FULLERENE C-60 AS A ETA(5)-LIGAND AND ETA(6)-LIGAND IN SANDWICH-TYPE PI-COMPLEXES WITH TRANSITION-METALS

The molecular and electronic structures of some hypothetical sandwich-type pi-complexes of transition metals with fullerene C-60 Were modeled. The M-C-60 bonds in eta(5)-C(60)MCp(+) complexes (M = Fe, Ru, Os) are less strong than the M-Cp bonds in ferrocene, ruthenocene, and osmocene, respectively. The eta(6)-C(60)MC(6)H(6) complexes (M Cr, Mo, W) should be less stable than their classical analogs (C6H6)M(C6H6). The coordination of a metal atom with the fullerene at its pentagonal face is more energetically favorable than at a hexagonal face.