High-resolution C-13 NMR study of oxygen intercalation in C-60

Solid-state high-resolution C-13 NMR has been used to investigate the physical properties of pristine C-60 after intercalation with molecular oxygen. By studying the dipolar and hyperfine interactions between Curie-type paramagnetic oxygen molecules and C-13 nuclei we have shown that neither chemical bonding nor charge transfer results from the intercalation. The O-2 molecules diffuse inside the solid C-60 and occupy the octahedral sites of the fee crystal lattice. The presence of oxygen does not affect the fast thermal reorientation of the nearest C-60 molecules. Using magic angle spinning we were able to separate the dipolar and hyperfine contributions to C-13 NMR spectra, corresponding to fullerenes adjacent to various numbers of oxygen molecules.