Anisotropic Contributions in the Chromatographic Elution Behavior of Fullerenes and Fullertubes

The retention behavior of fullerenes and fullertubes on a PYE column in reversed-phase chromatography was investigated to clarify the influence of their shapes on the separation process. The impact of anisotropy was further elucidated using a pair potential interaction model, together with experimental data and ab initio calculations, to evaluate its contribution to various parameters characterizing the interaction models. The findings indicate that the shape of fullerenes plays a more significant role than anticipated in the retention mechanisms, highlighting the necessity of considering the shape of fullerenes and fullertubes to accurately predict their retention times. Furthermore, a phenomenological pair potential was devised to demonstrate the feasibility of precisely predicting the retention times of fullerenes and fullertubes through first-principles calculations, regardless of their shape. The existence of such a model paves the way for the development of a method to identify isomers of fullerenes from minute amounts of sample.