A metallofullertube of Dy₂C₂@C₁₀₀ featuring single-molecule magnet behavior, binary single-molecule conductance states and ordered molecular assembly

Fullertubes and metallofullertubes, which are composed of nanotube segments and fullerene end-caps, are promising molecular carbon materials for advanced electronic devices. Herein, we report the synthesis and characterization of Dy₂C₂@D₅(450)-C₁₀₀, a new metallofullertube that features single-molecule magnet behavior, high single-molecule conductance, and ordered molecular assembly. Dy₂C₂@D₅(450)-C₁₀₀ possesses a zigzag-shaped [10,0] nanotube segment in its middle, two fullerene hemispheres on both sides, as well as a Dy₂C₂ cluster with kinked linear form within the cage. Owing to its encapsulation of two Dy³⁺ ions, Dy₂C₂@D₅(450)-C₁₀₀ exhibits magnetic hysteresis loops at temperatures up to 5 K. More importantly, Dy₂C₂@D₅(450)-C₁₀₀ could form stable molecular junctions between Au electrodes as determined by the scanning tunneling microscopy-break junction technique. Specifically, Dy₂C₂@D₅(450)-C₁₀₀ displays binary single-molecule conductance states at 10^−0.4G₀ and 10^−1.2G₀, corresponding to the configuration along its short and long axes, respectively. Furthermore, the ordered assembled structures of Dy₂C₂@D₅(450)-C₁₀₀ are characterized by TEM. These unique properties of Dy₂C₂@D₅(450)-C₁₀₀ indicate its potential applications as molecule-based magnetic semiconductor materials.