title: Variation of guest selectivity within [Fe4L4](8+) tetrahedral cages through subtle modification of the face-capping ligand.
abstract: We report here the host-guest behaviour of two isoelectronic [Fe4L4](8+) tetrahedral cages that differ only in the nature of their face-capping ligand and possess either triazine (L1) or benzene (L2) cores. Crystallography reveals these hosts to be flexible and adaptable, while NMR spectroscopy shows them to be selective and discriminating in their host-guest behaviour.
authors.affiliation: Department of Chemistry, University of Canterbury, Private Bag 4800, Christchurch 8140, New Zealand.
authors.forename: Alan
authors.initials: A
authors.lastname: Ferguson
authors.forename: Robert W
authors.initials: RW
authors.lastname: Staniland
authors.forename: Christopher M
authors.initials: CM
authors.lastname: Fitchett
authors.forename: Marie A
authors.initials: MA
authors.lastname: Squire
authors.forename: Bryce E
authors.initials: BE
authors.lastname: Williamson
authors.forename: Paul E
authors.initials: PE
authors.lastname: Kruger