Synthesis and characterization of a new energetic salt 1H-pyrazole-1-carboxamidine dinitramide and its thermal properties

Abstract

The new energetic compound 1H-pyrazole-1-carboxamidine dinitramide (PACADN) was synthesized by the reaction of silver dinitramide with 1H-pyrazole-1-carboxamidine hydrochloride. Its structure was confirmed by single-crystal X-ray diffraction, elemental analysis and Fourier transform infrared, ultraviolet–visible and nuclear magnetic resonance spectroscopy analyses. PACADN crystallizes in the orthorhombic space group Pnna. The thermal decomposition was studied with differential scanning calorimetry, thermogravimetry analysis and thermogravimetric tandem infrared spectrum. The results indicated that PACADN exhibits good resistance to thermal decomposition up to 433 K and has 90.24 % mass loss between 433 and 523 K by undergoing exothermic decomposition. The kinetic parameters of the thermal decomposition of PACADN were also obtained from the derivative thermogravimetry analysis data using Kissinger’s method, with E a = 143.2 kJ mol−1. Moreover, the detonation velocity and detonation pressure of PACADN were calculated as 7.2 km s−1 and 21 GPa by applying the Kamlet–Jacobs (as follows). $$ \begin{aligned} D & = 1.01(N\overline{M}^{1/2} Q^{1/2} )^{1/2} (1 + 1.3\rho ) \\ P & = 1.558\rho^{2} N\overline{M}^{1/2} Q^{1/2} .\\ \end{aligned} $$