Spectroscopic features and electronic properties on tetrazole-based energetic cocrystals under external electric field

Abstract

The optimized geometry, molecular orbitals, electronic properties and spectra wtheere calculated by DFT-B3LYP and PBE0 methods with 6–311 + g(d, p) and def2-TZVP basis sets. The results show that the change of electric field intensity has a great influence on the NH bond in the tetrazole ring skeleton, and it is more easily-broken under negative electric field. When the electric field changes, the NH bond is always the trigger bond. With the increase of external electric field, the energy gaps of 5-(nitrimino)-1H-tetrazole (A) and 1-methyl-5-(nitrimino)-1H-tetrazole (B) gradually become smaller, and chemical reactions are more likely to occur. Infrared and UV–Vis spectra show obvious vibration effects under external electric field, and both structures A and B show different degrees of red-shift or blue-shift. A and B exhibit basically similar properties under electric field, indicating that the hydrogen atoms and methyl groups on the tetrazole ring in the structure have little effect on the cocrystal.