Isolation of Large Cage Erbium Metallofullerenes

Indianapolis, IN

Erbium nitride clusters (i.e., Er3N) can be entrapped inside the cavity of fullerene cages. Of this family (e.g., Er3N@C2n) of compounds, Er3N@C80 is the dominant species. However, there is a paucity of literature on these clusters with larger cages (e.g., Er3N@C84, Er3N@C88, Er3N@C92). To achieve isolation of these higher cage metallofullerenes, we have developed a new 3-step purification method. In step 1, we introduce aminopropanol to selectively attack and remove fullerene contaminants from dissolved soot extract. After addition of this water-soluble, electron-rich amine, a much simpler mixture of fullerenes and metallofullerenes remains. In step 2, further selectivity is achieved via complexation/decomplexation with a Lewis acid (e.g., ZnCl2, MgCl2). In step 3, HPLC fraction collection readily provides a purified sample. In this poster presentation, we will discuss the findings for each of these purification stages.