DFT study of [Fe@B36N36]n+ (n=2, 3) endohedral nanocages: Chemical reactivity, NBO analysis and thermochemistry

• Endohedral Fen+ cations have considerable impact on natural population of B36N36.
• Encaged Fe2+ forms an endohedral triangular pyramid complex with B36N36 shell.
• Inclusion reactions of Fe cations with B36N36 are spontaneous at 298.15 K and 1 atm.
• Endohedral Fen+ cations significantly change the reactivity of B36N36 nanocage.

In this study, the structures, vibrational stabilities, energy gaps of B36N36 nanocage and its two endohedral derivatives, [Fe@B36N36]n+ (n=2, 3) were investigated via B3LYP hybrid functional of DFT. The transfer of charges and the inclusion energies of Fen+-encapsulated endohedrals were discussed as well. The detailed natural bond orbital (NBO) analysis revealed the nature of the hyperconjugative interactions of each nanocage. The NBO analysis specified an endohedral complex of Fe2+ with three nitrogen atoms of B36N36 while Fe3+ did not form such an endohedral complex. Also the global reactivity of the endohedrals based on NBO analysis was interpreted, and possible redox reactions of the studied nanocages were explained qualitatively.