BN-Doped Fullerenes: An NICS Characterization.

Heterofullerenes C58(BN), C54(BN)3, C48(BN)6, and C12(BN)24 and their hexaanions as well as the C58(BN) dimer have been investigated by ab initio calculations. On the basis of the computed nucleus independent chemical shifts (NICS) at the cage center and also at the center of individual rings, BN-doped fullerenes C58(BN), C54(BN)3, and C48(BN)6 are slightly more aromatic than C60, whereas the corresponding hexaanions are significantly less aromatic than C606-. The predicted NICS values may be useful for the identification of the heterofullerenes through their endohedral 3He NMR chemical shifts. Compared to C60, the dimerization of C58(BN) is calculated to be more exothermic by 16 kcal/mol.