Molecular design on a new family of azaoxaadamantane cage compounds as potential high-energy density compounds

A new family of azaoxaadamantane cage compounds were firstly designed by introducing the oxygen atom into hexanitrohexaazaoxaadmantane (HNHAA) to replace the N-NO2 group. Their properties including heats of formation (HOFs), detonation properties, strain energies, thermal stability, and sensitivity were extensively studied by using density functional theory. All of the title compounds exhibit surprisingly high density (rho > 2.01 g/cm(3)) and excellent detonation properties (detonation velocity (D) > 9.29 km/s and detonation pressure (P) > 40.80 GPa). In particular, B (4,8,9,10-tetraazadioxaadamantane) and C (6,8,9,10-tetraazadioxaadamantane) have a remarkably high D and P values (9.70 km/s and 44.45 GPa, respectively), which are higher than that of HNHAA or CL-20. All of the title compound have higher thermal stability and lower sensitivity (h(50) > 19.58 cm) compared with the parent compound HNHAA. Three triazatrioxaadamantane cage compounds, D (6,8,9-triazatrioxaadamantane), E (6,8,10-triazatrioxaadamantane), and F (8,9,10-triazatrioxaadamantane), are expected to be relatively insensitive explosives. All of the title compounds exhibit a combination of high denotation properties, good thermal stability, and low insensitivity.