Endohedral Fullerenes

Abstract The recent state in endohedral fullerenes is reviewed in terms of both sides of the fullerene: the new carbon cages including non‐IPR (IPR, isolated pentagon rule) structures as well as new species encaged in the inner fullerene void. A general principle is valid nowadays and used in endohedral fullerene research: the stabilizing ability of the encaged structure for the fullerene cage architecture and that of the fullerene cage for the encaged species. Thus, the cage size ranges from C 66 , the first non‐IPR fullerene cage, to C 100 while the encaged species are extended up to five atomic clusters as for Sc 3 C 2 . The world of endohedral fullerenes was significantly enlarged within the past seven years by the cluster fullerenes containing structures like the M 3 N nitrides. This review is focused on the new development of this amazing world of carbon nanostructures since 1999, including new structures, properties, and potential applications of endohedral fullerenes as well as prospects.