A femtosecond laser study of the endohedral fullerenes Li@C

The endohedral fullerenes La@C82 and Li@C60 have been studied in the gas phase with femtosecond laser excitation. The two molecules show qualitatively the same behaviour with respect to ion yield vs. pulse energy, but markedly different fragmentation patterns, with La@C82 fragmenting via the shrink-wrap mechanism and Li@C60 predominantly losing the metal atom in the first fragmentation step. The ion yields and electron energy distributions of La@C82 agree well with a recently developed model for fs laser ionisation of C60