Comparative EPR study of Cu@C60 and N@C60 endofullerenes

✍ Scribed by Claus Knapp; Norbert Weiden; Klaus-Peter Dinse

• Publisher: John Wiley and Sons
• Year: 2005
• Tongue: English
• Weight: 294 KB
• Volume: 43
• Category: Article
• ISSN: 0749-1581
• DOI: 10.1002/mrc.1661

✦ Synopsis

A comparative study of C 60 -based endohedral fullerenes was performed. From an analysis of spin relaxation times of the recently characterized Cu@C 60 metallo-endofullerene, it could be shown that the encased ion occupies a well-defined off-centre position even at room temperature. Localization on the timescale of an EPR experiment is combined with charge transfer of approximately two electrons, resulting in the EPR signature of a 3d 9 copper ion. This is in contrast to N@C 60 , for which a nearly complete decoupling from the cage is found. An upper limit for the variance of collision-induced modulation of the anisotropic nitrogen hfi is determined as hA 2 eff i 1/2 < 500 kHz by an analysis of cross peak intensities in a 2D EPR experiment.

Pulsed 95 GHZ ENDOR experiments have been performed to confirm that deformation-induced hyperfine anisotropies are expected to be very small in N@C 60 .