In Situ ESR Spectroelectrochemical Study of Sc4O2@C80: Endohedral Redox System
Electrochemical Society Meeting
The frontier molecular orbitals (MOs) of monometallofullerenes are essentially carbon cages MOs, and therefore electrochemical activity of such EMFs is mainly determined by the properties of the carbon cage, while the electronic state of the endohedral metal atoms remains barely constant irrespective of the charge of the whole EMF molecule. Starting from dimetallofullerenes, increasing complexity of the endohedral species opens the way to more peculiar electronic states in EMFs, and it is possible that some of these EMFs can exhibit endohedral redox activity. 1 By this term, we understand that the change of the charge of the EMF molecule (in particular, in electrochemical reaction on the electrode) results in the change of the valence state of the endohedral atoms. A new interesting type of EMFs are oxide clusterfullerenes such as Sc4O2@C80 and Sc4O3@C80. 2, 3 In Sc4O2@C80, Sc is in the mixed valence state – i.e., two Sc atoms are formally divalent with the bond between them. Both LUMO and HOMO in Sc4O2@C80 are localized on the Sc4O2 cluster;4, 5 likewise, DFT computations show that the spin density of the anion and cations are also localized on the cluster.4 Thus, Sc4O2@C80 is a promising object for endohedral electrochemistry. In this work we study electrochemical properties of Sc4O2@C80 and analyze spin density distribution in its cation- and anion-radicals by means of ESR spectroscopy and DFT calculations.
A A. Popov, N Chen, L Echegoyen, Steven Stevenson, and L Dunsch (2012).
In Situ ESR Spectroelectrochemical Study of Sc4O2@C80: Endohedral Redox System. Presented at Electrochemical Society Meeting, Seattle, WA.