Separation of C60 and C70 fullerenes in gram quantities by fractional crystallization

A simple and inexpensive method for the purification of gram quantities of >99.5% pure C60 and > 98% pure C70 by a fractional crystallization process in carbon disulfide or o-xylene is described. This process is based on the finding that C60 was enriched in the solid deposit, whereas C70 was enriched in the mother liquor during crystallization of fullerenes due to differential solubilities of these two fullerenes, C60 and C70, in these solvents.