The mixture of fullerene—C_(60) and —C_(70) was successfully separated in larger amount by liquid chromatogra- phy on graphite column.The column was first eluted with a mixture of hexane and toluene,and then with to...The mixture of fullerene—C_(60) and —C_(70) was successfully separated in larger amount by liquid chromatogra- phy on graphite column.The column was first eluted with a mixture of hexane and toluene,and then with toluene.The eluates were monitored by UV/visible absorption spectroscopy.Graphite column shows high perfor- mance for separation.and much larger quantities of pure C_(60) can be easily obtained. The synthesis of fullerenes(C_(60) and C_(70))in macroscopic quantities has stimulated scientists to study on the method for separating C_(60) and C_(70).Because of the poor solubility of fullerenes C_(60)/C_(70) in most organic solvents,the separation of C_(60) and C_(70) proved to be a challenging task.Most attempts at the separation have used silica and alu- mina as the stationary phase and a mixture of hexane and benzene(or toluene)as the mobile phase. Fullerenes,however,have only limited solubility in hexane,these separations are usually only achieved by limit- ing the amount of sample to a few milligrams.The hexane-silica technique using phenylglycine based HPLC columns appears to offer good separation,but only for submilligram amounts. The use of graphite powder as the stationary phase in liquid chromatography is an advanced separation tech- nique for fullerenes C_(60)/C_(70).The technique is based on that the fullerene-C_(60) is different from C_(70) in the de- gree of electron delocalisation,and C_(60) is much less diamagnetic than C_(70).It is expected that the dissimilarity will cause the C_(60)/C_(70) molecules to exhibit different interactions with graphite,and can be separated from each other on this basis.展开更多
文摘The mixture of fullerene—C_(60) and —C_(70) was successfully separated in larger amount by liquid chromatogra- phy on graphite column.The column was first eluted with a mixture of hexane and toluene,and then with toluene.The eluates were monitored by UV/visible absorption spectroscopy.Graphite column shows high perfor- mance for separation.and much larger quantities of pure C_(60) can be easily obtained. The synthesis of fullerenes(C_(60) and C_(70))in macroscopic quantities has stimulated scientists to study on the method for separating C_(60) and C_(70).Because of the poor solubility of fullerenes C_(60)/C_(70) in most organic solvents,the separation of C_(60) and C_(70) proved to be a challenging task.Most attempts at the separation have used silica and alu- mina as the stationary phase and a mixture of hexane and benzene(or toluene)as the mobile phase. Fullerenes,however,have only limited solubility in hexane,these separations are usually only achieved by limit- ing the amount of sample to a few milligrams.The hexane-silica technique using phenylglycine based HPLC columns appears to offer good separation,but only for submilligram amounts. The use of graphite powder as the stationary phase in liquid chromatography is an advanced separation tech- nique for fullerenes C_(60)/C_(70).The technique is based on that the fullerene-C_(60) is different from C_(70) in the de- gree of electron delocalisation,and C_(60) is much less diamagnetic than C_(70).It is expected that the dissimilarity will cause the C_(60)/C_(70) molecules to exhibit different interactions with graphite,and can be separated from each other on this basis.
