Charge‐Induced Reversible Rearrangement of Endohedral Fullerenes: Electrochemistry of Tridysprosium Nitride Clusterfullerenes Dy 3 N@C 2 n (2 n =78, 80)

The electrochemistry of three new clusterfullerenes Dy 3 N@C 2 n (2 n =78, 80), namely two isomers of Dy 3 N@C 80  (I and II) as well as Dy 3 N@C 78  (II), have been studied systematically including their redox‐reaction mechanism. The cyclic voltammogram of Dy 3 N@C 80  (I) ( I h ) exhibits two electrochemically irreversible but chemically reversible reduction steps and one reversible oxidation step. Such a redox pattern is quite different from that of Sc 3 N@C 80  (I), and this can be understood by considering the difference in the charge transfer from the encaged cluster to the cage. A double‐square reaction scheme is proposed to explain the observed redox‐reaction behavior, which involves the charge‐induced reversible rearrangement of the Dy 3 N@C 80  (I) monoanion. The first oxidation potential of Dy 3 N@C 80  (II) ( D 5 h ) has a negative shift of 290 mV relative to that of Dy 3 N@C 80  (I) ( I h ), indicating that lowering the molecular symmetry of the clusterfullerene cage results in a prominent increase in the electron‐donating property. The first and second reduction potentials of Dy 3 N@C 78  (II) are negatively shifted relative to those of Dy 3 N@C 80  (I, II), pointing to the former's lowered electron‐accepting ability. The significant difference in the electrochemical energy gaps of Dy 3 N@C 80  (I), Dy 3 N@C 80  (II), and Dy 3 N@C 78  (II) is consistent with the difference in their optical energy gaps.