Effects of Solvents on Reaction Products: Synthesis of Endohedral Metallofullerene Oxazoline and Epoxide.

Herein, we performed the reactions of M 3 N@ I h -C 80 (M = Sc and Lu) with the methanol (CH 3 OH) solution of TBAOH (note that both CH 3 O - and OH - are nucleophiles) in benzonitrile (PhCN) and dimethylformamide, respectively. It is found that OH - ions rather than CH 3 O - ions selectively attacked the fullerene cage to form the M 3 N@C 80 - -O - intermediate. Although the fullerene cage is initially attacked by OH - in both PhCN and DMF solvents, the products are quite different. In PhCN, two isomeric Sc 3 N@ I h -C 80 fullerooxazoline heterocyclic products ( 1 and 2 ) were synthesized. Whereas, in DMF, an epoxide of Lu 3 N@ I h -C 80 ( 3 ) was obtained. The preference for fullerooxazoline formation over that of fullerene epoxy in PhCN is well explained by density functional theory calculations. Plausible reaction mechanisms for the formation of metallofullerene oxazoline and epoxide were proposed based on the experimental and theoretical results.