title: Anisotropic nuclear spin interactions in H₂O@C₆₀ determined by solid-state NMR.
abstract: We report a solid-state NMR study of the anisotropic nuclear spin interactions in H₂O@C₆₀ at room temperature. We find evidence of significant dipole-dipole interactions between the water protons, and also a proton chemical shift anisotropy (CSA) interaction. The principal axes of these interaction tensors are found to be perpendicular. The magnitude of the CSA is too large to be explained by a model in which the water molecules are partially aligned with respect to an external axis. The evidence indicates that the observed CSA is caused by a distortion of the geometry or electronic structure of the fullerene cages, in response to the presence of the endohedral water.
authors.affiliation: School of Chemistry, University of Southampton, Highfield, Southampton SO17 1BJ, UK. mariac@soton.ac.uk
authors.forename: M
authors.initials: M
authors.lastname: Concistrè
authors.forename: S
authors.initials: S
authors.lastname: Mamone
authors.forename: M
authors.initials: M
authors.lastname: Denning
authors.forename: G
authors.initials: G
authors.lastname: Pileio
authors.forename: X
authors.initials: X
authors.lastname: Lei
authors.forename: Y
authors.initials: Y
authors.lastname: Li
authors.forename: M
authors.initials: M
authors.lastname: Carravetta
authors.forename: N J
authors.initials: NJ
authors.lastname: Turro
authors.forename: M H
authors.initials: MH
authors.lastname: Levitt
keywords: endohedral water fullerene; solid-state NMR; spin interaction