Energetic barrier for penetration of N, N+ and N++ through the centre of hexagonal rings of a C60 cage. A stability study of the endohedral complexes (N@C60, N+@C60 and N++@C

Theoretical studies of model endohedral fullerenes N@C₆₀, N⁺@C₆₀ and N⁺⁺@C₆₀ were performed, from their stability aspect. The possibility of N, N⁺ and N⁺⁺ entering a fullerene cage without breaking any C-C bonds was investigated. Assuming the inclusion energy and the height of the energetic barrier of transfer of N, N⁺ and N⁺⁺ through the hexagons of a C₆₀ cage as the determinants of the stability of studied complexes their values were calculated by the quantum chemical DFT/B3LYP/6-31G* method. The calculated inclusion energies with the BSSE correction in the cases of N⁺⁺, N⁺ and N are -603.4, -149.6 and 3.9 kcal/mol, respectively.