The nanoscale parameters of metal clusters and lattices have a crucial influence on the macroscopic properties of materials. Herein, we provide a detailed study on the size and shape of isolated yttrium carbide clusters in different fullerene cages. A family of diyttrium endohedral metallofullerenes with the general formula of Y 2C 2n (n = 40-59) are reported. The high field 13C nuclear magnetic resonance (NMR) and density functional theory (DFT) methods are employed to examine this yttrium carbide cluster in certain family members, Y 2C 2@D 5(450)-C 100, Y 2C 2@D 3(85)-C 92, Y 2C 2@C 84, Y 2C 2@C 3v(8)-C 82, and Y 2C 2@C s(6)-C 82. The results of this study suggest that decreasing the size of a fullerene cage with the same (Y 2C 2) 4+ cluster results in nanoscale fullerene compression (NFC) from a nearly linear stretched geometry to a constrained "butterfly" structure. The 13C NMR chemical shift and scalar 1J YC coupling parameters provide a very sensitive measure of this NFC effect for the (Y 2C 2) 4+ cluster. The crystal structural parameters of a previously reported metal carbide, Y 2C 3 are directly compared to the (Y 2C 2) 4+ cluster in the current metallofullerene study.
All Science Journal Classification (ASJC) codes
- Colloid and Surface Chemistry