Isolation and structure determination of missing fullerenes Gd@C(CF) through trifluoromethylation.

Our trifluoromethyl functionalization method enables the dissolution and isolation of missing metallofullerenes of Gd@C(CF) . After multi-stage high-performance liquid chromatography purification, Gd@C(CF) and two regioisomers of Gd@C(CF) are isolated. X-ray crystallographic analysis reveals that all of the isolated metallofullerenes react with CF groups on pentagons of the -symmetry C cages. Highest occupied molecular orbital-lowest unoccupied molecular orbital gaps of these trifluoromethylated derivatives, estimated by absorption spectra, are in the range 0.71-1.06 eV, consistent with density functional calculations.