Computational studies on tetrazole derivatives as potential high energy materials

Abstract

The tetrazole is an important functionality of the most of energetic materials due to 80% nitrogen content, stability, and high enthalpy of formation. The present structure-property relationship study focuses on the optimized geometries of tetrazole derivatives obtained from density functional theory (DFT) calculations at B3LYP/6-31G* levels. The heat of formation (HOF) of tetrazole derivatives have been calculated by designing the appropriate isodesmic reactions. The increase in nitro groups on azole rings shows the remarkable increase in HOF. Density has been predicted by using CVFF force field. Increase in the nitro group increases the density. Detonation properties of the designed compounds were evaluated by using the Kamlet-Jacobs equation based on predicted densities and HOFs. Designed tetrazole derivatives show detonation velocity (D) over 8 km/s and detonation pressure (P) of about 32 GPa. Thermal stability was evaluated via bond dissociation energies (BDE) of the weakest C-NO 2 bond at B3LYP/6-31G* level. Charge on the nitro group has been used to assess the sensitivity correlation. Overall, the study implies that designed compounds of this series are found to be stable and expected to be the novel candidates of high energy materials (HEMs).

Molecular design of aminopolynitroazole-based high-energy materials

“…Densities predicted using the cvff force field (Table 3) were used to calculate detonation characteristics, as they lead to marginally better results for nitro compounds [40,41]. The predicted density of the MTNI molecule (1.82 g/cm 3 ) using the cvff force field was to be found close to the experimental value (1.79 g/cm 3 ) [42].…”

“…Hence, the basis set 6-31 G* was chosen for further studies. Previous studies have shown that B3LYP/6-31 G* methods produce more reliable enthalpies of formation [38][39][40][41].…”

Quantum-chemical design of tetrazolo[1,5-b][1,2,4,5]tetrazine based nitrogen-rich energetic materials

“…show that the increase in nitro groups in a molecule improves the density and it also increases the chances of inter-and intramolecular hydrogen bonding between acidic hydrogen and oxygen present in molecule [34][35][36][37]. This clearly indicates that the -NO 2 group is an effective substituent for improving densities of the energetic materials.…”

DFT, Hirshfeld surfaces, spectral and in vivo cytotoxic studies of 7a-Aza-B-homostigmast-5-eno [7a,7-d] tetrazole

“…The heat of formation for 49 tetrazole derivatives was computed using density functional theory [11]. Since tetrazole derivatives have broad applications in medicine, biology, agriculture and in ammunitions [12][13][14][15] therefore there is a continuous surge for newer application of tetrazole and its derivatives [16][17][18][19][20]. In the present work, an interesting compound of the tetrazole family, 7a-Aza-B-homostigmast-5-eno [7a, 7-d],…”