Thin-layer chromatography of C-60 and C-70 fullerenes

It is shown that under TLC conditions a mixture of C-60 and C-70 fullerenes is separated on NH2, RP18, and diol plates and on neutral and basic alumina by use of such eluents as hexane and i-octane and their mixtures with xylene or 1,2-dichlorobenzene. Chamber saturation has a negative influence on the separation. The separation of C-60 and C-70 fullerenes on silica gel, however, is achieved by developing the plate with hexane containing 5% pyridine in a saturated chamber. The quantity of substance in the starting spot should not exceed 0-5 mu g. The chromatographic behavior is compared with that of benzo[a]pyrene, as both have similar 'molecular footprints'. The mechanism of retention of C-60 and C-70 fullerenes and the nonplanarity effect are discussed.