Exploring electronic structures for the most stable isomers of C _(12)B _6N _6 and B _6N _6C _(12) heterofullerenes based on NMR, NICS and NBO analysis: A DFT study

摘要

DFT calculations are applied to evaluate the effects of atomic arrangements of dopant atoms on electronic features of the most stable structures of (BC _2N) _6 including both C _(24) fullerene doped with six BN units (C _(12)B _6N _6; model 1-7) and B _(12)N _(12) nanocage doped with six CC units (B _6N _6C _(12); model 8-15). Our study reveals a relation between local structures, C _α, C _β, C _γ, and C _δ within the molecules and ~(13)C NMR signals. This is also observed with natural charges, so that the increase of negative charge on carbon is along with more shielding of corresponding carbon. All BN-substituted species (model 1-7) with the negative calculated NICS at their cage center are predicted to be aromatic, in contrast to C _(24) (NICS=±37). The predicted NICS values may be useful for the identification of the heterofullerenes through their endohedral ~3He NMR chemical shifts.