Facile Synthesis of an Extensive Family of Sc2O@C2n (n = 35–47) and Chemical Insight into the Smallest Member of Sc2O@C2(7892)–C70

An extensive family of oxide cluster fullerenes (OCFs) Sc2O@C2n (n = 35–47) has been facilely produced for the first time by introducing CO2 as the oxygen source. Among this family, Sc2O@C70 was identified as the smallest OCF and therefore isolated and characterized by mass spectrometry, 45Sc nuclear magnetic resonance, UV–vis–near-infrared absorption spectroscopy, cyclic voltammetry, and density functional theory calculations. The combined experimental and computational studies reveal a non-isolated pentagon rule isomer Sc2O@C2(7892)–C70 with reversible oxidative behavior and lower bandgap relative to that of Sc2S@C2(7892)–C70, demonstrating a typical example of unexplored OCF and underlining its cluster-dependent electronic properties.

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