Theoretical Studies on Energetic Nitrogen‐Rich Heterocyclic Substituted Derivatives of Pyrazino [2, 3‐e] [1, 2, 3, 4] Tetrazine‐1, 3‐di‐N‐oxide

Abstract

We used an effective approach to design a series of new energetic compounds by incorporating nitrogenous heterocyclic substituents (furazan, imidazole, triazole, oxazine, pyrazine, triazine, and tetrazine) together with two N-oxide into pyrazino [2, 3-e] [1, 2, 3, 4] tetrazine molecule. Their heat of formations (HOFs) were calculated by employing DFTÀ B3LYP method with 6-311G** basis set. The findings reveal that the substitution of the -N 3 and N 3 -substituted tetrazine groups causes a sufficiently large increase in the HOFs. The energy gap decreases for all the derivatives. The calculated values of detonation pressure and detonation velocity show that the substitution of the NF 2 -, N (NO 2 ) 2 -, and ONO 2 -substituted heterocycles is very helpful to enhance the detonation properties. The calculated bond dissociation energy values for few weakest bonds reflect that the nitrogen-nitrogen (N2-N3) bond in the pyrazino [2, 3-e] [1, 2,3, 4] tetrazine molecule is a weakest bond and ring cleavage may happen during thermal decomposition except for nitroxy (-ONO 2 ) substituted derivatives, where O-NO 2 bond may rupture rather than ring cleavage. By considering detonation properties, thermal stabilities, and other properties, 9 of our designed compounds may be consider as potential candidates of high energy density compounds because of their ambitious detonation performance and suitable thermal stability.[a] R.