Theoretical studies on the stability of the salts formed by DTDO with HNO 3 and HN(NO 2 ) 2

Abstract

Three stable conformations of salts formed from 3,6-diguanidino-1,2,4,5-tetrazine-1,4-di-N-oxide (DTDO) and HNO 3 and HN(NO 2 ) 2 were studied using the density functional theory. For two salts, free energies (Gs) and total energies (Es) of the three conformations increase in the same order. Intramolecular interactions in the three conformations, such as the hydrogen bonding interaction (E H ), the charge transfer (q), the binding energy (E b ), the dispersion energy (E dis ) and the second-order perturbation energy (E 2 ), decrease in completely opposite order to that of Gs and Es. Different conformations have distinct effects on the chemical stabilities and UV stabilities of two salts. Aromaticities of tetrazine in different conformations are slightly different. Although stabilities of the three conformations are different, their values are comparable.