SELECTIVE PI-FACIAL BINDING OF METAL-CATIONS TO TRIINDENOTRIPHENYLENEAS A POSSIBLE CATALYTIC ROUTE TO C-60 PRECURSORS - A MNDO, PM3 AND AB-INITIO SCF-MO STUDY

MNDO and PM3 SCF-MO calculations predict that in common with Li+, larg er ions such as Tl+. Pb+ or NH4+ are predicted to preferentially bind to the convex surface of 1 and hence are unlikely to encapsulate in an y dimerisation reaction. The calculated molecular electrostatic potent ial of 1 also reveals the convex face to be the better electron donor. Concave binding is predicted at the MNDO level for Na+ and K+ and the PM3 level for Ga+, but these results may be influenced by errors for these metals resulting in excessive stabilisation to re-faces. All ini tio calculations at the MP2/ECP-LAN1LDZ level predict that Ga+ has the highest binding energy of all these metals to benzene,and may constit ute the best candidate for synthetic efforts.