Solvent-mediated phase transformation of C60 crystals with well-defined hexagonal shape

CCl4-solvated C-60 crystals with hexagonal shape were grown by the liquid-liquid interfacial precipitation method with CCl4 and toluene as poor and good solvents, respectively. Interestingly, the morphology of the hexagonal crystals with the growth liquid are drastically changed with drying in air. A lot of fine rod crystals appear over the original crystals with air-drying, whereas the hexagonal outline of the original crystals is kept even after the transformation. Such change in the morphology is explained by the solvent-mediated phase transformation due to the dissolution of the original crystals by toluene and then re-precipitation of the rod crystals.