Chemical Purification of Gd3N@C88 Metallofullerene Using Alcohols and Lewis Acids

Tuesday, 3 October 2017
Prince George's Exhibit Hall D/E (Gaylord National Resort and Convention Center)
H. R. Thompson and S. Stevenson (Purdue University - Fort Wayne)
This project addresses the paucity of literature on trimetallic nitride fullerenes possessing carbon cages larger than C80. Herein, we present our chemical isolation of Gd3N@C88, which was selected based on the (1) few reports describing its fundamental chemistry and (2) curiosity of its candidacy as an effective MRI contrast agent. To date, MRI contrast agent development for metallic nitride fullerenes has focused on the more ubiquitous and smaller-cage Gd3N@C80 species. Excitement for Gd3N@C88 is predicated, in part, on the projected increased reactivity of its C88 cage. The higher reactivity could, in principle, allow more attached hydrophilic groups, which in turn would translate into better water-solubility and improved clearance from the body in biological systems. Prior to any application, though, the fundamental science must first be performed. We demonstrate that the unique chemical reactivity of Gd3N@C88 can be strategically manipulated into a separation strategy for its isolation from complex extract mixtures containing more than 50 different species of fullerene and metallofullerene contaminant species. We describe the use of amino alcohols and Lewis acids to obtain highly enriched samples of greater than 90% purity. For subsequent studies (e.g., medical) demanding a higher purity (>99%), the appropriate HPLC parameters and fraction collection are also discussed.