The electrochemical and paramagnetic properties of endohedral metallofullerenes (EMFs) have drawn extensive attention due to their huge potential in the fields of molecular devices, biomedicines, quantum information processing, etc. Exohedral modification of the fullerene carbon cage, such as in the classical Prato reaction, is an effective and facile approach to regulate the electronic structure and molecular dynamics of EMFs. In this work, novel pyrrolidine products of Sc₃N@C₈₀ and Sc₃C₂@C₈₀ were successfully synthesized via Prato reactions using L-cysteine and paraformaldehyde. Structure characterizations demonstrated that two regioisomers with a [5,6] and a [6,6] cycloaddition on the I_h-C₈₀ cage were obtained both for Sc₃N@C₈₀ and Sc₃C₂@C₈₀. Besides, the [6,6]-monoadduct of Sc₃N@C₈₀ was thermally stable while the [5,6]-monoadduct exhibited a retro-cycloaddition ability to recover the pristine Sc₃N@C₈₀. Electrochemical measurements revealed that the redox potential of Sc₃N@C₈₀ could be tuned via such exohedral modifications. Furthermore, the paramagnetic property and internal dynamics of the encapsulated Sc₃C₂ cluster of Sc₃C₂@C₈₀ can be well-regulated by controlling the spin density of the molecule. The present work could provide a new approach to regulate the electronic and/or spin structure of EMFs.

中文翻译：

---

调节内嵌金属富勒烯的电子和自旋结构：Sc3N@C80 和 Sc3C2@C80 的案例研究

内嵌金属富勒烯（EMFs）的电化学和顺磁性因其在分子器件、生物医学、量子信息处理等领域的巨大潜力而​​受到广泛关注。富勒烯碳笼的外嵌修饰，例如在经典的普拉托反应中，是调节 EMF 的电子结构和分子动力学的有效且简便的方法。_{在这项工作中，Sc 3} N@C ₈₀和 Sc ₃ C ₂ @C ₈₀的新型吡咯烷产物通过Prato 反应使用L-半胱氨酸和多聚甲醛。结构表征表明，对于 Sc ₃ N@C ₈₀和 Sc ₃ C ₂ @C ₈₀都获得了在I _h -C ₈₀笼上具有[5,6]和[6,6]环加成的两种区域异构体。_{此外，Sc 3} N@C ₈₀的[6,6]-单加合物具有热稳定性，而[5,6]-单加合物表现出逆环加成能力以恢复原始的 Sc ₃ N@C ₈₀。电化学测量表明，Sc ₃ N@C ₈₀的氧化还原电位可以通过这样的外嵌修饰。_{此外，Sc 3} C ₂ @C _{80封装的Sc 3} C ₂团簇的顺磁性和内部动力学可以通过控制分子的自旋密度得到很好的调控。目前的工作可以提供一种新方法来调节 EMF 的电子和/或自旋结构。