Characterizations of B and N heteroatoms as substitutional doping on structure, stability, and aromaticity of novel heterofullerenes evolved from the smallest fullerene cage C-20: a density functional theory perspective

摘要

The structural stabilities and electronic properties of C-20 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 (v(min)) 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 (Delta 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 B(5)N(5)C(10)with 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 (Delta H-at/C) of B8C12 shows it the most thermodynamic stable heterofullerenes of each. Copyright (C) 2016 John Wiley & Sons, Ltd.