Tetrazolo[1,5-b]pyridazine as a versatile scaffold for construction of multipurpose energetic materials

In this work, a fused-ring tetrazolo[4,3-b]pyridazine framework with catenated nitrogen chain was applied to develop new energetic materials with task-specific applications for different purposes. Their syntheses, characterizations and properties were extensively studied. Among them,6-methylnitramimo-7-nitro-8-aminotetrazolo[1,5-b]pyridazine (4) is a potential booster explosive with good detonation velocities (Dv: 8496 m s−1), detonation pressure (P: 28.7 GPa), impact sensitivity (IS: 3 J), friction sensitivity (FS: 112 N) and better decomposition temperature (Td: 200.7 °C) than PETN as well as suitable predicted shock sensitivity (P90% TMD: 1.839 GPa). 6-Nitramimo-7-amino-8-nitrotetrazolo[1,5-b]pyridazine (12) is a high-energy explosive (Dv: 8926 m s−1, P: 33.7 GPa), while bis((7-nitro-8-aminotetrazolo[1,5-b]pyridazin-6-yl)amino)ethane (9) is a heat-resistant explosive (Td: 303.1 °C) with high detonation performances (Dv: 8809 m s−1, P: 29.3 GPa) and low sensitivities (IS: 19 J, FS: 288 N). The analysis of crystal structure, Hirshfeld surface, fingerprint plot, bond dissociation energies (BDEs) and electrostatic potentials (ESP) was used to assess the energy density and sensitivity properties.