The derivatization of endohedral metallofullerenes (EMFs) has been used to characterize their properties and also to expand their range of potential applications. However, examples of synthetic methods for the derivatization of EMFs have been rather limited compared to those for empty fullerenes.

Masahiro Kako, University of Electro-Communications, Chofu, Japan, Shigeru Nagase, Kyoto University, Japan, Takeshi Akasaka, Tokyo Gakugei University, University of Tsukuba, Ibaraki, Foundation for Advancement of International Science, Ibaraki, all Japan, and Huazhong University of Science and Technology, Wuhan, China, and colleagues have used the photoreaction of Sc₃N@I_h-C₈₀ with silirane to give isomeric [5,6]- and [6,6]-carbosilylated adducts (example pictured).

Because of the electron-donating silyl groups, the redox potentials of these adducts are shifted to more negative values than those of related Sc₃N@I_h-C₈₀ derivatives functionalized with carbon-atom-based groups. This allows the electronic fine-tuning of EMFs, which could contribute to future applications of EMFs in molecular electronics. 

• Preparation, Structural Determination, and Characterization of Electronic Properties of [5,6]- and [6,6]-Carbosilylated Sc₃N@I_h-C₈₀,
  Masahiro Kako, Takeshi Sugiura, Kyosuke Miyabe, Masanori Yasui, Michio Yamada, Yutaka Maeda, Jing-Dong Guo, Shigeru Nagase, Takeshi Akasaka,
  Chem. Asian J. 2017.
  DOI: 10.1002/asia.201700506