Encapsulation of different chemical species inside fullerenes are new ways to protect or isolate from environment. In this study, hydrazoic acid, as an energetic molecule, was encapsulated inside fullerene as an endohedral host-guest complex H{{N}₃} @ {{C}₆₀} and its electronic structure was investigated using the M06-2X density functional method and the 6-311G (d, p) basis set. It was found that six stable structures for this endohedral complex exist in which the hydrazoic acid undergo significant geometrical change. On the other hand, spherical symmetry of the fullerene as surrounding cage suffers from presence of the endohedral hyrazoic acid molecule and deviates to ellipsoidal geometry. Gibbs free, binding and interaction energies analyses are also carried out and confirms unfavorable formation of endohedral complex H{{N}₃} @ {{C}₆₀}. Electronic deformation density analysis is also performed to get deeper insight into interaction of endohedral hydrazoic acid molecule with the fullerene’s interior walls and results show strong steric interaction between guest and host species.
Mongashti et al. (Wed,) studied this question.