Theoretical Studies on the Structures, Densities, Detonation Properties and Thermal Stability of Tris(triazolo)benzene and its Derivatives

Abstract

To look for superior and safe high-energy density materials (HEDMs), tris(triazolo)benzene and its R = ‒CN, ‒NHNO2, ‒N(NO2)2, ‒NH2, ‒N(NH2NO2), and ‒N(NO2ONO2) derivatives were studied at the B3LYP/6-311G(d, p) level of density functional theory (DFT). The energy content of the molecules was evaluated by calculating standard heats of formation, using isodesmic reaction. The results showed that all tris(triazolo)benzene derivations had high and positive heat of formation. The bond dissociation energies and bond orders for the weakest bonds were analyzed to investigate the thermal stability of the tris(triazolo)benzene derivatives. Most tris(triazolo)benzene derivatives for Ring-R had large bond dissociation energies (BDEs) which were over 140kJ · mol− 1except R = ‒N(NO2ONO2), which showed that the tris(triazolo)benzene derivatives had good thermodynamic stability. Impact sensitivity was evaluated using frontier orbital energies and characteristic heights (H50). These results indicated that incorporation with ‒NH2 is an effective means to decrease molecular sensitivity. Detonation velocities and pressures were estimated using modified Kamlet-Jacobs equations, based on the theoretical densities and heats of formation. These derivatives possess excellent detonation properties, for C, E, and, the detonation velocity are 9.38, and 9.98 km.s−1, and the detonation pressure are 43.68, and 48.41Gpa, respectively, the detonation performances are better than cyclotetramethylenetetranitramine (HMX). The detonation character of A, B, D, G, and F also are very close to that of HMX. Taking detonation performance and stability into consideration, the most of tris(triazolo)benzene derivatives may be good candidates of high energies materials.