Crystallographic Characterization and Structural Analysis of the First Organic Functionalization Product of the Endohedral Fullerene Sc₃N@C₈₀

The structure of Sc₃N@C₈₀−C₁₀H₁₂O₂, a Diels−Alder cycloadduct of Sc₃N@C₈₀, has been determined. The crystallographic data shows that cycloaddition occurs at a C−C bond of 6:5 ring junction, and that the fullerene C1−C2 bond is elongated and pulled out from the fullerene. The Sc₃N unit is well-ordered within the C₈₀ cage and positioned away from the site of addition. The proximity of the Sc atoms to the cage carbon atoms causes those carbon atoms to protrude slightly from the surface of the fullerene cage.