Preparation and enrichment of samarium endohedral fullerenes

A graphite anode packed with a powder mixture of Sm2Co17, SiC, and graphite with a high atomic ratio of Sm/C was vaporized by direct current are disch arge under improved conditions including high helium pressure, low electric current, and wide electrode gap. The soot produced was successively extrac ted by CS2 and pyridine, and the extracts were processed through column chr omatography on silica gel. Matrix-assisted laser desorption-ionization time -of-flight (MALD-TOF) mass spectrometry analysis indicated that a high yiel d of samarium endohedral fullerenes (Sm@C-2n) with Sm@C-84 as the most abun dant one was achieved. Possible reasons leading to this high yield are disc ussed.