Propellants Explosives Pyrotechnics, Vol.30, No.3, 191-195, 2005
Improved synthesis and X-ray structure of 5-aminotetrazolium nitrate
5-Aminotetrazolium nitrate was synthesized in high yield and characterized using Raman and multinuclear NMR spectroscopy (H-1, C-13, N-15). ne molecular structure of 5-aminotetrazolium nitrate in the crystalline state was determined by X-ray crystallography: monoclinic, P 2(1)/c, a = 1.05493(8) nm, b = 0.34556(4) nm, c = .1.4606(1) nm, beta = 90.548(9)degrees, V= 0.53244(8) nm(3), Z = 4, rho = 1.847 g cm(-3), R-1 = 0.034, wR(2) (all data) = 0.090. The thermal stability of 5-aminotetrazolium nitrate was determined using differential scanning calorimetry; the compound decomposes at 167 degrees C. The enthalpy of combustion (Delta(comb)H) of 5-aminotetrazolium nitrate ([CH4N5](+)[NO3](-)) was determined experimentally using oxygen bomb calorimetry: Delta(comb)H([CH4N5](+)[NO3](-)) = - 6020 +/- 200 kJ kg(-1). The standard enthalpy of formation (Delta(f)H degrees) of [CH4N5](+)[NO3](-) was obtained on the basis of quantum chemical computations at the electron-correlated ab initio MP2 (second order Moller-Plesset perturbation theory) level of theory using a correlation consistent double-zeta basis set (cc-pVTZ): Delta(f)H degrees([CH4N5](+)[NO3](-)(s)) = +87 kJ mol(-1) = +586 kJ kg(-1). The detonation velocity (D) and the detonation pressure (P) of 5-aminotetrazoliurn nitrate were calculated using the empirical equations by Kamlet and Jacobs: D([CH4N5](+)[NO3](-)) = 8.90 mm mu s(-1) and P([CH4N5](+)[NO3](-)) = 35.7 GPa.