Abstract
Endohedral
metallofullerenes constitute an appealing class of nanoscale building
blocks for fabrication of a wide range of noval materials. One open question
of fundamental importance is the precise nature of charge redistribution
with the carbon cages (Cn) upon metal encapsulation. Using ab
initio density functional theory, we systematically study the electronic
structure of metallofullerenes, focusing on the spatial charge redistribution.
For all large metallofullerenes (n >32), the valence electrons of the
metal atoms are all transferred to the fullerene states. Surprisingly, the
transferred charge is found to be highly localized inside the cage near
the metal cations, rather than uniformly distributed on the surfaces of
the carbon cage as traditionally belied. This counterintuitive charge
localization picture is attributed to the strong metal-cage interactions
within the systems. These findings may prove to be instrumental in the
design of novel fullerene-based functional nanomaterials.
1Supported by the DMSE program and grant no. DE-FG02-05ER46209
of USDOE, grant no. DMR-0606485 of USNSF, and NSF of China.
