Lewis Acidity of Pt-Doped Buckybowls, Fullerenes, and Single-Walled Carbon Nanotubes

The Lewis acidic character of alkyl and arylplatinum complexed has been investigated within density-functional theory with an emphasis on supramolecular structures (e.g., buckybowls, fullerenes, and nanotubes) doped with Pt atoms, By selective substitution of a single atom within a larger carbon framework with a Pt atom, the resulting species demonstrate a strong preference for interaction with small organic molecules, particularly polar substances via Lewis acid/Lewis base complexation. Coordination with CO and maleic anhydride offers a gauge of comparing the Lewis acidity of these alkyl and arylplatinum complexes. We have also examined the use of these organometallic species as catalysts for the Diels-Alder reaction and have found the curved pi-conjugation and delocalization of electrons offer modest rate enhancement and improvements in selectivity. Preliminary results suggest that extended molecular architectures such as Pt-doped nanotubes may provide selectivities that differ from that of traditional Lewis acid catalysts.