ANYL 339 |
| The electrochemistry of three new clusterfullerenes Dy3N@C2n (2n = 78, 80), namely two isomers of Dy3N@C80 (I and II) as well as Dy3N@C78 (II), is studied systematically including the redox reaction mechanism. Cyclic voltammogram (CV) of Dy3N@C80 (I) (Ih) exhibits two electrochemically irreversible but chemically reversible reduction steps and one reversible oxidation step. Such a redox pattern is quite different from Sc3N@C80 (I), and this is understood by considering their difference on the charge transfer from the encaged cluster to the cage. A double-square reaction scheme is proposed to explain the observed redox reaction behavior, involving the charge-induced reversible rearrangement of the Dy3N@C80 (I) monoanion. For Dy3N@C80 (II) (D5h), its first oxidation potential experiences a negative shift of 290 mV with respect to Dy3N@C80 (I) (Ih), indicating that lowering the molecular symmetry of the clusterfullerene cage results in the prominent increase of the electron donating property. Dy3N@C78 (II) gives obvious negative shifts in the first and second reduction potential compared to Dy3N@C80 (I, II), pointing to its lowered electron accepting ability. The significant difference on the electrochemical engergy gap of Dy3N@C80 (I), Dy3N@C80 (II), and Dy3N@C78 (II) is consistent with their difference on the optical energy gap. |
|
Analytical Approaches: Novel Materials
1:30 PM-4:40 PM, Thursday, 14 September 2006 Moscone Center -- Room 130, Oral
Division of Analytical Chemistry |