THEORETICAL STUDY ON THE STRUCTURES AND ELECTRONIC PROPERTIES OF Sc_3-nLa_nN@C_(80) (n = 0 - 3)

摘要

Endohedral metallofullerenes have attracted considerable interest as new spherical molecules with novel properties unexpected for empty fullerenes, Up to now, it has been demonstrated that group 3 and lanthanide metals can be trapped inside higher fullerenes. However, these are typically produced in low yields. In contrast, it has recently been found that metallofullerenes that involve a N atom with these metals are produced in high yield and purity as a new family of stable endohedral metallofullerenes . These Sc3-_nM_nN@C_m (M = Y, La, and lanthanides; n = 0 - 3; m = 68, 78, 80, etc.) family members are prepared using graphite rods filled with Sc_2O_3, M_2O_3, powdered graphite, and cobalt oxide under N_2 atmosphere. Among these, Sc_3N@C_(80) is a representative member and its yield is remarkably enhanced owing to the presence of N_2, making it possible to determine the structure by a single crystal X-ray diffraction study. This is notable because crystallization has long been a bottleneck in the structural determination of endohedral metallofullerenes. We report a theoretical study on the structures and electronic properties for the Sc_(3-n)La_nN@C_(80) (n = 0 - 3) series using density functional calculations.