Abstract
We have performed force field-based molecular dynamics and first principles density functional calculations on porphyrins and metalloporphyrins interacting with single-walled carbon nanotubes. The flattening of the porphyrin macrocycle is indicative of the self-assembly of these aromatic structures onto carbon nanotubes. An analysis of the charge distributions for conduction and valence bands reveals a distinct charge transfer behavior from the porphyrin macrocycle to the metallic or semiconducting tubes that sheds considerable light on the experimentally observed selectivity of semiconducting nanotubes.