Synthesis and evaluation of polycyclic high energy-density fuels

Abstract

Application of polycyclic compounds as high energy-density (HED) materials is an attractive prospect because of the enormous energy that can be tapped from their compact structures. Model studies reported on cubane, methylcubane and pentacycloundecane dimer showed that they are much more superior to conventional hydrocarbon fuels by virtue of their faster ignition, higher heat capacity, superior burning rate and greater heat release. However, the whole concept of employing highly strained polycyclic compounds as HED materials can be realized only through viable synthetic methods. Therefore, we report the synthesis of a novel polycyclic hydrocarbon dimer 1 from easily accessible bis-homocubanone and evaluation of its thermodynamic properties. Our studies revealed that this cage dimer 1 possesses desirable properties such as high positive heat of formation and specific impulse. Subsequently, we introduced nitro, azido and polynitrogen heterocycles to the polycarbocyclic skeleton (see 2-4) aimed at enhancing the energy output from the synthesized compounds. Preliminary theoretical and experimental studies suggest that these compounds are indeed potential candidates for their applications as fuels/fuel additives in a volume limited environment.