Theoretical investigation into structures and magnetic properties of smaller fullerenes and their heteroanalogues

The smaller fullerenes, C-20, C-24, C-28, C-32, C-36, C-40 and C-50, their hydrogenation products and selected B-, N- and P-doped analogues have been investigated systematically at the B3LYP/6-31G* density functional level of theory. The degree of spherical electron delocalization is evaluated by us ing the computed nucleus-independent chemical shifts ( NICS) at the cage ce nter and the individual ring centers of interest. The calculated NMR chemic al shifts and the NICS values at the cage center, which can be accessed by endohedral He-3 chemical shifts, should provide a basis for further experim ental characterization of these compounds.