Metallofullerenes Sc2@C82(I, II) and Sc2@C86(I, II): isolation and spectroscopic studies

The first isolation of Sc2@C82(I, II) and Sc2@C86(I, II) and their characterization by UV–Vis–NIR absorption spectroscopy are reported. The absorption spectra of Sc2@C82(I) and Sc2@C86(I) are markedly different from those of Sc2@C82(II) and Sc2@C86(II), respectively, indicating that the electronic structures of di-scandium metallofullerenes are dominated by the fullerene cages rather than the encapsulated atoms. Both UV–Vis–NIR absorption spectrometry and theoretical studies suggest that Sc2@C82(I) is a small band-gap metallofullerene. Furthermore, an ab initio calculation reveals that its electronic structure can be described as Sc24+@C824− similar to Sc2@C84.