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 Ce₂@D₅(450)-C₁₀₀, which has a tubular C₁₀₀ cage with a carbon nanotube segment and two fullerene end-caps. As there are structure correlations between tubular Ce₂@D₅(450)-C₁₀₀ and spherical Ce₂@I_h-C₈₀, their structure–property relationship has been compared by means of experimental and theoretical methods. Notably, single-molecule conductance measurement determined that the conductivity of Ce₂@D₅(450)-C₁₀₀ was up to eight times larger than that of Ce₂@I_h-C₈₀. Furthermore, supramolecular assembly of Ce₂@D₅(450)-C₁₀₀ and a [12]CPP nanohoop was investigated, and theoretical calculations revealed that metallofullertube Ce₂@D₅(450)-C₁₀₀ adopted a “standing” configuration in the cavity of [12]CPP. These results demonstrate the special nature of this kind of metallofullertube.