title: Structural alteration of hybrid supramolecular capsule induced by guest encapsulation.
abstract: Heterofunctionalized C(2v) symmetrical cavitand 1 with 4-pyridylethynyl and 3-carbamoylphenyl groups in alternating arrangement was designed and synthesized. A 1:1 mixture of the cavitand 1 and a cis-coordinated palladium(II) or platinum(II) complex self-assembled into a hybrid supramolecular capsule via both metal-ligand coordination bonds and hydrogen bonds. Formation of the capsular assembly was confirmed by NMR spectroscopy and mass spectrometry. The hybrid capsule encapsulated the appropriate guest, the molecular sizes of which fit the size of the capsular cavity. Structural alteration of the hybrid capsule was induced by the guest encapsulation. A C(2h) structure for the encapsulation complex was assigned by 2D NMR spectra analysis. Thermodynamic and kinetic properties of the guest encapsulation were investigated. The kinetics of in/out guest exchange was strongly influenced by hydrogen bonding in the hybrid capsule.
authors.affiliation: Department of Chemistry, Faculty of Science, Shizuoka University, 836 Ohya, Suruga-ku, Shizuoka 422-8529, Japan. smyaman@ipc.shizuoka.ac.jp
authors.forename: Masamichi
authors.initials: M
authors.lastname: Yamanaka
authors.forename: Masashi
authors.initials: M
authors.lastname: Kawaharada
authors.forename: Yuki
authors.initials: Y
authors.lastname: Nito
authors.forename: Hikaru
authors.initials: H
authors.lastname: Takaya
authors.forename: Kenji
authors.initials: K
authors.lastname: Kobayashi