cubane: A crystalline hydrocarbon,C8H8; r.d. 1.29; m.p. 131°C. It has anovel structure with eight carbonatoms at the corners if a cube, eachattached to a hydrogen. Cubane wascrystallite first synthesized in 1964 by PhilipEaton. The C–C–C bond angle of 90°is highly strained and cubane and itsderivatives have been investigated ashigh-energy fuels and explosives. Inparticular, octanitrocubane, in whichthe hydrogen atoms are replaced by-NO2 groups is possibly the mostpowerful chemical explosive known,although, so far, only small amountshave been synthesized. It decomposesto carbon dioxide and nitrogen:C8 (NO2)8 →8CO2 + 4N2