Theoretical investigations on heat of formation, detonation performance, and pyrolysis mechanism of 1,3,5,7,9,11-hexo(nitramine)-2,4,6,8,10,12- hexaazatetracyclo[5,5,0,0,0]dodecane

Abstract

The B3LYP/6-311G(d,p) method was used to investigate IR and Raman spectra, heat of formation, and thermodynamic properties of a newly designed polynitro cage compound 1,3,5,7,9,11-hexo(nitramine)-2,4,6,8,10,12-hexaazatetracyclo[5,5,0,0,0]dodecane. The detonation and pressure were evaluated by using the Kamlet−Jacobs equations based on the theoretical density and condensed heat of formation. The bond dissociation energies and bond orders for the weakest bonds were analyzed to investigate the thermal stability of the title compound. The results show that the N9−NO2 bond is predicted to be the trigger bond during pyrolysis. There exists an essentially linear relationship between the Wiberg bond indices of N−NO2 bonds and the charges –QNO2 on the nitro groups. The crystal structure obtained by molecular mechanics belongs to the P21 space group, with lattice parameters Z = 2, a = 10.9220 Å, b = 13.6669 Å, c = 9.4659 Å, and ρ = 2.05 g cm−3.