Manipulating Reactivity Differences for Isolating New Endohedral Metallofullerenes

Much excitement is due to the production of new types of endohedral clusters inside fullerene cages.  Scientists are also investigating the effect of increasing cage size versus the type and geometry of the entrapped cluster.  Along with the enthusiasm of synthesizing diverse families of metallofullerenes comes the technical hurdle of isolating purified compounds from increasingly complex mixtures in raw soot extract.  Based on reactivity differences between empty-cage fullerenes and endohedrals, one can fractionate and obtain separate samples of fullerenes and endohedrals.  Our newest results show even further selectivity such that we can now achieve a separation of endohedrals from other endohedrals.  An advantage of our new separation science is the non-HPLC approach.  I will discuss the complexation/decomplexation approach with Lewis acids to distinguish between different classes of endohedrals.  Further selectivity can be achieved by manipulating a binding step to amines, followed by kinetic differences during their release.