Structural characterization of the C₆₀[C(COOC₂H₅)₂] whiskers prepared by the liquid–liquid interfacial precipitation method

Fine whiskers of a C₆₀ derivative, i.e., C₆₀ monosubstituted by ethyl ester of malonic acid, C₆₀[C(COOC₂H₅)₂], were fabricated for the first time using a system of toluene with concentrated C₆₀[C(COOC₂H₅)₂] and isopropyl alcohol. The center-to-center distance of C₆₀[C(COOC₂H₅)₂] molecules along the close-packed direction of the C₆₀[C(COOC₂H₅)₂] whiskers was in the same range as that of the C₆₀ nanowhiskers prepared by the same method. The C₆₀[C(COOC₂H₅)₂] whiskers were assumed to take body-centered tetragonal or hexagonal close-packed crystal structures. The C₆₀[C(COOC₂H₅)₂] whiskers showed a high density of stacking faults. The C₆₀[C(COOC₂H₅)₂] whiskers with the growth direction different from the C₆₀ whiskers were observed.