The synthesis of three new isomers of C121 by neutron irradiation of C60 is reported in this paper. The re- sults indicate that lower flux ratio of thermal to fast neutrons
proper oxidation of C60
and longer irradiation time are advantageous to the formation of C121. This new nuclear method
by which three isomers of C121 were prepared for the first time
has opened a new way to synthesize other odd-numbered large carbon fullerene.