Noncovalent binding of carbon nanotubes by porphyrin oligomers.

(Figure Presented) Like the tentacles of an octopus: Porphyrin oligomers bind strongly to single-walled carbon nanotubes, and debundle multitube aggregates. The strength of this interaction increases sharply with the number of porphyrin units in the oligomer, and the affinity is greatest for chiral (7,5) and (8,6) tubes. Quantitative information on these noncovalent recognition processes was obtained from UV/Vis/NIR absorption (see picture) and fluorescence titrations. © 2011 Wiley-VCH Verlag GmbH and Co. KGaA