Reactivity of Open-Shell Metallofullerene Anions: Synthesis, Crystal Structures, and Electrochemical Properties of Benzylated Gd@C2v-C82

Abstract

The reactivity of the open-shell Gd@C2v-C82 with different charge states towards benzyl bromide was investigated. [Gd@C2v-C82]3− exhibited enhanced activity relative to Gd@C2v-C82 and [Gd@C2v-C82]−. The structural characterizations, including MALDI-TOF MS, UV-vis-NIR, and single crystal X-ray diffraction, indicate the formation of isomeric benzyl monoadducts of Gd@C2v-C82. All three monoadducts contain 1:1 mirror-symmetric enantiomers. Additionally, the addition of the benzyl group and its specific position result in distinct electrochemical behavior of the products compared to the parent Gd@C2v-C82. Theoretical studies demonstrate that only [Gd@C2v-C82]3− has a HOMO energy level that matches well with the LUMO energy level of the PhCH2 radical, providing a rationalization for the observed significantly different reactivity.