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

Abstract

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 (υmin) calculations show that except N10C10, all other BbNnC20‐(b + n) heterofullerenes with b, and n = 0, 4, 5, 8, and 10 are true minima. The calculated band gaps (∆EHOMO–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 (ΔHat/C) of B8C12 shows it the most thermodynamic stable heterofullerenes of each. Copyright © 2016 John Wiley & Sons, Ltd.