Sc2S@C2(7892)–C70: a metallic sulfide cluster inside a non-IPR C70 cage

Abstract

A new cage isomer of C₇₀, Sc₂S@C₂(7892)–C₇₀, has been isolated and characterized by mass spectrometry, UV-Vis-NIR absorption spectroscopy, cyclic voltammetry and DFT calculations. The combined experimental and computational studies lead to the unambiguous assignment of the cage symmetry to C₂(7892)–C₇₀. The comparison between Sc₂S@C₂(7892)–C₇₀ and related endohedral structures has been discussed. A close structural resemblance between Sc₂S@C₂(7892)–C₇₀ and Sc₂S@C_s(10 528)–C₇₂ suggests that the conversion of these two molecules may be the result of a simple insertion of C₂ and the structural difference between Sc₂S@C₂(7892)–C₇₀ and Sc₃N@C_2v(7854)–C₇₀ shows that the nature and geometry of the encaged cluster plays an important role on the selection of the non-IPR cage.