Theoretical study of endohedral metallofullerenes:: Sc3-nLanN@C80 (n=0-3)

To provide theoretical insight into the structures and properties of Sc3N@C-80, which has been isolated in high yield and purity as a new stable endohedral metallofullerene, density functional calculations are carried out for the Sc3-nLanN@C-80 (n = 0-3) series. Because of electron transfer from Sc3N to C-80, the electronic structure of Sc3N@C-80 is formally described as (Sc3N)C-6+(80)6-. The encapsulated Sc3N cluster takes a planar structure with long Sc-Sc distances and is highly stabilized inside the lh cage of C-80, which rotates rapidly. As the number of La atoms increases, the Sc3-nLanN cluster is forced to maintain a pyramidal structure in Sc3-nLanN@C-80. In addition, the C-80 cage takes an open-shell electronic structure due to an increase in the number of electrons transferring from Sc3-nLanN. These make the endohedral structure less stable and more reactive. (C) 2001 John Wiley & Sons, Inc.