A 3D nitrogen-rich heat-resistant supramolecular MOF with superior energetic performances assembled from Zn(II) and 5-aminotetrazole

Abstract

Heat-resistant explosives are pivotal for specialized applications demanding high thermal stability, essential in both civil and military sectors, especially in extreme environments. Our study focuses on the synthesis of a 3D nitrogen-rich supramolecular energetic metal-organic framework (MOF), Zn(ATZ)2 (1), using the 5-aminotetrazole (HATZ) ligand and Zn(II) ion. Structural analysis indicates that compound 1 adopts the orthorhombic CmCm space group and possesses a robust 2D network, characterized by strong π-π packing interactions between 2D layers, offering exceptional thermal stability up to 322 °C with minimal mechanical sensitivity. The standard molar enthalpy of formation (ΔfHo) and heat of detonation (ΔHdet) for compound 1 are calculated to be 7.08 kJ/g and 7.34 kJ/g, respectively. Remarkably, the ΔfHo of compound 1 significantly exceeds those of traditional heat-resistant explosives like RDX (0.32 kJ/g), HNS (0.17 kJ/g), TNT (–0.295 kJ/g), and TATB (–0.54 kJ/g), and is also higher than those of most reported energetic MOF materials. Similarly, its ΔHdet value surpasses those of common explosives such as TNT (4.144 kJ/g), HMX (5.525 kJ/g) and RDX (5.71 kJ/g), as well as the majority of reported energetic MOFs. Compound 1 also demonstrates impressive detonation properties with a velocity (D) of 7.22 km s-1 and a pressure (P) of 21.95 GPa, outperforming many other energetic MOF materials. These superior energetic characteristics position compound 1 as a strong candidate for heat-resistant explosives, showcasing its potential for future applications in demanding environments.