Formation of the First Derivatives of Endohedral Diterbium Fullerenes via Carbene Addition to a Large Carbon Cage

Abstract

The first derivatives of diterbium fullerenes were successfully synthesized through the photochemical reaction of a large carbon cage-based diterbium fullerene Tb₂C₉₀ with 2-admantane-2,3-[3H]-diazirine. A monoadduct isomer, Tb₂C₉₀Ad (Ad = admantylidene), was isolated by multi-stage high-performance liquid chromatography with toluene as eluent. The formation of a series of derivatives of diterbium fullerenes as well as the success in the isolation of Tb₂C₉₀Ad was confirmed by high-performance liquid chromatography and matrix-assisted laser adsorption/ionization time-of-flight mass analyses. Vis-NIR absorption showed that the electronic property of Tb₂C₉₀ was largely pertained in the derivative, although a slight red-shift was observed for Tb₂C₉₀Ad. Cyclic voltammetric determination indicated that the redox potential of Tb₂C₉₀Ad was shifted cathodically in comparison with pristine Tb₂C₉₀ owing to the electron transfer from Ad to carbon cage.

Keywords:

• Fullerene
• Metallofullerene
• Terbium
• Derivative
• Carbene addition

Funding

This work is supported by the National Natural Science Foundation of China (Nos. 51072047 and 21271067).