The encapsulation of clusters (or small molecules) in spheroidal fullerene cages provides a unique isolated environment that is important in describing their shape, dynamics, and physical properties. For the case of yttrium carbide clusters, we find that the (Y2C2)4+ cluster adopts a nearly linear geometry in large fullerene cages (~C100) and a butterfly structure in compressed smaller cages (~C80). Density functional theory (DFT) calculations support this prediction for the decreasingly smaller fullerene cage environments represented by Y2C2@D5(450)-C100, Y2C2@D3(85)-C92, and Y2C2@C3v(8)-C82. The latter two compounds were isolated and the 13C NMR results are in excellent agreement with the computational results. This bottoms-up nanoscale approach of compressing isolated clusters by decreasing fullerene cage size can be extended to other clusters and small molecules encapsulated in fullerenes.
Citation: Journal of the American Chemical Society
Pub Type: Journals
NMR, fullerene, yttrium carbide