Supramolecular Length-Dependent Encapsulation of C90, C100, C120 and C130: a Shape-Selective Approach to Fullertube Purification

There are no studies yet for the supramolecular encapsulation of fullertubes, i.e., soluble nanotubules of molecular carbon with hemispherical fullerene endcaps. Experimentally confirmed as a series of fixed diameter allotropic carbon differing by symmetry and nanotubular length (i.e., aspect ratio), the newly discovered [5,5] family of C90, C100, C120, and C130 fullertubes permits an excellent opportunity to probe their supramolecular encapsulation and to evaluate how fullertubes length is influencing the former. We report a nanocapsule with an inner cavity height (14.1 Å) capable of selective encapsulating fullertubes with a diameter of 7 Å. Results show an increased affinity for encapsulation in proportion to increasing tubular length. The order of affinity (Ka) follows a trend of [5,5]C90 < [5,5]C100 < [5,5]C120 < [5,5]C130. This tubular shape selectivity could someday be leveraged for “tuning” the isolation of yet to be discovered giant fullertubes of C150-C200. Molecular dynamic simulations corroborate this finding of supramolecular length-dependent encapsulation. To our knowledge, C120 is the largest fullerene or fullertube ever encapsulated in a supramolecular host-guest complex. This deposit includes parameter files of the nanocapsule and the fullertubes studied, output files of the simulations without solvent of the different systems and files releated to the well-tempered metadynamics carried out.