Design of functionalized C-N-linked fused oxadiazole-azoles and tetrazole backbones as high-energy-density materials

Developing high-energy density materials is crucial yet challenging. Designing and evaluating these compounds to find promising candidates is essential. This research used density functional theory to generate energetic compounds based on functionalized C-N-linked fused oxadiazole-azoles and tetrazole backbones. Their electronic structures, heats of formation, detonation properties, and stability were examined. The results show that most of the designed compounds have a high positive heat of formation, ranging from 434.1 to 1651.6 kJ/mol, and significantly higher density between 1.76 and 1.93 g/cm³. The predicted results on detonation properties show that compounds with nitro moiety in the functional group, such as -NO₂, -NHNO₂, -ONO₂, -CH(NO₂)₂, and -C(NO₂)₃, greatly improve detonation performance. These energetic properties emphasize the potential of C-N-linked fused oxadiazole-azoles and tetrazole backbones in developing new energetic materials.

Structural optimization of series A, B, and C compounds (7 derivatives each) was performed using the Gaussian 09 package at B3LYP/6-311G(d,p) level, followed by vibrational analysis. The electrostatic potential energy and wavefunction analysis were computed using the Multiwfn 3.8 package. The visualization of the non-covalent interaction and reduced density gradient was accomplished by the VMD 1.9.3 program.