Improved Synthesis and X‐Ray Structure of 5‐Aminotetrazolium Nitrate

Abstract 5‐Aminotetrazolium nitrate was synthesized in high yield and characterized using Raman and multinuclear NMR spectroscopy (1H, 13C, 15N). The molecular structure of 5‐aminotetrazolium nitrate in the crystalline state was determined by X‐ray crystallography: monoclinic, P 21/c, a=1.05493(8) nm, b=0.34556(4) nm, c=1.4606(1) nm, β=90.548(9)°, V=0.53244(8) nm3, Z=4, ϱ=1.847 g cm−3, R1=0.034, wR2 (all data)=0.090. The thermal stability of 5‐aminotetrazolium nitrate was determined using differential scanning calorimetry; the compound decomposes at 167 °C. The enthalpy of combustion (ΔcombH) of 5‐aminotetrazolium nitrate ([CH4N5]+[NO3]−) was determined experimentally using oxygen bomb calorimetry: ΔcombH([CH4N5]+[NO3]−)=−6020±200 kJ kg−1. The standard enthalpy of formation (ΔfH°) of [CH4N5]+[NO3]− was obtained on the basis of quantum chemical computations at the electron‐correlated ab initio MP2 (second order Møller‐Plesset perturbation theory) level of theory using a correlation consistent double‐zeta basis set (cc‐pVTZ): ΔfH°([CH4N5]+[NO3]−(s))=+87 kJ mol−1=+586 kJ kg−1. The detonation velocity (D) and the detonation pressure (P) of 5‐aminotetrazolium nitrate were calculated using the empirical equations by Kamlet and Jacobs: D([CH4N5]+[NO3]−)=8.90 mm μs−1 and P([CH4N5]+[NO3]−)=35.7 GPa.