A Density Functional Theory Investigation for the Open-Shell Metal-Carbide Endofullerene Lu_3C_2@C_(88)(D_2:35) and Closed-Shell Metal-Nitride Endofullerene Lu_3N@C_(88)(D_2:35)

摘要

By means of the density functional theory calculations, two C_(88)(D_2:35)-based endohedral fullerenes, Lu_3C_2@C_(88)(D_2:35) and Lu_3N@C_(88)(D_2:35) which encapsulate tri-lutetium carbide and tri-lutetium nitride cluster were investigated. For the cores in Lu_3C_2@C_(88) and Lu_3N@C_(88), the trivalent C_2 and N respectively template a butterfly-shaped endohedral moiety and a planar tri-lutetium cluster within the same D_2-symmetric C_(88) cage. Moreover, Lu_3N@C_(88) - D_2 has a closed-shell electronic structure but for Lu_3C_2@C_(88) - D_2, it owns an unpaired electron mainly localized on the internal Lu_3C_2 cluster. These results clearly showed that the core unit C_2~(3-) as well as N~(3-) play an important role in constructing molecular structures and electronic features of metallofullerenes. Furthermore, the electrochemical redox potentials, and vibrational frequencies of the two endofullerenes agree well with our experimental results. The electronic structures, ionization energies, electron affinities, inner clusters' dynamic motions of them have been predicted to further disclose the characters of these two metallofullerenes.