Computed electronic and vibrational spectra of the most stable isomers of C48N12 azafullerene

In the present paper, we report the electronic and vibrational spectra of the two most stable isomers of the fullerene derivative C48N12. Equilibrium structures and vibrational spectra are computed at the B3LYP-6/31G* level of theory and electronic excitations are obtained with the CNDO/S semiempirical Hamiltonian combined with configuration interaction calculations and with time dependent (TD) DFT (B3LYP/6-31G*) calculations. The C48N12 electronic spectra are predicted to be different from the spectrum of C60 owing to their lower symmetry and because different occupied and virtual orbitals are involved in the excitations. Both semiempirical and TD-DFT calculations indicate that the vertical energy of the lowest transition for the more stable isomer is ca. 2.4 eV above S0, similarly to the S1 energy of C60. In the less stable C48N12 isomer, the lowest transition is computed to be only 1.23 eV above S0, suggesting that this C48N12 isomer may have interesting semiconductor properties