A new cluster fullerene, Sc2 O@Td (19151)-C76 , has been isolated and characterized by mass spectrometry, UV/Vis/NIR absorption, (45) Sc NMR spectroscopy, cyclic voltammetry, and single-crystal X-ray diffraction. The crystallographic analysis unambiguously assigned the cage structure as Td (19151)-C76 , which is the first tetrahedral fullerene cage characterized by single-crystal X-ray diffraction. This study also demonstrated that the Sc2 O cluster has a much smaller ScOSc angle than that of Sc2 O@Cs (6)-C82 and the Sc2 O unit is fully ordered inside the Td (19151)-C76 cage. Computational studies further revealed that the cluster motion of the Sc2 O is more restrained in the Td (19151)-C76 cage than that in the Cs (6)-C82 cage. These results suggest that cage size affects not only the shapes but also the cluster motion inside fullerene cages.

An extensive family of oxide cluster fullerenes (OCFs) Sc 2 O@C 2n (n=35-47) has been facilely produced for the first time by introducing CO 2 as the oxygen source. Among this family, Sc 2 O@C 70 was identified as the smallest OCF and therefore isolated and characterized by mass spectrometry, 45 Sc NMR, UV-Vis-NIR absorption spectroscopy, cyclic voltammetry and DFT calculations. The combined experimental and computational studies reveal a non-IPR isomer 5 Sc 2 O@C 2 (7892)-C 70 with reversible oxidative behavior and lower bandgap relative to that of Sc 2 S@C 2 (7892)-C 70 , demonstrating a typical example of unexplored OCF and underlining its clusterdependant electronic properties.

A new oxide cluster fullerene, Sc2O@C(2v)(5)-C80, has been isolated and characterized by mass spectrometry, UV-vis-NIR absorption spectroscopy, cyclic voltammetry, (45)Sc NMR, DFT calculations, and single crystal X-ray diffraction. The crystallographic analysis unambiguously elucidated that the cage symmetry was assigned to C(2v)(5)-C80 and suggests that the Sc2O cluster is ordered inside the cage. The crystallographic data further reveals that the Sc1-O-Sc2 angle is much larger than that found in Sc2O@T(d)(19151)-C76 but almost comparable to that in Sc2O@Cs(6)-C82, suggesting that the endohedral Sc2O unit is flexible and can display large variation in the Sc-O-Sc angle, which depends on the size and shape of the cage. Computational studies show that there is a formal transfer of four electrons from the Sc2O unit to the C80 cage, i.e., (Sc2O)(4+)@(C80)(4-), and the HOMO and LUMO are mainly localized on the C80 framework. Moreover, thermal and entropic effects are seen to be relevant in the isomer selection. Comparative studies between the recently reported Sc2C2@C(2v)(5)-C80 and Sc2O@C(2v)(5)-C80 reveal that, despite their close structural resemblance, subtle differences exist on the crystal structures, and the clusters exert notable impact on their spectroscopic properties as well as interactions between the clusters and corresponding cages.

A complete regioisomer separation of indene-C60 bisadduct (IC60BA) for polymer solar cell (PSC) applications was conducted for the first time.