A Metallofullertube of Ce₂@C₁₀₀ with a Carbon Nanotube Segment: Synthesis, Single-Molecule Conductance and Supramolecular Assembly

Tubular fullerenes can be considered as end-capped carbon nanotubes with accurate structure, which are promising nanocarbon materials for advanced single-molecule electronic devices. Herein, we report the synthesis and characterization of a metallofullertube Ce-2@D-5(450)-C-100, which has a tubular C-100 cage with a carbon nanotube segment and two fullerene end-caps. As there are structure correlations between tubular Ce-2@D-5(450)-C-100 and spherical Ce-2@I-h-C-80, their structure-property relationship has been compared by means of experimental and theoretical methods. Notably, single-molecule conductance measurement determined that the conductivity of Ce-2@D-5(450)-C-100 was up to eight times larger than that of Ce-2@I-h-C-80. Furthermore, supramolecular assembly of Ce-2@D-5(450)-C-100 and a [12]CPP nanohoop was investigated, and theoretical calculations revealed that metallofullertube Ce-2@D-5(450)-C-100 adopted a "standing" configuration in the cavity of [12]CPP. These results demonstrate the special nature of this kind of metallofullertube.