C60 Cheese Sticks: Supramolecular Architecture of an Amphiphilic Fullerene Pentapod.

An amphiphillic fullerene pentaphenol derivative, C60(4-HOC6H4)5H, in an aprotic solvent N-methyl-2-pyrrolidone (NMP), spontaneously self-assembles to a hitherto unknown cheese stick-like (CS) structure. This fascinating structure is observed only for C60(4-HOC6H4)5H and only in dry NMP solvent. The reason for such unique self-assembly behavior is ascribed to solvating power typical of NMP. The CS structure is observed in a narrow concentration range of the solution. This indicates that there exists between the solute and the solvent an optimal interaction condition for CS to remain stable.