Fullerenes with encapsulated metals

Since the discovery of Cgo (Kroto et al. 1985) empty fullerenes and fullerenes with encapsulated metal atoms have attracted much attention of theoreticians and experimentalists. We caimot even cite all important articles in this quickly expanding field and we merely concentrate on the few quantum-chemical studies of endohedral lanthanide-fullerene complexes. 

Fullerenes are probably the most prominent baU-shaped molecules in organic chemistry. Repeatedly, this class of compounds has astonished the chemical community. One of these surprises was that fullerenes can encapsulate metal atoms as well as noble gases and atomic hydrogen (in formulas symbolized with , e.g. Sc Cg2). Endo-... 

In the last few years several endohedral fullerenes, Mm C , i.e., closed carbon cages C ( = 28, 60, 80, 82) with encapsulated metal atoms M or metal dimers M2, have been investigated by pseudopotential and density functional methods. Scalar-relativistic density functional calculations by Rosch et al. on Ce C2g yield a tetravalent cerium ion in the center of the cage. The C2g cage appears to be sufficiently small that the 4f orbitals contribute significantly... 

The final section of the volume contains three complementary review articles on carbon nanoparticles. The first by Y. Saito reviews the state of knowledge about carbon cages encapsulating metal and carbide phases. The structure of onion-like graphite particles, the spherical analog of the cylindrical carbon nanotubes, is reviewed by D. Ugarte, the dominant researcher in this area. The volume concludes with a review of metal-coated fullerenes by T. P. Martin and co-workers, who pioneered studies on this topic. 

The exohedral derivatives of fullerenes with organometallic compounds have received extensive attention and appropriate materials have been generated as catalysts, molecular devices, liquid crystals, and so on [10-13]. The discussion in this chapter will not address such materials but will only specifically examine endohedral metallofullerenes because they are viewed as more unique, fascinating, and promising due to the strong interactions between the encapsulated metallic species and the carbon cages [2]. 

Chemical formulas of fullerene compounds containing encapsulated metals are written with the symbol to designate encapsulation Examples are... 

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