Automated HPLC Separation of Endohedral Metallofullerene Sc@C2n and Y@C2n Fractions

Abstract

We describe an automated HPLC separation of the endohedral metallofullerenes such as Sc@C2n and Y@C2n from empty-cage fullerenes utilizing two polystyrene chromatographic columns (500 and 1000 Å) in series. Rapid separation of the metallofullerene fraction from the empty-cage fullerenes (e.g., C60) under anaerobic conditions is achieved. For the isolated Sc@C2n fraction, all even-carbon-membered species from Sc2@C74 to Sc2@C104 were identified by negative-ion chemical ionization mass spectrometry. In addition, Sc3@C82 was a prominent component of this fraction. For the separated Y@C2n sample, the mass spectral data indicate the presence of Y@C82 and all even-carbon-numbered diyttrium species from Y2@C82 to Y2@C104.