Entrapping a Group-VB Transition Metal, Vanadium, within an Endohedral Metallofullerene: VxSc3-xN@Ih-C80 (x=1, 2)

So far the entrapped metals for the isolated endohedral metallofullerenes (EMFs) are primarily limited to rare earth metals, whereas except group-IVB metals, whether it is possible to entrap other d-block transition metals remains unclear. Herein we report the successful entrapment of the group-VB transition metal vanadium(V) into fullerene cage, affording the heretofore unknown V-containing EMFs. Two novel V-containing EMFs-VxSc3-xN@C-80 (x = 1, 2)-were isolated, and their molecular structures were unambiguously determined by X-ray crystallography to be I-h(7)-C-80 cage entrapping the planar VSc2N/V2ScN clusters. VxSc3-xN@I-h(7)-C-80 (x = 1, 2) were further characterized by UV-vis-NIR and ESR spectroscopies and electrochemistry, revealing that the electronic and magnetic properties of VxSc3-xN@I-h(7)-C-80 (x = 1, 2) are tunable upon varying the number of entrapped V atoms (i.e., x value). The molecular structures and electronic properties of VxSc3-xN@I-h(7)-C-80 (x = 1, 2) were further compared with those of the reported analogous EMFs based on lanthanide metals and the adjacent group-IVB transition metal Ti, revealing the peculiarity of the group-VB transition metal V-based EMFs.