Wet Chemistry for Large Cage Metallofullerene Isolation

Tuesday, 3 October 2017: 11:40
Chesapeake K (Gaylord National Resort and Convention Center)
S. Stevenson and H. R. Thompson (Purdue University - Fort Wayne)
There is little information regarding the chemical reactivity of trimetallic nitride fullerenes in carbon cages above C80 (e.g., M3N@C82-112). Several reasons include the (1) low production yield from the electric-arc plasma reactor and (2) their presence in a complex mixture of often more than 50 types of species. This presentation addresses the latter hurdle for which we are presenting a novel separation strategy that uses only liquids. We have replaced all solid supports, such as aminosilica, with amino alcohols, which has the advantage of NH2 groups for attachment to fullerene cages and an OH group at the other end for an ease of transfer to an aqueous layer. Unreacted metallofullerenes would remain in the organic phase. In this strategy, desired metallofullerenes could be retained whereas empty-cage fullerene and highly reactive metallofullerenes would be, upon reaction, transferred to the water phase for a chemical separation. We have evaluated an array of different solvents and varied amino alcohols, their amounts and their reaction time to obtain optimal selectivity for M3N@C88 endohedrals. For improved selectivity, we can combine enriched samples of higher endohedrals obtained from this 1st stage (amino alcohol) with a 2nd stage (Lewis acids) to obtain isolated M3N@C88 (90% purity). For experiments requiring a higher purity sample, a quick HPLC pass allows the isolation of Gd3N@C88 in 98+% purity.