A study of two metal energetic complexes based on 4-amino-3-(5-tetrazolate)-furazan: synthesis, crystal structure, thermal behaviors and energetic performance

•The molecular structures of two compounds were confirmed by their crystal structures.•The thermal behaviors and decomposition mechanisms of two compounds were described, respectively.•Some parameters were calculated to evaluate the thermal stability and safety of two compounds. In this contribution, two metal energetic complexes Co(HCONHNH2)2(AFT)2·H2O (1) and [Pb(HCONHNH2)2(AFT)2]n (2) (HCONHNH2=formyl hydrazide and HAFT = 4-amino-3-(5-tetrazolate)-furazan) have been synthesized and characterized. The structures of compound 1 and 2 are characterized by single crystal X-ray diffraction. The tests show that 1 possesses One-dimensional (1D) chain structure and 2 exhibits two-dimensional (2D) energetic metal-organic framework (MOF). The thermal decomposition processes of compounds have been investigated by MS-FTIR-DSC-TG coupling technique. It's worth noting that both of them exhibit higher thermal stabilities. Moreover, gaseous products generated after thermal decomposition of compound 1 and 2 are CO2, NO2, N2O, CO, HCN, NH3, H2O, N2. The standard molar enthalpies of formation of 1 and 2 are calculated to be -4501.25 kJ·mol-1 and -1091.13 kJ·mol-1, respectively. Detonation velocity and detonation pressure are respectively 9.32 km·s−1, 42.13 GPa for 1 and 5.62 km·s−1, 18.36 GPa for 2. Surprisingly, compound 2 exhibits promising detonation velocity and detonation pressure, which are higher than those of TNT, RDX and HMX. The above-mentioned information on thermal behavior is available to analyze and evaluate the stability and thermal safety of 1 and 2. The sensitivity tests reveal they possess excellent insensitivities to impact and friction. All the characterizations show that they can be used as potential energetic materials.