning calorimetry (DSC) and gas IR spectroscopy. The heats of formation were calculated using bomb calorimetric measurements. In addition, the relevant detonation parameters, like the detonation pressure and velocity of detonation were calculated using the software EXPLO5 outperforming the values of TNT. Last but not least the sensitivities were determined using BAM methods showing moderate values against impact and friction (drophammer and friction tester) and the long-term stabilities were tested using Flexy Thermal safety calorimetry (TSC). X-ray crystallography: 5: monoclinic, P21/c, a = 370.06(2) pm, b = 2079.06(9) pm, c = 859.69(5) pm, β = 99.120(5)°, V= 65306(6) pm 3, Z = 4, ρcalc = 1.639 g cm-3; 6: monoclinic, P21, a = 365.39(2) pm, b = 788.82(5) pm, c = 1124.95(7) pm, β = 91.818(6), V= 32408(3) pm3, Z = 2, &calc = 1.651 g cm-3. © 2008 Wiley-VCH Verlag GmbH & Co. KGaA.