Octaazacubane


Octaazacubane is a hypothetical explosive allotrope of nitrogen with formula N8, whose molecules have eight atoms arranged into a cube. It can be regarded as a cubane-type cluster, where all eight corners are nitrogen atoms bonded along the edges. It is predicted to be a metastable molecule, in which despite the thermodynamic instability caused by bond strain, and the high energy of the N–N single bonds, the molecule remains kinetically stable for reasons of orbital symmetry.

Explosive and fuel

Octaazacubane is predicted to have an energy density of 22.9 MJ/kg, which is over 5 times the standard value of TNT. It has therefore been proposed as an explosive, and as a component of high performance rocket fuel. Its velocity of detonation is predicted to be 15,000 m/s, much more than octanitrocubane, the fastest known nonnuclear explosive.
Cubic gauche nitrogen has an energy density of 33 MJ/kg exceeding octaazacubane by 50%.