High-yield preparation of endohedral metallofullerenes by an improved DC arc-discharge method Original Research Article

The soot containing endohedral metallofullerenes Mx@C2n(M=Y, La, Tb and Sm; x=1, 2, 3; n⩾30) has been prepared by DC arc-discharge method under improved conditions including high helium pressure, low electric current, large gap distance between electrodes and high atomic ratio of M/C, with MNi2 alloys instead of metal oxides or pure metals as the encaged metal source, followed with extraction by CS2. The raw soot and extracts were analyzed by laser desorption mass spectrometry and results show that the relative yields of metallofullerenes, even if the usually low yield ones, Sm@C74 and Sm@C84 for example, are rather high. Some possible reasons leading to the high yield preparation are discussed.