A novel pentazolate with a delocalized cation and its cocrystal

Abstract

The chemistry of pentazolates has attracted considerable attention. Energetic 2,5,8-trinitro-2,3,5,6,8,9-hexahydro-2,3a,5,6a,8,9a-hexaazaphenalene nitrate (2), 2,5,8-trinitro-2,3,5,6,8,9-hexahydro-2,3a,5,6a,8,9a-hexaazaphenalene pentazolate (4), and their 1 : 1 cocrystal 5 were synthesized via nitrolysis and metathesis reactions, of which the structures were characterized by X-ray single crystal diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), and nuclear magnetic resonance spectroscopy (NMR), and the thermal stabilities were studied by thermogravimetric (TG) and differential scanning calorimetry (DSC). Compound 2 has a detonation velocity of 8285 m s⁻¹ and a detonation pressure of 27.30 GPa. Energetic cocrystal 5 has a good detonation velocity of 8612 m s⁻¹, a detonation pressure of 29.3 GPa and a high density of 1.74 g cm⁻³, which are higher than those of other non-metallic pentazolates and their cocrystals.