Characterizations of B and N heteroatoms as substitutional doping on structure,stability, and aromaticity of novel heterofullerenes evolved from the smallest fullerene cage C20: a density functional theory perspective

The structural stabilities and electronic properties of C₂₀ fullerene and some its incorporated boron and nitrogen derivatives are probed at B3LYP/AUG‐cc‐pVTZ level of theory. According to density functional theory results, the topology of inserted B or N heteroatoms in 20]‐fullerene perturbs strongly the stability, energy, geometry, charge, polarity, nucleus‐independent chemical shifts, aromaticity, and highest‐occupied molecular orbital and lowest‐unoccupied molecular orbital (HOMO–LUMO) gap of the resulting heterofullerenes. Vibrational frequency (υ_min) calculations show that except N₁₀C₁₀, all other B_bN_nC_{20‐(b + n)} heterofullerenes with b, and n = 0, 4, 5, 8, and 10 are true minima. The calculated band gaps (?E_HOMO–LUMO) of B₈C₁₂, and N₈C₁₂ (2.86 eV), show them the most stable heterofullerenes against electronic excitations. While 10 B substituting in equatorial position increase the conductivity of B₁₀C₁₀ through decreasing its band gaps, 10 N doping in equatorial position enhance stability of N₁₀C₁₀ against electronic excitations via increasing its band gaps. High natural bond orbital and Mulliken charge transfer on the surfaces of B atoms, especially B₅N₅C₁₀with five B–N bonds in the equatorial position, provokes further investigation on its possible application for hydrogen storage. Nucleus‐independent chemical shift values show that B₅N₅C₁₀ is the most aromatic species. The calculated heat of atomization per carbon (ΔH_at/C) of B₈C₁₂ shows it the most thermodynamic stable heterofullerenes of each. Copyright © 2016 John Wiley & Sons, Ltd.