Structures and energetics of pentahaptofullerene metal complexes

We analysed the geometrical structures and energetics of exo- and endo-pentaheptofullerene-M (M=Li and Tl) complexes by using the semiempirical Hartree-Fock (HF) PM3 method. The exohedral fullerene complexes are more stable than the endohedral. The most stable isomer is the vertical one for η 5 -C 60 Ph 5 Li and the tilted one for η 5 -C 60 Ph 5 Tl.