High Resolution 13C NMR study of oxygen intercalation in C60

TL;DR

This study uses high-resolution 13C NMR to analyze how oxygen molecules intercalate into C60, revealing that oxygen diffuses inside without chemical bonding or charge transfer, and does not alter C60's reorientation.

Contribution

It provides detailed NMR evidence showing oxygen intercalates physically into C60 without forming chemical bonds or affecting molecular dynamics.

Findings

Oxygen molecules occupy octahedral sites in C60 lattice.

No chemical bonding or charge transfer occurs during intercalation.

Oxygen diffusion does not hinder C60 molecular reorientation.

Abstract

Solid state high resolution $^{13}C$ 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 $^{13}C$ 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 fcc 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 $^{13}C$ NMR spectra, corresponding to buckyballs adjacent to various numbers of oxygen molecules.