title: Energetics of intercavity diffusion in a simple model of a low-density p-tert-butylcalix[4]arene crystal.
abstract: Potentials of mean force calculated for the diffusion of small guest molecules (CO(2) and CH(4)) between adjacent host cavities in the beta(0) p-tert-butylcalix[4]arene polymorph reveal sufficiently high barriers to diffusion to justify characterizing the lattice voids in this crystal as independent host cavities rather than as extended volumes. In addition, the calculated barrier heights are consistent with a "relay" model for gas diffusion in this ostensibly nonporous organic solid involving the lateral sliding of the host bilayers.
authors.affiliation: Department of Chemistry, University of Missouri, Columbia, Missouri 65211-7600, USA.
authors.forename: Matthew D
authors.initials: MD
authors.lastname: Breite
authors.forename: Jack R
authors.initials: JR
authors.lastname: Cox
authors.forename: John E
authors.initials: JE
authors.lastname: Adams