AUTOMATED HPLC SEPARATION OF ENDOHEDRAL METALLOFULLERENE SC-AT-C-2N AND Y-AT-C-2N FRACTIONS

We describe an automated HPLC separation of the endohedral metallofull erenes such as Sc@C-2n and Y@C-2n from empty-cage fullerenes utilizing two polystyrene chromatographic columns (500 and 1000 Angstrom) in se ries. Rapid separation of the metallofullerene fraction from the empty -cage fullerenes (e.g., C-60) under anaerobic conditions is achieved. For the isolated Sc@C-2n fraction, all even-carbon-membered species fr om Sc-2@C-74 to Sc-2@C-104 were identified by negative-ion chemical io nization mass spectrometry. In addition, Sc-3@C-82 was a prominent com ponent of this fraction. For the separated Y@C-2n sample, the mass spe ctral data indicate the presence of Y@C-82 and all even-carbon-nurnber ed diyttrium species from Y-2@C-82 to Y-2@C-104.